Title: Commonwealth v. Davis
Citation: N/A
Docket Number: SJC-13014
State: Massachusetts
Issuer: Massachusetts Supreme Court
Date: May 17, 2021

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SJC-13014 
 
COMMONWEALTH  vs.  MATTHEW DAVIS. 
 
 
 
Suffolk.     February 1, 2021. - May 17, 2021. 
 
Present:  Budd, C.J., Gaziano, Lowy, Cypher, Kafker, 
& Georges, JJ. 
 
 
Armed Assault with Intent to Murder.  Assault and Battery.  
Attempt.  Firearms.  Electronic Surveillance.  Global 
Positioning System Device.  Evidence, Videotape, 
Photograph, Authentication, Identification, Scientific 
test.  Practice, Criminal, Probation, Required finding. 
 
 
 
 
Indictments found and returned in the Superior Court 
Department on May 16, 2016. 
 
 
The cases were tried before Peter M. Lauriat, J. 
 
 
After review by the Appeals Court, the Supreme Judicial 
Court granted leave to obtain further appellate review. 
 
 
 
David Rassoul Rangaviz, Committee for Public Counsel 
Services, for the defendant. 
 
Andrew S. Doherty, Assistant District Attorney, for the 
Commonwealth. 
 
Maria Gonzalez Calvet, of the District of Columbia, Daniel 
W. Richards, of California, Michael A. Morales, of New York, 
Radha Natarajan, Katharine Naples-Mitchell, & Kirsten V. Mayer, 
for New England Innocence Project & another, amici curiae, 
submitted a brief. 
 
2 
 
 
 
LOWY, J.  On September 15, 2015, a Black man with long hair 
wearing a red or pink shirt or sweatshirt fired multiple shots 
at the driver's side window of a moving blue sedan.  The driver 
of the sedan, who was uninjured, fled from the scene and did not 
testify at trial.  The sole civilian witness who testified at 
trial did not witness the shooting itself but did see a Black 
man with braids and a red shirt running away from the location 
of the shooting.   
 
The defendant, Matthew Davis, became a suspect after police 
made an inquiry whether anyone wearing a global positioning 
system (GPS) device at the relevant time was in the vicinity of 
the shooting.  Due to his probation on a Federal drug charge, 
the defendant was wearing a GPS ankle monitor called an 
"ExactuTrack 1" (ET1), manufactured by BI, Inc. (BI).  Data from 
the defendant's GPS device showed he was at the location where 
the shooting took place very close in time to the shooting, and 
his speed matched the shooter's movements, according to 
surveillance footage and testimony from the civilian witness.  
After a jury trial, the defendant was convicted of armed assault 
with intent to murder, G. L. c. 265, § 18 (b), and related 
charges. 
 
On appeal, we consider whether the GPS evidence was 
sufficiently reliable to be admitted.  We conclude that the 
3 
 
judge abused his discretion in admitting the speed evidence, 
where the ET1's ability to measure speed had never been formally 
tested.  Because this error was prejudicial, we reverse the 
defendant's convictions. 
 
We also address the defendant's argument that the evidence 
was insufficient to support his convictions and hold that it was 
sufficient.  Finally, we address other arguments the defendant 
raised on appeal that may recur at retrial, including whether 
maps of the GPS data violated the defendant's confrontation 
rights, whether a cell phone video recording (video) of 
surveillance footage was properly authenticated, and whether it 
was proper for the prosecutor to ask the jury to identify the 
defendant as the shooter based on footage that did not show the 
shooter's face.1 
 
Background.  Because the defendant raises a sufficiency 
challenge, we recite the facts the jury could have found, in the 
light most favorable to the Commonwealth, reserving certain 
details for later discussion.  See Commonwealth v. Latimore, 378 
Mass. 671, 676-677 (1979). 
 
On the morning of September 15, 2015, at the corner of 
Baker Avenue and Quincy Street in the Dorchester section of 
 
 
1 We acknowledge the amicus brief submitted by the New 
England Innocence Project and Charles Hamilton Houston Institute 
for Race & Justice.  
4 
 
Boston, a man fired multiple gunshots at a blue sedan.  
Dispatchers received a 911 call reporting the shooting at 10:28 
A.M.  Responding police officers found an unoccupied blue sedan, 
with multiple bullet holes in the front window, crashed into a 
light pole.  Several shell casings and bullet fragments were on 
the ground. 
 
One of the responding officers, Sergeant Thomas Carty, 
canvased the area for potential witnesses as well as any cameras 
that may have captured the shooting.  He noticed a video camera 
affixed to a residential property on Baker Avenue.  A resident 
of that address allowed Carty to view the surveillance video, 
but the resident did not know how to download it or copy it to 
another device.  Carty instead used his cell phone to record a 
video of the surveillance video as it played on a computer 
screen. 
 
The resulting video -- which is not very high resolution -- 
shows a Black man with long braids or dreadlocks in a red or 
pink shirt or sweatshirt wearing a gray hat or cap.  The man 
runs towards an intersection raising his arm while holding a 
handgun.  As the man holds up the gun, a blue sedan is driven 
into the frame from the opposite direction and then collides 
with a light pole at the corner of the intersection.  After the 
crash, the driver gets out of the car and runs down the street.  
A little over a minute later, a man who appears to be the driver 
5 
 
returns to the car and gets into the driver's seat, before 
getting out of the car and again jogging away, across the 
street.  The video is not high enough resolution and is taken 
from too far away to discern any features of the shooter's face. 
 
At approximately 10:30 A.M. on the day of the shooting, a 
woman named Ilene Rock was standing on Bodwell Street near the 
corner of Columbia Road -- a couple of blocks away from the 
location of the shooting -- when she heard a noise that sounded 
like gunshots or a car backfiring.  Shortly after hearing the 
noise, she saw a Black man with thin braids wearing a red shirt 
run past her with his hand in his pocket.2  The man came within 
five or six feet of her, but she did not get a good look at his 
face because she was focused on his hands in his pocket.  The 
man ran down Bodwell Street and turned right onto Columbia Road 
toward Quincy Street.  Shortly thereafter, Rock heard sirens and 
saw police.   
 
2 Rock described the man she saw running as having "thin 
braids" and a "red shirt."  Thus, when referring to her 
testimony, we use that terminology.  The shooter's hair and 
dress are less clear from the video.  Thus, when describing the 
shooter in the video, we describe his hair as "braids or 
dreadlocks" and his clothing as a "red or pink shirt or 
sweatshirt."  The defendant asserts that he had dreadlocks, not 
braids, around the time of the shooting.  The photograph of him 
taken the day after the shooting that was admitted in evidence 
appears to confirm this. 
 
6 
 
 
At a later date, police showed Rock a photographic array 
that contained an image of the defendant.  Rock later testified 
that she "saw a few people that [she] thought looked similar [to 
the man she saw running], but [she] couldn't make a positive 
identification of him" because she "wasn't sure of the facial 
features enough to make a selection."  On three of the eight 
photographs, she made the notations "maybe the person I saw," 
"This might be him 80%," and "This is possibly the man I saw 
running."  None of those three photographs depicted the 
defendant. 
 
As part of their investigation, police made an inquiry into 
whether anyone wearing a GPS device was in the area at the time 
of the shooting.3  The defendant, who was wearing a GPS ankle 
monitor as part of his probation on a Federal drug case, had 
been.  The defendant's GPS device purported to show that at 
10:25 A.M. on the day of the shooting, he had been on Columbia 
Road near Brunswick Street travelling northeast at twenty-two 
miles per hour.  At 10:26 A.M., he was still travelling 
northeast on Columbia Road, now at thirty-two miles per hour.  
At 10:27 A.M., he was at the corner of Quincy Street and Baker 
Avenue -- the location of the shooting -- travelling at ten 
miles per hour.  At 10:28, he was on the corner of Baker Avenue 
 
3 The record does not describe with whom police made this 
inquiry. 
7 
 
and Bodwell Street travelling at eight miles per hour.  At 
10:29, he was on Columbia Road between Quincy and Bodwell 
travelling at eleven miles per hour.  At 10:30, he was on Quincy 
Street travelling at twenty-two miles per hour.  At 10:31, he 
was on Church Street travelling at fifteen miles per hour.  At 
10:32, he had stopped at his home. 
 
Approximately a week after the shooting, officers executed 
a search warrant at the defendant's home.  They found a red 
long-sleeved crew neck sweatshirt under a pile of clothes in the 
defendant's bedroom.  The sweatshirt tested negative for gunshot 
primer residue.  
 
After a jury trial in October 2017, the defendant was found 
guilty of armed assault with intent to murder, G. L. c. 265, 
§ 18 (b), and multiple lesser charges.4  The defendant then filed 
a timely notice of appeal, and the Appeals Court affirmed his 
 
 
4 In addition to armed assault with intent to murder (count 
one), the defendant was also found guilty of attempted assault 
and battery by means of discharging a firearm, G. L. c. 265, 
§ 15F (count two); carrying a firearm without a license, G. L. 
c. 269, § 10 (a) (count three); possession of ammunition without 
a firearm identification card, G. L. c. 269, § 10 (h) (1) (count 
four); and carrying a loaded firearm without a license, G. L. 
c. 269, § 10 (n) (count five).  On count three, the defendant 
had been indicted as an armed career criminal, G. L. c. 269, 
§ 10G (b).  After trial, he pleaded guilty to being an armed 
career criminal on that count.  Count four was then dismissed at 
the request of the Commonwealth. 
 
8 
 
convictions.  See Commonwealth v. Davis, 97 Mass. App. Ct. 633 
(2020).  We granted further appellate review. 
Discussion.  1.  Admission of expert testimony.  Before the 
GPS evidence was introduced at trial, the judge conducted a voir 
dire of the Commonwealth's expert, James Buck, manager of 
product development at BI.  Buck provided an overview of how GPS 
technology works in general, as well as described the ET1 model 
in particular.  He stated that at any given time, there are 
twenty-four active satellites circling the globe.  Signals from 
the satellites transmit to a receiver -- as in a GPS device -- 
and that data can be used to determine the device's speed and 
location.  The more satellites from which a device is receiving 
signals at any given time, the more accurate the speed and 
location data will be.   
GPS technology works slightly differently for speed from 
how it does for location.  To triangulate a device's location, 
it must receive signals from a minimum of three satellites.  To 
determine a device's speed and direction, on the other hand, it 
must receive signals from at least four satellites.5  With 
 
 
5 This is because speed measurements are based on a 
different frequency and utilize the Doppler effect.  In essence, 
the speed data is not based merely on doing algebra to calculate 
the average speed between two location points.  Instead, the 
device uses a different frequency to take a reading every 
millisecond of a satellite's position in the sky, and then, 
 
9 
 
respect to the ET1 specifically, Buck testified that it records 
the wearer's location and speed once per minute and sends the 
data over a cellular network to BI's headquarters in Colorado.6  
Buck stated that BI had conducted formal testing of the ET1's 
ability to measure location, but its ability to measure speed 
had never been formally tested. 
a.  Gatekeeper reliability.  Before offering expert 
testimony such as Buck's, the proponent must establish a 
sufficient foundation for a judge to determine whether the 
expert's opinion satisfies gatekeeper reliability.  See 
Commonwealth v. Patterson, 445 Mass. 626, 639 (2005), overruled 
on other grounds by Commonwealth v. Britt, 465 Mass. 87 (2013) 
("Trial judges serve a gatekeeper function with respect to 
expert opinion testimony based on specialized knowledge").  See 
also Mass. G. Evid. §§ 104(a), 702 (2021).  "If the process or 
theory underlying [an] . . . expert's opinion lacks reliability, 
that opinion should not reach the trier of fact."  Patterson, 
supra, quoting Commonwealth v. Lanigan, 419 Mass. 15, 26 (1994).  
 
based on that, uses the Doppler effect to determine the GPS 
device's velocity and direction. 
 
 
6 Specifically, Buck testified that the device takes a 
sample every fifteen seconds, and then selects the best sample 
of the four to log.  Although it is not entirely clear from the 
record, it appears the "best sample" is the one during which the 
device was communicating with the highest number of satellites. 
 
10 
 
Until 1994, we used the Frye test -- also called the 
general acceptance test -- to determine if proposed expert 
testimony was sufficiently reliable to reach the jury.  
Canavan's Case, 432 Mass. 304, 310 (2000).  See Lanigan, 419 
Mass. at 24; Frye v. United States, 293 F. 1013, 1014 (D.C. Cir. 
1923).  Under that test, "we required that in most circumstances 
'the community of scientists involved [must] generally accept[] 
the theory or process' for it to be admitted in evidence" 
(citation omitted).  Canavan's Case, supra.  The test proved to 
be useful because "if there is general acceptance of a theory or 
process in the relevant scientific community, [it] is likely 
reliable."  Id.  "However, we recognized that 'strict adherence 
to the Frye test' could result in reliable evidence being kept 
from the finder of fact.  For example, a new theory or process 
might be 'so logically reliable' that it should be admissible, 
even though its novelty prevents it from having attained general 
acceptance in the relevant scientific community."  (Citations 
omitted.)  Id.  In short, situations could arise where our law 
of evidence lagged behind recognizing what was otherwise 
reliable science. 
To account for this circumstance, in Lanigan, 419 Mass. at 
26, we adopted in part the United States Supreme Court's 
reasoning in Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 
593-594 (1993), which set forth five nonexclusive factors a 
11 
 
judge should consider in determining the reliability of proposed 
scientific evidence.  The five nonexclusive factors are "whether 
the scientific theory or process (1) has been generally accepted 
in the relevant scientific community; (2) has been, or can be, 
subjected to testing; (3) has been subjected to peer review and 
publication; (4) has an unacceptably high known or potential 
rate of error; and (5) is governed by recognized standards."  
Commonwealth v. Powell, 450 Mass. 229, 238 (2007).   
Although Daubert and Lanigan dealt specifically with 
scientific evidence, we have since recognized their application 
to scientific, technical, and other specialized knowledge.  See 
Commonwealth v. Pytou Heang, 458 Mass. 827, 844 (2011).  
Further, the Daubert-Lanigan factors are nonexclusive, and we 
have recognized the potential need to consider other factors 
depending on the nature of the expert testimony.  See, e.g., 
Commonwealth v. Hinds, 487 Mass. 212, 220-222 (2021) (discussing 
application of Daubert-Lanigan factors to social sciences); 
Canavan's Case, 432 Mass. at 314 n.5 ("Differing types of 
methodology may require judges to apply differing evaluative 
criteria to determine whether scientific methodology is 
reliable").  Using these nonexclusive factors to determine 
reliability is known as the Daubert-Lanigan test.   
We have not, however, entirely abandoned the Frye test.  In 
Lanigan, 419 Mass. at 26, we noted that in many cases general 
12 
 
acceptance will "be the significant, and often the only, issue."  
Lanigan's progeny make clear that reliability can still be 
established by general acceptance alone, without regard to the 
other Daubert-Lanigan factors.  See Patterson, 445 Mass. at 640-
641 (citing cases). 
If a theory or methodology has been established as reliable 
in our courts using one of these two standards in the past, then 
a judge may take judicial notice of its reliability.  See 
Daubert, 509 U.S. at 592 n.11 ("theories that are so firmly 
established as to have attained the status of scientific law, 
such as the laws of thermodynamics, properly are subject to 
judicial notice").  See also Mass. G. Evid. § 201. 
In contrast, when proposed expert testimony uses a new 
theory, or new methodology to apply an accepted theory, the 
proponent must establish its reliability using a Daubert-Lanigan 
analysis.  See Patterson, 445 Mass. at 648-649.  For example, in 
Patterson, the Commonwealth sought to introduce fingerprint 
evidence.  Id. at 627.  We held that the judge acted well within 
her discretion in finding that using the theory underlying 
fingerprint analysis was generally accepted.  Id. at 641.  
However, we also held that the judge erred by failing to conduct 
a Daubert-Lanigan analysis to determine whether a new technique 
based on that accepted theory was reliable.  Id. at 648-649.  
Similarly, in Commonwealth v. Camblin, 471 Mass. 639, 645 (2015) 
13 
 
(Camblin I), S.C., 478 Mass. 469 (2017) (Camblin II), we held 
that the judge erred by failing to conduct a Daubert-Lanigan 
analysis to determine the reliability of a new generation of 
breathalyzer devices, which used different techniques from those 
previously found reliable by our courts. 
Under both Daubert-Lanigan and Frye, we review a judge's 
decision to admit expert testimony as satisfying gatekeeper 
reliability under the abuse of discretion standard.  See 
Canavan's Case, 432 Mass. at 312.  "While our review under this 
standard is deferential and limited, it is not perfunctory.  A 
judge's findings must apply the correct legal standard to the 
facts of the case and must be supported by an examination of the 
record."  Patterson, 445 Mass. at 639.7 
 
7 The defendant also cites to cases that pertain not to the 
Daubert-Lanigan reliability standard, but to the necessity of a 
foundational showing of accuracy.  See Commonwealth v. Torres, 
453 Mass. 722, 737 (2009); Commonwealth v. Whynaught, 377 Mass. 
14, 17 (1979); Commonwealth v. Podgurski, 81 Mass. App. Ct. 175, 
185 (2012).  Usually the line between a preliminary question of 
fact upon which admissibility depends, such as gatekeeper 
reliability, see Mass G. Evid. §§ 104(a), 702, and conditional 
relevance, see Mass G. Evid. § 104(b), is clear.  See P.C. 
Giannelli, Understanding Evidence § 7.03 (5th ed. 2018) 
(discussing conditional relevancy).  Yet when the proposed 
evidence is the product of a technical device, such as it is in 
this case, the line between these evidentiary principles can 
blur.  "Radar evidence illustrates this point.  The reliability 
of evidence based on radar depends on (1) the validity of the 
underlying theory (e.g., the Doppler effect), (2) the validity 
of the technique applying that theory (e.g., the particular 
model of radar), and (3) the proper application of the technique 
on a particular occasion (e.g., use of tuning forks to calibrate 
 
14 
 
With this framework in mind, we turn to the GPS evidence of 
speed and location admitted in this case. 
b.  Speed.  As will become clear, the Commonwealth failed 
to lay the proper foundation to admit the ET1's speed 
measurements under either the Daubert-Lanigan or the Frye test.  
See generally Mass. G. Evid. §§ 104(a), 702.  Thus, the judge 
erred by admitting the speed evidence without the proper 
foundation. 
The defendant does not dispute the reliability of GPS 
technology over-all, nor do we.  The defendant's objection is to 
the reliability of the ET1 model specifically.  Nevertheless, we 
briefly discuss the reliability of GPS theory and methodology to 
give context to the issues raised.  
 
First, it is clear from both the record and our case law 
that GPS technology is generally accepted as reliable.  The 
judge found that GPS evidence has "been accepted in the field 
for a substantial number of years by virtually most populations 
 
the instrument)."  Id. at § 24.04 endnote 39.  In that scenario, 
the first two elements would be subject to gatekeeper 
reliability under Daubert-Lanigan or Frye.  The third element, 
in contrast, would in most instances be a matter of conditional 
relevance.  By inquiring into the third element, the judge would 
ask not whether the device was reliable, but rather whether a 
reasonable jury could find by a preponderance of the evidence 
that it was functioning properly at the time it was used.  In 
essence, the relevance of a measuring device is conditioned on 
whether a jury could find that it was functioning properly.  See 
Mass. G. Evid. § 104(b). 
15 
 
in the world."  In describing the history of GPS technology, 
Buck testified that, as early as 1957, researchers at Johns 
Hopkins University theorized that satellites could be used to 
triangulate location.  Our case law confirms that GPS technology 
is "widely used and acknowledged as a reliable relator of time 
and location data."  Commonwealth v. Thissell, 457 Mass. 191, 
198 (2010) (Thissell II). 
 
Second, because GPS technology uses a different methodology 
to measure speed from how it does location, that methodology, 
too, would need to satisfy gatekeeper reliability.  See Mass. G. 
Evid. §§ 104(a), 702.  See, e.g., Patterson, 445 Mass. at 628 
(new methodology based on accepted underlying theory must pass 
gatekeeper reliability).  Had the defendant objected to the 
reliability of the method used by GPS technology, in general, to 
measure speed, we expect that the Commonwealth would have been 
able to demonstrate that the use of GPS to measure speed is 
generally accepted or meets the requirements of Daubert-Lanigan. 
 
The defendant's objection at trial and his argument on 
appeal pertain to the reliability of the ET1 device 
specifically.  He argues that the ET1 does not meet the 
requirements of Daubert-Lanigan.  Chief among the defendant's 
concerns is the fact that the ET1's ability to measure speed has 
16 
 
never been formally tested.8  Given the complete lack of formal 
testing of the ET1 model for speed, there is also no known error 
rate.  Moreover, the defendant asserts that because the ET1 is 
proprietary, it is impossible to say whether the methodology it 
employs is generally accepted.  The proprietary nature also 
means it has not been subject to peer review.9  Finally, its 
accuracy is not governed by any recognized standards.  
 
We agree with the defendant that if a new model of a device 
is objected to on reliability grounds, it must pass gatekeeper 
reliability under either Daubert-Lanigan or Frye.  It is not 
sufficient to show merely that GPS technology is, in general, 
reliable without making any showing pertaining to the 
reliability of a particular model of a device.  The Commonwealth 
could meet that burden by showing that the new model itself 
satisfies the Daubert-Lanigan factors -- for example, that it 
 
8 Buck testified that BI had not done any formal testing to 
ensure that speed data was accurate.  Moreover, he had not 
"figured out and formulated a way to successfully [test speed] 
reliably and repeatedly."   
 
BI's informal testing consisted of having ten employees at 
any given time wear its devices and report back if there were 
any "speed irregularities."  But BI only conducts a "general 
review of the [data] points"; BI has not compared the ET1 speed 
data to any independent measurements of speed. 
 
 
9 Buck testified that there is "one person in the industry" 
who tests and compares different GPS devices, but the results of 
his testing are not made available to any of the companies in 
question, including BI. 
 
17 
 
has been tested or peer reviewed.  That is not the only way, 
however, to show that a new model is reliable.  For example, if 
an older model has previously been found reliable, the proponent 
need only show that the new model applies the same methodology 
as that prior one.10  Given that devices generally tend to 
improve, that will generally be sufficient to show that the new 
device, too, is reliable.  Here, the Commonwealth made neither 
showing.  It only showed that the GPS technology is a reliable 
theory.  For the speed data, it has not shown that the ET1 
itself -- either through testing or through its similarity to a 
generally accepted device -- reliably applies that accepted 
theory.  Thus, the judge abused his discretion in admitting the 
ET1 speed evidence.11 
Because on retrial the Commonwealth may again attempt to 
lay the proper foundation for the speed evidence, we comment on 
the remainder of the analysis.  If the Commonwealth attempts to 
show that a new model of a device is reliable by asserting that 
it is similar to a prior model, the defendant may object and 
 
10 This showing must be based on facts and data, not a 
conclusory statement that the devices are the same. 
 
11 In addition, because speed had never been tested, Buck 
did not have any margin of error within which the speed data was 
accurate.  This could lead the jury to overvalue its accuracy.  
For the location data, in contrast, Buck did not say that the 
ET1 could pinpoint one's exact location; he said that it was 
accurate within a certain number of feet. 
18 
 
move for a Daubert-Lanigan hearing on the new device.  This is 
essentially what occurred in Camblin I, 471 Mass. at 642.  
There, the Commonwealth sought to introduce evidence from a 
particular model of breathalyzer (Alcotest) that had not 
previously been reviewed by our courts.  Id. at 640.  The 
defendant moved for discovery of the device's computer source 
code, and that request was granted pursuant to a nondisclosure 
agreement.  Id. at 642.  The defendant retained experts to 
examine the source code.  Id.  The defendant then filed 
affidavits and reports contending that the source code contained 
thousands of errors and argued that the Alcotest used methods 
different from previous machines that had been reviewed by our 
courts.  Id. at 644.  On appeal, we held that because neither 
statute nor existing case law offered guidance about the 
reliability of the Alcotest's methodology, the judge should have 
held a Daubert-Lanigan hearing.  Id. at 650.12  We remanded the 
 
12 This is but one example of how a defendant may assert 
that a new model of device uses a different methodology from 
previous models.  We leave for another day how much a defendant 
needs to show to assert a device uses a new methodology in order 
to raise the issue.  At a minimum, however, "a defendant must 
file an appropriate pretrial motion stating the grounds for the 
objections and request a hearing."  Commonwealth v. Sparks, 433 
Mass. 654, 659 (2001). 
 
Further, we note that while in many scenarios it may be 
sufficient for the Commonwealth to show that a device applies 
the same methodology as prior versions, courts are not required 
to admit evidence from a device merely because such evidence has 
 
19 
 
case for that hearing, and then, in Camblin II, 478 Mass. at 
469-470, held that the judge did not abuse his discretion in 
finding that the Alcotest satisfied the Daubert-Lanigan 
standard.13  
c.  Location.  Next, the defendant objects to the admission 
of the ET1's location data.  We hold that the judge did not 
abuse his discretion in admitting the location data. 
 
previously been admitted.  See Commonwealth v. Shanley, 455 
Mass. 752, 763 n.15 (2010) ("we have not 'grandfathered' any 
particular theories or methods for all time").  We similarly 
leave for another day how much a defendant needs to show to call 
into question the reliability of a generally accepted device.  
See, e.g., Commonwealth v. Neal, 392 Mass. 1, 17-18 (1984) 
(rejecting defendant's argument that generally accepted model of 
breathalyzer was unreliable in light of recent discovery of its 
susceptibility to radio frequency interference). 
 
13 Given that the issue could also arise on retrial, we 
briefly comment on the difference between gatekeeper reliability 
and conditional relevance in this scenario.  If the defendant 
objects -- as he did here -- to the reliability of the ET1 model 
as a whole, then the Commonwealth bears the burden of showing 
that the ET1 passes gatekeeper reliability.  See Mass. G. Evid. 
§§ 104(a), 702.  See, e.g., Camblin I, 471 Mass. at 640 
(reliability of Alcotest device).  On the other hand, if the 
defendant objects to whether the specific ET1 device worn by the 
defendant on September 15, 2015, was functioning properly, then 
the issue is likely a matter of conditional relevance, for which 
the Commonwealth also bears the burden of laying the proper 
foundation.  See Mass G. Evid. § 104(b).  See, e.g., 
Commonwealth v. Torres, 453 Mass. 722, 737 (2009) (whether 
measuring device was calibrated); Commonwealth v. Neal, 392 
Mass. 1, 19 (1984) (whether particular breathalyzer unit was 
accurate at time test was performed); Commonwealth v. Whynaught, 
377 Mass. 14, 17 (1979) (whether individual radar speedmeter was 
calibrated); Commonwealth v. Podgurski, 81 Mass. App. Ct. 175, 
185-186 (2012) (whether individual scale was calibrated). 
20 
 
Unlike the speed data, the ET1's location data had been 
formally tested.  During voir dire, Buck described in detail the 
circular error of probability test BI had used to ensure the 
ET1's location data was accurate.  The test -- which was 
conducted at BI's headquarters in the suburbs of Boulder, 
Colorado -- involved leaving the device in a stationary position 
for six hours, and then recording the location data provided 
from the satellites and plotting it on a scatter graph.  Buck 
described the area as an industrial park, with no buildings over 
about three stories tall.  He stated that the test showed that 
ninety-eight percent of the ET1's location points are within 
sixteen feet of the expected circle, and fifty percent are 
within three feet.   
Against this conclusion, the defendant argues that the 
testing was not sufficient because it occurred in prime 
conditions that did not simulate real-world accuracy, especially 
in an urban environment.  Buck stated that the accuracy of a GPS 
device can be affected by tall buildings, which can block the 
signal between the satellite and the device.14  At trial, Buck 
 
14 Specifically, Buck testified that the satellite signal 
can be blocked by tall buildings, which have a "multipath 
effect."  Buck testified, "In other words, it's bouncing off of 
a building to get to the actual receiver which then delays your 
time of arrival which then increases the likelihood that you're 
going to have an error in [location data]." 
 
21 
 
stated that the device is tested on the rooftop in Colorado to 
get a "baseline" accuracy so that it can be compared to prior or 
future models.  Buck also acknowledged that the ET1 had never 
been tested in Boston or in any other urban environment.  That 
is why, he said, in the device manual BI tends to err on the 
side of caution in reporting the radius within which a GPS 
device can determine someone's location.  In this case, the 
manual indicated that the device was accurate to plus or minus 
ninety feet.15  That gives a far wider margin of error than the 
Colorado test, which determined that ninety-eight percent of the 
time the location points are accurate within sixteen feet.  At 
trial, when asked about the accuracy of each data point 
individually, Buck testified that they were within a margin of 
error of between forty feet and one-half the size of the court 
room.16 
The judge did not abuse his discretion in ruling that the 
defendant's objection went to the weight of the evidence, not 
its admissibility.  Buck acknowledged that the ET1 was likely 
less accurate in an urban environment than in Colorado, where 
 
15 It is unclear from the record whether this manual 
corresponded to the ET1 itself, or to a prior BI GPS model.  
Buck stated that the manual was from 2008 or 2009. 
 
16 The differing degrees of accuracy for each data point 
depended on how many satellites the GPS device was communicating 
with at any given time.  Buck went through each minute of the 
defendant's GPS data and posited its accuracy. 
22 
 
the baseline test occurred.  Consequently, Buck did not allege 
that BI's location points in an urban area would be within the 
same three- to sixteen-foot radius in which they had been in its 
baseline test in Colorado.  His testimony shows, however, that 
the Colorado test is still helpful as a baseline.  Unlike for 
speed, where there was no test of any kind to show that the 
ET1's speed data reliably applied an accepted methodology, for 
location data the Colorado test was sufficient to show that the 
ET1's location data did reliably apply an accepted methodology.  
Thus, the location data met the requirements of gatekeeper 
reliability, and the judge did not abuse his discretion in 
admitting it. 
 
d.  Prejudicial error.  Because the objection to the speed 
GPS data on Daubert-Lanigan grounds was preserved at trial, we 
review for prejudicial error.  "[T]he Commonwealth must show 
that any error 'did not influence the jury, or had but very 
slight effect.'"  Commonwealth v. Dargon, 457 Mass. 387, 399 
(2010), quoting Commonwealth v. Flebotte, 417 Mass. 348, 353 
(1994).  To this end, the Commonwealth argues that the speed 
data was not prejudicial because the other evidence was 
compelling and, to some extent, the speed data was "irrelevant" 
because the location data was itself incriminating.  We 
disagree. 
23 
 
 
In the Commonwealth's closing argument, the prosecutor made 
more than ten explicit references to speed.  When describing the 
GPS evidence, the prosecutor stated that when looking "not only 
[at] the locations, but also the speed, a bigger story will come 
up for this particular case."  The prosecutor used the speed 
data to match the defendant's movements to those of both the 
shooter in the video as well as the man Rock saw running.  The 
prosecutor stated that at the first two data points -- 10:25 
A.M. and 10:26 A.M. -- the defendant's speed was twenty-two and 
thirty-two miles per hour, showing he was likely in a car 
travelling down Columbia Road.  At 10:27 A.M. and 10:28 A.M., 
the defendant's speed slowed down to what was likely the speed 
of someone running.  This, the prosecutor said, was consistent 
with the shooter in the video running at the time of the 
shooting and immediately after.  Further, the speed was 
consistent with Rock's testimony of seeing a man in a red shirt 
running down the street with his hands in his pockets -- 
presumably fleeing the shooting.  After that, the defendant's 
speed increases again, showing that he is likely back in a car. 
 
The defendant's speed was not merely duplicative of his 
location.  It was crucial evidence used to correlate the 
defendant's movements to those of the shooter in the video and 
to the man Rock saw running.  Without the speed, a jury would 
have only been able to infer that the defendant was in the area 
24 
 
where the shooting took place.  With the speed, however, the 
jury could match the defendant's movements to those of the 
shooter in the video and the man Rock saw, thereby presenting a 
compelling narrative that the defendant was the shooter.  Thus, 
we cannot say that it "did not influence the jury, or had but 
very slight effect."  Dargon, 457 Mass. at 399, quoting 
Flebotte, 417 Mass. at 353.  We hold that admitting the speed 
data was prejudicial error and the defendant's convictions must 
be reversed. 
 
2.  Sufficiency of the evidence.  The defendant moved for a 
required finding of not guilty at the close of the 
Commonwealth's case, arguing the evidence was insufficient to 
support a conviction.  The motion was denied.  He reaffirms this 
argument on appeal, asserting that the admitted evidence is 
insufficient to prove his identity as the shooter where the 
Commonwealth's case is circumstantial and relies on "piling 
inference upon inference" (quotation and citation omitted).  
Commonwealth v. Ashford, 486 Mass. 450, 455 (2020).  We 
disagree. 
 
In assessing the sufficiency of the evidence, we consider 
"whether, after viewing the evidence in the light most favorable 
to the prosecution, any rational trier of fact could have found 
the essential elements of the crime beyond a reasonable doubt."  
Latimore, 378 Mass. at 677, quoting Jackson v. Virginia, 443 
25 
 
U.S. 307, 319 (1979).  "Circumstantial evidence is sufficient to 
find someone guilty beyond a reasonable doubt and inferences 
drawn from such circumstantial evidence 'need only be reasonable 
and possible; it need not be necessary or inescapable.'" 
Commonwealth v. Grandison, 433 Mass. 135, 141 (2001), quoting 
Commonwealth v. Lodge, 431 Mass. 461, 465 (2000).  "A conviction 
may not, however, be based on conjecture or on inference piled 
upon inference."  Commonwealth v. Jones, 477 Mass. 307, 316 
(2017). 
 
"If the evidence at trial was legally insufficient to 
sustain a verdict, a new trial would violate the prohibition 
against double jeopardy and would therefore be impermissible."  
Commonwealth v. Bacigalupo, 455 Mass. 485, 489 (2009).  
"Ordinarily, in determining the sufficiency of the evidence, we 
include evidence improperly admitted."  Id. at 490.  Thus, we do 
not exclude the improperly admitted speed evidence from our 
analysis and do not comment on whether the admitted evidence 
minus the speed data would have been sufficient to support a 
conviction.  See id. 
 
The Commonwealth primarily relied on three pieces of 
evidence to establish the defendant's guilt:  the GPS data, the 
video, and Rock's testimony.  We analyze each in turn.   
 
First, the GPS evidence established both the defendant's 
speed and his location.  It showed that he was at the 
26 
 
intersection where the shooting took place at 10:27 A.M. on the 
day of the shooting.17  The 911 call reporting the shooting was 
made approximately one minute later, at 10:28:24 A.M.  It is 
true that "mere presence at the scene of a crime, without more, 
is not sufficient to support a conviction."  Commonwealth v. 
Mazza, 399 Mass. 395, 399 (1987).  Yet the GPS established not 
only his location, but also his speed.  As discussed supra, the 
speed evidence helped to establish his identity as the shooter 
 
 
17 The defendant argues that the Commonwealth failed to show 
the precise time the shooting took place, and given the 
importance of the purportedly precise GPS data, such evidence 
was necessary to establish the defendant's guilt.  The defendant 
argues that if the shooting occurred at 10:27 A.M. -- when the 
defendant was at the intersection where the shooting took place 
-- then his location would have been incriminating, but at any 
other moment his location would have been exonerating.   
 
 
At trial, the defendant compared the 911 call to the video, 
arguing that one could infer that the shooting took place at 
10:28:07 A.M., when the defendant was a block away.  This 
argument was premised on the theory that a man on his cell phone 
appearing approximately one minute and thirty seconds into the 
video was the 911 caller, and that when the 911 caller asked 
someone "are you all right?" that was him speaking to the 
victim, who had briefly returned to the car.  While that was a 
cogent argument, the jury were not required to accept it.  
Whether the man on his cell phone in the video was the 911 
caller is unclear.  Moreover, one of the responding officers 
testified that she "believe[d] there was more than one call that 
morning."  Thus, even if the man on his cell phone in the video 
was in fact calling 911, that does not necessarily mean he is 
the same caller whose call was played for the jury. 
 
27 
 
by matching his movements to those of both the shooter as well 
as the man Rock saw in a red shirt shortly after the shooting.18 
 
Next, the video of the shooting showed that the gunman 
appeared to be a Black man with long braids or dreadlocks and a 
long-sleeved red or pink shirt or sweatshirt.  As the prosecutor 
argued in closing, the video was evidence that on the corner of 
Quincy Street and Baker Avenue, the shooter fired several shots 
at a moving car.  Thus, the video was probative of both the 
shooter's actions and his intent to kill.  As discussed infra, 
however, because the shooter's features were not clear from the 
video, it cannot alone give rise to an inference that the 
defendant was this shooter. 
 
Finally, Rock testified that she heard what could have been 
gunshots, and then saw a Black man with thin braids and a red 
shirt with his hands in his pocket run down Bodwell Street 
toward Columbia Road and turn right onto Columbia Road.19  The 
 
 
18 The defendant disputes the Commonwealth's proposed 
inference from the speed data that the defendant was travelling 
in a car, then got out and started running, and then reentered 
the car minutes later.  Absent the video or Rock's testimony, 
the speed data might not be probative of guilt.  Yet combined 
with that evidence, the speed data was probative of the 
defendant's identity as the shooter. 
 
 
19 Rock described the runner as having "thin braids" and did 
not describe him as having a beard.  The defendant points out 
that he had dreadlocks, not braids, as depicted in the 
photograph taken the day after the shooting.  Further, he had a 
light beard at the time. 
28 
 
runner's path matched the defendant's GPS device's tracked 
movements.  The fact that Rock failed to identify the defendant 
in a photographic array is fodder for cross-examination, but 
given that Rock admitted that she did not get a good look at the 
runner's face because she was focused on his hands, it does not, 
in the light most favorable to the Commonwealth -- and when 
combined with the other evidence showing the defendant's speed 
and location -- preclude the inference that the defendant was 
the man she saw running. 
 
We conclude that while the evidence at trial was not by any 
means overwhelming, it was sufficient to sustain the defendant's 
convictions.  See Jones, 477 Mass. at 318.  Evidence of the GPS 
speed and location data, the video, and Rock's observations 
permit the reasonable inference that the defendant was the 
shooter. 
3.  Other issues.  We turn now to other issues raised on 
appeal that may recur upon retrial. 
 
a.  Maps depicting GPS evidence.  The defendant argues that 
admitting maps depicting his location information violated his 
confrontation rights under the Sixth Amendment to the United 
States Constitution and art. 12 of the Massachusetts Declaration 
of Rights because no one from the third-party company that 
generated the maps testified at trial.  Additionally, the 
defendant argues admission of the maps violated the rule against 
29 
 
hearsay.  Because this issue was not raised at trial, we review 
for a substantial risk of a miscarriage of justice.  See 
Commonwealth v. AdonSoto, 475 Mass. 497, 504 (2016).  We 
conclude it does not create such a risk. 
 
At trial, the Commonwealth introduced maps showing the 
defendant's latitude and longitude points reported from the ET1 
from 10:25 A.M. to 10:32 A.M.  Buck testified that the maps were 
created by BI collecting the latitudes and longitudes of GPS 
points over time and sending them to a third-party mapping 
company.  The mapping company would then produce a map 
encompassing all the points.20  Finally, BI would plot the points 
onto the map.  Although the record is not entirely clear how the 
points are plotted on the map, it appears they are generated by 
a computer.21 
 
 
20 Specifically, Buck stated at voir dire:  "What we do is 
if you're looking to provide a map we can do it for [twenty-
four] hours, or [fifteen] minutes, whatever you want.  What we 
do is we take the specifics of the request, we gather those 
latitude[s] [and] longitudes, we send them off to a mapping 
company, such as Google, and then they render back the maps that 
would be containing those latitude[s] [and] longitude[s] and 
then we take and we put dots on the map representing the 
latitude[s] [and] longitude[s] for display . . . ." 
 
 
21 At voir dire in response to a question asking how BI 
ensures the points on the maps are accurate, Buck testified:  
"Because nobody can get to them, nobody can do anything with 
them.  When they get into the SQL database they're encrypted so 
that nobody can actually change the data within the database." 
30 
 
 
"Hearsay requires a 'statement,' i.e., 'an oral or written 
assertion or . . . nonverbal conduct of a person, if it is 
intended by the party as an assertion.'" Commonwealth v. 
Thissell, 74 Mass. App. Ct. 773, 776-777 (2009), S.C., Thissell 
II, 457 Mass. 191, quoting Commonwealth v. Whitlock, 74 Mass. 
App. Ct. 320, 326 (2009).  See Mass. G. Evid. § 801(a).  Whether 
a computer record contains a statement depends on whether the 
record is "computer-generated," "computer-stored," or a hybrid 
of both.  Thissell II, supra at 197 n.13.  Computer-generated 
records are created solely by the mechanical operation of a 
computer and do not require human participation.  Commonwealth 
v. Royal, 89 Mass. App. Ct. 168, 171-172 (2016).  For this 
reason, they cannot be hearsay. 
 
With the exception of the defendant's name, all of the 
information included in the maps was computer-generated.  The 
latitude, longitude, and speed points in the text boxes were 
generated by the GPS technology.  The maps themselves were 
rendered by a computer at the third-party mapping company.  And 
the dots on the map were rendered by BI's computer system.  
Thus, because the maps -- with the exception of the defendant's 
name -- were computer generated, they do not contain a statement 
and are not hearsay.  Further, because the maps were not 
hearsay, they did not violate the confrontation clause.  See 
31 
 
Pytou Heang, 458 Mass. at 854, citing Commonwealth v. Hurley, 
455 Mass. 53, 65 n.12 (2009). 
 
b.  Authentication of the surveillance video.  The 
Commonwealth introduced a cell phone video of surveillance video 
that allegedly depicted the shooting.  The defendant objected at 
trial, arguing that the underlying surveillance video had not 
been authenticated.  He renews this argument on appeal.22  
Because defense counsel preserved this argument at trial, we 
review "to determine whether the judge abused [his] discretion 
and, if so, whether the error resulted in prejudice to the 
defendant."  Commonwealth v. Connolly, 91 Mass. App. Ct. 580, 
586 n.6 (2017).  We hold that the judge did not abuse his 
discretion in admitting the surveillance video. 
 
"To satisfy the requirement of authenticating or 
identifying an item of evidence, the proponent must produce 
evidence sufficient to support a finding that the item is what 
the proponent claims it is."  Mass. G. Evid. § 901(a).  See 
Mass. G. Evid. § 104(b).  See also Commonwealth v. Purdy, 459 
Mass. 442, 448-449 (2011).  Authenticating a surveillance video 
is "typically . . . done through one of two means -- having an 
eyewitness testify that the video is a fair and accurate 
 
22 The defendant does not argue that Carty's cell phone 
video was not authenticated.  His argument both at trial and on 
appeal pertains to the underlying surveillance video. 
32 
 
representation of what he saw on the day in question, or having 
someone testify about the surveillance procedures and the 
methods used to store and reproduce the video material."  
Connolly, 91 Mass. App. Ct. at 586.   
 
These are not, however, the exclusive ways a video can be 
authenticated.  In addition, "[e]vidence may be authenticated by 
circumstantial evidence alone, including its '[a]ppearance, 
contents, substance, internal patterns, or other distinctive 
characteristics.'"  Commonwealth v. Siny Van Tran, 460 Mass. 
535, 546 (2011), quoting Mass. G. Evid. § 901(b)(4).  See Purdy, 
459 Mass. at 448-449 ("A judge making a determination concerning 
the authenticity of a communication sought to be introduced in 
evidence may look to 'confirming circumstances' that would allow 
a reasonable jury to conclude that this evidence is what its 
proponent claims it to be"); Commonwealth v. Nardi, 452 Mass. 
379, 396 (2008), quoting Commonwealth v. LaCorte, 373 Mass. 700, 
704 (1977) (proof of authenticity may take form of testimony 
"that circumstances exist which imply that the thing is what its 
proponent represents it to be"). 
 
The defendant relies on Connolly, 91 Mass. App. Ct. at 586-
588, for the proposition that where secondary evidence is 
introduced regarding the contents of a video, the underlying 
video must also be authenticated.  This is true.  "Of course, 
had the video been available at trial, the Commonwealth would 
33 
 
have had to authenticate it before it could be admitted."  Id. 
at 586.  A proponent is not exempt from our rules of 
authentication if he or she introduces a video of a video, 
instead of introducing the underlying video itself. 
Here, however, the underlying video was authenticated 
through plentiful circumstantial evidence indicating a jury 
could find that it was what it purported to be.  Carty testified 
that he saw a car, with its driver's side door open, that had 
crashed into a pole at the intersection of Quincy Street and 
Baker Avenue.  Across the street from where the car was crashed, 
Carty found seven shell casings and several bullet fragments.  
In addition, Carty said multiple still photographs were fair and 
accurate representations of the scene of the shooting and the 
crash.  Among these photographs were multiple of a blue sedan -- 
the same color and body style as that of the car in the cell 
phone video of the surveillance video -- that had crashed into a 
light pole bearing signs designating Quincy Street and Baker 
Avenue.  At least one of the photographs depicted a sign in 
front of the crashed car; the sign advertised a church and was 
black and white with red lettering. In the cell phone video, the 
same sign is visible in front of the car. 
In addition, Carty viewed the surveillance video in the 
immediate aftermath of the shooting after he personally 
approached the resident to whom the surveillance system 
34 
 
belonged.  That mitigates concerns that the video could have 
been manipulated.  Compare Connolly, 91 Mass. App. Ct. at 588 
(fact that officer did not obtain surveillance video until  
month after incident and did not testify about circumstances 
that led him to view video raised concern that video could have 
been manipulated).  Finally, Rock's testimony that she heard a 
sound like a car backfiring or gunshots, and then saw a Black 
man with braids, wearing a red shirt, and with his hands in his 
pockets, provides further circumstantial evidence to 
authenticate the video.  Thus, the circumstantial evidence was 
sufficient to enable a reasonable jury to find that the video 
was what it purported to be.  The judge did not abuse his 
discretion in admitting it.23 
 
c.  Commonwealth's argument that jurors could identify the 
defendant from a video.  Finally, the defendant argues that it 
was improper for the Commonwealth to urge the jury to identify 
 
 
23 The defendant argues that the video's time stamp raises 
questions about its authenticity.  For most of the cell phone 
video of the surveillance video, the time stamp in the upper-
right corner is not visible.  However, sixteen seconds into the 
cell phone video, the surveillance video time stamp appears to 
show "9/15/2015 11:33."  The defendant argues that even if we 
assume that the time stamp is off by an hour, 10:33 A.M. would 
not match up with the supposed time of the shooting, according 
to the defendant's GPS data points.  It is true that an accurate 
and more visible time stamp could have helped to authenticate 
the video.  See Connolly, 91 Mass. App. Ct. at 588.  Yet, given 
the substantial other circumstantial evidence, a time stamp was 
not necessary to authenticate the video.  
 
35 
 
him as the shooter based on grainy video of someone who only 
matched his generic description.  This issue is unpreserved, and 
thus we review for a substantial risk of a miscarriage of 
justice.  See AdonSoto, 475 Mass. at 504. 
 
In the Commonwealth's opening, the prosecutor twice urged 
the jury to identify the defendant based on the video.  The 
prosecutor stated, "You are going to be able to see who the 
person is on that video and you are going to be able to compare 
it to the person sitting in [the defendant's] chair.  I submit 
to you . . . , you will be able to tell that it's Mr. Davis."24  
In closing, the prosecutor did not explicitly suggest that the 
jury could identify the defendant based on the video.  He only 
stated that the video, in conjunction with the other evidence, 
showed that the defendant had committed the crimes.25   
 
 
24 Later, the prosecutor stated, "You are going to see the 
video . . . .  There was someone that looks incredibly similar 
to Mr. Davis raising his hand letting off seven rounds at a car 
. . . ." 
 
 
25 For example, the prosecutor stated, "[T]here are numerous 
pieces of evidence which will allow you to find beyond a 
reasonable doubt that Mr. Davis is the person depicted in that 
video." 
 
 
The closest the prosecutor came in the closing to asking 
the jury to identify the defendant based on the video was 
commenting that the defendant "[h]appens to look like the 
shooter."  We discern no error with this statement because 
unlike the opening, the prosecutor did not state that the jury 
could identify the defendant based on the video alone.  Instead, 
he merely stated that the defendant's appearance was consistent 
with the shooter's. 
36 
 
 
The defendant and amici liken the prosecutor's comments to 
a single-suspect showup identification without any of the 
procedural protections required for such an identification.  See 
Commonwealth v. German, 483 Mass. 553, 563 (2019), quoting 
Supreme Judicial Court Study Group on Eyewitness Evidence:  
Report and Recommendations to the Justices 92 (July 25, 2013) 
("most significant of pre-identification warnings is that 'the 
offender may or may not be in the photo array or lineup, or the 
person being shown in a showup'"); Commonwealth v. Forte, 469 
Mass. 469, 477 (2014) ("An identification stemming from a 
videotape containing only one individual is analogous to a one-
on-one identification, which is considered inherently 
suggestive").  Further, the defendant and amici argue that the 
general characteristics of being a Black man with long braids or 
dreadlocks are not enough to support reasonable suspicion, let 
alone the inference that one could identify the defendant based 
on the video.  See Commonwealth v. Warren, 475 Mass. 530, 535-
536 (2016) (general description of three Black males, two with 
dark clothing and one with red "hoodie" not sufficient for 
reasonable suspicion); Commonwealth v. Cheek, 413 Mass. 492, 496 
(1992) (description of "black male with a black 3/4 length goose 
[jacket]" not enough for reasonable suspicion because it "could 
have fit a large number of men who reside in . . . a 
predominately black neighborhood of the city").  Moreover, amici 
37 
 
argue that the characterization of a Black man with braids is a 
prime trigger for implicit bias, due to stereotypical 
associations about criminality based on this description. 
 
"The proper function of an opening is to outline in a 
general way the nature of the case which the counsel expects to 
be able to prove or support by evidence" (citation omitted).  
Commonwealth v. Sylvia, 456 Mass. 182, 188 (2010).  "The 
prosecutor's expectation must be 'reasonable and grounded in 
good faith.'"  Id., quoting Commonwealth v. Fazio, 375 Mass. 
451, 456 (1978).  "Absent a showing of bad faith or prejudice 
. . . the fact that certain evidence fails to materialize is not 
a ground for reversal" (citation omitted).  Id.  "[A] claim of 
improper [opening statement] by the prosecutor must be judged in 
light of the entire [statement], the judge's instructions to the 
jury, and the evidence actually introduced at trial" (citation 
omitted).  Commonwealth v. Barbosa, 477 Mass. 658, 669 (2017). 
 
We agree with the defendant that the Commonwealth's 
suggestions that the jury could identify the defendant based on 
the video were unreasonable.  The video is not high enough 
resolution and is taken from too far away to be able to discern 
any features of the shooter's face.  Cf. Commonwealth v. 
Vasquez, 482 Mass. 850, 861 (2019) (eyewitness unfamiliar with 
suspect would likely be unable to make identification based on 
poor quality video).  All one can see is that the shooter is a 
38 
 
Black man with long hair in braids or dreadlocks that extend 
down to his midback.26  As amici point out, braided hairstyles 
are not uncommon among Black people.  Given the shooter's common 
hairstyle and the inability to see any of his facial features, 
it was unreasonable for the Commonwealth to ask the jury to 
identify the defendant as the shooter in the video.  See Sylvia, 
456 Mass. at 188 (prosecutor's statements in opening must be 
based on reasonable expectation of what evidence will show).  
Because we reverse the defendant's convictions on other grounds, 
we need not determine whether these improper statements gave 
rise to a substantial risk of a miscarriage of justice. 
 
Conclusion.  The judgments against the defendant are 
reversed, the verdicts are set aside, and the case is remanded 
to the Superior Court for a new trial and further proceedings 
consistent with this opinion.   
 
 
 
 
 
 
 
So ordered.   
 
 
26 At trial, to show what the defendant looked like around 
the time of the shooting, the Commonwealth introduced a 
photograph of him taken the following day.  The photograph 
depicts the defendant's face and shows that his hair is in what 
appear to be thin dreadlocks.  However, because the dreadlocks 
extend behind the defendant's shoulders, a viewer can only tell 
that they are longer than shoulder length and not whether they 
are as long as the shooter's, which extend to about midback. 
Even if the length of the defendant's hair was similar to that 
of the perpetrator in the video, such evidence still would have 
fallen short of evidence from which the jury could have 
identified the defendant as the perpetrator depicted in the 
video.