Case Title: Commonwealth v. Mattis

Citation: 

Docket Number: 

State: massachusetts

Court: Massachusetts Supreme Court

Date: 2024-01-11T00:00:00Z

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SJC-11693 
 
COMMONWEALTH  vs.  SHELDON MATTIS. 
 
 
 
Suffolk.     February 6, 2023. - January 11, 2024. 
 
Present:  Budd, C.J., Gaziano, Lowy, Cypher, Kafker, Wendlandt, 
& Georges, JJ. 
 
 
Homicide.  Constitutional Law, Sentence, Cruel and unusual 
punishment, Parole.  Parole.  Practice, Criminal, Sentence, 
Parole. 
 
 
 
Indictments found and returned in the Superior Court 
Department on December 21, 2011. 
 
Following review by this court, 484 Mass. 742 (2020), 
findings of fact and a ruling of law were issued by Robert L. 
Ullmann, J. 
 
 
 
Ryan M. Schiff (Paul R. Rudof & Ruth Greenberg also 
present) for the defendant. 
 
Cailin M. Campbell, Special Assistant District Attorney 
(John C. Verner, Assistant District Attorney, also present) for 
the Commonwealth. 
 
The following submitted briefs for amici curiae: 
 
Darina Shtrakhman, of California, Matt K. Nguyen, of the 
District of Columbia, & Adam Gershenson for Jeffrey Aaron & 
others. 
 
Andrea Lewis Hartung, of Illinois, & Marsha L. Levick, of 
Pennsylvania, & Oren Nimni for the Sentencing Project & others. 
2 
 
 
Jonathan W. Blodgett, District Attorney for the Eastern 
District, & David F. O'Sullivan, Assistant District Attorney, 
for District Attorney for the Eastern District & another. 
 
Jasmine Gonzales Rose, of Oregon, Duke K. McCall, III, & 
Douglas A. Hastings, of the District of Columbia, Robert S. 
Chang, of Washington, Caitlin Glass, Neda Khoshkhoo, & Katharine 
Naples-Mitchell for Boston University Center for Antiracist 
Research & others. 
 
Kenneth J. Parsigian, Avery E. Borreliz, Erin M. Haley, & 
Martin W. Healy for Carol S. Ball & others. 
 
Benjamin H. Keehn, Committee for Public Counsel Services, & 
John J. Barter for Committee for Public Counsel Services. 
 
 
BUDD, C.J.  When it comes to determining whether a 
punishment is constitutional under either the Eighth Amendment 
to the United States Constitution or art. 26 of the 
Massachusetts Declaration of Rights, youth matters.  See, e.g., 
Miller v. Alabama, 567 U.S. 460 (2012); Graham v. Florida, 560 
U.S. 48 (2010); Roper v. Simmons, 543 U.S. 551 (2005); 
Diatchenko v. District Attorney for the Suffolk Dist., 466 Mass. 
655 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015).  In 
Miller, supra at 465, 476, the United States Supreme Court 
struck down mandatory life imprisonment without the possibility 
of parole for juveniles based in part on the "mitigating 
qualities of youth."  Approximately one and one-half years 
later, this court went further than Miller and concluded that 
sentencing a juvenile to life without parole in any circumstance 
would violate art. 26.  See Diatchenko I, supra at 669-670. 
The defendant, Sheldon Mattis, was convicted of murder in 
the first degree, among other charges, and was sentenced to a 
3 
 
mandatory term of life in prison without the possibility of 
parole, see G. L. c. 265, § 2 (a).  Commonwealth v. Watt, 484 
Mass. 742, 754-756 (2020).  On appeal, he challenged the 
constitutionality of his sentence as applied to him.  He argued 
that because he was eighteen years old at the time of the 
murder, he is entitled to the same protection as juvenile 
offenders (i.e., those from fourteen to seventeen years of age) 
convicted of murder in the first degree, who receive a term of 
life with the possibility of parole.  See G. L. c. 265, § 2 (b). 
Here, we consider whether our holding in Diatchenko I 
should be extended to apply to emerging adults, that is, those 
who were eighteen, nineteen, and twenty years of age when they 
committed the crime.1  Based on precedent and contemporary 
standards of decency2 in the Commonwealth and elsewhere, we 
conclude that the answer is yes.3 
 
1 For the purposes of this opinion, "emerging adult" is 
defined as someone who is eighteen, nineteen, or twenty years of 
age.  Although the record contains some references to 
individuals who are as old as twenty-four years of age as 
"emerging adults," the focus of the record and the Superior 
Court judge's factual findings, which guide our analysis today, 
are limited to offenders who are aged eighteen, nineteen, or 
twenty at the time of the crime. 
 
2 As discussed infra, our understanding of contemporary 
standards of decency is informed by the updated scientific 
record. 
 
3 We acknowledge the amicus briefs submitted by (1) twenty-
three retired Massachusetts judges, Boston Bar Association, and 
Massachusetts Bar Association; (2) seventeen neuroscientists, 
4 
 
Background.  1.  The homicide.  The evidence presented in 
the defendant's trial is summarized in Watt, 484 Mass. at 744-
745.4  We provide a condensed version of events as the jury could 
have found them.  On September 25, 2011, the defendant; his 
codefendant, Nyasani Watt; and another friend observed Kimoni 
Elliott standing outside a nearby convenience store.  Id. at 
744.  The defendant approached Elliott on a bicycle and asked 
him where he was from.  Elliott replied, "Everton."  Id.  The 
two then parted ways.  Id. 
Elliott met Jaivon Blake in a nearby parking lot while the 
defendant returned to Watt and said, "[B]e easy, because that's 
them kids."  Watt, 484 Mass. at 744-745.  A few minutes later, 
when Elliott and Blake were in view, the defendant handed Watt a 
gun and told Watt "to go handle that."  Id. at 745.  Watt rode 
toward Elliott and Blake on a bicycle and shot them from behind.  
Id.  Elliott survived gunshot wounds to his neck and right arm, 
 
psychologists, and criminal justice scholars; (3) Sentencing 
Project, Juvenile Law Center, and Roderick and Solange MacArthur 
Justice Center; (4) the Committee for Public Counsel Services; 
(5) Boston University Center for Antiracist Research, Fred T. 
Korematsu Center for Law and Equality, Center on Race, 
Inequality, and the Law, and Criminal Justice Institute at 
Harvard Law School; and (6) the district attorney for the 
Eastern district and the district attorney for the Plymouth 
district. 
 
4 The defendant and Watt were tried together, and their 
appeals were consolidated.  The decision was published under 
Watt's name. 
5 
 
but Blake died from a single gunshot wound to the torso.  Id. at 
744. 
2.  Procedural history and development of the record.  In 
2013, the defendant and Watt were tried jointly and convicted of 
murder in the first degree on the theories of deliberate 
premeditation and extreme atrocity or cruelty, among other 
charges.  Watt, who was seventeen at the time of the shooting, 
received a life sentence with the possibility of parole after 
fifteen years.5  Watt, 484 Mass. at 745.  See G. L. c. 265, § 2 
(b).  See also G. L. c. 127, § 133A; G. L. c. 279, § 24.  The 
defendant, who had turned eighteen approximately eight months 
prior to the crime, received a life sentence without the 
possibility of parole.  Watt, supra.  See G. L. c. 265, § 2 (a).  
See also G. L. c. 127, § 133A.  Each defendant filed a motion 
for a new trial.  Among other things, the defendant argued that 
his mandatory sentence of life without parole violated art. 26's 
prohibition of cruel or unusual punishment because he was under 
twenty-two years of age when he committed the murder.  A 
 
5 Sentencing in this case occurred after the United States 
Supreme Court's decision in Miller, but mere days before we 
issued our decision in Diatchenko I.  Despite not yet having our 
guidance on how to sentence such juveniles in the absence of new 
legislation on the matter, the judge correctly sentenced Watt to 
the equivalent penalty for murder in the second degree -- the 
"next-most severe sentence under the sentencing statute" 
available at the time for a juvenile convicted of murder in the 
first degree.  See Watt, 484 Mass. at 753. 
6 
 
Superior Court judge denied both motions, and the appeals from 
these denials were consolidated with the defendants' direct 
appeals.  Watt, supra at 743-744. 
We unanimously upheld the denial of both defendants' 
postconviction motions and affirmed all convictions.  Watt, 484 
Mass. at 765.  However, we remanded the defendant's case6 to the 
Superior Court for "development of the record with regard to 
research on brain development after the age of seventeen[, 
which] will allow us to come to an informed decision as to the 
constitutionality of sentencing young adults to life without the 
possibility of parole."  Id. at 756. 
A Superior Court judge, who had also been the trial judge, 
conducted three days of evidentiary hearings during which three 
expert witnesses -- neuroscientist Dr. Adriana Galván, forensic 
psychologist7 Dr. Robert Kinscherff, and forensic psychologist 
Dr. Stephen Morse -- testified on the topic of adolescent 
neurological and psychological development after the age of 
seventeen.8  The defendant also entered in the record the 
 
6 Because the art. 26 question did not apply to Watt, we 
remanded only the defendant's case to the Superior Court.  Watt, 
484 Mass. at 765. 
 
7 "[F]orensic psychology [i]s the use of psychological 
theories and methods and data to help the legal system resolve 
legal questions." 
 
8 The parties agree that all of the experts who submitted 
evidence in the record are duly qualified in the relevant fields 
7 
 
transcript of the testimony of a fourth expert witness, 
developmental psychologist Dr. Laurence Steinberg.9  The 
 
of neuroscience and forensic psychology, among other 
specialties, and are recognized as leaders in their respective 
professional fields. 
 
Galván holds a Ph.D. in neuroscience and is a tenured 
professor of psychology at the University of California, Los 
Angeles (UCLA), as well as the director of UCLA's Developmental 
Neuroscience Lab.  She has coauthored over one hundred book 
chapters and peer-reviewed studies, many of which have been 
published in leading journals in her field.  She has received 
numerous honors and awards, including the Presidential Early 
Career Award for Scientists and Engineers as well as the Troland 
Award from the National Academy of Sciences. 
 
Kinscherff holds both a juris doctor and a Ph.D. in 
clinical psychology.  He is a professor in the doctoral 
psychology program at William James College.  He has been 
qualified as an expert in forensic psychology numerous times and 
was formerly the Assistant Commissioner for Forensic Mental 
Health at the Department of Mental Health. 
 
Morse holds both a juris doctor and a Ph.D. in psychology 
and social relations.  He is a tenured professor of law and 
professor of psychology and law at the University of 
Pennsylvania.  He has written numerous articles on neuroscience 
and the law, many of which have been published in leading 
journals on law and neuroscience.  He has been qualified as an 
expert in at least twenty cases and was previously the Legal 
Director at the MacArthur Foundation's Law and Neuroscience 
Project. 
 
Galván and Kinscherff testified on behalf of the defendant.  
Morse testified on behalf of the Commonwealth. 
 
9 Steinberg holds a Ph.D. in human development and family 
studies.  He is a tenured professor at Temple University.  Over 
the course of forty years, he has authored scores of studies 
that have been published in peer-reviewed journals, including 
top journals in his field.  He has been qualified as an expert 
in developmental psychology approximately thirty times.  His 
research was cited in two of the leading Supreme Court cases on 
the Eighth Amendment's ban on cruel and unusual punishment as 
8 
 
Commonwealth and the defendant also submitted voluminous 
exhibits, including numerous scientific studies on adolescence 
and neurobiological maturity. 
The record was transmitted to us in May 2021 but did not 
include factual findings.  In December 2021, we again remanded 
this case, along with the case underlying our decision in 
Commonwealth v. Robinson, 493 Mass.     (2023), to the Superior 
Court for the development of factual findings based on the 
previously transmitted record.10  Specifically, we requested 
findings regarding "whether the imposition of a mandatory 
sentence of life without the possibility of parole for . . . 
those convicted of murder in the first degree who were eighteen 
to twenty-one at the time of the crime, violates [art.] 26." 
A different Superior Court judge issued factual findings in 
July 2022, concluding that the mandatory imposition of a 
sentence of life without parole for offenders who were eighteen, 
 
applied to juveniles.  See Miller, 567 U.S. at 471 (referencing 
Steinberg & Scott, Less Guilty by Reason of Adolescence:  
Developmental Immaturity, Diminished Responsibility, and the 
Juvenile Death Penalty, 58 Am. Psychologist 1009, 1014 [2003]); 
Roper, 543 U.S. at 569-573 (same).  Steinberg testified on 
behalf of the defendant in the case underlying our decision in 
Commonwealth v. Robinson, 493 Mass.     (2023), a case raising a 
nearly identical sentencing claim.  See note 10, infra. 
 
10 This case was paired with the one underlying Robinson, 
493 Mass.    , because, similarly to Mattis, Robinson asked this 
court to consider whether a sentence of life without parole is 
constitutional when applied to those who committed their crime 
while under twenty-one years of age. 
9 
 
nineteen, or twenty years old at the time they committed the 
crime is a violation of art. 26.  In particular, the judge found 
that emerging adults are "less able to control their impulses" 
and that "their reactions in [emotionally arousing] situations 
are more similar to those of [sixteen and seventeen year olds] 
than they are to those [twenty-one to twenty-two] and older."  
The case and its entire evidentiary record subsequently were 
transmitted back to this court, where the defendant argued that 
it is unconstitutional to sentence an emerging adult to life 
without the possibility of parole in any circumstance, and the 
Commonwealth argued that such a sentence is constitutional if 
imposed after an individualized hearing. 
Discussion.  Adopted in 1780, art. 26 states:  "No 
magistrate or court of law, shall . . . inflict cruel or unusual 
punishments."  In evaluating the constitutionality of a 
sentence, this court is guided by "[t]he fundamental imperative 
of art. 26 that criminal punishment be proportionate to the 
offender and the offense."  Diatchenko I, 466 Mass. at 671.  A 
punishment is unconstitutional (i.e., cruel or unusual) if it is 
so disproportionate to the crime that it "shocks the conscience 
and offends fundamental notions of human dignity."  Id. at 669, 
quoting Cepulonis v. Commonwealth, 384 Mass. 495, 497 (1981).11 
 
11 Similarly, the Eighth Amendment's prohibition on cruel 
and unusual punishment "flows from the basic 'precept of justice 
10 
 
1.  Constitutional framework.  To evaluate the 
proportionality of a mandatory life sentence imposed on a 
category of offenders (here, emerging adults), we look to 
precedent as well as what contemporary standards of decency, as 
defined by objective indicia, require.  See Graham, 560 U.S. at 
61, quoting Roper, 543 U.S. at 563-564 ("The Court first 
considers 'objective indicia of society's standards, as 
expressed in legislative enactments and state practice,' to 
determine whether there is a national consensus against the 
sentencing practice at issue. . . .  [Then] guided by 'the 
standards elaborated by controlling precedents and by the 
Court's own understanding and interpretation of the Eighth 
Amendment's text, history, meaning, and purpose,' . . . the 
Court must determine . . . whether the punishment in question 
violates the Constitution"); Roper, supra at 560-561.12  As for 
 
that punishment for crime should be graduated and proportioned' 
to both the offender and the offense."  Miller, 567 U.S. at 469, 
quoting Roper, 543 U.S. at 560. 
 
12 The dissent asserts that the "tripartite" test is the 
proper tool to analyze the constitutionality of the sentence 
here.  Post at    .  See Commonwealth v. Jackson, 369 Mass. 904, 
910-916 (1976).  That test considers (1) the nature of the 
offense and the offender in light of the degree of harm to 
society, (2) the sentence imposed and penalties prescribed for 
more serious crimes in Massachusetts, and (3) a comparison 
between the sentence imposed with the penalties prescribed for 
the same offense in other jurisdictions.  It traditionally has 
been used, both by this court and the Supreme Court, to assess 
whether a term-of-years sentence is grossly disproportionate to 
a given offense, considering all the circumstances of a 
11 
 
the latter, current scientific consensus regarding the 
characteristics of the class can help determine the contemporary 
standards of decency pertaining to that class.  See Diatchenko 
I, 466 Mass. at 659-661, 669-671.  See also Miller, 567 U.S. at 
471-472 ("Our decisions rested not only on common sense . . . 
but on science and social science as well"); Graham, supra at 
68; Roper, supra at 569-570; Commonwealth v. Okoro, 471 Mass. 
 
particular case.  Id.  See, e.g., Commonwealth v. Sharma, 488 
Mass. 85, 89-90 (2021); Commonwealth v. LaPlante, 482 Mass. 399, 
403 (2019); Commonwealth v. Perez, 477 Mass. 677, 685-686 
(2017), S.C., 480 Mass. 562 (2018); Opinions of the Justices, 
378 Mass. 822, 824-825 (1979).  See also Ewing v. California, 
538 U.S. 11 (2003); Harmelin v. Michigan, 501 U.S. 957 (1991); 
Solem v. Helm, 463 U.S. 277 (1983). 
 
Although the tripartite test incorporates elements of the 
approach we use today, it is of limited utility here.  Its 
"threshold comparison between the severity of the penalty and 
the gravity of the crime does not advance the analysis" where 
neither the sentence's proportionality to the charged offense 
nor the existence of a more serious offense in the Commonwealth 
is being challenged.  See Graham, 560 U.S. at 61.  Rather, our 
cases show, and Supreme Court precedent affirms, that it is the 
"categorical" framework, which focuses on contemporary standards 
of decency, that applies here, where the task is to assess 
whether a sentence is disproportionate when applied to an entire 
category of offenders.  See id. ("In cases turning on the 
characteristics of the offender, the Court has adopted 
categorical rules . . . [and] consider[ed] 'objective indicia of 
society's standards'"); Diatchenko I, 466 Mass. at 669 
(contemporary standards of decency render imposition of life 
without parole sentence on particular category of offenders 
unconstitutionally disproportionate).  See also, e.g., Roper, 
543 U.S. at 560-563 (standards of decency dictate death 
penalty's unconstitutionality when imposed on those under 
eighteen); Atkins v. Virginia, 536 U.S. 304, 321 (2002) 
(standards of decency dictate death penalty's 
unconstitutionality when imposed on those with intellectual 
disabilities). 
12 
 
51, 60 (2015) ("the determination that youth are 
constitutionally distinct from adults for sentencing purposes 
has strong roots in recent developments in the fields of science 
and social science"). 
a.  Precedent.  In a series of cases responding to 
challenges to juvenile sentences, the Supreme Court has 
consistently opined that the "mitigating qualities of youth" 
must be taken into consideration when it comes to sentencing.  
Johnson v. Texas, 509 U.S. 350, 367 (1993).  See, e.g., Jones v. 
Mississippi, 141 S. Ct. 1307, 1314 (2021), citing Miller, 567 
U.S. at 476; Johnson, supra ("A sentencer in a capital case must 
be allowed to consider the mitigating qualities of youth in the 
course of its deliberations over the appropriate sentence").  
For example, when striking down the death penalty for juveniles 
in Roper, the Court discussed the "relevance of youth as a 
mitigating factor" at length, concluding that "[o]nce the 
diminished culpability of juveniles is recognized, it is evident 
that the penological justifications for the death penalty apply 
to them with lesser force than to adults."  Roper, 543 U.S. at 
570-571. 
In Graham, 560 U.S. at 76, the Court noted that an 
"offender's age is relevant to the Eighth Amendment, and 
criminal procedure laws that fail to take defendants' 
youthfulness into account at all would be flawed."  The Court 
13 
 
concluded that it was unconstitutional to sentence juveniles who 
did not commit homicide to life without parole because they lack 
the maturity to be classified among the worst offenders 
deserving of the harshest punishments.  The Court further noted 
that although "[m]aturity can lead to that considered reflection 
which is the foundation for remorse, renewal, and rehabilitation 
. . . [a] young person who knows that he or she has no chance to 
leave prison before life's end has little incentive to become a 
responsible individual."13  Id. at 79. 
More recently in Miller, 567 U.S. at 476, in which the 
Court held that a judge must be able to consider "mitigating 
qualities of youth" in formulating a sentence, the Court 
reiterated that youth is not simply a "chronological fact" 
(citation omitted).  Rather, "[i]t is a time of immaturity, 
irresponsibility, impetuousness[,] and recklessness. . . .  It 
is a moment and condition of life when a person may be most 
susceptible to influence and to psychological damage. . . .  And 
its signature qualities are all transient" (citations and 
quotations omitted).  Id.  As a result, the Court reasoned, the 
Eighth Amendment forbids a sentencing scheme that mandates life 
 
13 Although Graham's ban on life sentences without the 
possibility of parole for juveniles applied only to nonhomicide 
crimes, as the Miller Court pointed out, "none of what [Graham] 
said about children -- about their distinctive (and transitory) 
mental traits and environmental vulnerabilities -- is crime-
specific."  Miller, 567 U.S. at 473. 
14 
 
without parole for juvenile offenders because such a scheme 
precludes a consideration of youth and the circumstances and 
characteristics attendant to it.  Id. at 479. 
Approximately one and one-half years after Miller was 
decided, we considered whether sentencing a juvenile offender to 
life without the possibility of parole comported with art. 26.  
See Diatchenko I, 466 Mass. at 661.  Ultimately, this court went 
further than Miller and concluded that because it is not 
possible to demonstrate that a juvenile offender is 
"irretrievably depraved," under the Massachusetts Declaration of 
Rights, such a sentence is cruel or unusual as imposed on a 
juvenile in any circumstance.  Id. at 670-671. 
Central to each of the foregoing cases is the "fundamental 
precept of justice that punishment for crime should be graduated 
and proportioned to both the offender and the offense" (citation 
and quotations omitted).  Id. at 669.  Until now, we have 
declined to consider extending Diatchenko I to offenders 
eighteen years of age and older.  See Watt, 484 Mass. at 755-
756, and cases cited.  However, we also recognized that 
"researchers continue to study the age range at which most 
individuals reach adult neurobiological maturity . . . and that 
such research may relate to the constitutionality of sentences 
of life without parole for individuals other than juveniles" 
(citation and quotation omitted).  Id.  The judge's findings in 
15 
 
this case, described more fully infra, confirm that the brains 
of emerging adults are similar to those of juveniles. 
b.  Contemporary standards of decency.  An assessment of a 
punishment's proportionality occurs "in light of contemporary 
standards of decency which mark the progress of society."  
Diatchenko I, 466 Mass. at 669, quoting Good v. Commissioner of 
Correction, 417 Mass. 329, 335 (1994).  See Okoro, 471 Mass. at 
61 (proportionality of punishment is determined based on "the 
evolving standards of decency that mark the progress of a 
maturing society" [citation omitted]).  Here, we consider the 
updated research on the brains of emerging adults, as well as 
the way emerging adults are treated in the Commonwealth and 
elsewhere, to determine whether a sentence of life without the 
possibility of parole is proportionate and thus constitutional 
when imposed upon that class of offenders. 
i.  Science and social science.  As mentioned supra, where 
modern scientific consensus regarding a particular class exists, 
it can be useful in determining the contemporary standards of 
decency as they relate to that class.  See Miller, 567 U.S. at 
471-472; Okoro, 471 Mass. at 59-60. 
Advancements in scientific research have confirmed what 
many know well through experience:  the brains of emerging 
adults are not fully mature.  Specifically, the scientific 
record strongly supports the contention that emerging adults 
16 
 
have the same core neurological characteristics as juveniles 
have.  As the Superior Court judge noted, "Today, 
neuroscientists and behavioral psychologists know significantly 
more about the structure and function of the brains of 
[eighteen] through [twenty year olds] than they did [twenty] 
years ago . . . ."  This is the result of years of targeted 
research and greater access to relatively new and sophisticated 
brain imaging techniques, such as structural magnetic resonance 
imaging (sMRI) and functional magnetic resonance imaging 
(fMRI).14  From the detailed evidence produced in the record, the 
judge made four core findings of fact regarding the science of 
emerging adult brains:  emerging adults (1) have a lack of 
impulse control similar to sixteen and seventeen year olds in 
emotionally arousing situations,15 (2) are more prone to risk 
taking in pursuit of rewards than those under eighteen years and 
those over twenty-one years, (3) are more susceptible to peer 
 
14 sMRIs allow researchers to examine the brain's anatomical 
structures at particular moments in time; fMRIs allow 
researchers to examine the brain's activation and responses to 
stimuli and environmental context.  As Galván testified, MRIs, 
particularly sMRIs, have allowed researchers "to see [a] fine 
grain view of the brain that other technologies would not 
allow." 
 
15 This also is referred to as being under "hot cognition."  
The experts testified that under "cold cognition," which is the 
absence of emotionally arousing circumstances, the emerging 
adult brain functions much more similarly to the older adult 
brain than to the adolescent brain. 
17 
 
influence than individuals over twenty-one years, and (4) have a 
greater capacity for change than older individuals due to the 
plasticity of their brains.  The driving forces behind these 
behavioral differences are the anatomical and physiological 
differences between the brains of emerging and older adults.  
See Steinberg, A Social Neuroscience Perspective on Adolescent 
Risk-Taking, 28 Developmental Rev. 78, 82-84, 85-89 (2008).  
These structural and functional differences make emerging 
adults, like juveniles, "particularly vulnerable to risk-taking 
that can lead to poor outcomes." 
We discuss each of the judge's four core factual findings 
in turn. 
A.  Impulse control.  The judge found that in terms of 
impulse control, emerging adults are more similar to sixteen and 
seventeen year old juveniles than to older adults.  That is, 
they are less able to control their impulses in emotionally 
arousing situations.  This finding is well supported by the 
record. 
Emerging adults still are experiencing the effects of "the 
sharp increase during puberty of certain hormones," lack a fully 
developed prefrontal cortex, which is "the part of the brain 
that most clearly regulates impulses," and lack fully developed 
connections "between the prefrontal cortex and other parts of 
the brain . . . that most clearly respond[] to rewards and 
18 
 
reward-related decision making."  All four experts agreed that 
compared to older adults, emerging adults are more impulsive, 
more concerned with their immediate circumstances, and less able 
to envision future consequences.  Galván explained that at least 
part of this distinction between emerging and older adults can 
be traced to differences in brain structure between the groups.  
"[T]he prefrontal cortex is the home for these abilities that we 
might say are what makes us adults . . . the ability to reason, 
the ability to think about how your actions today will have 
implications for the future."  As the brain matures, it 
"undergoes a process called pruning and [eliminates]" synapses 
and neurons that are not needed.  Advancements in sMRI data have 
allowed researchers "to measure this cortical thickness and 
thinning and the process continues through [eighteen], 
[nineteen], [twenty] years old." 
All of the other experts, including the Commonwealth's 
expert, agreed that the prefrontal cortex, an area of the brain 
associated with controlling impulses, is among the last brain 
regions to develop, and continues developing until the early to 
mid-twenties.  See Icenogle et al., Adolescents' Cognitive 
Capacity Reaches Adult Levels Prior to Their Psychosocial 
Maturity:  Evidence for a "Maturity Gap" in a Multinational, 
Cross-Sectional Sample, 43 Law & Hum. Behav. 69, 70 (2019); 
Sowell & others, In Vivo Evidence for Post-Adolescent Brain 
19 
 
Maturation in Frontal and Striatal Regions, 2 Nature Neurosci. 
859, 860-861 (1999); Steinberg et al., Around the World, 
Adolescence Is a Time of Heightened Sensation Seeking and 
Immature Self-Regulation, Developmental Sci., vol. 21, Mar. 
2018, at 1-4, 15-17. 
B.  Risk taking in pursuit of reward.  The judge found that 
"[a]s a group, [individuals eighteen through twenty years of 
age] in the United States and other countries are more prone to 
'sensation seeking,' which includes risk-taking in pursuit of 
rewards, than are individuals under age [eighteen] and over age 
[twenty-one]."  This finding similarly is well supported by the 
record. 
All of the experts agreed that emerging adults are more 
likely than children or older adults to engage in risky behavior 
and that risky behaviors tend to peak in late adolescence to 
early adulthood and then decline, with some experts asserting 
that this behavior plateaus around twenty-two years of age.  
Galván explained that fMRI studies evaluating the brain have 
shown that in individuals at least seventeen years of age, and 
up to twenty-one years of age, there is greater activity in the 
nucleus accumbens, a part of the brain associated with sensation 
seeking, than in older adults.  Additionally, fMRI studies have 
shown that the ventral striatum, a part of the brain that 
correlates with risk-taking behaviors, also is more active among 
20 
 
late adolescents and early adults than it is in older adults.  
This research tracks numerous real-world behaviors.  Emerging 
adults are overrepresented in multiple types of risky behavior, 
such as risky sexual behavior and risky driving behavior, in 
addition to risky criminal behavior.  See Roper, 543 U.S. at 
569, quoting Arnett, Reckless Behavior in Adolescence:  A 
Developmental Perspective, 12 Developmental Rev. 339 (1992) ("It 
has been noted that 'adolescents are overrepresented 
statistically in virtually every category of reckless 
behavior'"). 
Each expert discussed the so-called "age-crime curve," 
which is a widely recognized phenomenon illustrating that 
criminal behavior crests at some point from late adolescence to 
early adulthood before significantly declining.  Put succinctly, 
as with those under eighteen years of age, "late adolescence[16] 
 
16 All the experts referred to individuals from eighteen to 
twenty years of age as "late adolescents."  We refer to this age 
group as "emerging adults."  We do not agree with the dissent 
that this appellation indicates that we improperly are veering 
into the Legislature's lane.  As the Supreme Court noted when it 
declared the death penalty unconstitutional for juveniles, line 
drawing is a necessary task when considering categorical bans on 
unconstitutional sentences.  Roper, 543 U.S. at 574 ("Drawing 
the line at [eighteen] years of age is subject, of course, to 
the objections always raised against categorical rules.  The 
qualities that distinguish juveniles from adults do not 
disappear when an individual turns [eighteen].  By the same 
token, some under [eighteen] have already attained a level of 
maturity some adults will never reach.  For the reasons we have 
discussed, however, a line must be drawn"). 
21 
 
is a period in human development of increased risk taking, 
greater reactivity to high stress or highly emotionally arousing 
events and certain kinds of cognitive biases that, for example, 
lead them [(i.e., juveniles and emerging adults)] to not 
appraise a risk and apply it to themselves in the same way that 
an adult would."  See Galván et al., Earlier Development of the 
Accumbens Relative to Orbitalfrontal Cortex Might Underlie Risk-
Taking Behaviors in Adolescents, 26 J. Neurosci. 6885, 6885-6892 
(2006); Hawes et al., Modulation of Reward-Related Neural 
Activation on Sensation Seeking across Development, 283 
NeuroImage 763, 763-771 (2017); Rudolph et al., At Risk of Being 
Risky:  The Relationship Between "Brain Age" under Emotional 
States and Risk Preference, Developmental Cognitive Neurosci., 
vol. 24, 2017, at 93-106; Steinberg et al., Around the World, 
Adolescence Is a Time of Heightened Sensation Seeking and 
Immature Self-Regulation, supra at 1-4, 15-17. 
C.  Peer influence.  The judge also found that emerging 
adults "are more susceptible to peer influence" than older 
adults and that the presence of peers makes emerging adults 
"more likely to engage in risky behavior."  All four experts 
agreed that current research supports this conclusion. 
Steinberg's research in particular focuses on the ways in 
which the presence of peers affects decision-making and risk 
taking among different age groups.  In his work, he has found 
22 
 
that "even if the peers aren't explicitly encouraging anything, 
the mere presence of peers increases the likelihood that 
adolescents[17] will engage in [risky] behavior."  Although the 
presence of peers may influence behavior at any age, "peer 
influence is a much more serein [sic] and powerful factor during 
adolescence[18] than it is during adulthood."  See Breiner et al., 
Combined Effects of Peer Presence, Social Cues, and Rewards on 
Cognitive Control in Adolescents, 60 Developmental Psychobiology 
292, 292-302 (2018); Galván, Adolescent Brain Development and 
Contextual Influences:  A Decade in Review, 31 J. Res. on 
Adolescence 843, 852-853 (2021); Silva et al., Peers Increase 
Late Adolescents' Exploratory Behavior and Sensitivity to 
Positive and Negative Feedback, 26 J. Res. on Adolescence 696, 
696-705 (2015). 
D.  Capacity for change.  Finally, the judge found that 
emerging adults "have greater capacity to change than older 
individuals because of the plasticity of the brain during these 
years."  This finding is well supported by the record. 
"[P]lasticity refers to the ability [to] change in response 
to the environment."19  Although the brain has its greatest 
 
17 See note 16, supra. 
 
18 See note 16, supra. 
 
19 Galván explained that plasticity primarily occurs in the 
hippocampus, which is "a small brain region in the deep layers 
23 
 
plasticity in the early months of life, as Galván explained, 
"[t]he second wave [of plasticity] is during adolescence."20  In 
contrast, "adult capacity for change is diminished because" the 
fully mature brain is much less malleable.  Although the brain 
continues to change throughout one's lifespan, Steinberg 
testified that brain maturation is largely complete by as early 
as twenty-two years of age, and possibly up to twenty-five years 
of age.  The Commonwealth's expert agreed that "[m]ost 
adolescents[21] even those who commit serious crimes will age out 
of offending and will not become career criminals."  See Roper, 
543 U.S. at 570, quoting Johnson, 509 U.S. at 368, and citing 
Steinberg & Scott, Less Guilty by Reason of Adolescence:  
Developmental Immaturity, Diminished Responsibility, and the 
Juvenile Death Penalty, 58 Am. Psychologist 1009, 1014 (2003) 
("the signature qualities of youth are transient; as individuals 
mature, the impetuousness and recklessness that may dominate in 
younger years can subside").  See also Cauffman et al., A 
Developmental Perspective on Adolescent Risk-Taking and Criminal 
Behavior, c. 6 in The Handbook of Criminological Theory (2015); 
 
of the brain that has mostly been studied in the context of 
learning because plasticity or any plasticity-based changes are 
because we've learned something new." 
 
20 See note 16, supra. 
 
21 See note 16, supra. 
24 
 
Galván, Insights about Adolescent Behavior, Plasticity, and 
Policy from Neuroscience Research, 83 Neuron 262, 264 (2014). 
The evidence outlined supra provides a scientifically 
informed view of emerging adults' culpability and factors into 
our analysis whether contemporary standards of decency permit 
sentencing that cohort to life without the possibility of 
parole. 
ii.  Treatment of emerging adults in the Commonwealth and 
elsewhere.  To determine our contemporary standards of decency, 
in addition to referring to our own State statutes, see Good, 
417 Mass. at 335, we may look to other policies and programs in 
the Commonwealth, our precedent, other States' statutes, as well 
as other States' judicial rulings, and even international 
statutes and decisions, among other sources, see Okoro, 471 
Mass. at 61 (we commonly look to "judicial opinions and 
legislative actions at the State, Federal, and international 
levels," which "help to inform our understanding of what art. 26 
protects" [citation omitted]).  See also Thompson v. Oklahoma, 
487 U.S. 815, 821-831 (1988) (looking to State statutes and 
death penalty juries to divine contemporary standards of 
decency, and noting consistency with practices of other 
nations); Enmund v. Florida, 458 U.S. 782, 788 (1982) (looking 
to "historical development of the punishment at issue, 
legislative judgments, international opinion, and the sentencing 
25 
 
decisions juries have made"); Coker v. Georgia, 433 U.S. 584, 
596 (1977) ("important to look to the sentencing decisions that 
juries have made in the course of assessing whether capital 
punishment is an appropriate penalty").  As discussed infra, a 
combination of statutes passed here and elsewhere, as well as 
recent decisions in Washington and Michigan, indicate that our 
contemporary standards of decency do not support imposing life 
without parole sentences on emerging adults. 
To begin, the Legislature has determined that emerging 
adults require different treatment from older adults, 
specifically in the penological context.  For example, the 
Department of Youth Services (department) statutorily is 
authorized to maintain custody of young people adjudicated as 
youthful offenders up to twenty-one years of age.  See 
Commonwealth v. Terrell, 486 Mass. 596, 599-600, 603 (2021); 
G. L. c. 119, § 58.  This sentencing scheme also permits the 
imposition of "dual" sentences for youthful offenders, requiring 
them to remain in the department's custody until they are 
twenty-one years of age before beginning their "adult sentence" 
at a house of correction.  G. L. c. 119, § 58 (b). 
Further, in 2018, as part of a set of sweeping reforms, the 
Legislature authorized the Department of Correction and county 
houses of correction to "establish young adult correctional 
units."  These units provide "targeted interventions, age 
26 
 
appropriate programming and a greater degree of individual 
attention" for individuals in custody "ages [eighteen] to 
[twenty-four]."  G. L. c. 127, § 48B (a).  Notably, the 
Legislature also formed the Task Force on Emerging Adults in the 
Criminal Justice System (task force), which released a report in 
2020 concluding that emerging adults "are a unique population 
that requires developmentally-tailored programming and 
services."22  Emerging Adults in the Massachusetts Criminal 
Justice System:  Report of the Task Force on Emerging Adults in 
the Criminal Justice System (Feb. 26, 2020), 2020 Senate Doc. 
No. 2840, at 6.  See St. 2018, c. 69, § 221. 
Massachusetts is not alone in recognizing that emerging 
adult offenders require different treatment from older adult 
offenders.  For example, the District of Columbia now provides a 
 
22 Noting that the dual sentencing scheme for youthful 
offenders under G. L. c. 119, § 58, applies only to juveniles, 
and that the task force's recommendations for emerging adults do 
not include offenders convicted of murder in the first degree, 
Justice Lowy's dissent concludes that neither demonstrates 
contemporary standards of decency here in the Commonwealth.  
Post at    .  See G. L. c. 119, § 74; Emerging Adults in the 
Massachusetts Criminal Justice System:  Report of the Task Force 
on Emerging Adults in the Criminal Justice System (Feb. 26, 
2020), 2020 Senate Doc. No. 2840, at 10.  To the contrary, both 
examples demonstrate that the Legislature and other community 
members recognize that emerging adult offenders benefit from 
being treated differently from older adult offenders.  Cf. 
Thompson v. Oklahoma, 487 U.S. 815, 823 (1988) (distinct 
treatment of younger juveniles compared to older juveniles "in 
criminal sanctions and rehabilitation" is evidence of 
contemporary standards of decency [citation omitted]). 
27 
 
chance at sentence reduction for people who were under twenty-
five years old when they committed a crime.  D.C. Code § 24-
403.03.  In 2019, Illinois enacted a law allowing parole review 
at ten or twenty years into a sentence for most crimes, 
exclusive of sentences to life without parole, if the individual 
was under twenty-one years old at the time of the offense.  730 
Ill. Comp. Stat. 5/5-4.5-115.  Effective January 1, 2024, 
Illinois also ended life without parole for most individuals 
under twenty-one years old, allowing review after they serve 
forty years.  Ill. Pub. L. No. 102-1128, § 5 (2022).  California 
has extended youth offender parole eligibility to individuals 
who committed offenses before twenty-five years of age.  Cal. 
Penal Code § 3051.  Similarly, in 2021, Colorado expanded 
specialized program eligibility, usually reserved for juveniles, 
to adults who were under twenty-one when they committed a 
felony.  Colo. House Bill No. 21-1209 (2021) (enacted).  In 
Wyoming, "youthful offender" programs were revised to offer 
reduced and alternative sentencing for those under thirty years 
old.  Wyo. Stat. Ann. §§ 7-13-1002, 7-13-1003. 
Legislation outside of the penological context is also 
instructive in ascertaining contemporary standards of decency.  
In Thompson, 487 U.S. at 838, the Supreme Court determined that 
the death penalty was unconstitutional when imposed on a fifteen 
year old offender based, in part, on then-current nonpenological 
28 
 
State statutes that treated younger juveniles differently from 
those closer to age eighteen.  Among other things, the Court 
noted that "in all but one State a [fifteen]-year-old may not 
drive without parental consent, and in all but four States a 
[fifteen]-year-old may not marry without parental consent" 
(footnote omitted).  See id. at 824-825. 
Similarly, Massachusetts, like most States, distinguishes 
emerging adults from older adults on a range of issues, granting 
rights and imposing responsibilities in a graduated manner.  For 
example, one must be eighteen years of age to enter binding and 
enforceable contracts, to sit on a jury, to purchase lottery 
tickets, and to drive a common carrier motor vehicle.23  See 
G. L. c. 231, § 85O; G. L. c. 234A, § 4; G. L. c. 10, § 29; 
G. L. c. 159A, § 9.  However, one must be twenty-one years of 
age to purchase and sell alcoholic beverages, to purchase 
tobacco products, to obtain a license to carry a handgun, to be 
a police officer, and to gamble.  See G. L. c. 138, § 34; G. L. 
c. 270, § 6; G. L. c. 140, § 131 (d) (iv); G. L. c. 31, § 58; 
G. L. c. 22C, § 10; G. L. c. 23K, §§ 25 (h), 43.  These statutes 
reflect the commonly held view that emerging adults generally 
 
23 Moreover, young adults who have reached eighteen years of 
age may "continue to be considered 'minors'" for purposes of 
parental support.  Eccleston v. Bankosky, 438 Mass. 428, 429 
(2003), quoting Stolk v. Stolk, 31 Mass. App. Ct. 903, 904-905 
(1991).  See G. L. c. 208, § 28. 
29 
 
are not equipped to assume all the responsibilities of 
adulthood, especially with respect to high risk activities.  Cf. 
Thompson, 487 U.S. at 824-825. 
We are not the first State Supreme Court to appreciate the 
distinct ways in which our laws bear on emerging adults.  
Recently, the high courts in Washington and Michigan prohibited 
the mandatory imposition of life without the possibility of 
parole for those who are from eighteen to twenty years of age, 
and for those who are eighteen years of age, respectively.  In 
Matter of the Personal Restraint of Monschke, 197 Wash. 2d 305 
(2021), the Supreme Court of Washington considered evolving 
standards of decency, updated brain science, and precedent to 
conclude that mandatory sentences of life without parole violate 
the Washington Constitution when meted out to those under 
twenty-one when they committed the crime.  See id. at 325-326. 
One year later, the Supreme Court of Michigan looked at the 
issue as it pertained to eighteen year old offenders.  The court 
reasoned that because "the Eighth Amendment dictates that youth 
matters in sentencing," and because brain science has 
demonstrated that eighteen year old individuals possess the same 
attributes of youth as do juveniles, mandatorily subjecting an 
eighteen year old defendant to life in prison is "unusually 
excessive imprisonment and thus a disproportionate sentence that 
constitutes 'cruel or unusual punishment' under [the Michigan 
30 
 
Constitution]."  People v. Parks, 510 Mich. 225, 234, 255 
(2022).24 
Twenty-two States and the District of Columbia do not 
mandate life without parole in any circumstance.25  Of the 
remaining twenty-eight States, only twelve (including 
Massachusetts) mandate life without parole.26  Moreover, the 
 
24 However, both the Washington and Michigan courts 
determined that a sentence of life without the possibility of 
parole could be imposed on young adult offenders after an 
individualized sentencing hearing to consider the offender's 
youth.  See Parks, 510 Mich. at 240-241; Matter of the Personal 
Restraint of Monschke, 197 Wash. 2d at 327-328. 
 
25 In those twenty-two States and the District of Columbia, 
the highest penalties are imposed only on discretionary bases.  
See Alaska Stat. § 12.55.125; D.C. Code § 22-2104; Ga. Code Ann. 
§ 16-5-1; Idaho Code Ann. §§ 18-4004, 19-2515; 720 Ill. Comp. 
Stat. 5/9-1; Ind. Code §§ 35-50-2-3, 35-50-2-9; Ky. Rev. Stat. 
Ann. § 532.030; Me. Rev. Stat. tit. 17-A, § 1603; Md. Code Ann., 
Crim. Law §§ 2-201, 2-203; Mont. Code Ann. § 45-5-102(2); Nev. 
Rev. Stat. § 200.030(4)(a)-(b); N.M. Stat. Ann. § 31-18-13; N.Y. 
Penal Law §§ 60.06, 70.00(5); N.D. Cent. Code § 12.1-32-01; Ohio 
Rev. Code Ann. §§ 2929.02, 2929.04; Okla. Stat. tit. 21, 
§ 701.9; Or. Rev. Stat. § 163.107; R.I. Gen. Laws §§ 11-23-2, 
12-19.2-1 to 12-19.2-5; S.C. Code Ann. § 16-3-20; Tenn. Code 
Ann. § 39-13-204; Utah Code Ann. § 76-5-203; Wis. Stat. 
§ 973.014(1g)(c)-(2); Wyo. Stat. Ann. § 6-2-101. 
 
26 See G. L. c. 265, § 2 (a) ("any person who is found 
guilty of murder in the first degree shall be punished by 
imprisonment in the state prison for life and shall not be 
eligible for parole pursuant to [G. L. c. 127, § 133A"); Colo. 
Rev. Stat. § 18-1.3-401(1)(a)(V)(F), (4)(a)(I)-(II) ("A person 
. . . shall be punished by life imprisonment" without 
possibility of parole); Del. Code Ann. tit. 11, § 4209 ("Any 
person who is convicted of first-degree murder for an offense 
that was committed after the person had reached [his or her] 
eighteenth birthday shall be punished by . . . imprisonment for 
the remainder of the person's natural life without benefit of 
probation or parole or any other reduction"); Haw. Rev. Stat. 
31 
 
statutes in at least two of those States provide an opportunity 
to avoid the mandatory nature of the sentence.27  Twelve States 
mandate life without parole as an alternative to a discretionary 
death sentence,28 and five States only mandate life without 
 
§ 706-656 ("Persons eighteen years of age or over at the time of 
the offense who are convicted of first degree murder or first 
degree attempted murder shall be sentenced to life imprisonment 
without the possibility of parole"); Iowa Code § 902.1 (on 
conviction of murder in first degree, "the court shall . . . 
commit the defendant . . . for the rest of the defendant's life 
. . . [and the defendant] shall not be released on parole unless 
the governor commutes the sentence to a term of years"); Mich. 
Comp. Laws § 750.316 (any person "who commits . . . first degree 
murder . . . shall be punished by imprisonment for life without 
eligibility for parole"); Minn. Stat. § 609.106 ("the court 
shall sentence a person to life imprisonment without possibility 
of release . . . [if] the person is convicted of first-degree 
murder"); N.H. Rev. Stat. Ann. § 630:1-a(III) ("A person 
convicted of a murder in the first degree shall be sentenced to 
life imprisonment and shall not be eligible for parole at any 
time"); 18 Pa. Cons. Stat. § 1102 ("a person who has been 
convicted of a murder of the first degree . . . shall be 
sentenced to . . . a term of life imprisonment"); Va. Code Ann. 
§ 18.2-10(a) ("Any person who was [eighteen] years of age or 
older at the time of the offense and who is sentenced to 
imprisonment for life upon conviction of a Class 1 felony shall 
not be eligible for . . . parole"); Wash. Rev. Code § 10.95.030 
(any person "convicted of the crime of aggravated first degree 
murder shall be sentenced to life imprisonment without 
possibility of release or parole"); W. Va. Code § 61-2-2 
("Murder of the first degree shall be punished by confinement in 
the penitentiary for life"). 
 
27 Iowa allows its Governor to commute the sentence to a 
term of years.  Iowa Code § 902.2.  Hawaii obligates the parole 
board to submit an application to its Governor to commute the 
sentence to one permitting parole after twenty years.  Haw. Rev. 
Stat. § 706-656. 
 
28 See Ala. Code § 13a-6-2(c); Ariz. Rev. Stat. Ann. §§ 13-
751(A), 13-1105(D); Ark. Code Ann. § 5-10-101(c); Fla. Stat. 
§ 775.082; Kan. Stat. Ann. § 21-6617 (for capital murder); La. 
32 
 
parole if aggravating circumstances exist.29  Massachusetts is 
one of only ten States that currently require eighteen through 
twenty year old individuals who are convicted of murder in the 
first degree to be sentenced to life without parole. 
We also may consider where other nations stand in this 
analysis.  See Okoro, 471 Mass. at 61.  See also Graham, 560 
U.S. at 80 ("The judgments of other nations and the 
international community are not dispositive as to the meaning of 
the Eighth Amendment," but "[t]he Court has looked beyond our 
Nation's borders for support for its independent conclusion that 
a particular punishment is cruel and unusual").  The United 
Kingdom has banned life without parole for any offender under 
twenty-one years of age at the time of the offense.  Sentencing 
Act 2020, c. 17, § 322, sch. 21, par. 2 (U.K.).  And in 2022, 
the Supreme Court of Canada unanimously ruled that life without 
parole sentences were unconstitutional for all offenders, 
regardless of age.  R. v. Bissonnette, 2022 SCC 23.  The 
foregoing examples suggest that the "evolving standards of 
decency that mark the progress of a maturing society" referenced 
 
Rev. Stat. Ann. § 14:30(C); Miss. Code Ann. §§ 47-7-3(1)(d), 97-
3-21; Mo. Rev. Stat. § 565.020; Neb. Rev. Stat. § 28-105; N.C. 
Gen. Stat. § 14-17; S.D. Codified Laws § 22-6-1; Tex. Penal Code 
Ann. § 12.31. 
 
29 See Cal. Penal Code § 190.2; Conn. Gen. Stat. §§ 53a-
35a(1)(B), 53a-54b; N.J. Stat. Ann. § 2C:11-3; Va. Code Ann. 
§§ 18.2-10, 18.2-31; Vt. Stat. Ann. tit. 13, § 2303. 
33 
 
in Miller, 567 U.S. at 469, trend away from life without parole 
for emerging adults (citation omitted). 
2.  Life without parole for emerging adults violates art. 
26.  Our comprehensive review informs us that Supreme Court 
precedent, as well as our own, dictates that youthful 
characteristics must be considered in sentencing, that the 
brains of emerging adults are not fully developed and are more 
similar to those of juveniles than older adults, and that our 
contemporary standards of decency in the Commonwealth and 
elsewhere disfavor imposing the Commonwealth's harshest sentence 
on this cohort.  Consequently, we conclude that a sentence of 
life without the possibility of parole for emerging adult 
offenders violates art. 26.30  See Diatchenko I, 466 Mass. at 
670. 
3.  Remedy.  Because we have determined that it is 
unconstitutional to sentence emerging adults to life without the 
possibility of parole, we invalidate those provisions of our 
 
30 The contemporary standards of decency that govern our 
decision today do not suggest a societal consensus that those 
aged twenty-one and above should be treated differently from 
older adults.  Thus, while we acknowledge that the scientific 
record in this case suggests that the unique attributes of youth 
may persist in young adults older than twenty-one, our art. 26 
proportionality analysis does not rely on science alone.  See 
Libby v. Commissioner of Correction, 385 Mass. 421, 435 (1982), 
quoting District Attorney for the Suffolk Dist. v. Watson, 381 
Mass. 648, 661-662 (1980) ("Article 26, like the Eighth 
Amendment, bars punishments which are 'unacceptable under 
contemporary moral standards'"). 
34 
 
criminal code that deny the possibility of parole to this 
cohort.  General Laws c. 265, § 2, which was amended after 
Diatchenko I was decided, sets forth the penalty for murder in 
the first degree, distinguishing between the penalties for 
adults and juveniles: 
"(a) Except as provided in subsection (b), any person who 
is found guilty of murder in the first degree shall be 
punished by imprisonment in the [S]tate prison for life and 
shall not be eligible for parole pursuant to [G. L. c. 127, 
§ 133A]. 
 
"(b) Any person who is found guilty of murder in the first 
degree who committed the offense on or after the person's 
fourteenth birthday and before the person's eighteenth 
birthday shall be punished by imprisonment in the [S]tate 
prison for life and shall be eligible for parole after the 
term of years fixed by the court pursuant to [G. L. c. 279, 
§ 24]." 
 
Although we hold that it is unconstitutional to sentence 
individuals from eighteen to twenty years of age to life without 
the possibility of parole, we must "as far as possible, . . . 
hold the remainder [of the statute] to be constitutional and 
valid, if the parts are capable of separation and are not so 
entwined that the Legislature could not have intended that the 
part otherwise valid should take effect without the invalid 
part."  Diatchenko I, 466 Mass. at 672, quoting Boston Gas Co. 
v. Department of Pub. Utils., 387 Mass. 531, 540 (1982).  See 
G. L. c. 4, § 6, Eleventh ("The provisions of any statute shall 
be deemed severable, and if any part of any statute shall be 
adjudged unconstitutional or invalid, such judgment shall not 
35 
 
affect other valid parts thereof").31  Here, because emerging 
adults do not fit within the exception described in G. L. 
c. 265, § 2 (b), we must invalidate that portion of G. L. 
c. 265, § 2 (a), that denies parole eligibility to those from 
eighteen to twenty years old.  See Diatchenko I, supra at 673.  
Likewise, we also must invalidate that portion of the parole 
statute, G. L. c. 127, § 133A, that denies parole to those from 
eighteen to twenty years of age.32 
Because the Legislature does not currently provide a parole 
eligibility scheme for this category of offenders, we look to 
the next-most severe sentence under the sentencing scheme to 
determine the floor of parole eligibility.  See Watt, 484 Mass. 
at 753-754, citing Diatchenko I, 466 Mass. at 672-673.  For 
emerging adults convicted of murder in the first degree on or 
 
31 Notably, the Legislature specifically provides for the 
severability of G. L. c. 265, § 2.  See St. 1982, c. 554, § 7 
("If any of the provisions of [G. L. c. 265, § 2,] or the 
application thereof to any person or circumstances is held 
invalid, such invalidity shall not affect other provisions or 
applications of this act which can be given effect without the 
invalid provisions or applications, and to this end the 
provisions of this act are declared severable"). 
 
32 General Laws c. 127, § 133A, states in relevant part: 
 
"Every prisoner who is serving a sentence for life in a 
correctional institution of the commonwealth, . . . except 
prisoners serving a life sentence for murder in the first 
degree who had attained the age of [eighteen] years at the 
time of the murder . . . shall be eligible for parole at 
the expiration of the minimum term fixed by the court under 
[G. L. c. 279, § 24]." 
36 
 
after today's decision, that means applying G. L. c. 279, § 24, 
as amended through St. 2014, c. 189, § 6, which sets parole 
eligibility for juvenile offenders who have committed murder in 
the first degree: 
"In the case of a sentence of life imprisonment for murder 
in the first degree committed by a [juvenile], the court 
shall fix a minimum term of not less than [twenty] years 
nor more than [thirty] years; provided, however, that in 
the case of a sentence of life imprisonment for murder in 
the first degree with extreme atrocity or cruelty committed 
by a [juvenile], the court shall fix a minimum term of 
[thirty] years; and provided further, that in the case of a 
sentence of life imprisonment for murder in the first 
degree with deliberately premeditated malice aforethought 
committed by a [juvenile], the court shall fix a minimum 
term of not less than [twenty-five] years nor more than 
[thirty] years." 
 
 
However, the defendant in this case was sentenced to life 
without the possibility of parole pursuant to G. L. c. 265, 
§ 2 (a), prior to the enactment of the aforementioned 
legislative changes in 2014, post-Diatchenko I.  Therefore, this 
defendant and other emerging adults sentenced to life without 
the possibility of parole prior to July 25, 2014, may only be 
resentenced to the constitutionally permissible penalty 
available at that time -- life with the possibility of parole 
after fifteen years.  See Commonwealth v. Costa, 472 Mass. 139, 
146 (2015) (resentencing limited to available statutory penalty 
in effect at time of conviction). 
By providing an opportunity for parole, we do not diminish 
the severity of the crime of murder in the first degree because 
37 
 
it was committed by an emerging adult.  Likewise, our decision 
today "should not be construed" to suggest that emerging adults 
receiving the benefit of resentencing under today's holding 
"should be paroled once they have served a statutorily 
designated portion of their sentences."  Diatchenko I, 466 Mass. 
at 674.  However, as we stated in Diatchenko I, we must 
recognize the "unique characteristics" of emerging adults that 
render them "constitutionally different" from adults for 
purposes of sentencing.  Id., citing Miller, 567 U.S. at 471.  
As such, they must be granted a "meaningful opportunity to 
obtain release based on demonstrated maturity and 
rehabilitation" before the Massachusetts parole board, who will 
"evaluate the circumstances surrounding the commission of the 
crime, including the age of the offender, together with all 
relevant information pertaining to the offender's character and 
actions during the intervening years since conviction."  
Diatchenko I, supra, quoting Graham, 560 U.S. at 75. 
Conclusion.  We remand this matter to the Superior Court 
for resentencing consistent with this opinion. 
 
 
 
 
 
 
So ordered. 
 
 
 
KAFKER, J. (concurring).  I concur with the court's 
comprehensive review of the expert testimony, the judge's fact 
finding, and the applicable law.  I write separately to 
emphasize in particular that the letter and spirit of our 
trailblazing decision in Diatchenko v. District Attorney for the 
Suffolk Dist., 466 Mass. 655, 669 (2013) (Diatchenko I), S.C., 
471 Mass. 12 (2015) (Diatchenko II), directs us to reach the 
same conclusion today that we reached a decade ago and extend 
those very same protections to the age group at issue -- 
eighteen through twenty year olds. 
In our landmark decision in Diatchenko I, we relied on the 
best science available at the time, legislative recognition of 
the legal differences between juveniles and adults in other 
contexts, and the special protections of art. 26 of the 
Massachusetts Declaration of Rights to declare that the 
Legislature's imposition of life sentences without the 
possibility of parole for juveniles was unconstitutional, 
because juveniles are less culpable than adults and more capable 
of change.  We also employed distinctive reasoning that I 
discuss in some detail infra.  In so doing, we provided greater 
protections for juveniles under art. 26 than the United States 
Supreme Court had under the Eighth Amendment to the United 
States Constitution, precluding not only mandatory life 
sentences without the possibility of parole but also 
2 
discretionary sentences of life without the possibility of 
parole. 
In the instant case, we are presented with comprehensive 
fact finding evaluating further advancements in developmental 
cognitive neuroscience and developmental psychology,1 
demonstrating that eighteen through twenty year olds share the 
same characteristics that distinguished juveniles from adults in 
Diatchenko I and that rendered them less culpable and more 
capable of change.  The extensive briefing also demonstrates 
legislative recognition that eighteen through twenty year olds 
similarly require differential treatment from those twenty-one 
and older in other relevant and related contexts.  Indeed, when 
this age group has been recognized by the Legislature to require 
differential treatment, the legal rights in question implicate 
those same distinctive characteristics. 
Due to this convergence of science and law, I conclude that 
art. 26 precludes both mandatory and discretionary life 
 
 
1 As one of the experts testified, the fields of 
developmental cognitive neuroscience and developmental 
psychology work in tandem with one another.  "Cognitive 
neuroscience is the study of the brain and the cognitive 
operations . . . the brain supports, including thinking and 
decision-making," or "higher cognitive tasks or operation[s]," 
while the "developmental component" refers "to the study of the 
brain as it develops over time and across the lifespan."  
Comparatively, "developmental . . . psychology is concerned with 
behavior," and often "the research studies that are conducted in 
developmental neuroscience are first informed by behaviors that 
are observed in studies of development[al] psychology." 
3 
sentences without the possibility of parole for those who are 
older than eighteen but younger than twenty-one at the time they 
committed murder in the first degree.  Thus, after serving from 
twenty-five to thirty years in prison as now prescribed by the 
Legislature for juvenile murderers, these eighteen through 
twenty year olds likewise shall have the possibility of 
convincing the parole board that they have redeemed themselves 
in prison, have taken responsibility for the terrible deaths 
that they caused in their youth, and deserve to be paroled.2 
 
1.  Discussion.  a.  Diatchenko, differentiating 
characteristics, and State constitutional law.  Our reasoning in 
Diatchenko I built on the foundation of the United States 
Supreme Court's Eighth Amendment analysis in Miller v. Alabama, 
567 U.S. 460 (2012), particularly "three significant 
characteristics differentiating juveniles from adult offenders."  
Diatchenko I, 466 Mass. at 660. 
"First, children demonstrate a lack of maturity and an 
underdeveloped sense of responsibility, leading to 
recklessness, impulsivity, and heedless risk-taking.  
Second, children are more vulnerable to negative influences 
and outside pressures, including from their family and 
peers . . . .  Finally, a child's character is not as well 
formed as an adult's; his traits are less fixed and his 
 
2 I note that the defendant here was convicted prior to the 
passage of the 2014 legislation that required from twenty-five 
to thirty years before parole eligibility, and thus is eligible 
for consideration for parole, as this court explained in 
Diatchenko I, after fifteen years in prison.  See Diatchenko I, 
466 Mass. at 673-674 (explaining reasons for fifteen year parole 
eligibility date at time). 
4 
actions less likely to be evidence of irretrievable 
depravity."  (Quotations, citations, and alterations 
omitted.) 
 
Id.  Together, these characteristics demonstrated that juveniles 
possessed "diminished culpability" and a "heightened capacity 
for change."  Cf. id. at 661, quoting Miller, supra at 479.  
Recognizing these differences and "[a]n ever-growing body of 
research in developmental psychology and neuroscience [that] 
continues to confirm and strengthen the Court's conclusions," 
Miller, supra at 472 n.5, the Supreme Court concluded that a 
mandatory imposition of a sentence of life without the 
possibility of parole for juveniles was cruel and unusual in 
violation of the Eighth Amendment, id. at 479.  The Court did, 
however, allow a discretionary imposition of this sentence based 
on an individualized hearing, requiring judges to consider "how 
children are different, and how those differences counsel 
against irrevocably sentencing them to a lifetime in prison."  
Id. at 480. 
 
We then took a significant additional step in Diatchenko I, 
466 Mass. at 670-671, and went well beyond the Supreme Court's 
Eighth Amendment protections, concluding that the greater 
protection afforded by art. 26 also prohibited the discretionary 
imposition of life without parole for juveniles convicted of 
murder in the first degree.  We determined, consistent with the 
scientific evidence presented, that "a conclusive showing of 
5 
traits such as an 'irretrievably depraved character,' . . . can 
never be made, with integrity, by the Commonwealth at an 
individualized hearing to determine whether a sentence of life 
without parole should be imposed on a juvenile homicide 
offender."  Id. at 669-670, quoting Roper v. Simmons, 543 U.S. 
551, 570 (2005).  More specifically, we held that because "the 
brain of a juvenile is not fully developed, either structurally 
or functionally, by the age of eighteen, a judge cannot find 
with confidence that a particular offender, at that point in 
time, is irretrievably depraved."  Diatchenko I, supra at 670.  
Thus, we concluded that our State Constitution prohibited trial 
judges from attempting to make individualized findings that were 
impossible to make reliably at the time of sentencing, and so we 
imposed a categorical ban on the imposition of this sentence for 
juveniles.  Id. at 669-670. 
 
As the Superior Court judge comprehensively found and as 
the court explains in its opinion, the scientific evidence here 
demonstrates that the same three characteristics that 
distinguished juveniles from adults in Diatchenko I, 466 Mass. 
at 669-670, distinguish eighteen through twenty year olds in 
essentially the same way.  No one disputes those findings or the 
6 
science on which they are based, including the authors of the 
dissenting opinions written in the instant case.3 
 
I therefore emphasize that, based on the fact findings 
here, we cannot distinguish in any way this case from Diatchenko 
I on scientific grounds.  That science was also, as explained 
ante, a significant factor in the decision in Diatchenko I, 466 
Mass. at 669-670, helping to convince this court to provide 
greater protection under the State Constitution than the Supreme 
Court provided under the Federal Constitution when the Supreme 
Court's allowance of discretionary life without parole sentences 
for juveniles who committed murder in the first degree could not 
be reconciled with the science.  Evolving science helps inform 
evolving standards of decency.  Cf. Helling v. McKinney, 509 
U.S. 25, 36 (1993) (regarding prison conditions, Eighth 
Amendment analysis requires both "scientific and statistical 
inquiry into the seriousness of the potential harm" and 
"assess[ment] whether society considers the risk . . . to be so 
 
 
3 On remand, the judge heard expert testimony and oral 
argument and accepted an additional exhibit in evidence, before 
issuing findings of fact and conclusions of law on whether 
mandatory life without parole sentences for eighteen through 
twenty year old offenders violates art. 26.  Neither party 
disputes his factual findings.  Among those findings, the judge 
clarified that his findings were limited to those up to age 
twenty-one because, while one expert, Dr. Adriana Galván, 
included twenty-one year olds in her developmental cognitive 
neuroscience research, another expert, Dr. Laurence Steinberg, 
did not include them in his developmental psychology research. 
7 
grave that it violates contemporary standards of decency").  We 
particularly were concerned that trial judges would be required 
to make findings that the science demonstrated were not 
possible.  Diatchenko I, supra.  See the amicus brief submitted 
by twenty-three retired Massachusetts judges and others, at 36-
40.4 
 
4 The Supreme Court has, over the vigorous dissent of the 
author of Miller and two other Justices, since held that, for 
the individualized hearings required by the Eighth Amendment, "a 
finding of fact regarding a child's incorrigibility is not 
required" (quotation, citation, and alteration omitted).  Jones 
v. Mississippi, 141 S. Ct. 1307, 1314-1315 (2021), quoting 
Montgomery v. Louisiana, 577 U.S. 190, 211 (2016).  That the 
Supreme Court does not now require an explicit finding on 
incorrigibility under its line of Eighth Amendment cases does 
not change our previous determination under art. 26 that such a 
finding is necessary to justify a sentence of life without 
parole for those under eighteen because our State constitutional 
protections are greater than those of the Eighth Amendment.  See 
Diatchenko I, 466 Mass. at 670. 
 
Nor is our determination in Diatchenko I inconsistent with 
our decision in Commonwealth v. Perez, 477 Mass. 677, 679 (2017) 
(Perez I), S.C., 480 Mass. 562 (2018) (Perez II), which required 
an individualized hearing "where a juvenile is sentenced for a 
nonmurder offense or offenses and the aggregate time to be 
served prior to parole eligibility exceeds that applicable to a 
juvenile convicted of murder."  That hearing is different from 
the individualized hearing that we concluded was not possible in 
Diatchenko I, 466 Mass. at 669-670, because the hearing required 
by Perez I does not concern whether parole eligibility is 
necessary, as all juvenile offenders are entitled to parole 
eligibility after Diatchenko I.  See Perez II, supra at 569.  
Rather, it asks judges to consider the permissibility of a 
longer term of imprisonment prior to parole eligibility for 
nonmurder offenses than for murder in the first degree.  See 
Perez I, supra; Perez II, supra.  Our decision in Perez I, supra 
at 686, also established a presumption against such longer 
parole eligibility sentences under art. 26 and therefore set a 
8 
Other important aspects of Diatchenko I also should apply 
equally here.  We emphasized, for example, that life sentences 
without the possibility of parole were deemed particularly 
severe for those required to stay in prison from youth to death; 
indeed, we went so far as to compare such sentences to the death 
penalty, which we already had deemed "unconstitutional under 
art. 26."  See Diatchenko I, 466 Mass. at 670 (describing life 
sentences without possibility of parole for juveniles as being 
"strikingly similar" to death penalty).  That same reasoning 
applies to eighteen through twenty year olds, who likewise are 
fated to spend the vast majority of their lives in prison with 
no hope of release at any time.  If this case is to be 
distinguished from Diatchenko I, it must therefore be on other 
grounds, each of which I address and reject infra, turning once 
again to Diatchenko I for guidance. 
 
b.  The Legislature's right to define the punishment for 
the crime and distinguish juveniles from adult offenders.  
Justices Lowy and Cypher in their dissents emphasize that great 
deference is owed to the Legislature's right to define the 
punishment for criminal behavior and define the line between 
juvenile and adult offenders.  See post at    ,     (Lowy, J., 
dissenting); post at     (Cypher, J., dissenting).  As a general 
 
very high bar to justify them, which we confirmed and clarified 
in Perez II, supra at 571-573. 
9 
principle, I wholeheartedly agree with these propositions.  But 
in Diatchenko I, we did not defer to the punishment established 
by the Legislature or to the line drawing (or, in that case, the 
absence of line drawing) between juveniles and adults.  Rather, 
we concluded that the punishment, without necessary line 
drawing, was unconstitutional.  Diatchenko I, 466 Mass. at 658-
659.  In sum, we did not defer to the Legislature; we concluded 
that it acted unconstitutionally. 
 
Unlike the Supreme Court in its line of cases regarding 
acceptable criminal punishments for juveniles under the Eighth 
Amendment, we also did not define explicitly a fixed 
constitutional line for life sentences without the possibility 
of parole when we decided Diatchenko I.  Compare Roper, 543 U.S. 
at 574 ("The age of [eighteen] is the point where society draws 
the line for many purposes between childhood and adulthood.  It 
is, we conclude, the age at which the line for death eligibility 
ought to rest" [emphasis added]), with Diatchenko I, 466 Mass. 
at 669-670 (relying on "current scientific research on 
adolescent brain development" to reach conclusion that "the 
judge cannot ascertain, with any reasonable degree of certainty, 
whether imposition of this most severe punishment is 
warranted").  In defining that line previously in the death 
penalty context, the Supreme Court also recognized that it had 
itself recently set that line at sixteen and then moved it.  
10 
Roper, supra at 561-562.  Perhaps recognizing that this line was 
not fixed for all purposes and might too be a moving target for 
sentences of life without the possibility of parole, we did not 
attempt such analysis or decide that it was applicable 
regardless of the science.  Instead, we only answered what we 
were asked:  whether it was constitutional to sentence 
"juveniles" to life without the possibility of parole as the 
Legislature provided, and we concluded that it was not, because 
the science demonstrated that juveniles were less culpable and 
capable of change.  Diatchenko I, supra at 671.  We then 
referenced and relied on a statutory definition of "juvenile" to 
define the scope of our holding at the time.  Id. at 659 n.8, 
673 n.17.5 
The question then becomes whether there is a meaningful 
constitutional difference between overruling the Legislature's 
decision that it is permissible to sentence juveniles to life in 
prison without the possibility of parole and overruling the 
Legislature's decision that it is permissible to sentence 
eighteen through twenty year olds to life in prison without the 
possibility of parole, when the fact finding regarding the 
 
5 I do not in any way seek to redefine eighteen through 
twenty year olds as juveniles.  Rather, I consider eighteen 
through twenty year olds as a distinct legal category as 
explained infra, as the Legislature itself has done in a variety 
of contexts. 
11 
scientific evidence now conclusively demonstrates that eighteen 
through twenty year olds, just like juveniles, are less culpable 
for their crimes and more capable of change than adults. 
Justices Lowy and Cypher find such a basis in deference to 
the Legislature:  we should defer to the Legislature because it 
did not exclude eighteen to twenty year olds from a statute that 
provides for life sentences without the possibility of parole 
for murder in the first degree.  See post at    ,     (Lowy, J., 
dissenting); post at     (Cypher, J., dissenting).  The same, 
however, was true for juveniles when we decided Diatchenko I, 
466 Mass. at 672-673.  Although the Legislature at that time 
authorized life sentences without the possibility of parole for 
juveniles, as explained supra, we found such punishment 
unconstitutional.  Id. 
Justices Lowy and Cypher in their dissents also state that 
we should defer to the Legislature because it has defined 
eighteen as a fixed line between juveniles and adults.6  I 
 
 
6 Justice Cypher posits that the extension of rights to 
those over the age of eighteen has always been granted first by 
the Legislature and not the courts, and so we would be the first 
to define protections for a certain category of individuals 
based on an age group of our definition.  Post at     (Cypher, 
J., dissenting).  The latter consideration ignores, however, the 
evolution of Federal juvenile death penalty jurisprudence, which 
involved judicial line drawing based on age without reliance on 
a clearly legislatively defined age group.  In Thompson v. 
Oklahoma, 487 U.S. 815, 823, 838 (1988), a plurality of the 
Supreme Court prohibited the imposition of the death penalty for 
those under the age of sixteen at the time they committed their 
12 
conclude, as does the court, that the legislative line drawing 
is more nuanced.  The Legislature does not uniformly provide 
eighteen through twenty year olds with the full benefits and 
responsibilities of those twenty-one and older.  Rather, the 
Legislature recognizes that eighteen, nineteen, and twenty year 
olds fall into a distinct category requiring special 
consideration; they are permitted certain legal rights but not 
others.  See State House News Service (Sen. Sess.), June 28, 
2018 (statement of Sen. Jason Lewis, chair of Joint Committee on 
Public Health) (regarding tobacco purchasing age limit, "there 
really is no single age of adulthood in our society"; [w]e make 
decision[s] on a case-by-case basis depending on the activity").  
For example, they are entitled to vote, serve on a jury or in 
the military, and drive a car.  See G. L. c. 51, § 1 (voting); 
G. L. c. 234A, § 4 (jury); G. L. c. 90, § 8 (driving).  See also 
Requirements to enlist in the U.S. military, USA.gov, 
 
offense.  This decision stood in contrast to the many ways in 
which the age of eighteen stood as a demarcation between 
juveniles and adults. 
 
 
The Court in Thompson, 487 U.S. at 838, had been asked to 
"'draw a line' that would prohibit the execution of any person 
who was under the age of [eighteen] at the time of the offense."  
The Court limited its decision, however, to "the case before" it 
and so drew the line at sixteen.  In 2005, in Roper, 543 U.S. at 
570-571, the Court took the opportunity to extend Thompson to 
protect all juveniles -- those up to age eighteen -- from the 
imposition of the death penalty.  In both instances, the 
judiciary -- not the Legislature -- extended these protections.  
For us to do the same would not, therefore, be unprecedented. 
13 
https://www.usa.gov/military-requirements 
[https://perma.cc/Y9MG-HWG4] (beginning at age seventeen).  But 
they cannot purchase and sell alcohol or tobacco, serve as a 
State police officer, gamble, or even supervise drivers with 
learner's permits.  See G. L. c. 138, § 34 (alcohol); G. L. 
c. 270, § 6 (tobacco); G. L. c. 31, § 58 (municipal police 
officer); G. L. c. 22C, § 10 (State police officer); G. L. 
c. 23K, § 43 (gambling); G. L. c. 90, § 8B (learner's permits).  
They are also excluded from purchasing marijuana by a ballot 
initiative, demonstrating that the public recognizes a similar 
distinction.  G. L. c. 94G, § 7 (a).  Their rights regarding 
firearms are also more limited than those twenty-one and over.  
G. L. c. 140, § 131 (d) (iv) (license to carry large capacity 
firearm restricted to those twenty-one and over). 
I thus emphasize that legal rights from which eighteen 
through twenty year olds are excluded appear to implicate and 
reflect a legislative concern about the very characteristics 
that are at issue in this case:  "a lack of maturity and an 
underdeveloped sense of responsibility, leading to recklessness, 
impulsivity, and heedless risk-taking" and a greater 
"vulnerab[ility] . . . to negative influences and outside 
pressures, including from their family and peers" (quotations 
and citations omitted).  Diatchenko I, 466 Mass. at 660.  
Senator Patricia Jehlen, the author of an amendment to the 
14 
expanded gaming bill that prohibited marketing to individuals 
under twenty-one, stated:  "The bill itself says that casinos 
may not allow people under the age of [twenty-one]. . . .  
Current Massachusetts law says you can't buy alcohol if you're 
under [twenty-one].  I think that these are consistent that 
people's brains have not matured by the time they're 
[eighteen]."  State House News Service (Sen. Sess.), Oct. 11, 
2011.  Likewise, the legislative history regarding increasing 
the age for tobacco consumption to twenty-one shows that the 
Legislature was concerned about the underdeveloped brains of 
young people, including those above eighteen.  See State House 
News Service (Sen. Sess.), June 28, 2018 (statement of Sen. 
Jason Lewis) ("Our young people are particularly 
susceptible. . . .  [Nicotine] has harmful health impacts on the 
developing brain. . . .  It helps [to] get tobacco products out 
of high school social networks"); Press Release, Senate Passes 
Jason Lewis Bill to Protect Youth from the Health Risks of 
Tobacco and Nicotine Addiction (June 30, 2018), 
https://senatorjasonlewis.com/2018/06/30/tobacco-21 
[https://perma.cc/6MQM-QHXQ] (quoting Sen. President Harriette 
L. Chandler, "This legislation protects young adults whose minds 
and bodies are still developing . . .").  See also Governor's 
Legislative Files, House Bill No. 4218, "An Act increasing the 
minimum age for appointment as a police officer," Bill Summary 
15 
(2003) ("Advocates of this legislation suggest increasing the 
minimum age for appointment for the position of police officer 
will ensure that individuals taking on the responsibilities 
associated with modern policing posses[s] the requisite life 
skills and maturity").7 
The criminal justice system also reflects special 
consideration for this age group, again reflecting the special 
characteristics of eighteen through twenty year olds.  For 
example, the Legislature has authorized the Department of Youth 
Services to maintain custody of young people adjudicated to be 
youthful offenders up to age twenty-one.  G. L. c. 119, § 58.  
Likewise, the Massachusetts Sentencing Guidelines have 
instructed judges to consider the developmental characteristics 
of eighteen through twenty year olds even when they have been 
tried as adults.  The Legislature has also, in its recent 
comprehensive criminal justice reform, authorized the State and 
 
7 Federal legislative history of the highway funding law 
that led Massachusetts to raise the drinking age to twenty-one 
discussed similar concerns.  See Hearing before Subcommittee on 
Surface Transportation of the United States Senate Committee on 
Commerce, Science, and Transportation on Oversight of the 
National Highway Traffic Safety Administration (Sept. 13, 1983), 
reprinted in Legislative History of the Surface Transportation 
Assistance Act of 1982 Amendments (1984) (statement of Robert S. 
Vinetz, M.D.) (younger drivers' high rate of motor vehicle 
accidents due to "especially deadly combination of being new and 
inexperienced drivers, of having the tendency toward increased 
risk-taking, of having an exaggerated belief in their own 
invulnerability and in experimenting with alcohol and drugs"). 
16 
county prison systems to "establish young adult correctional 
units" with "targeted interventions, age appropriate 
programming[,] and a greater degree of individual attention" for 
those within this age group and also extended such consideration 
to those as old as twenty-four, G. L. c. 127, § 48B.  In sum, 
the Legislature has recognized that eighteen through twenty year 
olds are a distinct category requiring special consideration, at 
least regarding legal rights that implicate risky, impulsive, 
and potentially dangerous behavior and peer pressure -- the very 
characteristics at issue in this case. 
Given this legislative recognition of the need for 
differential treatment of eighteen through twenty year olds in 
such contexts, and the science and fact finding in this case, 
which equates eighteen through twenty year olds to juveniles on 
the relevant three characteristics that rendered juveniles less 
culpable for their crimes, more capable of change, and thus 
entitled to the possibility of parole in Diatchenko I, 466 Mass. 
at 660, I conclude that eighteen through twenty year olds should 
likewise be entitled to State constitutional protection from 
life sentences without the possibility of parole.  As in 
Diatchenko I, we should not defer to the Legislature when it 
recognizes the distinctive characteristics of the eighteen 
through twenty year old defendants at issue and treats them 
differently from those twenty-one and over in many ways, but 
17 
then disregards those differences for our most severe criminal 
punishments.  Upholding such sentences means that we disregard 
the best science and continue to impose the most severe penalty 
on a distinct legal category of individuals that we know are 
less culpable and more capable of change.8 
For all these reasons, this court in Diatchenko I, 466 
Mass. at 671, declared the statute unconstitutional as applied 
to a certain age group.  Deference to the Legislature's 
determination of a punishment that we, in Diatchenko, analogized 
to the death penalty is different from ordinary deference.  To 
determine whether such a punishment is cruel or unusual is a 
critical function of this court, and one that the court has 
exercised with particular vigilance despite the objections of 
dissenting justices calling for greater deference to the 
Legislature.  See id. at 672.  See also, e.g., Commonwealth v. 
Colon-Cruz, 393 Mass. 150, 181 (1984) (Wilkins, J., dissenting); 
 
8 I also concur with the court's decision to limit this 
relief to those under twenty-one.  Unlike eighteen to twenty 
year olds, those twenty-one and over have been considered by the 
Legislature to have the full benefits and responsibilities of 
adults.  I consider the Legislature's recognition of the need 
for differential treatment of those eighteen to twenty in a 
variety of other contexts when the legal rights in question 
implicate the same distinctive characteristics at issue in this 
case to be an important component of the analysis.  That 
legislative recognition is absent when we consider those twenty-
one and over.  It is the convergence of law and science, not 
just science alone, that governs the art. 26 analysis here. 
18 
id. (Nolan, J., dissenting); District Attorney for Suffolk Dist. 
v. Watson, 381 Mass. 648, 687 (1980) (Quirico, J., dissenting).9 
 
c.  The role of the tripartite analysis in Diatchenko I.  
Another exceptional aspect of the Diatchenko I decision is the 
legal authority to which this court turned for guidance and 
support.  We did not expressly employ the tripartite analysis 
from Commonwealth v. Jackson, 369 Mass. 904, 910, 913 (1976), 
and Cepulonis v. Commonwealth, 384 Mass. 495, 497-498 (1981) 
(considering "the penalties prescribed for the same offense in 
other jurisdictions"), and therefore tie our decision to how 
most other States treated like offenders by applying the third 
step of that analysis.  We did not even compare ourselves to 
other States or express concern that we were providing greater 
protection than those other States.  Again, this is a critical 
and distinctive aspect of Diatchenko I.  Instead, relying on our 
own State Constitution, a legislatively defined category, which 
in that case was juveniles, and comprehensive fact finding 
grounded in science, to ensure the objectivity and integrity of 
our decision-making process, we broke new ground in this 
landmark decision, like other seminal State constitutional 
 
 
9 The deference recommended here has similarities to those 
dissents.  See, e.g., Colon-Cruz, 393 Mass. at 184-185 (Nolan, 
J., dissenting).  It is important to remember that Diatchenko I, 
466 Mass. at 670, made the comparison between life without the 
possibility of parole and the death penalty.  This is another 
critical aspect of Diatchenko I that we cannot ignore. 
19 
decisions we have issued.10  Compare Goodridge v. Department of 
Pub. Health, 440 Mass. 309, 312, 339 n.31 (2003) (recognizing 
that "our decision marks a change in the history of our marriage 
law" while noting only three other States' courts had taken 
affirmative steps to recognize same-sex marriage under their 
Constitutions while Federal government had not); Watson, 381 
Mass. at 650, 662 (striking down death penalty for violating 
art. 26 because it was "unacceptably cruel under contemporary 
standards of decency" despite lack of "unanimity of public 
opinion" as it was "administered with unconstitutional 
arbitrariness and discrimination"). 
 
For further support when deciding Diatchenko I, 466 Mass. 
at 285 n.16, we turned to the author of our State Constitution, 
John Adams, and even widened our perspective internationally.  
We noted Adams's reminder that "we belong to an international 
community that tinkers toward a more perfect government by 
learning from the successes and failures of our own structures 
and those of other nations."  Id., citing J. Adams, Preface, A 
Defence of the Constitutions of Government of the United States 
of America (1797).  We also referenced the United Nations 
 
10 I note that Diatchenko I has been cited in 127 decisions, 
including fifty out-of-State cases.  See Goldstein, One of One:  
Justice Gants and Lessons from the Keo Case, 62 B.C. L. Rev. 
2827, 2828 (2021) (referring to Diatchenko I as "momentous 
decision[]"). 
20 
Convention of the Rights of the Child, which bans life in prison 
without parole for juveniles.  Diatchenko I, supra. 
Given the distinct letter and spirit of Diatchenko I 
described in detail supra, and the undisputed factual findings 
here demonstrating that eighteen through twenty year olds share 
the same relevant characteristics regarding diminished 
culpability and heightened capacity for change as juveniles, I 
conclude that we should extend the very same protections 
provided to Gregory Diatchenko to eighteen through twenty year 
olds.  I discern no basis for distinguishing them given the 
distinct reasoning developed in Diatchenko I.  A sentence of 
life in prison without parole eligibility review for those up to 
age twenty-one -- individuals with diminished culpability and a 
heightened capacity for change -- is no less cruel or unusual 
than it is for those up to age eighteen.  Cf. Diatchenko I, 466 
Mass. at 670-671.  Thus, we should have been "obliged to declare 
part of [this statute] unconstitutional," id. at 672, and have 
provided these eighteen through twenty year old homicide 
offenders with "a meaningful opportunity for release on parole," 
should they "demonstrate[] maturity and rehabilitation," so that 
their "life sentence [is] constitutionally proportionate," 
Diatchenko II, 471 Mass. at 29-30. 
d.  Limited remedy.  We also, as in Diatchenko I, 466 Mass. 
at 671, need only hold a very specific application of the 
21 
statute unconstitutional.  As we explained in Diatchenko I, "the 
unconstitutionality of this punishment arises not from the 
imposition of a sentence of life in prison, but from the 
absolute denial of any possibility of parole" for a class of 
offenders who a trial judge cannot reliably determine to be 
irretrievably depraved at the time of sentencing.  See id.  Once 
they have a chance to mature, however, that decision, as well as 
the other factors relevant to parole, would and should be made 
by a parole board.  That decision would also be made after many 
years of imprisonment.  See id. at 674.  Under current law, 
those under age eighteen who are convicted of murder in the 
first degree are eligible for parole only after serving from 
twenty-five to thirty years for murder convicted with deliberate 
premeditation and thirty if the murder was committed with 
extreme atrocity or cruelty.  G. L. c. 279, § 24.  I would 
extend the same opportunity to those older than eighteen but 
under the age of twenty-one.  Essentially, the legislative 
regime imposed for juvenile murderers would be extended to 
eighteen to twenty year olds without further changes in the 
statutory scheme. 
 
The possibility of such reformative change after a lengthy 
period of incarceration has also been demonstrated since we 
decided Diatchenko I.  Of the juvenile offenders who were 
serving mandatory life sentences without parole at the time of 
22 
the Diatchenko I decision and have since received parole 
hearings, seventy-four percent have been granted parole.  As 
Diatchenko I and its aftermath have demonstrated, the 
possibility of redemption exists for the young, even those who 
have committed the most horrible crimes, after they have spent 
many years in prison maturing and taking responsibility for the 
terrible deaths that they caused in their youth. 
For all these reasons, I conclude that a sentence of life 
without the possibility of parole for eighteen through twenty 
year olds constitutes cruel or unusual punishment under art. 26 
of our Declaration of Rights.  That applies to both 
discretionary as well as mandatory life sentences without the 
possibility of parole for those eighteen through twenty years of 
age. 
 
 
 
WENDLANDT, J. (concurring, with whom Gaziano, J., joins).  
The determination whether the Commonwealth's harshest punishment 
is so disproportionate to the offender as to shock the conscious 
is neither one we abdicate to the Legislature, as marshalled by 
the dissent, nor one we rest on the shoulders of scientists and 
social scientists.  I write to clarify what should be pellucid:  
it is our constitutional duty to ensure prescribed punishments 
pass constitutional muster, and nothing in art. 30 of the 
Massachusetts Declaration of Rights prevents us from doing so.  
To be faithful to the enormity of this charge, we must undertake 
a comprehensive review of our statutes, the scientific record, 
our collective experiences, and common sense. 
Having examined these sources, I conclude that they confirm 
what any parent of adult children can tell you:  a child does 
not go to bed on the eve of her eighteenth birthday and awaken 
characterized by a lessened "transient rashness, proclivity for 
risk, and inability to assess consequences."  Miller v. Alabama, 
567 U.S. 460, 472 (2012).  In recognition of this indisputable 
fact, society does not treat the transition from childhood to 
adulthood as a binary act accomplished at age eighteen; becoming 
an adult is much more fluid, with development continuing long 
after a child's eighteenth birthday.  In the ways that matter 
for the Commonwealth's harshest punishment, young adults of the 
ages of eighteen, nineteen, and twenty share key characteristics 
2 
 
with their under-eighteen year old peers; they "have diminished 
culpability and greater prospects for reform" than older adults 
and "are less deserving of the most severe punishments."  See 
id. at 471, quoting Graham v. Florida, 560 U.S. 48, 68 (2010).  
For this reason, condemning a person in the process of "growing 
up" to die in prison on the basis that she falls on the "wrong" 
side of an arbitrary line drawn at age eighteen is inconsistent 
with "the evolving standards of decency that mark the progress 
of a maturing society" (citation omitted).  Graham, supra at 58.  
Accordingly, I agree with the court that imposition of life 
without the possibility of parole on young adults ages eighteen, 
nineteen, and twenty is unconstitutional. 
 
1.  Legislature's treatment of young adults.  Undoubtedly, 
the first source in the determination of our contemporary 
standards of decency that define the bounds of cruel punishment 
is legislative enactments.  See Good v. Commissioner of 
Correction, 417 Mass. 329, 335 (1994) ("In divining contemporary 
standards of decency, we may look to State statutes and 
regulations, which reflect the public attitude as to what those 
standards are").  See also Graham, 560 U.S. at 61, quoting Roper 
v. Simmons, 543 U.S. 551, 563 (2005) ("The Court first considers 
'objective indicia of society's standards, as expressed in 
legislative enactments and state practice' . . ."); Atkins v. 
Virginia, 536 U.S. 304, 312 (2002) ("the clearest and most 
3 
 
reliable objective evidence of contemporary values is the 
legislation enacted by the country's legislatures" [quotation 
and citation omitted]).1 
 
Our statutes reflect legislative recognition that maturity 
is a gradual endeavor,2 and that while age eighteen is a 
milestone, society does not view it as the end of the 
metamorphosis toward adulthood.  As the court and Justice Kafker 
thoroughly catalogue, for many activities considered by society 
to require greater care, less risk taking, and more resilience 
 
1 In concluding that a mandatory sentence of life in prison 
without the possibility of parole violated the Eighth Amendment 
to the United States Constitution when imposed on juvenile 
nonhomicide offenders, the United States Supreme Court 
considered that, although thirty-seven State legislatures 
permitted the sentence, only eleven States imposed the sentence 
in practice, and vanishingly few juvenile offenders actually 
received it.  See Graham, 560 U.S. at 62-67 (only approximately 
123 juvenile nonhomicide offenders were serving sentences of 
life without parole; seventy-seven of those offenders were in 
Florida, and the remainder were in just ten States).  See also 
Atkins, 536 U.S. at 316 (considering that "even in those States 
that allow the execution of [offenders with intellectual 
disabilities], the practice is uncommon," in concluding that "a 
national consensus has developed" against executing such 
individuals).  Because the sentence is mandatory for all adults 
over the age of eighteen in Massachusetts, see G. L. c. 265, 
§ 2 (a), we cannot look to sentencing practices as they pertain 
to young adult offenders. 
 
2 As Justice Cypher notes, post at    , at a point earlier 
than the age of eighteen, the Legislature has recognized that 
one commences the transition from being a child to being an 
adult and therefore awards certain freedoms to these young 
people before they turn eighteen years old.  For example, young 
women, as early as age sixteen, can obtain an abortion without 
parental consent.  See G. L. c. 112, § 12R. 
4 
 
to peer pressure, the Legislature continues to treat young 
adults over the age of eighteen like juveniles.  To engage in 
these activities legally, young adults must wait until they are 
twenty-one. 
This special treatment exemplifies the Legislature's 
acknowledgment of two facts:  first, that the impetuousness of 
youth, the proclivity to risk taking, and the susceptibility to 
peer pressure are not attributes exclusive to those under the 
age of eighteen, and instead continue into young adulthood; and 
second, that these attributes are not fixed, but generally fade 
over time because young adults, like juveniles, are 
characterized by a malleability of character.3 
 
2.  Science and social science.  Of course, consideration 
of legislation is the beginning; it is not the end of our 
analysis under art. 26 of the Massachusetts Declaration of 
Rights.  To be faithful to our responsibility to protect 
individuals from cruel or unusual punishment meted out by the 
 
3 Private institutions also recognize that young adults are 
not ready for all the responsibilities of adulthood.  See, e.g., 
K.U. Lindell & K.L. Goodjoint, Juvenile Law Center, Rethinking 
Justice for Emerging Adults:  Spotlight on the Great Lakes 
Region, at 12 (2020) ("while not a statutory restriction, most 
car rental companies limit rentals to individuals under age 
[twenty-five], recognizing the increased risk posed by this age 
group").  See also Metz, How Age and Gender Affect Car Insurance 
Rates, Forbes Advisor (updated Aug. 17, 2023), https://www 
.forbes.com/advisor/car-insurance/rates-age-and-gender [https: 
//perma.cc/LB8G-PHEG] ("The high car insurance rates that young 
drivers pay start to go down at age [twenty-five]"). 
5 
 
State, we cannot be blind to the truths that the scientific 
sources with which we have been presented show.4 
Our experiment with scientific fact finding on the topic of 
adult brain development validates the graduated treatment of 
young persons reflected in our statutes.  The court's careful 
review of this record is undisputed.  In brief, it shows that 
neuroscientists see in their magnetic resonance imaging (MRI) 
scans corroboration for that which we experience in life; the 
brain characteristics of persons even years older than eighteen 
mirror those of persons under eighteen.  The brain generally 
continues to develop through the mid-twenties.  Until some ill-
defined point in the third decade of life, adults, especially 
 
4 See, e.g., Miller, 567 U.S. at 471 (determination that 
life in prison without possibility of parole for juveniles 
violates Eighth Amendment rested "not only on common sense -- on 
what 'any parent knows' -- but on science and social science as 
well" [citation omitted]); Graham, 560 U.S. at 68 (considering 
"developments in psychology and brain science" in Eighth 
Amendment proportionality analysis as to life in prison without 
possibility of parole for juveniles convicted of nonhomicide 
offenses); Roper v. Simmons, 543 U.S. 551, 569 (2005) 
(considering what "any parent knows" and what "scientific and 
sociological studies . . . tend to confirm" to conclude death 
penalty for juveniles violates Eighth Amendment); Diatchenko v. 
District Attorney for the Suffolk Dist., 466 Mass. 655, 669 
(2013), S.C., 471 Mass. 12 (2015) (concluding imposition of 
sentence of life in prison without possibility of parole for 
juveniles, even after individualized hearing, violates art. 26 
of Massachusetts Declaration of Rights "[g]iven current 
scientific research on adolescent brain development"). 
6 
 
men,5 generally are more impulsive and their brains are more 
plastic than those of older adults.6 
3.  Collective experience and common sense.  Significantly, 
while the findings based on current technological advances in 
brain science show substantial similarities between juveniles 
and young adults, we do not check our common sense at the 
laboratory door.  Our statutes, experiences, and common sense 
tell us that there is no magic switch to the process of growing 
up, and that fact, now buttressed by neuroscientific data and 
informed by social science studies, must be weighed in the 
exercise of our duty to determine whether punishment is cruel or 
unusual.  See Matter of the Personal Restraint of Monschke, 197 
Wash. 2d 305, 306 (2021) ("Modern social science, our precedent, 
 
5 See L. Brizendine, The Female Brain 44 (2006) (finding 
that female brain "matures two or three years earlier than the 
male brain").  See also Cauffman & Steinberg, (Im)maturity of 
Judgment in Adolescence:  Why Adolescents May Be Less Culpable 
Than Adults, 18 Behav. Sci. & L. 741, 753 (2000) (finding that 
"females exhibit greater psychosocial maturity than males"). 
 
6 Scientific studies report brain maturation at different 
ages:  sometimes at the age of twenty-one, sometimes at twenty-
two, sometimes at twenty-three or twenty-five, and sometimes in 
the middle to late twenties.  Moreover, studies report that 
certain aspects of brain development, such as susceptibility to 
peer pressure and impulse control, also appear to mature at 
different rates. 
 
7 
 
and a long history of arbitrary line drawing have all shown that 
no clear line exists between childhood and adulthood").7 
 
The scientific snapshot in this case confirms that which is 
apparent in our laws and in our treatment of this age cohort 
more generally –- namely, that in the ways that matter for 
criminal sentencing, young adults are similar to juveniles.  
Like juveniles, young adults have "an underdeveloped sense of 
responsibility, leading to recklessness, impulsivity, and 
heedless risk-taking"; they are more vulnerable to peer 
pressure; and their "character is not as well formed as an 
adult's . . . and [their] actions [are] less likely to be 
evidence of irretrievabl[e] deprav[ity]" (quotations omitted).  
Diatchenko v. District Attorney for the Suffolk Dist., 466 Mass. 
 
7 The parties in this case ask us to consider the 
constitutionality of the punishment of life in prison without 
the possibility of parole when it is imposed on defendants aged 
eighteen, nineteen, and twenty.  That the scientific record is 
not precise as to where the line should be drawn, see note 6, 
supra, should come as no surprise given our collective 
experiences showing that, while some generalizations may be 
drawn, in the end "growing up" is an individualized endeavor.  
This does not mean that "we may as well give up and let the 
[L]egislature draw its arbitrary lines."  Matter of the Personal 
Restraint of Monschke, 197 Wash. 2d at 323.  At the least, in 
response to the only question with which we have been presented 
in this case, I conclude that drawing a fixed line at the age of 
eighteen, thereby leaving young adults aged eighteen, nineteen, 
and twenty to the punishment, is not supported by our statutes, 
the scientific data and social science, our collective 
experiences, or common sense. 
8 
 
655, 660 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015), 
quoting Miller, 567 U.S. at 471. 
Relying on these hallmarks of youth, the United States 
Supreme Court concluded that mandatory life in prison without 
the possibility of parole is a cruel punishment when applied to 
juveniles.  Miller, 567 U.S. at 489.  And, in view of these 
characteristics of juveniles, we separately concluded that art. 
26 prohibits the mandatory imposition of this punishment.  See 
Diatchenko I, 466 Mass. at 667.  We also concluded that art. 26 
offers greater protections to our children than are available 
under the Eighth Amendment to the United States Constitution.  
Specifically, we concluded that, in view of the hallmarks of 
youth that characterize juveniles, art. 26's greater protection 
prohibits so-called Miller hearings to determine whether, on an 
individualized consideration of a particular juvenile homicide 
defendant's circumstances, the sentence of life without the 
possibility of parole was proportionate.  Id. at 669-671.  
Because the aforementioned review of our statutes, the 
scientific data, collective experiences, and common sense 
confirms that these same qualities characterize young adults, it 
necessarily follows that art. 26 prohibits the punishment as 
applied to this cohort.  For these reasons, I concur. 
 
 
LOWY, J. (dissenting, with whom Cypher and Georges, JJ., 
join).  I cannot say that society, through its elected 
officials, may not express its revulsion of the crime of murder 
in the first degree by imposing a punishment of life without the 
possibility of parole on adults without offending our 
Declaration of Rights.  Therefore, I respectfully dissent. 
The power to "define a crime and ordain its punishment" is 
an exclusively legislative function, and "in judging legislative 
determinations of crimes and punishments, we exercise our powers 
of review with great caution" (citation omitted).  Opinions of 
the Justices, 378 Mass. 822, 830 & n.7 (1979).  For the crime of 
murder in the first degree, the Legislature has deemed the 
mandatory imposition of life without the possibility of parole 
to be the appropriate punishment for adults eighteen and older 
convicted of this offense.  While we have an obligation to 
intervene when the Legislature acts unconstitutionally, unless 
the punishment the Legislature imposes is "so disproportionate" 
that it "shocks the conscience and offends fundamental notions 
of human dignity" (citation omitted), Cepulonis v. Commonwealth, 
384 Mass. 495, 497 (1981), we must exercise restraint and uphold 
it, see art. 26 of the Massachusetts Declaration of Rights; 
Eighth Amendment to the United States Constitution. 
 
In this case, the defendant argues that, in light of recent 
advances in scientific brain research concerning young adults, 
2 
 
the line between those who may constitutionally be subject to 
the mandatory imposition of life without the possibility of 
parole and those who may not should be at the age of twenty-one, 
rather than at the age of eighteen.  Our analysis for 
determining whether a punishment is constitutionally 
disproportionate considers whether the punishment is cruel or 
unusual in light of "contemporary standard[s] of decency" 
(citation omitted).  Libby v. Commissioner of Correction, 385 
Mass. 421, 431 (1982).  We look to statutes enacted by the 
Legislature, along with regulations, as the best objective 
evidence for divining contemporary values.  See Good v. 
Commissioner of Correction, 417 Mass. 329, 335 (1994).  Doing so 
is not affording uncritical deference to the Legislature's 
choice of punishment, but rather it is a direct application of 
our constitutional doctrine that looks to legislation to derive 
contemporary values.  Indeed, "legislatures, not courts, are 
constituted to respond to the will and consequently the moral 
values of the people."  See Gregg v. Georgia, 428 U.S. 153, 175 
(1976), quoting Furman v. Georgia, 408 U.S. 238, 383 (1972) 
(Burger, C.J., dissenting).  Consequently, to determine whether 
this mandatory sentence violates art. 26, we must look to 
legislative evidence to determine whether the line that the 
defendant urges us to draw at the age of twenty-one is one that 
is consistent with society's contemporary values. 
3 
 
 
Contrary to the court's conclusion that it is, the 
objective sources of contemporary standards of decency in the 
Commonwealth simply do not reflect a public consensus that life 
without parole, when imposed mandatorily on individuals from 
eighteen to twenty who have been convicted of murder in the 
first degree, is cruel or unusual.  Rather, the Legislature has 
definitively drawn the line between childhood and adulthood at 
eighteen, and objective indicia of contemporary standards of 
decency in the Commonwealth demonstrate support for, rather than 
objection to, treating individuals within this age range as 
adults in our criminal justice system when they commit the crime 
of murder in the first degree. 
 
Where individuals from eighteen to twenty-one have been 
deemed adults by the Legislature and society, precedent relating 
to the sentencing of juveniles -- who are "constitutionally 
different from adults for purposes of sentencing" -- is inapt.  
Miller v. Alabama, 567 U.S. 460, 471 (2012).  Thus, our decision 
in Diatchenko v. District Attorney for the Suffolk Dist., 466 
Mass. 655, 669 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015), 
cannot resolve the question of the proportionality of the 
mandatory sentence challenged in this case.  In Diatchenko I, we 
did not purport to draw a line between juveniles and adults.  
Our focus, rather, was on a category of individuals -- 
predefined by the Legislature -- and our inquiry as to that 
4 
 
category was precise and limited.  See id. at 659 n.8.  Where 
the United States Supreme Court concluded in Miller, supra at 
469, that imposing mandatory life without parole on juveniles 
violates the Eighth Amendment, we were addressing only the 
discretionary imposition of such a sentence, i.e., whether, 
under art. 26, an individualized assessment of a juvenile 
offender could ever result in a determination that "a sentence 
of life without parole should be imposed on a juvenile homicide 
offender."  Diatchenko I, supra at 670.  We concluded that art. 
26 did not permit such an individualized assessment at the time 
of sentencing. 
 
As it relates to the court's conclusion that this mandatory 
sentence is categorically unconstitutional, scientific brain 
research, untethered to societal views expressed through 
legislation, can neither draw the line between childhood and 
adulthood nor manufacture a new category of individuals entitled 
to distinct constitutional treatment for purposes of determining 
whether a sentence is constitutionally disproportionate under 
art. 26.  And, even if it could, science does not definitively 
place the line of brain maturation at twenty-one, but rather 
suggests that it extends into the mid-twenties.  Perhaps nothing 
speaks louder to the flaws in the court's holding that this 
mandatory sentence violates art. 26 than the court having 
crafted a line that ends at age twenty-one, thereby engaging in 
5 
 
legislative line drawing inconsistent with the science upon 
which it relies.  Where punishment is involved, we must look to 
society and the Legislature to determine where the appropriate 
line is and where it should be. 
 
Our assessment under art. 26 is not whether the mandatory 
imposition of life without the possibility of parole for 
individuals from eighteen to twenty-one is, in our view, wise, 
prudent, or even best for society.  Our inquiry is limited to 
whether the punishment, chosen by the Legislature, is so 
disproportionate that it reaches the level of cruel or unusual.  
See Diatchenko I, 466 Mass. at 669.  Because, under our 
contemporary standards of decency and precedent, the mandatory 
imposition of life without the possibility of parole on adults 
who commit murder in the first degree when they are from 
eighteen to twenty-one is not "so disproportionate" that "it 
'shocks the conscience and offends fundamental notions of human 
dignity,'" id., quoting Cepulonis, 384 Mass. at 497, the 
sentence does not violate art. 26's proscription against cruel 
or unusual punishment.  It therefore must be upheld. 
 
Background.  On September 25, 2011, fourteen year old 
Kimoni Elliott was visiting his schoolmate and friend, Jaivon 
Blake, who lived in the area of Geneva Avenue and Everton Street 
in the Dorchester section of Boston.  Elliott lived on Everton 
Street in Dorchester.  That afternoon, Elliott was standing 
6 
 
outside a convenience store on Geneva Avenue near Levant Street 
in Dorchester, an area controlled by the "Flatline" gang.  
Elliott was looking for somebody old enough to purchase rolling 
papers for marijuana cigarettes for him.  The defendant, 
eighteen year old Sheldon Mattis, was a member of the Flatline 
gang.  He had been playing football on Levant Street with some 
other people when he observed Elliott walking toward the 
convenience store.  The defendant approached Elliott and offered 
to purchase rolling papers for him, and after doing so, the 
defendant asked Elliott where he was from.  When Elliott 
responded, "Everton," the defendant assumed that Elliott was a 
member of a rival gang. 
 
Elliott and Blake then met in a nearby parking lot and 
started walking up Geneva Avenue towards Blake's home while the 
defendant returned quickly towards Levant Street.  Minutes 
later, the defendant met with seventeen year old Nyasani Watt on 
the corner of Levant Street and Geneva Avenue.  He turned his 
bicycle over to Watt and handed Watt his gun.  The defendant 
then pointed out Elliott and Blake to Watt, patted him on the 
back, and told him that Watt "needed to go handle that."  Watt 
complied.  Watt approached the victims from behind while on the 
bicycle and fired multiple shots at them.  Blake fell to the 
ground and later died from his injuries.  Elliott, despite being 
shot in the neck and arm, survived. 
7 
 
 
Discussion.  1.  Judicial review of punishment designated 
by the Legislature.  "[T]he power of punishment is vested in the 
legislative, not in the judicial department.  It is the 
[L]egislature, not the [c]ourt, which is to define a crime and 
ordain its punishment."  Opinions of the Justices, 378 Mass. at 
830 n.7, quoting United States v. Wiltberger, 18 U.S. (5 Wheat.) 
76, 95 (1820).  Entrusted with this authority, "[t]he 
Legislature has great latitude to determine what conduct should 
be regarded as criminal and to prescribe penalties to vindicate 
the legitimate interests of society."  Commonwealth v. Jackson, 
369 Mass. 904, 909 (1976).  The Legislature's judgment in this 
area is thus "to be accorded due respect," Opinions of the 
Justices, supra at 830, and it is subject only to the 
constitutional limitations imposed by the Eighth Amendment and 
art. 26, see Jackson, supra. 
 
Article 26, which affords greater protections than the 
Eighth Amendment, proscribes cruel or unusual punishment; the 
"touchstone" of this proscription is proportionality.  
Commonwealth v. Yat Fung Ng, 491 Mass. 247, 271 (2021).  This 
"flows from the basic 'precept of justice that punishment for 
crime should be graduated and proportioned' to both the offender 
and the offense."  Diatchenko I, 466 Mass. at 669, quoting 
Miller, 567 U.S. at 469.  Our role as the judiciary is therefore 
to determine whether the punishment designated by the 
8 
 
Legislature is "so disproportionate to the offense as to 
constitute cruel [or] unusual punishment."1  Cepulonis, 384 Mass. 
at 496. 
 
"To reach the level of cruel [or] unusual, the punishment 
must be so disproportionate to the crime that it 'shocks the 
conscience and offends fundamental notions of human dignity.'"  
Diatchenko I, 466 Mass. at 669, quoting Cepulonis, 384 Mass. at 
497.  In conducting this analysis, we consider "contemporary 
standards of decency which mark the progress of society."  
Diatchenko I, supra, quoting Good v. Commissioner of Correction, 
417 Mass. 329, 335 (1994).  "But in judging legislative 
determinations of crimes and punishments, we exercise our powers 
of review with great caution."  Opinions of the Justices, 378 
Mass. at 830.  See Jackson, 369 Mass. at 909 ("It is thus with 
restraint that we exercise our power of review to determine 
whether the punishment before us exceeds the constitutional 
limitations imposed by the Eighth Amendment and by art. 26"). 
 
"Therefore, in assessing a punishment selected by a 
democratically elected [L]egislature against the constitutional 
measure, we presume its validity."  Gregg, 428 U.S. at 175.  See 
Jackson, 369 Mass. at 909, quoting Weems v. United States, 217 
 
 
1 Article 26 prohibits the infliction of "cruel or unusual 
punishments," while the Eighth Amendment proscribes "cruel and 
unusual punishments." 
9 
 
U.S. 349, 379 (1910) ("The function of the [L]egislature is 
primary, its exercises fortified by presumptions of right and 
legality, and is not to be interfered with lightly, nor by any 
judicial conception of their wisdom or propriety").  "[W]hile we 
have an obligation to insure that constitutional bounds are not 
overreached, we may not act as judges as we might as 
legislators."  Gregg, supra at 174-175.  "We may not require the 
[L]egislature to select the least severe penalty possible so 
long as the penalty selected is not cruelly inhumane or 
disproportionate to the crime involved.  And a heavy burden 
rests on those who would attack the judgment of the 
representatives of the people."  Id. at 175.  Accordingly, "a 
heavy burden is on the sentenced defendant to establish that the 
punishment is disproportionate to the offense for which he was 
convicted."  Commonwealth v. Bianco, 390 Mass. 254, 260-261 
(1983), quoting Commonwealth v. O'Neal, 369 Mass. 242, 248 
(1975) (Tauro, C.J., concurring). 
In concluding that the mandatory imposition of life 
imprisonment without the possibility of parole for individuals 
from eighteen to twenty-one who have been convicted of murder in 
the first degree violates art. 26, the court considers 
contemporary standards of decency and prior precedent.  See ante 
at    .  Rather than consider science as an independent factor 
in assessing proportionality, the court, for the first time, 
10 
 
concludes that "current scientific consensus regarding the 
characteristics of the class can help determine the contemporary 
standards of decency pertaining to that class."  Id. at    .  
The incorporation of science -– with which I agree -– into the 
consideration of contemporary standards of decency in the 
constitutional analysis of art. 26 risks diluting the value of 
both science and contemporary standards of decency in analyzing 
proportionality.  To understand contemporary standards of 
decency, we must look to "'objective indicia of society's 
standards, as expressed in legislative enactments and state 
practice[,]' to determine whether there is a national consensus 
against the sentencing practice at issue." Graham v. Florida, 
560 U.S. 48, 61 (2010), quoting Roper v. Simmons, 543 U.S. 551, 
552 (2005).  Science, no doubt, is a valuable source in 
considering proportionality, as well as in assisting 
legislatures in how best to line draw around sentencing. 
But science and contemporary standards of decency, although 
both vitally important, are distinct sources of information.  It 
is necessary to independently examine how elected officials and 
States have chosen to express consensus on the proportionality 
of punishment, themselves having had the opportunity to weigh 
myriad factors, including scientific development, in their 
decision-making processes.  The judge's factual findings in July 
2022 as to the brain development of emerging adults were well 
11 
 
supported, and indeed I embrace them.  But the court's 
incorporation of science into contemporary standards of decency 
does not change the outcome of this case.  Nothing about 
mandatory life imprisonment without the possibility of parole 
for individuals from eighteen to twenty-one who have been 
convicted of the most heinous crime of murder in the first 
degree -- either with deliberate premeditation, with extreme 
atrocity or cruelty, or with actual malice in the commission or 
attempted commission of a crime punishable with life 
imprisonment -- offends contemporary standards of decency.  See 
Commonwealth v. Okoro, 471 Mass. 51, 61 (2015) ("art. 26 
nevertheless 'draw[s] its meaning from the evolving standards of 
decency that mark the progress of a maturing society,' such that 
developments in the area of juvenile justice in judicial 
opinions and legislative actions at the State, Federal, and 
international levels help to inform our understanding of what 
art. 26 protects" [citation omitted]). 
Accordingly, I address contemporary standards of decency, 
precedent, and science in turn. 
 
2.  Contemporary standards of decency.  "Article 26 bars 
punishments which are found to be cruel or unusual in light of 
contemporary standards of decency which mark the progress of 
society."  Good, 417 Mass. at 335.  The evaluation of 
contemporary standards of decency to assess disproportionality 
12 
 
"should be informed by 'objective factors to the maximum 
possible extent.'"  Atkins v. Virginia, 536 U.S. 304, 312 
(2002), quoting Harmelin v. Michigan, 501 U.S. 957, 1000 (1991) 
(Kennedy, J., concurring in part and concurring in the 
judgment).  Proportionality "judgments should not be, or appear 
to be, merely the subjective views of individual Justices," 
Rummel v. Estelle, 445 U.S. 263, 274 (1980), quoting Coker v. 
Georgia, 433 U.S. 584, 592 (1977) (plurality opinion), and 
therefore "courts should pay special attention to objective 
factors deciding whether a practice violates 'the contemporary 
standard of decency.'"  Libby, 385 Mass. at 431, quoting Rhodes 
v. Chapman, 452 U.S. 337, 347 (1981).  See Coker, supra at 611 
(Burger, C.J., dissenting), quoting Furman, 408 U.S. at 431 
(Powell, J., dissenting) ("[W]here, as here, the language of the 
applicable [constitutional] provision provides great leeway and 
where the underlying social policies are felt to be of vital 
importance, the temptation to read personal preference into the 
Constitution is understandably great.  It is too easy to 
propound our subjective standards of wise policy under the 
rubric of more or less universally held standards of decency"). 
 
"[T]he 'clearest and most reliable objective evidence of 
contemporary values is the legislation enacted by the . . . 
[L]egislature[].'"  Atkins, 536 U.S. at 312, quoting Penry v. 
Lynaugh, 492 U.S. 302, 331 (1989).  See Gregg, 428 U.S. at 175, 
13 
 
quoting, Furman, 408 U.S. at 383 (Burger, C.J., dissenting) 
("[I]n a democratic society legislatures, not courts, are 
constituted to respond to the will and consequently the moral 
values of the people").  Thus, "[i]n divining contemporary 
standards of decency, we may look to State statutes and 
regulations, which reflect the public attitude as to what those 
standards are."  Good, 417 Mass. at 335.  In other words, our 
doctrinal framework for interpreting the text looks, in part, to 
legislative judgments for objective evidence of contemporary 
values.  When we infuse normative values into the open-ended 
provisions of art. 26's proscription against "cruel or unusual 
punishments," our doctrine protects against the great danger of 
judges infusing their own values into their interpretation of 
contemporary standards of decency by considering legislative 
judgments as to crime and punishment. 
 
Beginning generally with legislation relating to 
individuals from eighteen to twenty-one, our Commonwealth 
considers these individuals adults, and has done so 
unequivocally for more than forty years.  See G. L. c. 4, § 7, 
Forty-eighth to Fifty-first, inserted by St. 1973, c. 925 ("In 
construing statutes [in the Commonwealth] the following words 
shall have the meanings herein given . . . :  'Minor' shall mean 
any person under eighteen years of age. . . .  'Full age' shall 
mean eighteen years of age or older. . . .  'Adult' shall mean 
14 
 
any person who has attained the age of eighteen. . . .  'Age of 
majority' shall mean eighteen years of age").  Individuals in 
this category have been granted rights in Massachusetts 
generally associated with adulthood.  See art. 3 of the 
Amendments to the Constitution of the Commonwealth, as amended 
through art. 100 of the Amendments (right to vote); G. L. 
c. 234A, § 4 (serving on jury); G. L. c. 207, §§ 7, 24 (entering 
marriage); G. L. c. 231, § 85O (entering contracts).2  This 
includes the right to make decisions having potentially life-
altering effect.  See Norwood Hosp. v. Munoz, 409 Mass. 116, 
122-123 (1991) (common-law and State constitutional right for 
competent adults to refuse medical treatment, even where 
treatment may be lifesaving). 
 
Nothing in the statutes that restrict certain activities to 
individuals over the age of twenty-one alters or changes the age 
at which the Legislature has determined adulthood begins.  
Certainly none of the statutes on which the court or 
 
 
2 See also Office of Attorney General, When You Turn 18, 
https://www.mass.gov/doc/your-guide-to-understanding-your-
rights-responsibilities-and-how-to-protect-yourself-when-you-
turn-18/download#:~:text=You're%2018!,and%20responsibilities 
%20of%20an%20adult [https://perma.cc/QU9M-YV72] ("You're 18!  In 
Massachusetts you've now reached the age of legal adulthood.  
With this milestone, you have nearly all the legal rights and 
responsibilities of an adult.  Among your new rights are the 
right to vote and serve on a jury, to marry, to enlist in the 
military or choose medical care, and to be responsible for any 
contracts you sign"). 
15 
 
concurrences rely suggests that the activity restricted is 
limited only to "adults."3  See G. L. c. 138, § 34 (must be 
twenty-one years of age to purchase and sell alcoholic 
beverages); G. L. c. 270, § 6 (must be twenty-one years of age 
to purchase tobacco products), G. L. c. 140, § 131 (d) (iv) 
(must be twenty-one years of age to obtain license to carry 
handgun); G. L. c. 22C, § 10 (must be twenty-one years of age to 
be State police officer); G. L. c. 31, § 58 (must be twenty-one 
years of age to be municipal police officer); and G. L. c. 23K, 
§ 25 (h) (must be twenty-one years of age to gamble or be in 
gambling area). 
 
Article 26's requirements, however, are not adjudged by an 
amorphous consideration of contemporary standards of decency as 
they relate to age generally.  Those contemporary standards of 
decency must relate to some extent to the crime and punishment 
at hand.  After all, the relevant inquiry is whether the 
 
 
3 Relying on statutes that restrict or permit activities to 
persons of a certain age is not an appropriate measure to 
determine when society deems a person an adult, particularly 
where those statutes do not expressly limit the activity to 
"adults."  For instance, several statutes restrict certain 
activities to those over the age of sixteen, such as operating a 
motor vehicle, G. L. c. 90, § 10, and working without a permit, 
G. L. c. 149, § 90, but we would not consider those statutes as 
evidence that a sixteen year old is an adult.  Instead, the best 
and most reliable evidence of when society considers the 
beginning of adulthood is the point at which the Legislature 
defines a person as an adult -- eighteen.  See G. L. c. 4, § 7, 
Fiftieth. 
16 
 
challenged punishment is "cruel or unusual in light of 
contemporary standards of decency."  Good, 417 Mass. at 335. 
In this context, not only has the Legislature expressly provided 
that individuals eighteen and older are adults in our 
Commonwealth, see G. L. c. 4, § 7, Fiftieth, but it also has 
determined that these individuals are responsible as adults in 
our criminal justice system, see G. L. c. 119, §§ 52-54 
(proceedings against children under eighteen in Juvenile Court 
not deemed criminal).  This has included the mandatory 
imposition of life without parole on individuals over eighteen 
convicted of murder in the first degree.  See G. L. c. 265, § 2.  
If the Legislature, responding to the will of the people, wished 
to extend the age that individuals are treated as juveniles, 
rather than adults, in our court system, it knows how to do so.  
See St. 2013, c. 84, §§ 25, 26, amending G. L. c. 119, § 74 
(expanding juvenile jurisdiction to eighteen year olds). 
 
Statutes and regulations throughout our Commonwealth do not 
even suggest that contemporary standards of decency consider the 
mandatory imposition of life without parole on adults from 
eighteen to twenty-one to be cruel or unusual punishment for the 
crime of murder in the first degree.  The sources upon which the 
court relies do not address contemporary common views, 
particularly as they relate to offenders within this age range 
charged with murder. 
17 
 
 
To begin, the court's reliance on a statute authorizing 
youthful offenders to be committed to the Department of Youth 
Services until the age of twenty-one is misplaced.  That the 
Legislature has designated, among several permissible 
punishments for a child under the age of eighteen who has been 
adjudicated a youthful offender, commitment to the Department of 
Youth Services until the age of twenty-one is not relevant to 
society's views of punishment for those who commit crimes while 
eighteen or over, let alone the crime of murder.  See G. L. 
c. 119, §§ 54, 58.  Rather, this is a sentencing scheme limited 
to juveniles.  Moreover, the court relies on a task force formed 
by the Legislature on emerging adults to suggest that 
contemporary standards favor providing distinct treatment to 
those from eighteen to twenty-one in our criminal legal system.  
See ante at note 22.  However, the task force defined "emerging 
adults" as individuals from ages eighteen to twenty-four, not 
twenty-one, and in its report proposing certain changes to our 
system applicable to this age group, it, importantly, excluded 
from those changes the crime of murder.  Specifically, the task 
force found, as the science demonstrates, see infra, that 
individuals ages eighteen to twenty-four, "while possessing the 
cognitive capacity to make deliberative decisions, are more 
likely to be more impulsive, less future-oriented, more unstable 
in emotionally charged settings, and more susceptible to peer 
18 
 
and other outside influences."  Emerging Adults in the 
Massachusetts Criminal Justice System:  Report of the Task Force 
on Emerging Adults in the Criminal Justice System (Feb. 26, 
2020), 2020 Senate Doc. No. 2840, at 6-7.  Even so, in making 
its proposals for consideration by the Legislature, the task 
force provided several options for changes to our current system 
but excluded from all these proposals individuals of this age 
group charged with the crime of murder.  Some examples included 
extending the juvenile justice system, except in murder cases; 
creating a "young adult offender" category, excluding high-level 
offenses such as murder; providing judges with discretion to 
refer certain cases to juvenile court, excluding high-level 
offenses such as murder; and creating an "emerging adult" court 
session, excluding individuals charged with the crime of murder.  
Id. at 7, 9-10. 
 
Furthermore, although, as the defendant and Justice 
Kafker's concurrence point out, the Advisory Sentencing 
Guidelines (guidelines) recommended by the Massachusetts 
Sentencing Commission in 2017 provide that research concerning 
the brain development of emerging adults, which it defines as 
individuals "up to and including age [twenty-one]" (emphasis 
added), may be considered at sentencing, the guidelines are 
intended to assist with discretionary sentencing and are 
inapplicable to mandatory sentencing provisions such as those 
19 
 
designated for the crime of murder in the first degree.  See 
Massachusetts Sentencing Commission, Advisory Sentencing 
Guidelines 4, 7-8 (Nov. 2017) ("In making these Sentencing 
Guidelines advisory, rather than voluntary, the Commission 
intends to provide a starting point for consideration, and not a 
constraint on judicial discretion in fashioning an appropriate 
sentence. . . .  [T]he Commission has no authority to abolish 
minimum mandatory sentences or to change other statutory penalty 
provisions").  More importantly, the guidelines do not reflect 
public consensus, nor do they purport to do so.4  The guidelines 
were never enacted by the Legislature, and thus have not taken 
effect.  See G. L. c. 211E, § 3 (a) (1) ("The commission . . . 
shall recommend sentencing guidelines, which shall take effect 
only if enacted into law" [emphasis added]). 
 
The suggestion in Justice Kafker's and Justice Wendlandt's 
concurrences that it is uncritical deference to the Legislature 
that drives my conclusion that we must uphold the imposition of 
 
 
4 Within the guidelines themselves, the Massachusetts 
District Attorneys Association responded in objection both to 
the guidelines being issued to guide judges, without approval 
and consent from the Legislature, and to the substance of the 
guidelines based on the district attorneys' "collective 
experience, the rights of victims of crime, the impact of the 
opioid epidemic, and [the district attorneys'] vital role as 
elected officials, protecting the public and representing the 
public's interest" (footnote omitted).  See Massachusetts 
Sentencing Commission, Advisory Sentencing Guidelines 12-13 
(Nov. 2017). 
20 
 
life without parole on individuals from eighteen to twenty-one 
deeply misunderstands my position.  It is our constitutional 
doctrine looking to contemporary standards of decency that 
commands that we consider our Legislature's judgments as to what 
age constitutes adulthood.  We must ground our art. 26 
proportionality analysis to reflect society's values as 
expressed through legislative judgments.  The objective indicia 
of contemporary standards of decency in our Commonwealth reflect 
a societal view that individuals from eighteen to twenty-one are 
adults, and nothing from these objective sources demonstrates 
that society's evolving standards of decency consider the 
mandatory imposition of life without parole to be cruel or 
unusual when imposed on individuals within this age range who 
have been convicted of murder in the first degree. 
 
These standards of decency are not unique to the 
Commonwealth.  In ascertaining evolving standards of decency, 
"judicial opinions and legislative actions at the State, 
Federal, and international levels help to inform our 
understanding of what art. 26 protects."  Okoro, 471 Mass. at 
61.  As discussed in detail infra, thirty-six jurisdictions 
permit the imposition of this punishment for this category of 
homicide offenders, and only two States before today have 
concluded, under their own Constitutions, that the mandatory 
21 
 
imposition of life without parole on adults from eighteen to 
twenty-one is cruel or unusual.5 
 
3.  Precedent.  Precedent relied on by the court is 
specific to the sentencing of juveniles under the age of 
eighteen and does not apply to the sentencing of adults.  When 
considering the proportionality of a sentencing practice as it 
relates to a particular class of offenders, precedent from both 
the Supreme Court and this court distinguishes juveniles under 
the age of eighteen from adults eighteen and older. 
 
The Supreme Court first made this distinction explicit in 
Roper, 543 U.S. 551.  Looking to objective indicia of national 
consensus and societal understandings, supported by scientific 
and sociological studies, the Court concluded that the 
imposition of the death penalty on juvenile homicide offenders 
violates the Eighth Amendment's proscription against cruel and 
unusual punishment.  See id. at 567-570.  Importantly, the Court 
recognized in Roper that the qualities that distinguish 
juveniles from adults "do not disappear when an individual turns 
 
 
5 The court's reliance on the twenty-three jurisdictions 
that do not mandate life without parole for any crime regardless 
of the age of the offender as evidence that contemporary 
standards of decency deem cruel or unusual the imposition of 
life without parole for offenders from eighteen to twenty-one 
for the crime of murder in the first degree confounds logic.  To 
follow the court's reasoning would be to suggest that the 
sentence of life without parole is cruel or unusual in the eyes 
of contemporary standards of decency for any offender convicted 
of the offense. 
22 
 
[eighteen]."  Id. at 574.  Rather, because "[t]he age of 
[eighteen] is the point where society draws the line for many 
purposes between childhood and adulthood," the Court, deferring 
to societal norms informed by legislative enactments, determined 
eighteen to be the defining line at which a person may be 
treated as an adult for the purpose of punishment.  Id. at 569, 
574, Appendices B-D.  The cases following Roper have all 
operated within this societal line. 
 
In Graham, 560 U.S. 48, the Court next addressed juveniles 
convicted of nonhomicide offenses sentenced to life imprisonment 
without the possibility of parole.  In answering the question of 
proportionality, the Court again turned to objective indicia of 
national consensus, expressed through legislative enactments and 
State practice, and considered the culpability of juveniles as 
compared to the severity of the punishment in order to inform 
its own independent judgment whether the sentencing practice 
violated the Eighth Amendment.  Id. at 61-63, 67.  This analysis 
led the Court to conclude that, for juveniles who have not 
committed homicide offenses, the imposition of life without 
parole is cruel and unusual under the Eighth Amendment.  Id. at 
82. 
 
Miller, 567 U.S. at 465, which followed Graham, formed the 
basis for our jurisprudence in the Commonwealth concerning 
proportionality as it relates to sentencing practices applied to 
23 
 
juveniles.  In Miller, the Supreme Court held that "mandatory 
life without parole for those under the age of [eighteen] at the 
time of their crimes violates the Eighth Amendment's prohibition 
on 'cruel and unusual punishments.'"  Id.  The Court in Miller 
predicated its conclusion on two strands of precedent:  the 
first, including Roper and Graham and their consideration of the 
culpability of juveniles in light of the severity of the 
sentences imposed; and the second, involving the prohibition 
against the mandatory imposition of capital punishment due to 
the absence of consideration of the individual characteristics 
of the offender and the details of the offense.  See id. at 470. 
 
From Roper and Graham's teachings, the Court declared in 
Miller that "children are constitutionally different from adults 
for purposes of sentencing."  Miller, 567 U.S. at 471.  This 
declaration rests firmly on principles of common sense, science, 
and social science regarding children, their unique 
characteristics, and how they have been treated in the law.  Id. 
at 471-472, 481.  Based on these principles regarding children, 
considered in conjunction with cases where individualized 
sentencing is required before the death penalty is imposed, the 
Court concluded that the Eighth Amendment requires an 
individualized assessment of youth and its attendant 
24 
 
characteristics before such a harsh penalty may be imposed on a 
juvenile homicide offender.6  See id. at 475-477, 479-480. 
 
In so ruling in Miller, the Court emphasized that its 
holding was limited to children, and that its precedent on adult 
sentencing was not applicable to the sentencing of juvenile 
offenders.  Id. at 481 ("Harmelin[, which addressed 
constitutionality of life without parole sentence for adult 
convicted of possessing 672 grams of cocaine,] had nothing to do 
with children and did not purport to apply its holding to the 
sentencing of juvenile offenders").  Indeed, as the Court noted, 
"a sentencing rule permissible for adults may not be so for 
children."  Id.  The Court cited several examples of punishments 
that "generally comport[] with the Eighth Amendment" -- except 
when it comes to children -- and emphasized that "'[o]ur history 
is replete with laws and judicial recognition' that children 
cannot be viewed simply as miniature adults.'"  Id., quoting 
J.D.B. v. North Carolina, 564 U.S. 261, 274 (2011).  And thus, 
 
 
6 Because the decision in Miller did not categorically bar a 
penalty for a class of offenders but was based on principles 
established in Roper and Graham, as well as the Supreme Court's 
individualized sentencing cases, the Court relied less on 
"objective indicia of society's standards" to gauge a national 
consensus.  See Miller, 567 U.S. at 483.  The Court, 
nevertheless, surveyed the various jurisdictions and counted 
twenty-nine (twenty-eight States and the Federal government) 
that mandatorily imposed life without parole on juvenile 
homicide offenders.  Id. at 482-483 & n.9. 
25 
 
the Court noted, "it is the odd legal rule that does not have 
some form of exception for children."7  Miller, supra. 
 
With this Supreme Court precedent concerning juvenile 
sentencing as the foundation, we decided Diatchenko I, 466 Mass. 
at 657-658.  Our inquiry in Diatchenko I was limited and 
precise, given Miller's prior determination that the mandatory 
imposition of life without the possibility of parole for 
juvenile offenders was disproportionate under the Eighth 
Amendment.  See Diatchenko I, supra at 667 ("Pursuant to Miller, 
[567 U.S. at 479, 489], we conclude that this mandatory sentence 
violates both the Eighth Amendment prohibition against 'cruel 
and unusual punishment[]' and the analogous provision of the 
Massachusetts Declaration of Rights set forth in art. 26").  The 
remaining question for us in Diatchenko I was whether an 
individualized assessment of a juvenile offender could ever 
 
 
7 It is worth noting that when the Supreme Court has 
assessed whether punishment is barred by the Eighth Amendment 
when applied to a category of offenders who are not juveniles, 
it has placed great emphasis on contemporary standards of 
decency, gleaned from legislative judgments.  See Atkins, 536 
U.S. at 313-316, 321 (death penalty for intellectually disabled 
unconstitutional, determined by "review[ing] the judgment of 
legislatures that have addressed the suitability of imposing the 
death penalty on the [intellectually disabled] and then 
consider[ing] reasons for agreeing or disagreeing with their 
judgment"); Ford v. Wainwright, 477 U.S. 399, 406-410 (1986) 
(death penalty for insane prisoners unconstitutional where 
execution of them was condemned at common law, and at time of 
decision "no State in the Union permit[ted] the execution of the 
insane"). 
26 
 
constitutionally justify the imposition of life without parole 
under art. 26.  Id. at 668.  We concluded that the answer to 
that singular question was no.  Id. at 670-671.  In light of the 
unique characteristics of juvenile offenders, we concluded that 
an individualized assessment could never result in a 
determination that a juvenile was "irretrievably depraved," at 
the time of sentencing, such that "a sentence of life without 
parole should be imposed on a juvenile homicide offender."  Id. 
at 670, quoting Roper, 543 U.S. at 570. 
While we relied on "current scientific research on 
adolescent brain development," combined with "the myriad 
significant ways that this development impacts a juvenile's 
personality and behavior," in Diatchenko I, 466 Mass. at 669, to 
make this determination, our focus was on a legislatively 
defined category of individuals constitutionally deserving of 
special treatment.  We did not look to science to carve out this 
group; legislation had already defined it.  See id. at 659 n.8.  
We determined that, "under art. 26, the 'unique characteristics 
of juvenile offenders' should weigh more heavily in the 
proportionality calculus than the United States Supreme Court 
required under the Eighth Amendment," Commonwealth v. Perez, 477 
Mass. 677, 683 (2017), S.C., 480 Mass. 562 (2018), quoting 
Diatchenko I, supra at 671, and we used scientific research to 
augment this weighing. 
27 
 
 
Two features of our decision in Diatchenko I render it 
unsuited and unable to answer the question before us today.  The 
first, and most pronounced, reason:  it was limited to juveniles 
under the age of eighteen.  See Diatchenko I, 466 Mass. at 659 
n.8.  More specifically, the decision was limited to a class of 
offenders predefined by the Legislature as juveniles.  Indeed, 
the decision in Diatchenko I made painstakingly clear that its 
holding was restricted to juvenile offenders under the age of 
eighteen.8  Justice Kafker's concurrence poses the question 
 
 
8 See Diatchenko I, 466 Mass. at 658-659 ("We further 
conclude that the mandatory imposition of a sentence of life in 
prison without the possibility of parole on individuals who were 
under the age of eighteen when they committed the crime of 
murder in the first degree violates the prohibition against 
'cruel or unusual punishments' in art. 26 of the Massachusetts 
Declaration of Rights, and that the discretionary imposition of 
such a sentence on juvenile homicide offenders also violates 
art. 26 because it is an unconstitutionally disproportionate 
punishment when viewed in the context of the unique 
characteristics of juvenile offenders" [emphases added]); id. at 
669 ("In the present circumstances, the imposition of a sentence 
of life in prison without the possibility of parole for the 
commission of murder in the first degree by a juvenile under the 
age of eighteen is disproportionate not with respect to the 
offense itself, but with regard to the particular offender" 
[emphasis added]); id. at 671 ("With current scientific evidence 
in mind, we conclude that the discretionary imposition of a 
sentence of life in prison without the possibility of parole on 
juveniles who are under the age of eighteen when they commit 
murder in the first degree violates the prohibition against 
'cruel or unusual punishment[]' in art. 26" [emphasis added]); 
id. ("Given the unique characteristics of juvenile offenders, 
they should be afforded, in appropriate circumstances, the 
opportunity to be considered for parole suitability" [emphasis 
added]); id. at 673 ("In light of our conclusion that the 
imposition of a sentence of life in prison without the 
possibility of parole on juvenile offenders who are under the 
28 
 
"whether there is a meaningful constitutional difference between 
overruling the Legislature's decision that it is permissible to 
sentence juveniles to life in prison without the possibility of 
parole and overruling the Legislature's decision that it is 
permissible to sentence eighteen through twenty year olds to 
life in prison without the possibility of parole."  See ante 
at    .  But Diatchenko I answers that question; there is.  The 
decision in Diatchenko I rested on the recognition that 
juveniles are "constitutionally different from adults for 
purposes of sentencing."  Id. at 670, 674, quoting Miller, 567 
U.S. 460, 471.  See Diatchenko I, supra at 675 (Lenk, J., 
concurring) ("Pivotal to this holding . . . is the recognition 
that 'children are constitutionally different from adults for 
purposes of sentencing'" [citation omitted]).  In Diatchenko I, 
we did not venture to determine who qualified as a juvenile or 
look to science to draw the line between childhood and 
adulthood; instead, we relied on the prefixed line established 
by society and the Legislature to issue our holding.  See id. at 
659 n.8.  Where that prefixed line places eighteen, nineteen, 
and twenty year olds on the side of adulthood, and thus not 
 
age of eighteen when they commit the crime of murder in the 
first degree is unconstitutional, the language in the fourth 
sentence of G. L. c. 265, § 2, which sets forth the exception to 
parole eligibility, is invalid as applied to juvenile homicide 
offenders" [emphases added]). 
29 
 
entitled to distinct constitutional treatment, Diatchenko I does 
not dictate the result here.  As the Supreme Court in Miller 
underscored, precedent relating to adult sentencing is not 
applicable to juveniles, and inversely, precedent relating to 
juvenile sentencing is not applicable to adults.  See Miller, 
567 U.S. at 481. 
 
The second reason Diatchenko I cannot resolve the 
categorical question in this case relates to the court's inquiry 
there and the reliance on science to assess proportionality.  As 
discussed infra, science is important when considering 
proportionality as it relates to the offender.  Diatchenko I, 
466 Mass. at 669-670, establishes that.  But, as the court, the 
concurrences, and the parties all must and, at least implicitly, 
do acknowledge, science alone cannot determine whether a 
sentence is constitutionally disproportionate under art. 26.  
See ante at note 30 (court's opinion), note 9 (Kafker, J., 
concurring), note 7 (Wendlandt, J., concurring).  Because the 
Supreme Court in Miller had already undertaken a proportionality 
analysis, considering primarily precedent, augmented by science 
and contemporary standards, and it deemed the mandatory 
imposition of life without parole on juveniles unconstitutional, 
our own proportionality analysis was abbreviated and related 
only to the discretionary imposition of that sentence.  
Diatchenko I, supra at 670-671.  We relied on Miller, as well as 
30 
 
its consideration of Graham and Roper, for the proportionality 
calculus as it relates to the mandatory imposition of life 
without parole on juveniles.  But in light of our determination 
that art. 26 is more protective than the Eighth Amendment, we 
looked to science, as well as sociological understandings, 
concerning youth to render our decision regarding the 
discretionary imposition of life without parole on juveniles, 
and only on juveniles.  Diatchenko I, supra. 
 
4.  Science.  Importantly, we have never suggested that 
scientific research untethered to any legislation can create a 
new category of individuals entitled to special treatment under 
our Constitution.  In creating such a category, the court 
impermissibly engages in legislative line drawing, detached from 
our constitutional analysis.  To demonstrate this, one need look 
no further than the location of the line drawn.  The court 
includes within its category of "emerging adults" individuals 
from eighteen to twenty-one.  See ante at note 1.  This line, 
once framed by the defendant as being properly placed at the age 
of twenty-two, was urged to be drawn at twenty-one on remand 
when the case was paired with Commonwealth v. Robinson, 493 
Mass.     (2023). 
 
Although the judge's factual findings are limited to 
individuals eighteen through twenty years old, much of the 
scientific expert testimony and studies supporting those 
31 
 
findings included individuals twenty-one years of age (and in 
some instances older) as it relates to impulsivity, self-
regulation in an emotionally aroused state, sensation seeking, 
and brain plasticity.  Both of the experts who testified for the 
defendant, Drs. Adriana Galván and Robert Kinscherff, defined 
"young adults" or "late adolescents" to include twenty-one year 
old individuals, and their testimony concerning brain maturity 
often extended to those individuals.  While Dr. Laurence 
Steinberg purported to limit his testimony to eighteen, 
nineteen, and twenty year olds, the research articles in the 
record that he coauthored, and which undergirded his testimony, 
grouped together individuals eighteen through twenty-one years 
32 
 
old ,9 and in some instances through twenty-two years old.10  
Galván was also involved in the studies that routinely grouped 
 
 
9 See Breiner et al., Combined Effects of Peer Presence, 
Social Cues, and Rewards on Cognitive Control in Adolescents, 60 
Developmental Psychobiology 292, 292-294 (2018) ("The final 
participant sample consisted of 71 adolescents [ages 13-17 years 
old, M = 15.48, SD = 1.24; 33 males, 38 females]; 48 young 
adults [ages 18-21 years-old, M = 19.64, SD = 1.03; 25 males, 23 
females]; and 57 adults [ages 22-25 years-old, M = 23.34, SD = 
1.01; 28 males, 29 females]"); Cohen et al., When Is an 
Adolescent an Adult?  Assessing Cognitive Control in Emotional 
and Nonemotional Contexts, 27 Psychol. Sci. 549, 550 (2016) ("A 
total of 110 usable scans were included in the final analyses 
reported here [41 teens -- 23 females and 18 males, ages 13-17 
years, M = 16.19, SD = 1.20; 35 young adults -- 17 females and 
18 males, ages 18-21 years, M = 19.88, SD = 1.09; 34 adults -- 
17 females and 17 males, ages 22-25 years, M = 24.08, SD = 
1.04"); Icenogle et al., Adolescents' Cognitive Capacity Reaches 
Adult Levels Prior to Their Psychosocial Maturity:  Evidence for 
a "Maturity Gap" in a Multinational, Cross-Sectional Sample, 43 
Law & Hum. Behav. 69, 74 (2019) (participants divided into seven 
age groups:  "10-11 years, 12-13 years, 14-15 years, 16-17 
years, 18-21 years, 22-25 years, and 26-30 years"); Rudolph et 
al., At Risk of Being Risky:  The Relationship Between "Brain 
Age" under Emotional States and Risk Preference, Developmental 
Cognitive Neurosci., vol. 24, 2017, at 93-94 ("all participants 
-- M = 19.05, SD = 3.91; 11 children -- 6 female, ages 10-12 
years, M = 11.55, SD =0.89; 80 teens -- 45 female, ages 13-17 
years, M = 15.77, SD = 1.44; 58 young adults -- 33 females, ages 
18-21 years, M = 19.86, [SD = ]1.11; 63 adults -- 34 females, 
ages 22-25 years, M = 23.7, SD = l.03"); Steinberg et al., 
Around the World, Adolescence Is a Time of Heightened Sensation 
Seeking and Immature Self-Regulation, Developmental Sci., vol. 
21, Mar. 2018, at 6 ("each study site attempted to recruit at 
least 30 males and 30 females from each of seven age groups:  
10-11 years, 12-13 years, 14-15 years, 16-17 years, 18-21 years, 
22-25 years, and 26-30 years"). 
 
 
10 See Chein et al., Peers Increase Adolescent Risk Taking 
by Enhancing Activity in the Brain's Reward Circuitry, 
Developmental Sci., vol. 14, Mar. 2011, at 3 ("Data from 40 
subjects [14 adolescents -- eight female, ages 14-18 years, M = 
15.7, SD = 1.5; 14 young adults -- seven female, ages 19-22 
years, M = 20.6, SD = 0.9; and 12 adults -- six female, ages 24-
33 
 
eighteen through twenty-one year old individuals together.  And, 
notably, her testimony concerning brain plasticity -- the 
ability to change in response to different circumstances or 
environment -- indicated development until the mid-twenties.  If 
twenty-one year old individuals, and even beyond, suffer from 
the same brain deficiencies as eighteen, nineteen, and twenty 
year old individuals, by the court's logic, the mandatory 
imposition of life without parole on them must too be 
unconstitutional.  However, because the defendant cut off his 
request for relief at the age of twenty-one, the court does not 
conclude as much.  Accordingly, not only is the line at twenty-
 
29 years, M = 25.6, SD = 1.9] were included in analyses"); 
Gardner & Steinberg, Peer Influence on Risk Taking, Risk 
Preference, and Risky Decision Making in Adolescence and 
Adulthood:  An Experimental Study, 41 Developmental Psychol. 
625, 625-627 (2005) ("In this study, 306 individuals in 3 age 
groups -- adolescents [13–16], youths [18–22], and adults [24 
and older] -- completed 2 questionnaire measures assessing risk 
preference and risky decision making, and 1 behavioral task 
measuring risk taking"); Silva et al., Adolescents in Peer 
Groups Make More Prudent Decisions When a Slightly Older Adult 
Is Present, 34 Psychol. Sci. 322, 323 (2016) ("In the present 
study, we investigated how the presence of peers affects 
decision making among late adolescents [ages 18–22] and whether 
the previously documented effect of peers on adolescents' risk 
taking can be reduced or reversed by the presence of a slightly 
older adult [age 25–30]"); Silva et al., Peers Increase Late 
Adolescents' Exploratory Behavior and Sensitivity to Positive 
and Negative Feedback, 26 J. Res. on Adolescence 696, 697 (2015) 
("We focus on late adolescents [ages 18-22] because there is 
considerable evidence that the prevalence of certain real-life, 
high-stakes risk behaviors [e.g., binge drinking, substance use, 
reckless driving, and unprotected sex] is highest among 18- to 
22-year olds"). 
34 
 
one not crafted by the Legislature or society, as it must be, it 
is not even scientifically crafted.  In this area of crime and 
punishment particularly, the court must resist judicially 
crafting this line.  See Commonwealth v. Brown, 466 Mass. 676, 
685 (2013), S.C., 474 Mass. 576 (2016) (expressing "concern for 
judicial law-making" in area of "defining crimes and their 
punishments" [citation omitted]). 
 
The problem with the court defining this category of 
individuals based on science is not only that the science it 
uses applies beyond the chronological category that the court 
creates, but also that neuroscience does not limit itself to 
young adults.  If we look only to neuroscience to determine who 
is or who is not entitled to distinct constitutional treatment 
for sentencing purposes, what categories are off limits?  The 
court, purportedly based on science, creates the category of 
"emerging adults," but what about declining adults with 
dementia; those with early-onset Alzheimer's disease; those with 
brain tumors or genetic deficiencies; and those with a low 
intelligence quotient, but not low enough to constitute an 
intellectual disability? 
 
In advocating against unilaterally drawing the line of 
adulthood beyond the age of eighteen -- where the Legislature 
and society have placed it -- I do not discount that the current 
scientific research on the brain development of individuals ages 
35 
 
eighteen to twenty-one (and, in some instances, to mid-twenties) 
shows deficiencies in the ability to self-regulate in 
emotionally arousing situations, as well as increased sensation 
seeking and susceptibility to peer pressure.  Nor do I disregard 
the research on developmental brain plasticity and its 
continuation into an individual's mid-twenties, suggesting a 
greater capacity for change.  The judge found the scientific 
experts to be reliable.  Policy considerations, however, are for 
the Legislature.  Our role in this area of crime and punishment 
is limited, and we must remain disciplined when assessing 
whether the punishment, chosen by the Legislature, is so 
disproportionate that it "shocks the conscience and offends 
fundamental notions of human dignity" to reach the level of 
cruel or unusual.  Cepulonis, 384 Mass. at 497, quoting Jackson, 
369 Mass. at 910. 
 
The challenged punishment in this case is not.  
Contemporary standards of decency, ascertained properly through 
objective sources, consider these individuals adults and do not 
remotely suggest a societal attitude or consensus that 
mandatorily imposing life without the possibility of parole on 
such individuals when they commit murder in the first degree is 
cruel or unusual.  As a result, precedent relating to the 
sentencing of juveniles, who are constitutionally different from 
adults for purposes of sentencing, is inapplicable.  Scientific 
36 
 
research cannot create a category of individuals entitled to 
specialized constitutional treatment, and indeed, it does not 
support the category created by the court.  Further, when we 
look beyond just the nature of the offender and consider other 
factors relevant to the proportionality analysis, see infra, it 
becomes clear that this punishment does not violate art. 26. 
 
5.  Applicability of tripartite proportionality analysis.  
Although the considerations on which the court bases its 
decision -- contemporary standards of decency, science, and 
precedent -- do not support its conclusion that the mandatory 
imposition of life without parole on individuals from eighteen 
to twenty-one reaches the level of constitutional 
disproportionality, I would not abandon application of the 
tripartite analysis for evaluating categorical challenges to the 
proportionality of a sentencing practice.  Contemporary 
standards, science, and precedent are all important to assessing 
proportionality, but, as the court considers them, each focuses 
only on the nature of the offender.  The proportionality 
analysis under art. 26 requires a more comprehensive inquiry.  
See Commonwealth v. Sharma, 488 Mass. 85, 89, quoting 
Commonwealth v. Concepcion, 487 Mass. 77, 86, cert. denied, 142 
S. Ct. 408 (2021) (tripartite analysis "requires [1] an 'inquiry 
into the nature of the offense and the offender in light of the 
degree of harm to society,' [2] 'a comparison between the 
37 
 
sentence imposed here and punishments prescribed for the 
commission of more serious crimes in the Commonwealth,' and [3] 
'a comparison of the challenged penalty with the penalties 
prescribed for the same offense in other jurisdictions'"). 
 
We adopted the tripartite analysis in Jackson, 369 Mass. at 
910, and have, thus far, not confined it to individual 
proportionality challenges.  As the court recognizes, see ante 
at note 12, we have on multiple occasions used the tripartite 
analysis to evaluate categorical challenges to the 
proportionality of sentencing provisions based on the nature of 
the offense, without considering the individual circumstances of 
an offender sentenced according to those provisions.  See 
Commonwealth v. Therriault, 401 Mass. 237, 239-240 (1987) 
(challenge to one-year minimum mandatory prison term for 
homicide by motor vehicle while intoxicated); Opinions of the 
Justices, 378 Mass. at 829 (facial examination whether proposed 
"bills' mandatory sentencing provisions -- including the 
requirement that a twenty-five year mandatory sentence in State 
prison be imposed on persons found manufacturing, distributing 
dispensing, or possessing with intent to distribute, certain 
narcotics having a street value in excess of $25,000" -- were 
constitutionally disproportionate); Jackson, supra at 909 
(challenge to one-year mandatory sentence imposed for carrying 
firearm without license). 
38 
 
 
Additionally, we have used the tripartite analysis to hold 
that a sentencing practice is constitutionally disproportionate, 
at least presumptively, when applied to an entire category of 
individuals.  See Perez, 477 Mass. at 686 (concluding, based on 
application of tripartite analysis, that "a juvenile defendant's 
aggregate sentence for nonmurder offenses with parole 
eligibility exceeding that applicable to a juvenile defendant 
convicted of murder is presumptively disproportionate," and that 
only after hearing according to Miller, 567 U.S. at 479, could 
that presumption be rebutted). 
 
While, in Diatchenko I, we did not expressly state whether 
we were or were not considering the tripartite analysis, our 
conclusion was based on the considerations associated with the 
first prong of the tripartite analysis:  "the imposition of a 
sentence of life in prison without the possibility of parole for 
the commission of murder in the first degree by a juvenile under 
the age of eighteen is disproportionate not with respect to the 
offense itself, but with regard to the particular offender" 
(emphasis added).  See Diatchenko I, 466 Mass. at 669.  
Importantly, in cases where we have explicitly applied the 
tripartite analysis, we have cited this portion of our decision 
in Diatchenko I for its applicability to the first prong of the 
tripartite analysis.  See Concepcion, 487 Mass. at 88; 
Commonwealth v. LaPlante, 482 Mass. 399, 406 (2019).  See also 
39 
 
Perez, 477 Mass. at 684-685 (discussing applicability of 
Diatchenko I's reasoning to first prong of tripartite 
framework). 
 
Diatchenko I's reliance on just one prong of the tripartite 
analysis to assess proportionality is not unique.  In addition 
to Diatchenko I, we have made determinations, both in favor and 
against proportionality, by analyzing less than all three prongs 
of the tripartite test.  See Perez, 477 Mass. at 685-687 
(because sentence in that case was disproportionate under first 
two prongs of tripartite analysis, court "need not discuss the 
third prong").  See also LaPlante, 482 Mass. at 404 n.4 (where 
no "more serious crimes" to be compared with defendant's, "case 
defie[d] direct application of the second . . . prong" of 
tripartite analysis).  That all three prongs of the tripartite 
analysis do not fit neatly in every circumstance does not 
justify now abandoning its application for categorical 
challenges.11 
 
I would not discard this well-established framework, 
particularly in cases like this.  The tripartite analysis was 
adopted to cabin the "inherent subjectivity" involved in 
 
 
11 California, the jurisdiction from which we adopted the 
tripartite analysis, has applied the analysis to assess whether, 
categorically, the imposition of life without parole on 
offenders younger than sixteen convicted of kidnapping is 
disproportionate under its own State Constitution.  See In re 
Nuñez, 173 Cal. App. 4th 709, 725-731 (2006). 
40 
 
assessing proportionality.  See Opinions of the Justices, 378 
Mass. at 830.  See Harmelin, 501 U.S. at 986 ("the 
proportionality principle becomes an invitation to imposition of 
subjective values").  Where the analysis involves questions, 
such as whether a punishment "shocks the conscience," "offends 
fundamental notions of human dignity," or is in accord with 
contemporary standards of human decency, the issue of 
disproportionality is vulnerable to a subjective approach; the 
framework was developed intentionally to combat subjectivity and 
create objective criteria to guard against improper judicial 
encroachment on exclusively legislative territory.  See Opinions 
of the Justices, 378 Mass. at 830; Jackson, 369 Mass. at 910.  
See also Atkins, 536 U.S. at 312, quoting Harmelin, supra at 
1000 ("Proportionality review under those evolving standards 
should be informed by '"objective factors to the maximum 
possible extent"'"). 
 
The issue of subjectivity is central to my concern with the 
court's decision not to apply the tripartite analysis.  When we 
deviate from the objective framework developed to mitigate 
subjectivity, we risk infusing our own personal values into the 
open-ended provisions of the Constitution, which fosters 
mistrust that threatens the continued vitality of judicial 
review and an abiding respect for the judiciary.  With this in 
41 
 
mind, I would apply the doctrinal framework adopted specifically 
to guard against these concerns. 
 
a.  First prong.  Under the first prong of the tripartite 
analysis for analyzing proportionality, we consider "the nature 
of the offense and the offender in light of the degree of harm 
to society."  Jackson, 369 Mass. at 910.  The considerations of 
contemporary standards of decency, science, and precedent 
addressed supra, and addressed by the court ante, examine 
proportionality as it relates to the nature of the offender.  
These considerations, however, do not consider the nature of the 
offense in light of the harm to society, which must also take 
into account the Legislature's legitimate reasons for imposing 
such a punishment.  See Jackson, supra ("The penological 
purposes of the prescribed punishment are also relevant to this 
analysis . . ."). 
The nature of the offense of murder and the harm the crime 
inflicts on society and its victims warrant a punishment 
commensurate with the crime.  Cf. Jackson, 369 Mass. at 910.  
"Clearly the severity of the penalty, in the case of a serious 
offense, is not enough to invalidate it where the nature of the 
penalty is rationally directed to achieve the legitimate ends of 
punishment."  Id., quoting Trop v. Dulles, 356 U.S. 86, 111 
(1958) (Brennan, J., concurring).  Imposing a punishment 
commensurate with the crime "reflects society's and the victim's 
42 
 
interests in seeing that the offender is repaid for the hurt he 
caused."  Kennedy v. Louisiana, 554 U.S. 407, 442 (2008).  
"Society is entitled to impose severe sanctions . . . to express 
its condemnation of the crime and to seek restoration of the 
moral imbalance caused by the offense."  Graham, 560 U.S. at 71. 
 
The penological justifications for imposing life without 
the possibility of parole are incapacitation, deterrence, and 
retribution.  See Diatchenko I, 466 Mass. at 670-671.  Since the 
punishment the Legislature has chosen to further these goals 
neither "shocks the conscience" nor offends "contemporary 
standards of decency which mark the progress of society" 
(citations omitted), id. at 669, it is not within our authority 
to question the wisdom of this decision, so long as the sentence 
is not "so totally without penological justification that it 
results in the gratuitous infliction of suffering," Gregg, 428 
U.S. at 183.  See id. at 182-183 ("we cannot invalidate a 
category of penalties because we deem less severe penalties 
adequate to serve the ends of penology" [citation and quotation 
omitted]). 
 
b.  Second prong.  The second prong involves "a comparison 
between the sentence imposed here and punishments prescribed for 
the commission of more serious crimes in the Commonwealth."  
Sharma, 488 Mass. at 89, quoting Concepcion, 487 Mass. at 86.  
As with other cases where we have applied the tripartite 
43 
 
framework, because the crime of murder in the first degree is 
the most serious offense in the Commonwealth, and the punishment 
of life without the possibility of parole, which is imposed 
mandatorily for this crime, is the most severe punishment in the 
Commonwealth, this case "defies direct application of the second 
. . . prong" of the tripartite analysis.  LaPlante, 482 Mass. at 
404 n.4.  We turn then to the third prong. 
 
c.  Third prong.  Under the third prong of the tripartite 
analysis, we compare "the challenged penalty with the penalties 
prescribed for the same offense in other jurisdictions."  
Sharma, 488 Mass. at 89, quoting Concepcion, 487 Mass. at 86. 
 
The court cites at least ten States that currently mandate 
the imposition of life without the possibility of parole on all 
adult offenders convicted of an offense equivalent to murder in 
the first degree in the Commonwealth –- a count that does not 
include the Federal government, which also does so.  See ante at 
note 26.  One State, Michigan, mandatorily imposes life without 
the possibility of parole for offenders over the age of eighteen 
convicted of such a crime.  See People v. Parks, 510 Mich. 225, 
268 (2022).12 
 
 
12 And at least nine more States mandate a sentence of life 
without the possibility of parole for adult offenders 
adjudicated guilty of murder under certain circumstances.  The 
Michigan Supreme Court cited six such jurisdictions:  
"California, Cal. Penal Code [§] 190.2; Connecticut, Conn. Gen. 
Stat. [§§] 53a-35a and 53a-54b; Hawaii, Haw. Rev. Stat. 
44 
 
 
While not legislatively mandated, sixteen States and the 
District of Columbia authorize the imposition of life without 
the possibility of parole on adult offenders convicted of a 
crime equivalent to what the Commonwealth defines as murder in 
the first degree,13 while others authorize similarly harsh 
 
[§§] 706-656 and 706-657; Kansas, Kan. Stat. Ann. [§§] 21-6620, 
21-5401(a)(6), and 21-6617; Texas, Tex. Penal Code Ann. 
[§§] 12.31 and 12.32; and Vermont, Vt. Stat. Ann., tit. 13, 
§§ 2303 and 2311."  Parks, 510 Mich. at 263 n.16.  I also found 
the following:  New Jersey, N.J. Stat. Ann. § 2C:11-3; Oregon, 
Or. Rev. Stat. § 163.107; and Virginia, Va. Code Ann. §§ 18.2-
10, 18.2-31, 18.2-32.  Indeed, some of these States impose life 
imprisonment without the possibility of parole on less egregious 
grounds than the standard in Massachusetts of deliberate 
premeditation; extreme atrocity or cruelty; or actual malice in 
the commission or attempted commission of a crime punishable 
with life imprisonment. 
 
 
13 These jurisdictions include Georgia, Ga. Code Ann. § 16-
5-1; Indiana, Ind. Code § 35-50-2-3; Kentucky, Ky. Rev. Stat. 
Ann. §§ 507.020, 532.030; Maine, Me. Rev. Stat. tit. 17-A, 
§ 1603, § 2314; Montana, Mont. Code Ann. § 45-5-102(2); Nevada, 
Nev. Rev. Stat. § 200.030; New Mexico, N.M. Stat. Ann. §§ 30-2-
1, 31-18-14; North Dakota, N.D. Cent. Code §§ 12.1-16-01, 12.1-
32-01; Oklahoma, Okla. Stat. tit. 21, § 701.9; South Carolina, 
S.C. Code Ann. § 16-3-20; Tennessee, Tenn. Code Ann. § 39-13-
202; Vermont, Vt. Stat. Ann. tit. 13, § 2303; West Virginia, W. 
Va. Code §§ 61-2-2, 62-3-15; and Wyoming, Wyo. Stat. Ann. § 6-2-
101.  Additionally, the District of Columbia, Hawaii, and 
Illinois permit the imposition of life without parole for 
murders committed in heinous, atrocious, or cruel circumstances 
comparable to murder in the first degree in the Commonwealth 
under the theory of extreme atrocity or cruelty.  See D.C. Code 
§ 22-2104.01 (where murder was especially heinous, atrocious, or 
cruel); Haw. Rev. Stat. § 706-657 (where murder in second degree 
was especially heinous, atrocious, or cruel); 730 Ill. Comp. 
Stat. 5/5-8-1 (where "murder was accompanied by exceptionally 
brutal or heinous behavior indicative of wanton cruelty"). 
45 
 
sentences for the equivalent crime.14  Accordingly, when viewed 
in total, thirty-six jurisdictions (thirty-four States, the 
Federal government, and the District of Columbia) legislatively 
authorize the imposition of life without the possibility of 
parole for adult offenders -- including those ages eighteen, 
nineteen, and twenty -- convicted of the equivalent of murder in 
the first degree.  See Jackson, 369 Mass. at 913 (considering 
States that permit same or similar punishment, even if not 
mandated). 
 
No jurisdiction has categorically prohibited by judicial 
decision the imposition of this penalty for homicide offenders 
eighteen and older as cruel or unusual punishment.  While, as 
the court notes, Washington and Michigan have declared, under 
their own State Constitutions, that the mandatory imposition of 
life without parole on eighteen through twenty year old 
individuals (Washington) and eighteen year old individuals 
(Michigan), respectively, is unconstitutional, see Matter of the 
Personal Restraint of Monschke, 197 Wash. 2d 305, 312 (2021); 
 
 
14 For example, Alaska and New Jersey both impose a minimum 
of thirty years imprisonment without parole eligibility for 
murder in the first degree.  See Alaska Stat. § 12.55.125; N.J. 
Stat. Ann. § 2C:11-3. 
 
46 
 
Parks, 510 Mich. at 268, this hardly represents a consistent 
trend.15  See ante at    . 
 
Where the challenged penalty in this case, when imposed on 
individuals from eighteen to twenty-one, is permitted by thirty-
six jurisdictions across the country and is specifically 
mandated in eleven jurisdictions; where other jurisdictions 
impose similarly harsh penalties for similar crimes; and where 
no other jurisdiction has interpreted its Constitution as 
 
 
15 Moreover, both Michigan and Washington have 
constitutional requirements that differ from our own.  Michigan, 
for instance, permits juveniles to be sentenced to life without 
the possibility of parole following an individualized hearing.  
See People v. Taylor, 510 Mich. 112, 128 (2022).  Thus, in 
imposing such a requirement for eighteen year old offenders 
under its State Constitution, the Michigan Supreme Court looked 
to Miller for guidance, without having to wrestle with 
Diatchenko-like precedent deeming such discretionary sentencing 
unconstitutional.  See Parks, 510 Mich. at 265-266.  While the 
Washington Supreme Court has interpreted its Constitution to bar 
both the mandatory and discretionary imposition of life without 
parole for juvenile offenders, as we have, in the case in which 
that court permitted such a punishment to be imposed on eighteen 
to twenty year old offenders after an individualized hearing, 
unlike in this case, there was no argument that the punishment 
should be categorically barred as unconstitutional for that 
class of offenders.  See Matter of the Personal Restraint of 
Monschke, 197 Wash. 2d at 325.  Moreover, in making such a 
determination, the Washington Supreme Court declined to apply 
either of its constitutional tests for assessing whether a 
punishment is categorically cruel under its Constitution.  Id. 
at 312.  The court's own precedent in State v. Fain, 94 Wash. 2d 
387 (1980), and State v. Bassett, 192 Wash. 2d 67 (2018), called 
for the application of a proportionality test and a categorical 
bar analysis when considering cruelty.  The court deferred to 
neither of these controlling doctrines in making its decision.  
Matter of the Personal Restraint of Monschke, supra.  Thus, its 
constitutional analysis as it relates to this punishment for 
this class of offenders diverges significantly from our own. 
47 
 
requiring mandatory parole eligibility for adults from eighteen 
to twenty-one, the disparity between Massachusetts and others 
reflects nothing "more than different exercises of legislative 
judgment . . . a difference between unrestrained power and that 
which is exercised under the spirit of constitutional 
limitations formed to establish justice."  Jackson, 369 Mass. at 
914, quoting Weems, 217 U.S. at 381.  It does not lend itself to 
a conclusion that the imposition of life without parole on 
individuals eighteen, nineteen, and twenty years old, who have 
been convicted of murder in the first degree, violates art. 26.  
See Cepulonis, 384 Mass. at 499 (where difference between 
punishment in Massachusetts and "that prescribed in other States 
is merely one of degree[,] [i]t is not violative of art. 26 or 
of the Eighth Amendment"). 
 
Conclusion.  As the judiciary, we must proceed with extreme 
restraint when exercising our power to review punishment 
designated by the Legislature to determine whether it exceeds 
the bounds of art. 26's requirements.  Applying the analysis 
specifically established to cabin our review when assessing 
proportionality under art. 26, the punishment that the 
Legislature prescribed in this case, when applied to individuals 
from eighteen to twenty-one, is not so disproportionate to this 
class of offenders, nor the crime of murder in the first degree, 
particularly in light of the harm caused to society by murder in 
48 
 
the first degree and the Legislature's legitimate justifications 
for imposing such a punishment.  In the Commonwealth, 
individuals eighteen and older are considered adults; they 
receive the rights and consequences associated with adulthood; 
and the contemporary standards of decency, expressed through 
legislation, demonstrate support for this severe punishment for 
this most severe crime. 
 
While the scientific research concerning the brain function 
and development of eighteen through twenty-five year old 
individuals may cause the Legislature to consider raising the 
age of individuals convicted of murder in the first degree who 
are entitled to parole eligibility, where, under our 
constitutional framework, the punishment is not "so 
disproportionate" that it "shocks the conscience and offends 
fundamental notions of human dignity," Cepulonis, 384 Mass. at 
497, quoting Jackson, 369 Mass. at 910, it does not violate art. 
26's proscription against cruel or unusual punishment.  I 
respectfully dissent. 
 
 
 
CYPHER, J. (dissenting).  A significant amount of time and 
energy has been expended to prove through science what the 
Legislature knew when it promulgated its first statute 
concerning juveniles:  young males take more risks and are more 
impulsive than older males.  See R.S. (1836), c. 143, § 18 
(providing that certain children convicted of offense punishable 
by incarceration in State prison shall instead serve sentence in 
house of correction or county jail); Governor's Anti-Crime 
Council, Juvenile Code Study and Revision Project, History of 
Massachusetts Statutes Relating to Delinquent Youth 1 (July 
1985) ("[The] pattern of treating juvenile offenders [in 
Massachusetts] differently than their adult counterparts began" 
with adoption of Revised Statutes of 1836). 
Whether this court should eliminate the imposition of 
mandatory sentences of life imprisonment without the possibility 
of parole for those convicted of murder in the first degree who 
were from age eighteen to twenty at the time of the crime 
implicates many important considerations.  The most significant 
consideration for us in this case is whether the sentencing 
scheme violates art. 26 of the Massachusetts Declaration of 
Rights, the prohibition against cruel or unusual punishment.  If 
it does not violate art. 26, then we must admit that, however we 
may view life sentences without parole, for any age over 
seventeen or as mandatory sentences for any crime, we are not 
2 
 
the appropriate branch to change the sentence.  If we are to do 
so, we violate art. 30 of the Massachusetts Declaration of 
Rights, the separation of powers doctrine. 
I fully agree with the principal arguments outlined in 
Justice Lowy's dissent, ante; namely, it is the Legislature, not 
the judiciary, that prescribes punishment, Opinions of the 
Justices, 378 Mass. 822, 830 & n.7 (1979), and the Legislature's 
choice of punishment for adults convicted of murder in the first 
degree, i.e., imprisonment for life without the possibility of 
parole, is not so disproportionate to the offense as to rise to 
the level of cruel or unusual punishment under art. 26.  See 
G. L. c. 127, § 133A (parole eligibility disallowed for those 
"serving a life sentence for murder in the first degree who had 
attained the age of [eighteen] years" at time of crime); 
Diatchenko v. District Attorney for the Suffolk Dist., 466 Mass. 
655, 669 (2013) (Diatchenko I), S.C., 471 Mass. 12 (2015).  In 
addition, I agree that the tripartite analysis for 
proportionality, as adopted in Commonwealth v. Jackson, 369 
Mass. 904, 910 (1976), is the proper framework for evaluating 
categorical challenges to a sentencing scheme.  See Commonwealth 
v. Concepcion, 487 Mass. 77, 86, cert. denied, 142 S. Ct. 408 
(2021), quoting Cepulonis v. Commonwealth, 384 Mass. 495, 497-
498 (1981) (determination whether sentence is disproportionate 
to crime requires "[1] an 'inquiry into the nature of the 
3 
 
offense and the offender in light of the degree of harm to 
society,' [2] 'a comparison between the sentence imposed here 
and punishments prescribed for the commission of more serious 
crimes in the Commonwealth,' and [3] 'a comparison of the 
challenged penalty with the penalties prescribed for the same 
offense in other jurisdictions'"). 
Indeed, the virtue of the tripartite analysis is that it is 
flexible enough to accommodate "softer," offender-specific 
considerations, see Commonwealth v. Perez, 477 Mass. 677, 684-
685 (2017), S.C., 480 Mass. 562 (2018), quoting Diatchenko I, 
466 Mass. at 670 (factoring "diminished culpability and greater 
prospects for reform" of juvenile defendant into first prong of 
tripartite analysis), while offering a (mostly) objective 
framework for assessing proportionality, see Opinions of the 
Justices, 378 Mass. at 830 (tripartite test created to mitigate 
against "the inherent subjectivity" that "shocks the conscience" 
standard invariably entails).1 
 
1 In certain circumstances, one or more of the three prongs 
may be inapt.  The crime of murder in the first degree provides 
an illustrative example.  See Commonwealth v. LaPlante, 482 
Mass. 399, 404 n.4 (2019) (case involving juvenile convicted of 
multiple homicide "defies direct application of second Cepulonis 
prong" because there are no "more serious crimes to which . . . 
multiple homicide ought to be compared").  However, I view this 
"limitation" as a useful feature.  The fact that there are no 
"more serious" crimes against which to compare homicide reminds 
us that homicide uniquely is devastating among the offenses one 
member of our society can inflict on another.  See Perez, 477 
Mass. at 687, quoting Graham v. Florida, 560 U.S. 48, 69 (2010) 
4 
 
 
I write separately, however, for four reasons:  first, to 
note that the parties, in urging us to extend juvenile 
sentencing protections to a novel subset of adults, ask us to 
commandeer the job of the Legislature to fashion criminal 
punishment.  Accepting such an invitation runs afoul of bedrock 
principles of the separation of powers as articulated in art. 
30.  See Opinions of the Justices, 378 Mass. at 830 & n.7.  See 
also United States v. Davis, 139 S. Ct. 2319, 2337 (2019) 
(Kavanaugh, J., dissenting) ("when we overstep our role in the 
name of enforcing limits on [the Legislature], we do not uphold 
the separation of powers, we transgress the separation of 
powers"). 
 
Second, it is a mistaken notion that our prior decisions in 
Diatchenko I and Perez are controlling on the question of 
constitutionality because those cases involved a group of 
offenders already recognized by the Legislature and the United 
 
("[t]here is a line 'between homicide and other serious violent 
offenses against the individual'").  For the victims of 
homicide, "[l]ife is over" and nothing left remains, Coker v. 
Georgia, 433 U.S. 584, 598 (1977); for survivors, they are left 
with lifelong grief and psychological damage.  See Armour & 
Umbreit, The Ultimate Penal Sanction and "Closure" for Survivors 
of Homicide Victims, 91 Marq. L. Rev. 381, 381 (2007) ("Studies 
of family members of homicide victims found that sixty-six 
percent could not find meaning after five years").  This 
limitation of the second prong relative to homicide should be 
viewed as prophylactic, in the sense that it cautions judges 
against the contemporary impulse to lessen the consequences for 
violators of society's greatest crime. 
5 
 
States Supreme Court, Miller v. Alabama, 567 U.S. 440 (2012), as 
constitutionally set apart from other offenders.  See Diatchenko 
I, 466 Mass. at 670-671 (all sentences of life without 
possibility of parole for juvenile offenders violate art. 26).  
See also Perez, 477 Mass. at 686 (juvenile's aggregate sentence 
for nonmurder offenses prior to parole eligibility is 
"presumptively disproportionate" if it "exceed[s] that 
applicable to a juvenile . . . convicted of murder"). 
 
Third, I write to call attention to the inherent 
capriciousness of judicial line drawing; particularly where, as 
here, the court follows the neuroscience only as far as to 
extend juvenile sentencing privileges to one class of adult 
offenders, i.e., those from age eighteen to twenty at the time 
of the offense, while omitting another tranche of adults that 
the developmental science says also is deserving of protection.  
See E.S. Scott & L. Steinberg, Rethinking Juvenile Justice 208, 
238 (2008) ("studies of brain development indicate that 
continued maturation takes place until at least age twenty-five 
or so" [emphasis added]). 
Fourth and last, I write to illustrate that arbitrary 
reliance on developmental neuroscience, as proposed infra, 
raises troubling, if unintended, implications for other groups 
6 
 
exposed to our criminal laws.2  By depicting the effect that such 
application of the science might have on these groups, I hope to 
highlight the perils that can come from judges believing that 
they are following "the science," wherever it may lead. 
1.  Separation of powers.  Article 30 is unique in that it 
is more explicit than the Federal Constitution in calling for 
the separation of the powers of the three branches of 
government.  Edwards v. Commonwealth, 488 Mass. 555, 567 (2021).  
Article 30 provides: 
"In the government of this [C]ommonwealth, the legislative 
department shall never excise the executive and judicial 
powers, or either of them:  the executive shall never 
exercise the legislative and judicial powers, or either of 
them; the judicial shall never exercise the legislative and 
 
2 Specifically, the court's application of the science, as 
advanced by the parties, (1) reinforces unfair (and oftentimes 
unnecessary) distinctions between older and younger offenders; 
(2) raises serious questions about the rights of mature 
juveniles, in addition to adults from age eighteen to twenty, to 
make decisions about their health care and reproduction, see 
Maroney, The False Promise of Adolescent Brain Science in 
Juvenile Justice, 85 Notre Dame L. Rev. 89, 103-107, 118 (2009) 
(describing well-intentioned use of brain imaging studies by 
advocates to argue for reduced culpability and sanctions for 
juvenile offenders while expressing concern that this reliance 
could translate to arguments against granting autonomy to 
adolescents in other areas); and (3) dispenses with any 
expectation that our legal norms can influence the development 
of juveniles, rather than the other way around.  See Buss, What 
the Law Should (And Should Not) Learn from Child Development 
Research, 38 Hofstra L. Rev. 13, 52 (2009) (Buss, Child 
Development) (reasoning that ways in which juveniles and young 
adults "perceive their relationship with their society and their 
government . . . may matter more, for the successful functioning 
of our legal regime and the effective exercise of individual 
rights, than their acquisition of certain higher level 
capacities"). 
7 
 
executive powers, or either of them; to the end it may be a 
government of laws and not of men."3 
 
 
In recognition of art. 30, we often have insisted on the 
"scrupulous observance" of the limitations of each branch of 
government.  Edwards, 488 Mass. at 567, quoting New Bedford 
Standard-Times Publ. Co. v. Clerk of the Third Dist. Court of 
Bristol, 377 Mass. 404, 410 (1979).  The principle of judicial 
restraint that embodies art. 30 "recognizes 'the inability and 
undesirability of the judiciary substituting its notions of 
correct policy for that of a popularly elected Legislature.'"  
Joslyn v. Chang, 445 Mass. 344, 351-352 (2005), quoting Zayre 
Corp. v. Attorney Gen., 372 Mass. 423, 433 (1977). 
 
Here, through the use of labels, the court shapes the issue 
merely as invalidating an unconstitutional statute.  Ante 
at    .  In substance, however, the court circumvents the 
Legislature's power and substitutes its own notions of correct 
 
3 In contrast, the Federal Constitution states:  "All 
legislative Powers herein granted shall be vested in a Congress 
of the United States, which shall consist of a Senate and House 
of Representatives."  Art. I, § 1, of the United States 
Constitution.  It also vests the judicial power of the United 
States "in one [S]upreme Court, and in such inferior Courts as 
the Congress may from time to time ordain and establish."  Art. 
III, § 1, of the United States Constitution.  The doctrine of 
the separation of powers long has been recognized by Federal 
law.  See K.J. v. Superintendent of Bridgewater State Hosp., 488 
Mass. 362, 367 (2021).  However, unlike art. 30 of the 
Massachusetts Declaration of Rights, the Federal Constitution 
does not call explicitly for the separation of powers among the 
three branches of government.  See Gray v. Commissioner of 
Revenue, 422 Mass. 666, 671 n.5 (1996). 
8 
 
policy based on the parties' submission of ever-changing 
neuroscience.  See Joslyn, 445 Mass. at 351-352. 
In drawing hard lines between juveniles and "emerging 
adults,"4 and older adult offenders, the court points to 
instances in which the Legislature has opted not to treat 
individuals from ages eighteen through twenty-one in the same 
manner that it does adults.  Ante at    .  For example, those 
who are age eighteen may serve on a jury and vote.  See G. L. 
c. 234A, § 4 (right to serve on jury); G. L. c. 51, § 1 (right 
to vote).  But they may not gamble or purchase alcohol or 
tobacco.  See G. L. c. 23K, §§ 25 (h), 43 (right to gamble); 
G. L. c. 138, § 34 (right to purchase alcohol); G. L. c. 270, 
§ 6 (right to purchase tobacco). 
While there are instances in which individuals from age 
eighteen to twenty-one are treated differently under the law 
from individuals over age twenty-one, where such a distinction 
has been made, it has been made through legislative action, 
i.e., the enactment of a statute.  See, e.g., G. L. c. 23K, § 43 
(must be age twenty-one to gamble in Commonwealth gaming 
establishment); G. L. c. 138, § 34 (must be age twenty-one to 
purchase, deliver, or sell alcohol); G. L. c. 270, § 6 (must be 
 
4 As styled by the court and the parties, "emerging adults" 
is defined as someone aged eighteen or older, but under age 
twenty-one. 
9 
 
age twenty-one to purchase tobacco).5  Neither the parties, nor 
the court, have pointed to a single instance in which the 
judiciary has taken it on itself to make such a distinction 
between individuals in the newly minted "emerging adult" 
category and adults, as it seeks to do here.6  That the court and 
 
5 In his concurrence, Justice Kafker invokes these "21+" 
statutes to suggest that the Legislature has, effectively, set 
aside "emerging adults" as a distinct legal subclass deserving 
of protection.  See ante at note 9 (Kafker, J., concurring) ("I 
consider the Legislature's recognition of the need for 
differential treatment of those eighteen to twenty in a variety 
of other contexts when the legal rights in question implicate 
the same distinctive characteristic at issue in this case to be 
an important component of the analysis").  I reject that 
inference, at least as it relates to sentencing for violent 
crime.  If the Legislature wishes to refine the age of majority 
for sentencing young adults who have committed murder, as it has 
done for entitlement to common vices, professional licensure, 
etc., then it certainly knows how to do so. 
 
6 Justice Kafker points to the Supreme Court's decision in 
Thompson v. Oklahoma, 487 U.S. 815, 838 (1988) (Eighth and 
Fourteenth Amendments to United States Constitution prohibit 
death penalty for defendants convicted of murder in first degree 
committed while under age sixteen), as precedent for the use of 
judicial fiat to extend protections to a novel subset of 
individuals, based solely on age, sans any existing basis in 
statute or code to do so.  See ante at note 7 (Kafker, J., 
concurring) (starting with Thompson, supra, evolution of Federal 
juvenile death penalty jurisprudence "involved judicial line 
drawing based on age without reliance on a clearly legislatively 
defined age group").  This reliance ignores, I think, two facts:  
first, that the Supreme Court in Thompson, like the court today, 
expressly drew its "line" to match the age of the appellant at 
the time he committed the crime.  See Thompson, supra 
("Petitioner's counsel . . . have asked us to 'draw a line' that 
would prohibit the execution of any person who was under the age 
of [eighteen] at the time of the offense.  Our task today, 
however, is to decide the case before us . . .").  Second, it 
ignores those Federal statutes and codes in place at the time of 
the Thompson decision that placed fifteen year olds firmly 
10 
 
the parties can point only to legislative action to support 
their creation of this "emerging adult" category7 furthers the 
position that the drawing of this line is best left to the 
popularly elected Legislature.  See Zayre Corp., 372 Mass. at 
443-444 (while statute may contain faults, those statutory 
 
within the category of "juvenile," as defined by Congress.  See, 
e.g., id. at 851-852 (O'Connor, J., concurring in judgment) 
(noting that bill recently passed by United States Senate 
authorizing capital punishment for certain drug offenses, 134 
Cong. Rec. 14117, 14118 [1988], "prohibit[ed] application of 
[death] penalty to persons below the age of [eighteen] at the 
time of the crime"); Juvenile Justice and Delinquency Prevention 
Act of 1974, Pub. L. No. 93-415, 88 Stat. 1109, 1133 (1974) 
(operative Federal statute concerning juvenile justice at time 
of Thompson decision defined "juvenile" as "a person who has not 
attained his eighteenth birthday"). 
 
7 Such "action" extends to the Legislature's creation of the 
Legislative Task Force on Emerging Adults in the Criminal 
Justice System (task force) in 2018.  See ante at note 22; St. 
2018, c. 69, § 221.  In its report, the task force concluded 
that "[e]merging adults . . . in the criminal justice system are 
a unique population that requires developmentally-tailored 
programming and services."  Emerging Adults in the Massachusetts 
Criminal Justice System:  Report of the Task Force on Emerging 
Adults in the Criminal Justice System (Feb. 26, 2020), 2020 
Senate Doc. No. 2840, at 6 (Report of the Task Force).  However, 
as noted by Justice Lowy, ante, any attempt to derive 
contemporary standards of decency concerning mandatory life 
sentences for young adults from the proposals authored by the 
task force is misplaced, because the task force (i) defined 
"emerging adults" as individuals from age eighteen to twenty-
four, and (ii) excluded the crime of murder from its proposed 
carceral reforms.  See ante at    ; Report of the Task Force, 
supra at 10.  Further, if the conclusion of the task force is 
that the young adult prison population requires developmentally 
tailored programming and services, this court is powerless to 
implement such reforms, along with its reformulation of parole 
eligibility for adults from age eighteen to twenty convicted of 
murder. 
11 
 
faults that fail to rise to equivalent of constitutional 
infirmity are better left for Legislature to resolve). 
The proper exercise of judicial restraint and 
acknowledgment of the bedrock principle of separation of powers 
found in art. 30 may lead, at times, to results that feel 
difficult.  See Commonwealth v. Baez, 480 Mass. 328, 332 (2018) 
(no violation of art. 26 where Legislature's statutory scheme 
allowed even predicate offenses that were committed when 
defendant was under age eighteen to count toward enhanced 
mandatory minimum sentences under Armed Career Criminal Act).  
See also Commonwealth v. Guzman, 469 Mass. 492, 498 n.9 (2014) 
(Legislature's decisions to limit discretion of sentencing 
judges by imposition of mandatory minimum sentences does not 
derogate separation of powers); Commonwealth v. Smith, 431 Mass. 
417, 417-420 (2000) (art. 30 compelled dismissal of indictment 
for two counts of incest, pursuant to G. L. c. 272, § 17, based 
on defendant's molestation of his daughter and forcing her to 
perform oral sex on him, because such conduct did not constitute 
"sexual intercourse" as defined by Legislature's specific choice 
of words in statute). 
Here, although much is made of neuroscience, and the fact 
that this group of "emerging adults" lacks maturity and 
responsibility, such that they are prone to risk taking and 
negative influence from their peers, the science alone, 
12 
 
accompanied with the Justices' personal and moral beliefs, is 
not enough to take this decision away from the Legislature.  
Novel discoveries about how certain areas of the brain may 
function does not explain "why" and "how" we make the decisions 
we make.  The human exercise of free will is the foundation of 
our criminal law; it is not reducible to magnetic resonance 
imaging (MRI) scans.  But, if it is so reducible, then that is 
something over which the citizens and their representatives 
should engage in vigorous debate.  The capacity for change and 
reform for the individuals that fit in this "emerging adult" 
category also does not tip the scale, as it is difficult to 
conclude that any human being is incapable of change and reform, 
regardless of his or her age.  See Commonwealth v. O'Neal, 369 
Mass. 242, 273 (1975) (Tauro, C.J., concurring) ("The great 
responsibility of a judge is to exercise his [or her] best 
judgment in applying his [or her] interpretation of the law to 
the facts.  No judge should ever be concerned with whether his 
[or her] decision will be popular or unpopular. . . .  
[P]olitical considerations of the day, contemporary public 
emotions [no matter what their motivation], and personal 
philosophies are completely foreign and irrelevant to the 
exercise of [a judge's] judicial power.  This is the very 
essence of judicial duty -- no less should be given and no more 
should be required"). 
13 
 
Therefore, where contemporary personal and moral beliefs 
may lend themselves toward the opposite result, the express 
limitations placed on the judiciary under art. 30 constrain us 
from making the determination that abolition of sentences of 
life without the possibility of parole for individuals from age 
eighteen to twenty-one in this "emerging adult" category is 
appropriate.  See Baez, 480 Mass. at 332-333 (Gants, C.J., 
concurring) (acknowledging Legislature's power to impose 
mandatory minimum sentences, while also encouraging Legislature 
to reconsider wisdom and fairness of statutory scheme that 
allows predicate offenses, committed when defendant was 
juvenile, to count toward enhanced mandatory minimum sentences 
under Armed Career Criminal Act).  While scrupulous observation 
of these limitations sometimes may be difficult, the 
constitutional principle of the separation of powers among the 
branches is too fundamental to our form of government to be 
disregarded on a case-by-case basis.  See Opinion of the 
Justices, 365 Mass. 639, 640-641 (1974). 
2.  Diatchenko I and Perez do not control the issue 
presented.  In addition to our long-standing jurisprudence under 
art. 30, which mandates the separation of powers in instances 
such as this, it is necessary to write separately to emphasize 
that neither Diatchenko I nor Perez binds us in any manner on 
the constitutionality of the punishment in question. 
14 
 
As already outlined extensively and carefully in Justice 
Lowy's dissenting opinion, ante, our holding in Diatchenko I, 
466 Mass. at 658, was limited expressly to "individuals who were 
under the age of eighteen when they committed the crime of 
murder in the first degree."  The Legislature already had 
determined which individuals were juveniles.  In Diatchenko I, 
we concluded that mandatory sentences of life without parole for 
juvenile offenders were disproportionate under art. 26.  Id. at 
658-659.  Importantly, we limited our proportionality analysis 
only to juvenile offenders, i.e., those "defendants who were 
under the age of eighteen at the time they committed murder in 
the first degree," because juvenile offenders constituted a 
group of individuals already extensively recognized by the 
Legislature as a group in need of protections different from 
those afforded to the average offender.  See id. at 658 n.8, 
citing G. L. c. 119, § 72B.  See also G. L. c. 119, §§ 52-74 
(delinquency determination and procedures set forth by 
Legislature).  In Diatchenko I, we used neuroscience, social 
science, and contemporary standards of social norms, as did the 
Supreme Court in Miller, 567 U.S. 440, to operate within those 
already-defined age parameters created by the Legislature and 
held that the continued practice of sentencing juvenile 
offenders to life without the possibility of parole for murder 
15 
 
in the first degree violated the protections of art. 26.  
Diatchenko I, supra at 660, citing Miller, supra at 471. 
The same is true for our decision in Perez.  In Perez, 477 
Mass. at 679, we held "that where a juvenile is sentenced for a 
nonmurder offense or offenses, and the aggregate time to be 
served prior to parole eligibility exceeds that applicable to a 
juvenile convicted of murder, the sentence cannot be reconciled 
with art. 26 unless, after a hearing on the factors articulated 
in Miller[, 567 U.S. at 477-478], the judge makes a finding that 
the circumstances warrant treating the juvenile more harshly for 
parole purposes than a juvenile convicted of murder" (emphasis 
added). 
The decision in Perez came on the heels of our decision in 
Diatchenko I, 466 Mass. 655, and involved juvenile offenders 
convicted of crimes not punishable by life without the 
possibility of parole who were faced with sentences that 
provided for time to be served prior to parole eligibility that 
exceeded the time applicable to juveniles convicted of murder in 
the first degree.  Perez, 477 Mass. at 677-679.  In conducting a 
proportionality analysis under art. 26, we acknowledged what we 
already previously had accepted in Diatchenko I, and what the 
Supreme Court already had accepted in Miller, i.e., that 
"children are constitutionally different from adults for [the] 
16 
 
purposes of sentencing."  See Perez, supra at 683, quoting 
Miller, 567 U.S. at 471. 
We reiterated that "the 'unique characteristics of juvenile 
offenders' should weigh more heavily in the [art. 26] 
proportionality calculus" (emphasis added).  Perez, 477 Mass. at 
683, quoting Diatchenko I, 466 Mass. at 671.  Such 
characteristics included diminished culpability and greater 
prospects for reform.  See Perez, supra at 684.  Despite our 
recognition in Perez of the neuroscience that we previously 
acknowledged in Diatchenko I, our holding in Perez operated 
entirely within an already-defined binary set by the 
Legislature, i.e., juvenile offenders and nonjuvenile offenders.  
Thus, as with Diatchenko I, it is necessary to emphasize that 
Perez also does not control the issue presented because it, too, 
involved the category of juvenile offenders, for whom the 
Legislature had provided extensive procedures and protections, 
see G. L. c. 119, §§ 52-74, as opposed to the "emerging adult" 
category of individuals about whom the Legislature has spoken 
very little. 
3.  Arbitrary line drawing.  The court uproots the 
legislatively drawn age at which an offender may be sentenced to 
life without the possibility of parole for murder in the first 
degree.  See G. L. c. 127, § 133A.  Perhaps nothing speaks 
louder to the flaws in the court's reasoning, however, than 
17 
 
having crafted a line that ends at age twenty-one, thereby 
engaging in legislative line drawing inconsistent with the 
science on which it relies.  See Icenogle et al., Adolescents' 
Cognitive Capacity Reaches Adult Levels Prior to Their 
Psychosocial Maturity:  Evidence for a "Maturity Gap" in a 
Multinational, Cross-Sectional Sample, 43 Law & Hum. Behav. 69, 
70 (2019) (neuroscientific evidence indicating that brain 
development, and concomitant ability to self-regulate, continues 
to develop during early twenties); Steinberg, A Social 
Neuroscience Perspective on Adolescent Risk-Taking, 28 
Developmental Rev. 78, 83 (2008) (self-regulatory competence for 
young adults "occurs gradually and is not complete until the 
mid-[twenties]"); Steinberg, The Influence of Neuroscience on 
U.S. Supreme Court Decisions about Adolescents' Criminal 
Culpability, 14 Nature Revs. Neurosci. 513, 515-516 (2013) 
(individuals "in their early [twenties]" more likely than older 
adults to engage in "risky behaviour;" seek "novel" and 
18 
 
rewarding "sensation[s];" and possess "low" "impulse 
control").8,9 
 
By not holding to the line drawn by the Legislature, i.e., 
eighteen, or the line drawn roughly by contemporary 
neuroscience, i.e., twenty-five, the "[court]'s holding simply 
replaces [one] unfairness with another."  People v. Parks, 510 
Mich. 225, 287 (2022) (Clement, J., dissenting).  Defendants who 
are age twenty years and 364 days at the time of their crime 
would be afforded the possibility of parole; defendants who are 
 
8 See also United States v. Gall, 374 F. Supp. 2d 758, 762 
n.2 (S.D. Iowa 2005), rev'd, 446 F.3d 884 (8th Cir. 2006), 
rev'd, 552 U.S. 38 (2007) ("Recent studies on the development of 
the human brain conclude that human brain development may not 
become complete until the age of twenty-five"); Brain Immaturity 
Could Explain Teen Crash Rate, Wash. Post, Feb. 1, 2005 (recent 
National Institutes of Health study suggested "that the region 
of the brain that inhibits risky behavior is not fully formed 
until age [twenty-five]"). 
 
9 Or, put differently, the court is unwilling to follow the 
scientific consensus as to the age at which impulsivity, self-
regulation in an emotionally aroused state, sensation seeking, 
and brain plasticity all calcify for the purposes of criminal 
culpability.  But see Buss, Child Development, 38 Hofstra L. 
Rev. at 46 ("in the end, culpability is necessarily a legal 
judgment, not a psychological one, so the suggestion that 
developmental findings determine culpability is just 
misleading"); Fuchs & Flügge, Adult Neuroplasticity:  More Than 
40 Years of Research, Neural Plasticity, May 4, 2014, at 1-2 
(factors such as stress, adrenal and gonadal hormones, 
neurotransmitters, growth factors, certain drugs, environmental 
stimulation, learning, and aging change neuronal structures and 
functions of adult brains and may induce generation of new 
neurons, i.e., neurogenesis).  This fails to reckon with the 
naked fact that our most sacred and profane choices often emerge 
from the depths of the psyche, something neuroscience has not 
yet been able to map. 
19 
 
one day older would have no such opportunity.  The court 
"readily admits that the science does not support that dividing 
line either."10  Id.  See ante at     ,    . 
 
Imposed by judicial fiat, twenty-one minus a day is not 
tethered to hard science, nor is it joined to "contemporary 
standards of decency" as reflected in our criminal statutes.  
Good v. Commissioner of Correction, 417 Mass. 329, 335 (1994).  
There appears to be no clear limiting principle,11 and as a 
result, we soon would see claims arguing that we should extend 
Diatchenko I protections to those aged twenty-one years (or 
older) at the time of their crime.  After all, if the science 
 
10 The science also does not conclude that female offenders 
suffer the same alleged inability to control themselves.  
Following the court's reasoning, girls and women should be 
treated more harshly.  For a full discussion of this point, see 
note 24, infra. 
 
11 The court offers no material justification for limiting 
the category of "emerging adults" to those from age eighteen to 
twenty other than that that is the range requested by the 
defendant when his case was paired with Commonwealth v. 
Robinson, 493 Mass.     (2023).  Tellingly, prior to the two 
cases being joined, the defendant urged twenty-two as the 
appropriate age cap.  While the judge's factual findings were 
limited to individuals aged eighteen through twenty at the time 
of commission, much of the scientific expert testimony and 
studies supporting those findings included individuals twenty-
one years of age (and in some instances older) as it relates to 
salient categories of neurocognitive development, e.g., "Many of 
Dr. Galvan's studies included [twenty-one year olds] in the 
group of 'late adolescents' who were studied"; "for purposes of 
assessing the constitutionality of mandatory life-without-parole 
sentences, the brain science relied upon by the Court lends some 
support for treating [eighteen] through [twenty-one year olds] 
differently than older persons." 
20 
 
says that individuals at age twenty-one have all the same 
psychosocial limitations as those age seventeen, then, according 
to the court's reasoning, the mandatory imposition of life 
without the possibility of parole also must be unconstitutional 
as applied to a twenty-one year old.  Such are the consequences 
when an appellate court invokes science selectively to achieve a 
policy outcome while "ignor[ing] the possibility that the age of 
majority is based less on scientific exactitude, and more on 
'society's judgments about maturity and responsibility.'"  
Matter of the Personal Restraint of Monschke, 197 Wash. 2d 305, 
332 (2021) (Owens, J., dissenting), quoting Davis v. Department 
of Licensing, 137 Wash. 2d 957, 974 (1999). 
 
Cognizant that any line drawn by the court in this matter 
would be, by definition, "both overinclusive and 
underinclusive," the remedy proposed by the parties simply is 
overbroad.  Parks, 510 Mich. at 275 (Bernstein, J., concurring), 
citing Roper v. Simmons, 543 U.S. 551 (2005).  Until today, no 
court in the country has imposed a blanket prohibition on 
nondiscretionary sentences of life without parole for adults 
over age eighteen but under age twenty-one who have been 
convicted of murder.  See Parks, supra at 244-245 (requiring 
trial judge to conduct individualized sentencing hearing for 
convicted murderers who killed while they were eighteen years of 
age prior to imposing life sentence); Matter of the Personal 
21 
 
Restraint of Monschke, 197 Wash. 2d at 324-325 (same, but 
includes those from ages nineteen to twenty).  When we are 
called on to remedy "constitutional infirmity,"12 be it in a 
statute, procedural practice, or rule, the principles of 
judicial restraint mandate that we dispassionately remove the 
offending part while leaving the nonoffending whole as intact as 
possible, as a surgeon would.  Zayre Corp., 372 Mass. at 444.  
See Ramirez v. Commonwealth, 479 Mass. 331, 338 (2018), quoting 
Ayotte v. Planned Parenthood of N. New England, 546 U.S. 320, 
329 (2006) (in "confronting a constitutional flaw in a statute, 
. . . a court 'should try not to nullify more of a legislature's 
work than is necessary'").  See, e.g., Herrmann v. Attorney 
Gen., 492 Mass. 51, 59 (2023); Planned Parenthood League of 
Mass., Inc. v. Attorney Gen., 424 Mass. 586, 603 (1997) (Lynch, 
J., dissenting) ("striking down a statute as unconstitutional is 
a dramatic exercise of judicial power to be used sparingly").  
That the defendant barely entertains individualized sentencing 
hearings as a less drastic remedy demonstrates that he is in 
 
12 In this case, the alleged infirmity is that portion of 
G. L. c. 265, § 2, as amended through St. 1982, c. 554, § 3, 
that sets forth the penalty for murder in the first degree and 
distinguishes between the penalties for adults and juveniles.   
See Commonwealth v. Watt, 484 Mass. 742, 754-756 (2020).  Also 
affected is that portion of the parole statute, G. L. c. 127, 
§ 133A, that denies parole to those from age eighteen to twenty. 
22 
 
search of a movement court.13,14  We would be wise to reject his 
invitation. 
 
13 I am not suggesting that this court should, in lieu of a 
blanket ban on the sentence, require that judges conduct an 
individualized hearing before imposing life without the 
possibility of parole for adults from ages eighteen through 
twenty convicted of murder in the first degree.  Both outcomes, 
as discussed supra, wrest power impermissibly from the 
Legislature.  I do, however, respect that other appellate 
courts, contemplating the same alleged violation of their 
respective constitutions, trust their trial judges to weigh the 
developmental neuroscience and make the correct call.  See 
Parks, 510 Mich. at 244 ("Michigan Constitution requires that 
[young adults] convicted of first-degree murder receive the same 
individualized sentencing procedure . . . as juveniles who have 
committed first-degree murder"); Matter of the Personal 
Restraint of Monschke, 197 Wash. 2d at 311 (State constitutional 
bar against "cruel punishment" requires "courts to exercise 
complete discretion to consider mitigating circumstances 
associated with the youth of any juvenile defendant, even when 
faced with mandatory statutory language" [citation and quotation 
omitted]).  See, e.g., United States v. Gonzalez, 981 F.3d 11, 
22 (1st Cir. 2020), cert. denied, 141 S. Ct. 1710 (2021) 
(Miller, 567 U.S. at 480, stands for proposition that "so long 
as the defendant's youth is taken account in the sentencing 
process, a sentencer's ability to impose a life-without-parole 
sentence is not foreclosed" [citation, quotations, and 
alterations omitted]). 
 
14 Subject to the rules of evidence, there is nothing that 
prevents the defense from offering the above research on 
neurodevelopmental science to the jury at trial.  Indeed, in a 
murder trial, it is the job of the "jurors [to] find the facts, 
including those facts or issues on which they hear psychiatric 
testimony," such as the defendant's mental capacity at the time 
of the killing or whether he lacked the criminal responsibility 
for murder.  Commonwealth v. Gould, 380 Mass. 672, 679 (1980).  
See Commonwealth v. Muller, 477 Mass. 415, 431 (2017) 
(Commonwealth must prove criminal responsibility beyond 
reasonable doubt); Commonwealth v. Oliveira, 445 Mass. 837, 848-
849 (2006) ("reduced mental capacity is relevant to the jury's 
exercise of their broad discretion as a reflection of the 
community's conscience").  Given that the research relied on by 
the court raises concomitant issues of control, agency, and 
23 
 
 
One additional point -- the age-crime curve is one of the 
most well-known graphs in criminology.  It shows, in relevant 
part, that the male "rate of offending by age rises in 
midadolescence, peaks in the later teen years,"15 and begins 
dropping precipitously "around age twenty," and "[b]y the 
midtwenties, the rate of offending for most crimes is much 
lower" (footnotes omitted).  Buss, Kids Are Not So Different:  
The Path from Juvenile Exceptionalism to Prison Abolition, 89 U. 
Chi. L. Rev. 843, 879-880 (2022) (Buss, Juvenile 
Exceptionalism).  Put another way, the age-crime curve 
demonstrates that most offenders stop offending somewhere from 
 
culpability, it is perfectly reasonable to put such research 
before the collective wisdom of the jury to consider in 
determining whether to render a verdict of murder in the first 
or second degree, manslaughter, or not guilty.  See Commonwealth 
v. Philyaw, 55 Mass. App. Ct. 730, 737 (2002), quoting United 
States v. McKinney, 429 F.2d 1019, 1023 (5th Cir.), modified on 
rehearing, 434 F.2d 831 (1970), cert. denied, 401 U.S. 922 
(1971) (jury may "leaven [their] deliberations with [their] 
wisdom and experience" so long as jury do not "bring extra facts 
into the jury room"). 
 
15 It is well known, and not controversial to state, that 
males commit much more crime than females.  See Federal Bureau 
of Investigation, Criminal Justice Information Services 
Division, 2019 Crime in the United States, https://ucr.fbi.gov 
/crime-in-the-u.s/2019/crime-in-the-u.s.-2019/tables/table-
42/table-42.xls [https://perma.cc/HA49-KT7W] (in 2019, men 
accounted for ninety-seven percent of persons arrested for 
murder, ninety-three percent of persons arrest for sex offenses, 
eighty-eight percent of persons arrested for murder and 
nonnegligent manslaughter, seventy-nine percent of persons 
arrested for other violent crimes, and sixty-two percent of 
persons arrested for property crimes). 
24 
 
age eighteen to twenty-five.  See id. at 880; Farrington, 
Loeber, & Howell, Young Adult Offenders:  The Need for More 
Effective Legislative Options and Justice Processing, 11 
Criminology & Pub. Pol'y 729, 734-735 (2012) ("highest 
concentration of desistance takes place during early adulthood 
irrespective of age of [first crime]"). 
There are many theories regarding why criminal desistance 
occurs in early adulthood.  Social scientists, however, 
generally accept that youthful offenders stop offending 
primarily because they have attained full psychosocial maturity 
and have begun to assume adult roles.  Buss, Juvenile 
Exceptionalism, 89 U. Chi. L. Rev. at 880.  If the court is to 
take the drastic step of departing from the statutory age of 
majority in favor of following the purported science, then it 
should at least be bold enough to follow the science whole 
cloth.  In a typically developing individual in our culture, 
"[b]rain and behavioral maturation continues . . . until roughly 
[age] twenty-five"; therefore, extending the protections of 
Diatchenko I to this age at least would "be consistent with the 
[c]ourt's developmental logic."  Id. at 881.  That the court 
presses no further than age twenty reflects two things:  
justified unease with extending youthful offender protections to 
what will be, for most violent criminals, the lifespan of their 
25 
 
criminal careers;16 and more important, tacit recognition that it 
should be "up to the Legislature to balance the science with 
society's penological goals."  Parks, 510 Mich. at 299 (Clement, 
J., dissenting).  See Gregg v. Georgia, 428 U.S. 153, 174–175 
(1976) ("while [appellate courts] have an obligation to insure 
that constitutional bounds are not overreached, we may not act 
as judges as we might as legislators"); Jackson, 369 Mass. at 
909, quoting Weems v. United States, 217 U.S. 349, 379 (1910) 
(basic functions of Legislature, such as proscribing punishment, 
"not to be interfered with lightly, nor by any judicial 
conception of their wisdom or propriety"). 
4.  Unintended consequences.  In arguing that art. 26 
forbids the imposition of a sentence of life without parole for 
adults from ages eighteen through twenty, the court and the 
defendant rely heavily on four core factual findings made by the 
judge, namely, that young adults, in relation to their older 
peers, (i) demonstrate less impulse control; (ii) are more prone 
to risk taking in pursuit of rewards; (iii) are more susceptible 
to peer influence; and (iv) have greater capacity for change 
 
16 See Garrett, Seal-Carlisle, Modjadidi, & Renbeg, Life 
Without Parole Sentencing in North Carolina, 99 N.C. L. Rev. 
279, 286 (2021) (data associated with commission of crime 
reveals high correlation between criminality and age, "with 
[twenty-five] years of age considered the peak of one's criminal 
career"). 
26 
 
owing to the plasticity of their brains.17  See ante at    .  The 
fourth finding has immense import; it is young adults' 
neuroplasticity that warranted the extension of Diatchenko I and 
ruled out individualized sentencing hearings.  See ante 
at     (Kafker, J., concurring).  See also Diatchenko I, 466 
Mass. at 670, citing Graham v. Florida, 560 U.S. 48, 68 (2010) 
("Simply put, because the brain of [an 'emerging adult'] is not 
fully developed, either structurally or functionally, by the age 
of [twenty-one], a judge cannot find with confidence that a 
particular offender, at that point in time, is irretrievably 
depraved"). 
 
17 The novel technology relied on by the court and the 
parties (e.g., structural MRIs [sMRIs] and functional MRIs 
[fMRIs]) may explain why young men possess a greater biological 
proclivity to commit violent crimes.  I note, however, that 
scant research exists on the effect that committing violent 
crimes -- murder, in particular -- has on brain development in 
juveniles and young adults.  Most of the research on murder and 
the young brain either (i) focuses causally on the decision to 
kill, see Cope et al., Abnormal Brain Structure in Youth Who 
Commit Homicide, Neuroimage:  Clinical, vol. 4, 2014, at 800-801 
(MRI data comparing adolescent homicide offenders to 
incarcerated adolescents who did not commit homicide showed 
reduced gray matter volumes in medial and lateral temporal lobes 
in adult offenders); or (ii) traces the parts of the brain most 
active during the act of killing, see Molenberghs et al., The 
Neural Correlates of Justified and Unjustified Killing:  An fMRI 
Study, 10 Soc. Cognitive & Affective Neurosci. 1397, 1397 (2015) 
(activation found in lateral orbitofrontal cortex during 
simulation where participants were made to watch first-person 
perspective animated video recordings in which they imagined 
themselves to be shooting innocent civilians). 
27 
 
 
I accept, as I must unless they clearly are erroneous, the 
judge's factual findings relating to neurocognitive development 
in young adults.  Moreover, while I disagree with the result 
reached by the court, I accept that it engaged in a good-faith 
proportionality analysis in relation to the science and social 
science credited at hearing.  See, e.g., Diatchenko I, 466 Mass. 
at 660-661, 669 (art. 26 proportionality analysis requires court 
to consider science, social science, contemporary standards of 
decency, law of other States, and "common sense").18  Having said 
that, I believe the court's application of the neuroscience to 
eighteen through twenty year olds, particularly as it relates to 
brain plasticity, is short-sighted and has corresponding 
implications for populations that the court did not consider, 
 
18 Arguably, Diatchenko I also violates art. 30.  By 
removing the judge's ability to weigh particularly heinous 
factors in capital cases, the court went much further, 
unnecessarily so, than the Supreme Court required in Miller.  
See, e.g., Commonwealth v. O'Brien, 432 Mass. 578, 592 (2000) 
(juvenile tried as adult sentenced to life without parole in 
connection with murder of mother of close friend, who was 
stabbed ninety-eight times); Commonwealth v. Berry, 420 Mass. 
95, 114 (1995) (life sentence affirmed for juvenile convicted of 
breaking into apartment and murdering eighty-seven year old 
widow with butcher knife in her sleep); Commonwealth v. 
LaPlante, 416 Mass. 433, 444 (1993), S.C., 482 Mass. 399 (2019) 
(life sentence affirmed for juvenile convicted of raping and 
killing pregnant mother and drowning her two children). 
28 
 
i.e., older adult offenders,19 mature minors,20 and at-risk 
juveniles.  I address each group in turn. 
a.  Older offenders.  The goals of sentencing a convicted 
criminal to a term of confinement include "punishment, 
deterrence, incapacitation, and rehabilitation."  Commonwealth 
v. McIntyre, 436 Mass. 829, 833 (2002), citing Commonwealth v. 
Power, 420 Mass. 410, 414 (1995), cert. denied, 516 U.S. 1042 
(1996).  When judges impose sentences, they strive "to penalize 
offenders in such a way that they understand the reasonableness 
of the punishment, 'free of any legitimate hatred for the system 
that punished [them], and without the unnecessary venom we 
generate by excessive [punishment].'"  McIntyre, supra at 834, 
quoting Nygaard, On the Philosophy of Sentencing:  Or, Why 
Punish?, 5 Widener J. Pub. L. 237, 266 (1996). 
As noted supra, the court relies heavily on research on 
brain plasticity, and its persistence into an individual's 
twenties, to hold that a sentence of mandatory life without 
parole for adults from ages eighteen through twenty violates 
art. 26.  See Diatchenko I, 466 Mass. at 669.  Properly framed, 
however, their principal reason for concluding that eighteen 
through twenty year olds deserve better treatment at sentencing 
 
19 I.e., those offenders ages twenty-five and older at the 
time of their crime (older offenders). 
 
20 Females, in particular. 
29 
 
"is also, by implication, an account of why [older] adults [do 
not]."  Buss, Juvenile Exceptionalism, 89 U. Chi. L. Rev. at 
882. 
Invoking the science of neuroplasticity to extend 
Diatchenko I protections to "emerging adults" signals that older 
offenders, sapped of their neurological capacity for change, are 
incarcerated primarily for punishment and societal deterrence.  
By contrast, the jailing of offenders who are from ages eighteen 
to twenty or juveniles at the time of their crimes, whose brains 
have yet to calcify, sounds squarely in rehabilitation.21  See 
Buss, Juvenile Exceptionalism, 89 U. Chi. L. Rev. at 883 
(concern that "[t]he more that special qualities and treatment 
are identified and justified for [an] exceptionalist group 
[i.e., "emerging adults" and juvenile offenders], the more the 
unexceptional group [i.e., older offenders] is defined by their 
lack of these qualities and their disqualification from special 
treatment").  This dichotomy entrenches needlessly the 
distinctions between older offenders, on one end, and juveniles 
and young adults, on the other.  Worse still, it may be 
considered biological fatalism that is plainly at odds with the 
data on recidivism, which shows that juvenile prisoners, once 
 
21 This necessarily raises ethical questions about whether 
society can claim rehabilitation as a justification for jailing 
any criminal beyond age twenty-five. 
30 
 
released, reoffend at a rate higher than their adult peers.  See 
K. Wade et al., Wisconsin Legislative Audit Bureau, Report 08-3, 
A Review:  17-Year-Old Offenders in the Adult Criminal Justice 
System, Department of Correction, at 7 (Feb. 2008) (seventeen 
year old offenders subject to adult jurisdiction were 
reincarcerated more often than adult offenders); Woolard et al., 
Juveniles within Adult Correctional Settings:  Legal Pathways 
and Developmental Considerations, Int'l J. Forensic Mental 
Health, vol. 4, 2005, at 7 (compilation of statistics from 
fifteen States indicate that juveniles released from State 
prisons are rearrested at rate sixteen percent higher than adult 
counterparts).  Moreover, I conclude that such fatalism toward 
adult offenders contradicts a central precept of our criminal 
justice system:  that we are not only our worst act and, 
consequently, every offender has the capacity to change 
regardless of the age at which he or she offended.22 
 
22 Arguably, deterrence and public protection are important 
sentencing considerations, as they are necessary for a stable, 
peaceful society.  It may be impossible to know whether a person 
has changed; thus, I would not second-guess the Legislature's 
policy choices in this area.  There may be a point, however, at 
which the Legislature determines that there is no need for 
deterrence or public protection at a certain age.  This is not a 
determination for the court unless the Legislature amends the 
sentence for murder and provides judges with the mandate to 
craft the most appropriate term of years in the unique 
circumstances of the case.  See, e.g., Conn. Gen. Stat. §§ 53a-
35a, 53a-45 (class A felony of murder punishable by "a term not 
less than twenty-five years nor more than life"); D.C. Code 
§ 22–2104 (sentence for "murder in the first degree shall be not 
31 
 
Finally, the court's unwieldy application of neurocognitive 
science threatens to exacerbate further differences in how we 
sentence juveniles and how we sentence older offenders.  More 
specifically, the sentencing provisions governing juveniles are 
grounded on "increasingly sophisticated social-scientific 
understandings" of their capacity, whereas the sentencing 
provisions for older offenders take no account of those factors.  
Buss, What the Law Should (And Should Not) Learn from Child 
Development Research, 38 Hofstra L. Rev. 13, 42 (2009) (Buss, 
Child Development).  Cf. Strough & Bruine de Bruin, Decision 
Making Across Adulthood, Annual Rev. of Developmental Psychol., 
vol. 2, 2020, at 357 ("Age-related declines in fluid reasoning 
ability and working memory can compromise the quality of older 
adults' decision making when decisions are complex"). 
b.  Mature juveniles.  Relative to other States, 
Massachusetts law affords minors some autonomy to consent to 
well-counseled treatment for their physical and mental health 
care.  See Baird v. Attorney Gen., 371 Mass. 741, 754 (1977) 
(recognizing "mature minor" rule in Commonwealth for 
nonemergency medical treatment where [1] best interests of minor 
are served by not notifying parents of intended medical 
 
less than [thirty] years nor more than life imprisonment without 
release"); 730 Ill. Comp. Stat. 5/5-4.5-20 (providing for 
sentence of "not less than [twenty] years and not more than 
[sixty] years" for murder in first degree). 
32 
 
treatment and [2] minor can give informed consent to that 
treatment); G. L. c. 123, § 10 (minors aged sixteen or seventeen 
may consent to admission at mental health treatment facility); 
104 Code Mass. Regs. § 25.03 (2016) (clarifying that mental 
health providers may, pursuant to Massachusetts's "mature minor" 
rule, elect to provide mental health treatment without notifying 
minor's parents).  This autonomy encompasses the ability of 
certain minors to control their sexual health and reproduction, 
see G. L. c. 111, § 24E (enabling sexually active minors of 
childbearing age access to family planning services offered 
through Department of Public Health); G. L. c. 112, § 12F (same, 
but for treatment of human immunodeficiency virus and enumerated 
sexually transmitted diseases), and, if desired, avail 
themselves of the protections provided by the so-called "ROE 
Act" to terminate a pregnancy, see G. L. c. 112, § 12R 
(permitting abortion procedure for patients sixteen and older on 
obtaining patient's written informed consent). 
In short, it is Commonwealth policy to respect, through 
legislation, the capacity of late adolescents to make certain 
decisions regarding their physical and mental health as well as 
their bodily autonomy.  In reaching its conclusion, however, the 
court applies neuroscience selectively to argue that our 
youngest adults, to say nothing of teenagers, are not fully 
33 
 
capable of discerning basic right from wrong.23  I reject that 
inference. 
The application of cognitive neuroscience to, in essence, 
infantilize young adults as a class undercuts the collective 
wisdom of the Commonwealth, which clearly favors trusting young 
people with decisions of (even) life-altering import.  Of more 
concern, the court's paternalism "rais[es] troubling questions 
about" the rights of adolescents, girls in particular,24 "to make 
 
23 See Wagland & Bussey, Appreciating the Wrongfulness of 
Criminal Conduct:  Implications for the Age of Criminal 
Responsibility, 22 Legal & Crim. Psychol. 130, 130 (2017) (eight 
year olds demonstrated that they were just as likely as older 
children and adults to understand wrongfulness of criminal 
behavior and be able to distinguish criminal behavior from 
mischievous behavior). 
 
24 Indeed, the court's and the parties' yoking of 
neurodevelopmental science to abstract notions of culpability 
and redeemability, taken to its logical extent, would have 
disparate impact on the sentencing of girls, who mature faster 
than boys "in many respects relevant to [the] law."  Buss, Child 
Development, 38 Hofstra L. Rev. at 40.  See L. Brizendine, The 
Female Brain 44 (2006) (claiming that biological differences 
between males and females result in females maturing two or 
three years earlier); Cauffman & Steinberg, (Im)maturity of 
Judgment in Adolescence:  Why Adolescents May Be Less Culpable 
than Adults, 18 Behav. Sci. & L. 741, 753, 758 (2000) (females 
exhibit greater psychosocial maturity than males).  My 
colleagues in the majority likely would bristle at the 
suggestion that girls, owing to their psychosocial "head start," 
warrant a harsher punishment than boys of the same age who 
commit the same crime.  See, e.g., Dahl, Adolescent Brain 
Development:  A Period of Vulnerabilities and Opportunities, 
1021 Annals N.Y. Acad. Sci. 1, 12-16 (2004) (studies show 
"significant positive correlation between pubertal maturation 
and sensation seeking" in both boys and girls, which is 
associated with greater risk-taking behaviors).  Yet if age is 
the best proxy for determining whether someone has the 
34 
 
medical decisions or decisions about [their] sexual health."  
Berk, Children, Development, and the Troubled Foundations of 
Miller v. Alabama, 44 L. & Soc. Inquiry 752, 759 (Aug. 2019) 
(Berk, Troubled Foundations).  By invoking neuroscience to treat 
young adults as a separate constitutional class, we invariably 
call into question "a variety of domains concerning the choices 
of young people."  Id. at 760.  See Maroney, The False Promise 
of Adolescent Brain Science in Juvenile Justice, 85 Notre Dame 
L. Rev. 89, 159 (2009) ("Undue emphasis on the immature brain 
also might alter our societal commitment to allow teens 
incrementally greater control over important aspects of their 
lives," such as whether to access reproductive and sexual health 
services unilaterally).  The court may attempt to confine its 
analysis to the criminal sphere, but it is unclear why the 
application should remain so limited.  Berk, Troubled 
Foundations, supra. 
The public's trust in the capacity of our adolescents and 
young adults to make certain decisions regarding their health 
care has been codified into law by our representative 
Legislature.  See, e.g., G. L. c. 112, § 12R; G. L. c. 123, 
§ 10; G. L. c. 111, § 24E.  I would not overrule that collective 
 
neurological capacity for change, then surely any factor that is 
highly correlated with "brain age" and maturation, such as 
biological sex, also is relevant. 
35 
 
wisdom which holds "emerging adults" fully to account for their 
decision to commit murder.  See G. L. c. 127, § 133A (excluding 
convicted murderers aged eighteen or older at time of crime from 
statutory right to parole).  See, e.g., Opinions of the 
Justices, 378 Mass. at 830 (judgment of Legislature to prescribe 
appropriate penalties must be "accorded due respect" by this 
court). 
c.  At-risk juveniles.  Connecting the line of cases from 
the Supreme Court's decision in Roper, 543 U.S. at 569-570, to 
the court's decision today is the question how, precisely, 
should the science of brain development affect the law.  See id. 
at 569, quoting Johnson v. Texas, 509 U.S. 350, 367 (1993) ("as 
any parent knows and as the scientific and sociological studies 
. . . tend to confirm, '[a] lack of maturity and an 
underdeveloped sense of responsibility are found in youth more 
often than in adults'").  Modern neuroscience, weighed properly, 
is an important, albeit supplementary, factor in our art. 26 
analysis for disproportionate punishment.  See Perez, 477 Mass. 
at 686; Diatchenko I, 466 Mass. at 671.  See also Miller, 567 
U.S. at 471.  I do, however, question whether our focus should 
be less on the extent to which our knowledge of brain 
development should influence the law, and more on how knowledge 
of the law ultimately may have an impact on development.  See 
36 
 
Buss, Child Development, 38 Hofstra L. Rev. at 48 (reciprocal 
relationship exists between childhood development and law).25 
Children in Massachusetts know that their legal rights and 
responsibilities forever are altered on turning eighteen.  
Indeed, knowledge of this situation becomes largely unavoidable 
for adolescents in the years leading up to their eighteenth 
birthday.  See G. L. c. 149, §§ 86, 89 (employers required to 
have youth employment permits on file for all workers fourteen 
to seventeen); G. L. c. 90, § 8B (must be sixteen years old to 
apply for learner's permit); G. L. c. 69, § 1D (requiring 
passing score on Massachusetts comprehensive assessment system, 
administered in tenth grade, as prerequisite for graduation).  
In short, they are on notice.  On reaching our age of majority, 
adults in Massachusetts inherit the largest bundle of rights 
 
25 Courts have been led astray by the appeal of following 
what, at the time, appeared to be science.  The examples are 
numerous, and we are familiar with some of the more egregious 
examples here in the Commonwealth.  See Commonwealth v. Kater, 
409 Mass. 433, 447-448 (1991), S.C., 412 Mass. 800 (1992) and 
432 Mass. 404 (2000) (testimony aided in whole or in part by 
hypnosis no longer admissible "because it is unreliable").  See 
also Commonwealth v. Coutu, 88 Mass. App. Ct. 686, 694 n.4 
(2015) (spectral evidence used to convict defendants at Salem 
witch trials).  I am not equating modern neuroscience with 
hypnosis or spectral evidence.  Rather, I note that our 
understanding of this area of science is far from complete, 
especially in that murky area where reflexive action ends and 
our (distinctly) human choice to act originates.  Using 
neurodevelopmental science to assess culpability risks ignoring 
hundreds of years of philosophy as well as learning from other 
societal structures. 
37 
 
they ever will receive;26 conversely, they know that they also 
are exposed to the full consequences of their criminal acts in 
adult courts.27 
As a court, we must be careful not to disregard the 
developmental impact that this knowledge has in "nudging" 
children in the direction of "that unrealized adult ideal."  
Buss, Child Development, 38 Hofstra L. Rev. at 15.  See Berk, 
Troubled Foundations, 44 L. & Soc. Inquiry at 765-766 ("If age 
is understood not simply as a 'gross proxy,' . . . but as 
marking the boundary of a democratic pre-commitment to care for 
young people, it is easier . . . to justify drawing a firm line 
at eighteen or establish . . . consistency [with] the mature 
minor doctrine").  It is easy to shift the line in deference to 
what the latest science tells us; harder still is accepting that 
the present line, though imperfect, serves an aspirational 
function separate and apart from being simply "the point where 
 
26 See, e.g., G. L. c. 231, § 85O (must be age eighteen to 
be party to binding and enforceable contracts); G. L. c. 234A, 
§ 4 (must be age eighteen to sit on jury); G. L. c. 10, § 29 
(must be age eighteen to purchase lottery ticket); and G. L. 
c. 159A, § 9 (must be age eighteen to drive common carrier motor 
vehicle). 
 
27 I recognize, of course, that certain charges against 
juveniles are mandated by statute to be tried in the Superior 
Court rather than the Juvenile Court.  See, e.g., G. L. c. 119, 
§ 74, as amended through St. 2013, c. 84, §§ 25-26 (charges of 
murder in first or second degree against person from ages 
fourteen through seventeen must be brought in Superior Court). 
38 
 
society draws the line for many purposes between childhood and 
adulthood."  Roper, 543 U.S. at 574.  How we expose young people 
to our law matters; we inhibit their growth as citizens when we 
treat the law as an abstract, malevolent force from which they 
require protection, rather than as those wise restraints that 
make us all more free. 
5.  Conclusion.  For all the reasons stated herein, and for 
all the reasons cited in Justice Lowy's dissent, ante, a 
sentence of life without the possibility of parole for adults 
aged eighteen to twenty does not constitute cruel or unusual 
punishment under art. 26 of our Declaration of Rights.  I 
respectfully dissent.