Title: People v. Schuller
Citation: N/A
Docket Number: S272237
State: California
Issuer: California Supreme Court
Date: August 17, 2023

IN THE SUPREME COURT OF 
CALIFORNIA 
 
THE PEOPLE, 
Plaintiff and Respondent, 
v. 
JASON CARL SCHULLER, 
Defendant and Appellant. 
 
S272237 
 
Third Appellate District 
C087191 
 
Nevada County Superior Court 
F16000111 
 
 
August 17, 2023 
 
Justice Groban authored the opinion of the Court, in which 
Chief Justice Guerrero and Justices Corrigan, Liu, Kruger, 
Jenkins, and Evans concurred. 
 
Justice Liu filed a concurring opinion, in which Justice Evans 
concurred. 
 
1 
PEOPLE v. SCHULLER 
S272237 
 
Opinion of the Court by Groban, J. 
 
 
California defines the crime of murder as the unlawful 
killing of a human being with malice aforethought.  The 
prosecution here relied on a theory of express malice, which 
requires an intent to unlawfully kill.  (See People v. Lasko (2000) 
23 Cal.4th 101, 107 (Lasko); Pen. Code, § 188.)  Under the 
doctrine of imperfect self-defense, however, “[i]f a person kills 
. . . in the unreasonable but good faith belief in having to act in 
self-defense, the belief negates what would otherwise be malice, 
and that person is guilty of voluntary manslaughter . . . , not 
murder.”  (People v. McCoy (2001) 25 Cal.4th 1111, 1116.)  A 
defendant charged with murder is entitled to an instruction on 
imperfect self-defense when there is substantial evidence to 
support the theory.  (See People v. Breverman (1998) 19 Cal.4th 
142, 162 (Breverman).) 
In this case, the Court of Appeal found that the trial court 
erred in denying defendant’s request for an instruction on 
imperfect self-defense.  The court further concluded that the 
error was a matter of state law only, and thus subject to the 
“reasonable probability” standard for evaluating prejudice set 
forth in People v. Watson (1956) 46 Cal.2d 818, 836 (Watson).  
The court explained, however, that even if it were to assume the 
instructional error was subject to the stricter “beyond a 
reasonable 
doubt” 
standard 
that 
applies 
to 
federal 
constitutional errors (see Chapman v. California (1967) 386 
U.S. 18, 24 (Chapman)), it would still find Schuller had suffered 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
2 
 
no prejudice based on the “overwhelming evidence that [he] was 
not acting in any form of self-defense.”  (People v. Schuller (2021) 
72 Cal.App.5th 221, 238 (Schuller).)  
We granted review to decide the appropriate standard for 
evaluating prejudice in this context.  We now hold that when the 
record contains substantial evidence of imperfect self-defense, 
the trial court’s failure to instruct on that theory amounts to 
constitutional error and is thus subject to review under the 
federal Chapman standard.  “A jury misinstruction that relieves 
the prosecution of its burden to prove an element of the crime — 
by either misdescribing the element or omitting it entirely — 
violates [the federal Constitution].”  (People v. Hendrix (2022) 
13 Cal.5th 933, 942 (Hendrix); see People v. Wilkins (2013) 
56 Cal.4th 333, 349 (Wilkins) [“incomplete” or “misleading” 
instruction on element of the crime constitutes federal 
constitutional error].)  When imperfect self-defense is at issue, 
the malice element of murder requires the People to show the 
absence of that circumstance beyond a reasonable doubt.  
(People v. Rios (2000) 23 Cal.4th 450, 463 (Rios).)  Thus, when 
there is substantial evidence to support the theory, the failure 
to instruct on imperfect self-defense amounts to an incomplete 
instruction on an actual element of murder, namely malice.  In 
the absence of such an instruction, jurors would have no reason 
to conclude they cannot find malice (and thus cannot return a 
verdict of murder) if they harbor a reasonable doubt as to 
whether the defendant acted in the actual, but unreasonable, 
belief in the need for self-defense.  Because this form of 
misinstruction precludes the jury from making a finding on a 
factual issue that is necessary to establish the element of malice, 
it qualifies as federal error.  (See In re Winship (1970) 397 U.S. 
358, 364 (Winship) [“the Due Process Clause protects the 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
3 
 
accused against conviction except upon proof beyond a 
reasonable doubt of every fact necessary to constitute the crime 
with which he is charged”]; Neder v. United States (1999) 
527 U.S. 1, 10 (Neder) [“erroneous instruction [that] precludes 
the jury from making a finding on the actual element of the 
offense” amounts to constitutional error].) 
We further hold that the Court of Appeal’s harmless error 
analysis did not comport with the standards for evaluating 
prejudice required under Chapman, supra, 386 U.S. 18.  As we 
recently clarified in In re Lopez (2023) 14 Cal.5th 562 (Lopez), 
that standard compels the reviewing court to reverse the 
conviction unless it concludes that no “rational juror who made 
the findings reflected in the verdict and heard the evidence at 
trial could have had reasonable doubt regarding the findings 
necessary to convict the defendant [absent the instructional 
error].”  (Id. at p. 591.)  Because the court’s analysis indicates 
that it did not “fully appreciate[] the proper standard for 
harmlessness” (id. at p. 568), we reverse the judgment affirming 
Schuller’s conviction and remand the matter with directions 
that the court reconsider whether the failure to instruct on 
imperfect self-defense was harmless beyond a reasonable doubt.  
(See id. at p. 592 [remanding question of prejudice where court’s 
analysis showed it did not apply the standard that Chapman 
requires].) 
I. 
BACKGROUND 
 
The Nevada County District Attorney charged defendant 
Jason Schuller with the first degree murder of W.T. and further 
alleged that Schuller had personally used and discharged a 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
4 
 
firearm causing death.  (Pen. Code, §§ 187, 12022.53.)1  Schuller 
pleaded not guilty by reason of insanity and the case proceeded 
to trial.  
A. Trial Court Proceedings 
1. Evidence at trial 
a. Prosecution’s case-in-chief 
Jesse McKenna, W.T.’s neighbor and close friend, testified 
that Schuller visited W.T. frequently and had temporarily lived 
at his residence.  In early 2016, however, W.T. told McKenna 
that Schuller was no longer welcome at his home.  On the night 
of March 20, 2016, McKenna returned from a dinner and was 
surprised to see Schuller’s vehicle, a white Chrysler 300, parked 
outside of W.T.’s home.  Shortly after McKenna entered his 
house, he heard multiple rounds of gunshots and then saw 
Schuller’s car speed away from W.T.’s home.   
As McKenna approached W.T.’s residence he saw W.T.’s 
daughter H.T., who lived in a second-floor unit directly above 
W.T., pacing in front of the window.  McKenna knocked on H.T.’s 
door and asked her if she had heard gunshots.  She said she was 
uncertain what she had heard, but that a noise had caused her 
apartment to rattle.  McKenna then went downstairs to check 
on W.T.  When he entered the residence, he saw “flames coming 
out of [the] house” and W.T.’s burning body lying on the floor.  
McKenna ran back to his house to retrieve a fire extinguisher.  
When he returned, H.T. had come down to her father’s 
apartment.  As McKenna tried to put out the fire, he noticed that 
all four burners of the gas stove had been opened and “turned 
on full bore without flames,” like someone was trying to “blow 
 
1  
All further statutory citations are to the Penal Code. 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
5 
 
the place up.”  McKenna called 911 and provided a description 
of Schuller’s car.  
H.T. testified that Schuller had become friends with her 
father and started staying on his couch from time to time.  On 
the night of March 20, 2016, she observed Schuller’s car parked 
outside her father’s apartment.  Shortly thereafter, she heard a 
succession of sounds like metal hitting metal coming from the 
residence and then “a very loud sound that physically shook the 
house.”  She then observed Schuller’s vehicle leaving the home 
at a high rate of speed.  When H.T. entered the apartment, she 
observed smoke and her father’s body lying on the ground 
surrounded by shell casings, with his dentures out of his mouth. 
Shortly after Schuller was seen leaving W.T.’s residence, 
police began pursuing a white Chrysler 300 in the area.  
Schuller was driving the vehicle and refused to stop, resulting 
in a 38-mile high-speed pursuit that ended only after the 
vehicle’s tires were punctured with strip spikes.  The handgun 
used in the shooting of W.T. was found in the car.  
Investigating officers testified that 13 shell casings were 
recovered from the area near W.T.’s body.  A gun case, a gas can 
and a large knife were found on the kitchen table.  Although 
there was significant blood spatter on the walls and floor, there 
was no blood on the knife.  W.T.’s cell phone was found under 
the table with a bullet lodged in it.  The apartment had 
sustained fire damage and smelled of gas.  Nevada County Fire 
District Chief Jim Turner determined that gasoline had been 
poured on the body and ignited.  An autopsy revealed W.T. had 
sustained nine gunshot wounds to the left side of his head, with 
five shots entering the “facial area” and four shots entering 
above his ear in the “cranial area.”  W.T.’s body also exhibited 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
6 
 
significant burn injuries.  According to the pathologist, the 
nature of the burn markings indicated W.T.’s body had been 
ignited after he was dead.  
b. The defense’s case 
Schuller testified that he met W.T. after moving from 
Nebraska to California in 2013.  Over the next few years, 
Schuller lived with W.T. from time to time and visited him often.  
In 2016, Schuller was injured in a car accident and began 
experiencing visions of his dead ancestors and a “beautiful 
light.”  He described the light as “a gift of god” and had heard 
voices telling him to be “careful who [he] share[d] the light with.”  
Schuller stated that he believed he was sent to “pave the way 
for the second coming . . . of Christ” and that a battle was being 
fought with “Satan’s army.”  In March of 2016, Schuller drove to 
Nebraska in response to voices directing him to perform an 
operation there.  Schuller claimed that during his drive to 
Nebraska he was shot at and attacked with grenades but did not 
suffer any injuries.  
While in Nebraska, Schuller visited his sister.  She 
testified that Schuller seemed to be experiencing visual and 
auditory hallucinations at the time of the visit, telling her that 
people were “following him” and telling him to shut up.  His 
sister also reported that Schuller appeared to be in fear for his 
life and was uncharacteristically aggressive.  
Schuller eventually decided to drive back to California.  
One day before the killing of W.T., Nevada police officers 
stopped Schuller on suspicion of reckless driving.  Schuller told 
the officers that three men were trying to attack him with 
needles.  He further stated that “the entire police force and 
agencies of the world [we]re letting Satan” do something and 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
7 
 
commented on the “fake light.”  At one point, an officer stepped 
on an aluminum strip that produced a popping noise, causing 
Schuller to believe a gunshot had been fired and that the officers 
were trying to hurt him.  The officers eventually allowed 
Schuller to go, believing he was not a danger to himself or 
others.  
Schuller testified that he arrived back in California on 
March 20 and went straight to W.T.’s house.  After the two had 
shared several drinks, W.T. asked Schuller to get rid of a firearm 
that Schuller had stored at W.T.’s house.  W.T. retrieved the gun 
and placed it in a case on the kitchen table, asking Schuller to 
take it with him when he left the next morning.  
Schuller explained that he “ended up sharing the light 
with” W.T., who initially experienced “over-whelming joy.”  
Later in the night, however, Schuller shared the light with W.T. 
again, but was unable to get the light back.  Schuller testified 
that W.T. looked outside with a smile on his face and said, “See, 
I told you I could take it from him.”  W.T. then pulled a knife 
from a kitchen drawer and tried to “stab at [Schuller].”   
Schuller grabbed the gun on the kitchen table and asked 
W.T. if he was “Lucifer,” to which W.T. responded yes.  Schuller 
stated that he then put the gun down and said, “Yeah, right, 
. . . .  You’re not Lucifer.”  As soon as Schuller set the gun down, 
W.T. “went for the gun and raised the knife.”  Schuller then 
picked the gun up again, took a step back, and “pulled the 
trigger.”  Schuller said he was “in fear for [his] life” because W.T. 
had a “big knife.”  
Schuller was uncertain whether he fired more than one 
shot but recalled the bullet hitting W.T. “right in the head and 
he went down to the ground.  The knife . . . f[ell] out of his hand.”  
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
8 
 
Schuller testified that W.T. then “pushed himself up off the 
ground,” which “shocked” Schuller, causing him to “jump[] back” 
and “pull[ the trigger] four or five more times.”   Schuller could 
not recall how the knife got back on the table.  When asked why 
he shot W.T. four or five more times, Schuller testified he was 
“scared” because W.T. had yelled “You f’d up” and was then able 
to “push himself up . . . off the ground . . . without hesitation.”  
After firing the second round of shots, Schuller retrieved 
W.T.’s cell phone and attempted to call 911.  However, he was 
unable to unlock the phone, which kept ringing.  Schuller then 
heard a loud gasp and saw W.T.’s dentures fly at him, which 
scared Schuller again, causing him to “pull the trigger three 
more times.”  Schuller continued trying to call 911 with W.T.’s 
phone, but the phone kept ringing so Schuller shot it several 
times.  Schuller finally decided to leave the residence but felt “a 
hundred thousand demons [sweep] through” him.  Schuller 
turned and saw a demon enter W.T.’s body.  Schuller attempted 
to “kill the demon” by pouring gasoline on W.T.’s body and 
igniting it.  Schuller then left the home to travel to Monterey. 
 
On cross-examination, Schuller admitted that in his 
initial statements to the police he never claimed to have shot 
W.T. in self-defense because he “did not know who to trust.”  
Instead, Schuller had told the police W.T. was gay and trying to 
come on to him.  
c. Prosecution’s rebuttal witnesses  
A detective testifying as a rebuttal witness for the 
prosecution explained that he had monitored calls Schuller 
made to friends and family from jail after his arrest.  According 
to the detective, Schuller appeared “lucid and normal” during 
his initial conversations about the case.  In subsequent calls 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
9 
 
Schuller revealed that he intended to pursue a “mental health 
defense.”  After that intent became clear, the detective noticed a 
difference in how Schuller talked in his conversations.  He began 
speaking “much more” about conspiracy theories, including “law 
enforcement conspiring against him” and “angels and demons 
. . . [a]ffecting things in his everyday life.”  
 
The prosecution also called two forensic psychologists who 
had been appointed by the court to evaluate Schuller.  The first 
psychologist opined that defendant was exaggerating or feigning 
psychiatric distress.  The psychologist did not believe Schuller 
was mentally ill but acknowledged that his extensive drug use 
could have caused hallucinations.  The psychologist testified 
that Schuller’s decision to burn W.T.’s body and then attempt to 
evade police demonstrated knowledge of wrongdoing and an 
understanding of consequences. 
The second psychologist likewise testified that she 
believed defendant was “malingering or exaggerating his mental 
health condition.”  The psychologist noted that during Schuller’s 
initial recorded jailhouse conversations, he had discussed his 
case at length but made no mention of any psychiatric 
symptoms, hallucinations, seeing demons or any of the problems 
that he later described to the psychologist.  
2. Defense’s request for instruction on imperfect self-
defense  
Prior to closing argument, the defense requested an 
instruction on voluntary manslaughter based on imperfect self-
defense.  The prosecution opposed, arguing that Schuller’s 
testimony demonstrated that any alleged belief in the need to 
defend himself was the result of delusions, and thus amounted 
to a claim of insanity that could only be raised in the sanity 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
10 
 
phase of the trial.  (See People v. Elmore (2014) 59 Cal.4th 
121, 130, 146 (Elmore) [“the doctrine of unreasonable self-
defense is [not] available when belief in the need to defend 
oneself is entirely delusional”; such a claim must instead be 
raised at “a sanity trial”].)   
The defense, however, argued that Schuller’s imperfect 
self-defense claim was not based on “purely delusional belief[s]” 
(Elmore, supra, 59 Cal.4th at p. 130), but rather was supported 
by the objective circumstances of the crime scene.  Specifically, 
Schuller had testified that W.T. attempted to attack him with a 
knife while reaching for a firearm, and a knife and an empty gun 
case had been recovered from the kitchen table.  According to 
the defense, while Schuller’s testimony suggested his reactions 
to W.T. may have been “distorted by mental illness,” there was 
nonetheless sufficient evidence to support a finding that he 
mistakenly believed the actual circumstances required him to 
act in self-defense.  (See id. at p. 146 [“defendants who 
mistakenly believed that actual circumstances required their 
defensive act may argue they are guilty only of voluntary 
manslaughter, even if their reaction was distorted by mental 
illness”].) 
The trial court ultimately sided with the prosecution, 
concluding that Schuller’s testimony demonstrated his “reaction 
[to W.T.] was produced by the mental disturbance alone, which 
is the very thing that the cases talk about as being for the sanity 
phase, not for the guilt phase.”  The court acknowledged that a 
knife was found on the kitchen table but concluded that was 
insufficient to warrant an instruction on imperfect self-defense.  
The court did, however, instruct the jury that it could consider 
evidence of Schuller’s mental condition “in deciding whether [he 
had] acted with deliberation and premeditation.”  
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
11 
 
3. Closing argument and jury verdict 
Because Schuller had admitted that he intentionally shot 
W.T. in the head and the trial court had denied his request for 
an instruction on imperfect self-defense, the sole issue contested 
at closing argument was whether Schuller should be found 
guilty of premeditated first degree murder or second degree 
murder.   
The prosecution emphasized to the jury that “self-defense 
was [not] an option . . . in this case” and that there was “no legal 
self-defense argument that [it could] even consider.”  The 
prosecution explained that in light of the absence of any such 
possible defense, the element of malice had been conclusively 
established by Schuller’s admission that he repeatedly shot 
W.T. in the head.  The prosecution further contended that the 
manner of the killing and Schuller’s subsequent attempts to 
burn the body and evade the police showed he had acted not only 
with malice, but also with deliberation and premeditation.  
Finally, the prosecution discussed how the jury should evaluate 
the “mental health evidence,” noting that multiple psychologists 
had testified Schuller appeared to be exaggerating his condition 
as a means to avoid criminal liability.   
In response, the defense argued that Schuller’s testimony 
showed he was suffering from a “severe mental health crisis” 
that had caused him to believe W.T. was “a physical threat . . . 
and that is why he killed.”  The defense theorized that Schuller’s 
“delusional state of mind” had led him to believe that “W.T. was 
allied with forces of darkness” and “react[] to things that weren’t 
there.”  According to Schuller, this evidence raised at least a 
reasonable doubt whether his “paranoid beliefs” had caused him 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
12 
 
to act out of a perceived fear for his life rather than with 
deliberation and premeditation.  
The jury found Schuller guilty of first degree murder.  
Following the determination of guilt, the trial proceeded to the 
sanity phase.  The jury was unable to reach a decision on that 
issue and a second jury was empaneled.  The second jury found 
that Schuller was legally sane at the time of the shooting.   
B. Court of Appeal Proceedings 
On appeal, Schuller argued the trial court erred in 
refusing to instruct on imperfect self-defense because the 
evidence showed his fear of W.T. was not based purely on 
delusion.  The appellate court agreed, concluding that Schuller’s 
account of the “shooting was not entirely delusional.”  (Schuller, 
supra, 72 Cal.App.5th at p. 233.)  The court explained that 
Schuller had testified he feared for his life because W.T. had 
come at him with a knife and a knife had been found at the scene 
of the crime.   
Having found error, the court next evaluated whether 
Schuller had suffered prejudice.  The parties disputed whether 
the instructional error amounted to a violation of state law, 
requiring the court to evaluate prejudice under the “reasonably 
probable” standard articulated in Watson, supra, 46 Cal.2d 818, 
or a violation of the federal Constitution, requiring prejudice to 
be evaluated under the “beyond a reasonable doubt” standard 
set forth in Chapman, supra, 386 U.S. 18.  While acknowledging 
some courts had applied the Chapman standard to a trial court’s 
failure to instruct on imperfect self-defense (see People v. 
Dominguez (2021) 66 Cal.App.5th 163; People v. Thomas (2013) 
218 Cal.App.4th 630), the court found that our prior decisions in 
Breverman, supra, 19 Cal.4th 142, and People v. Gonzalez (2018) 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
13 
 
5 Cal.5th 186 (Gonzalez), compelled Watson review.  The court 
further concluded, however, that the error was harmless under 
both the Watson and Chapman standards.  
Schuller filed a petition seeking review of the appellate 
court’s finding that the failure to instruct on imperfect self-
defense was not prejudicial. 
II. 
DISCUSSION 
The sole question presented in this case is whether the 
trial court’s error in declining Schuller’s request for an 
instruction on imperfect self-defense was prejudicial.2  To 
answer this question, we must address two issues.  First, we 
must decide what standard for evaluating prejudice — 
Chapman or Watson — applies to this form of instructional 
error.  Second, we must assess the Court of Appeal’s finding that 
the error was harmless. 
 
2  
Although the Court of Appeal noted that Schuller’s 
instructional 
claim raised 
an 
apparent 
issue 
of 
first 
impression — whether imperfect self-defense is available when 
“a defendant’s story is that a real person attacked him, but there 
are delusional components to the defendant’s description of 
what happened” (Schuller, supra, 72 Cal.App.5th at p. 233) — 
the People did not seek review of the court’s finding that it was 
error to deny an instruction under such circumstances.  Nor 
have they raised that issue in their briefing before this court.  
Accordingly, we have no occasion to evaluate whether Schuller’s 
testimony that W.T. threatened him with a knife was sufficient 
to support an instruction on imperfect self-defense.  We proceed 
under the assumption that such an instruction should have been 
provided.   
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Opinion of the Court by Groban, J. 
 
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A. Does Watson or Chapman Review Apply?  
1. Overview of standards for evaluating prejudice 
“The ‘generally applicable California test for harmless 
error’ is set forth in Watson, supra, 46 Cal.2d 818.  [Citation.]  
Under the Watson test, we deem an error harmless unless it is 
‘reasonably probable’ the outcome would have been different in 
the absence of the error.  [Citation.]  As a general matter, this 
test applies to ‘ “ ‘incorrect, ambiguous, conflicting, or wrongly 
omitted 
instructions 
that 
do 
not 
amount 
to 
federal 
constitutional error.’ ” ’ [Citation.]  
“ ‘In contrast, we evaluate the harmlessness of violations 
of the federal Constitution under the standard set forth in 
Chapman[, supra, 386 U.S. 18].’  [Citation.]  This ‘stricter’ 
standard of review requires reversal unless the error is 
‘harmless beyond a reasonable doubt.’  [Citation.]  Among the 
constitutional 
errors 
subject 
to 
Chapman 
review 
is 
misinstruction of the jury on one or more elements of the offense.  
[Citation.]  This is because the federal Constitution requires 
‘criminal convictions to rest upon a jury determination that the 
defendant is guilty of every element of the crime with which he 
is charged, beyond a reasonable doubt.’ ”  (Hendrix, supra, 
13 Cal.5th at p. 942.)  Applying those principles, we have held 
that Chapman review applies to instructional errors that 
“misdescribe[]” (Hendrix, at p. 942) an element of the charged 
offense or are otherwise “incomplete and misleading” (Wilkins, 
supra, 56 Cal.4th at p. 349) with respect to the findings 
necessary to prove an element of the offense.  (See People v. 
Brooks (2017) 3 Cal.5th 1, 69.)  The key inquiry is whether the 
instruction operated to “preclude[] the jury from making a 
finding” (Neder, supra, 527 U.S. at p. 10) on any fact necessary 
to establish an element of the offense.  (See Winship, supra, 
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Opinion of the Court by Groban, J. 
 
15 
 
397 U.S. at p. 364 [due process requires prosecution to prove 
“beyond a reasonable doubt . . . every fact necessary to 
constitute the [charged] crime”].)  
Here, Schuller argues that the trial court’s denial of a 
request to instruct on imperfect self-defense operated to 
misdescribe the malice element of murder, and thus constitutes 
federal constitutional error.  The Attorney General, in contrast, 
argues that because “the absence of imperfect self-defense is 
[not] an element of malice murder,” the error is one “of state law 
only.”  He further contends that our prior decisions have 
repeatedly held that this form of instructional error amounts to 
a failure to instruct on a lesser included offense and is thus 
“governed by Watson.” 
2. Summary of applicable legal principles governing 
imperfect self-defense 
California law separates criminal homicide into two 
classes:  the greater offense of murder and the lesser offense of 
manslaughter.  (See Rios, supra, 23 Cal.4th at p. 460.)  Murder 
is defined as “the unlawful killing of a human being . . . with 
malice aforethought” (§ 187, subd. (a)),  while manslaughter is 
defined as “the unlawful killing of a human being without 
malice” (§ 192).  Thus, the “distinguishing feature [between the 
two offenses] is that murder includes, but manslaughter lacks, 
the element of malice.”  (Rios, at p. 460.)  Malice exists when “an 
unlawful homicide was committed with the ‘intention 
unlawfully to take away the life of a fellow creature’ (§ 188), or 
with awareness of the danger and a conscious disregard for life.”  
(Rios, at p. 460.)3 
 
3  
While the Penal Code recognizes these two distinct forms 
of malice — commonly referred to as express and implied 
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Opinion of the Court by Groban, J. 
 
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“Generally, the intent to unlawfully kill constitutes 
malice.”  (Breverman, supra, 19 Cal.4th at p. 153.)  However, 
California law recognizes two circumstances where “a finding of 
malice may be precluded, and the offense limited to 
manslaughter, even when an unlawful homicide was committed 
with intent to kill” (Rios, supra, 23 Cal.4th at p. 460):  (1) when 
a person kills “ ‘ “in a ‘sudden quarrel or heat of passion’ 
[citation], or . . . [(2) when a person] kills in ‘unreasonable self-
defense’ — the unreasonable but good faith belief in having to 
act in self-defense [citations].” ’ ”  (Ibid.)  “These mitigating 
circumstances reduce an intentional, unlawful killing from 
murder to voluntary manslaughter ‘by negating the element of 
malice that otherwise inheres in such a homicide [citation].’ ”  
(Id. at p. 461, quoting Breverman, at p. 154.)  The circumstance 
at issue in this case, imperfect self-defense, “obviates malice 
because that most culpable of mental states ‘cannot coexist’ with 
an actual belief that the lethal act was necessary to avoid one’s 
own death or serious injury at the victim’s hand.”  (Rios, at 
p. 461; see Elmore, supra, 59 Cal.4th at p. 134 [“ ‘ “A person who 
actually believes in the need for self-defense necessarily believes 
he is acting lawfully.”  [Citation.]  Because express malice 
requires an intent to kill unlawfully, a killing in the belief that 
one is acting lawfully is not malicious’ ”].)  A defendant charged 
with murder is entitled to an instruction on imperfect self-
defense if there is substantial evidence to support the theory.  
(See Elmore, at p. 134; Breverman, supra, 19 Cal.4th at p. 162.)   
Thus, the relationship between murder and voluntary 
manslaughter — and more specifically the relationship between 
 
malice — in this case Schuller has conceded that he intended to 
kill the victim but contends he did so in imperfect self-defense. 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
17 
 
murder and unreasonable self-defense — is somewhat “unique” 
in our criminal law.  (Rios, supra, 23 Cal.4th at p 459.)  While 
“closely resembl[ing] an affirmative defense” (People v. Barton 
(1995) 12 Cal.4th 186, 199), imperfect self-defense is “not a true 
defense; rather, it is a shorthand description of one form of 
voluntary manslaughter.  And voluntary manslaughter . . . is 
not a defense but a crime . . . .”  (Id. at p. 200.)   
We have previously held that given how California has 
chosen to structure its homicide laws, when imperfect self-
defense is at issue in a murder case, the People must prove the 
absence of that circumstance “beyond a reasonable doubt . . . in 
order to establish the . . . element of malice.”  (Rios, supra, 
23 Cal.4th at p. 462, italics omitted.)  The state’s duty to 
disprove imperfect self-defense follows from the high court’s 
decision in Mullaney v. Wilbur (1975) 421 U.S. 684 (Mullaney), 
which considered the constitutionality of a Maine homicide law 
that placed the burden of proving provocation as a means of 
negating the malice element of murder on the defendant.  Maine 
defined murder as an unlawful killing with malice aforethought 
and defined malice as an intentional killing in the absence of 
provocation.  It defined manslaughter as an intentional killing 
without malice.  (Id. at pp. 684–687, 696–698.)  Thus, as in 
California, the offense of murder in Maine required malice (id. 
at p. 684), with “heat of passion on sudden provocation” (id. at 
p. 703) operating to negate malice and reduce the crime to 
manslaughter.  Maine, however, placed the burden of proving 
heat of passion on the defendant.   
The Supreme Court held that under this statutory 
scheme, placing the burden of proving heat of passion on the 
defendant violated “the due process requirement, as defined in 
[Winship, supra, 397 U.S. at p. 364], that the prosecution prove 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
18 
 
beyond a reasonable doubt every fact necessary to constitute the 
crime charged.”  (Mullaney, supra, 421 U.S. at p. 685.)  In its 
analysis, the court acknowledged that “as a formal matter[,] the 
absence of the heat of passion on sudden provocation is not a 
‘fact necessary to constitute the crime’ of [murder] in Maine.”  
(Id. at p. 697.)  The court concluded, however, that the rule of 
Winship is “concerned with substance rather than . . . 
formalism” (Mullaney, at p. 699), and because “Maine ha[d] 
chosen to distinguish those who kill in the heat of passion from 
those who kill in the absence of this factor” (id. at p. 698), due 
process required the state to prove the absence of heat of passion 
beyond a reasonable doubt.  (See id. at p. 704.) 
Since Mullaney was decided, we have repeatedly cited the 
decision in support of the proposition that when provocation or 
imperfect self-defense are at issue, the prosecution is compelled 
to disprove those circumstances beyond a reasonable doubt.  
(See Rios, supra, 23 Cal.4th at p.  462; People v. Bloyd (1987) 
43 Cal.3d 333, 349; cf. Smith v. United States (2013) 568 U.S. 
106, 110 (Smith).)  California’s standard jury instructions on 
voluntary manslaughter include this requirement.  (CALCRIM 
Nos. 570, 571.) 
3. The instructional error qualifies as a violation of 
the federal Constitution 
Although our standard instructions do not suffer the same 
defect at issue in Mullaney, we agree with Schuller that the high 
court’s holding bears equally on the error at issue here — a 
failure to instruct on these theories when substantial evidence 
supports them.  Given how California has chosen to structure 
the relationship between murder and voluntary manslaughter, 
a trial court’s failure to instruct on imperfect self-defense 
amounts to an incomplete instruction on the malice element of 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
19 
 
murder and is therefore subject to Chapman review for 
constitutional error.  (See Wilkins, supra, 56 Cal.4th at p. 349 
[Chapman review applies to “incomplete” or “misleading” 
instruction on element of the crime].)   
As explained above, the high court’s holding in Mullaney 
makes clear that when substantial evidence of imperfect self-
defense is present, the malice element of murder requires the 
People to prove beyond a reasonable doubt not only that the 
defendant committed an unlawful, intentional killing, but also 
that the defendant did not kill in an actual but unreasonable 
belief in the need for self-defense.  (See Mullaney, supra, 
421 U.S. at p. 704 [“the Due Process Clause requires the 
prosecution to prove beyond a reasonable doubt the absence of 
the heat of passion on sudden provocation when the issue is 
properly presented in a homicide case”]; see also Rios, supra, 
23 Cal.4th at p. 462 [“If the issue of provocation or imperfect 
self-defense is . . . ‘properly presented’ in a murder case 
[citation], the People must prove beyond reasonable doubt that 
these circumstances were lacking in order to establish the 
murder element of malice” (italics omitted)]; ante, at pp. 15–18.)  
Stated more simply, because malice is absent when imperfect 
self-defense is present, the prosecution cannot prove malice 
without disproving imperfect self-defense.4  (See Rios, at p. 461 
[evidence of imperfect self-defense “is relevant . . . to determine 
whether malice has been established, thus allowing a conviction 
 
4  
These rules of course apply only when imperfect self-
defense is at issue.  If a person has been charged with murder 
and there is no evidence that would support a finding of 
imperfect self-defense, the question of imperfect self-defense is 
not part of the malice inquiry.  (See generally Rios, supra, 
23 Cal.4th at pp. 461–462.)   
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
20 
 
of murder, or has not been established, thus . . . limiting the 
crime to . . . voluntary manslaughter” (italics omitted)].)   
Without an instruction on imperfect self-defense, the 
jurors in this case were never informed that if they harbored a 
reasonable doubt whether Schuller was operating under an 
actual but unreasonable belief in the need for self-defense, they 
were required to acquit him of murder for lack of malice.  (Cf. 
Wilkins, supra, 56 Cal.4th at p. 348 [applying Chapman review 
where the trial court failed to instruct jury that the continuous 
transaction element of felony murder was absent if the 
defendant “had reached a place of temporary safety before the 
fatal act occurred”].)  Indeed, the record demonstrates that at 
closing argument the prosecution told the jury the element of 
malice had been conclusively established because Schuller 
admitted he intentionally shot the victim and had failed to 
proffer any legally valid theory of self-defense.  Schuller, in turn, 
was unable to argue to the jury that he lacked the requisite 
malice to have committed murder, arguing only that his 
perceptions of W.T.’s conduct raised a reasonable doubt as to 
whether the killing was committed with deliberation and 
premeditation.  In other words, the lack of instruction forced 
Schuller 
to 
concede, 
and 
enabled 
the 
prosecution 
to 
affirmatively argue, that Schuller’s belief in the need to defend 
himself was entirely immaterial to the jury’s determination of 
malice.  Thus, on the record before us, it is clear the trial court’s 
misinstruction precluded the jury from making a factual 
finding — the absence of imperfect self-defense beyond a 
reasonable doubt — that was necessary to prove an “actual 
element” of the charged offense of murder — malice.  (Neder, 
supra, 527 U.S. at p. 10, italics omitted.)  Chapman review is 
therefore appropriate.  
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
21 
 
The Court of Appeal reached a different conclusion, 
reasoning that whatever merit there might be in Schuller’s 
theory of federal constitutional error, two prior decisions of this 
court — Breverman, supra, 19 Cal.4th 142, and Gonzalez, supra, 
5 Cal.5th 186 — have held that this form of instructional error 
amounts to a violation of state law only.  The Attorney General 
presents a similar argument, contending that “[t]hese 
authorities strongly suggest that the issue in this case is 
settled.”  We disagree. 
In Breverman, supra, 19 Cal.4th 142, we held that 
manslaughter qualifies as a lesser included offense of murder, 
and thus a trial court has a sua sponte duty to instruct on heat 
of passion and imperfect self-defense when the evidence raises 
a question as to those issues.  (See id. at pp. 153–155.)  However, 
we rejected the defendant’s assertion that a trial court’s failure 
to instruct on those issues qualifies as a violation of the federal 
Constitution.  (Id. at p. 165.)  Noting that the high court had 
never “recogniz[ed] a federal constitutional right to instructions 
on lesser included offenses in noncapital cases” (ibid.), we held 
that “the rule requiring sua sponte instructions on all lesser 
necessarily included offenses supported by the evidence derives 
exclusively from California law” (id. at p. 169).  Thus, any 
violation of that duty was subject to review under Watson’s 
reasonable probability standard.    
Notably, however, in a dissenting opinion that directly 
tracks the argument Schuller presents here, Justice Kennard 
argued the instructional error amounted to a violation of the 
federal Constitution.  (See Breverman, supra, 19 Cal.4th at 
p. 190 (dis. opn. of Kennard, J.) [“murder instructions that fail 
to inform the jury it may not find the defendant guilty of murder 
if heat of passion is present are incomplete instructions on the 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
22 
 
element of malice”].)  In a responding footnote, the majority 
explained that it need not address whether the misinstruction 
had “caused the definition of the malice element of murder . . . 
to be incomplete” (id. at p. 170, fn. 19, italics omitted) because 
the defendant never raised that specific argument.  The majority 
concluded that the “merits” of such a theory should “await a case 
in which they have been clearly raised and fully briefed.”  (Ibid.; 
see People v. Moye (2009) 47 Cal.4th 537, 558, fn. 5 [declining to 
address whether failure to instruct on provocation resulted in 
incomplete definition of malice because the defendant had not 
raised that theory]; Lasko, supra, 23 Cal.4th at p. 113 
[acknowledging that the Breverman majority had “declined to 
consider whether [failure to instruct on provocation] violated the 
federal Constitution by giving the jury an incomplete definition 
of malice, an element of murder”].)  Having specifically 
preserved consideration of the theory of constitutional error that 
Schuller raises here, Breverman cannot be said to preclude those 
arguments.   
In Gonzalez, supra, 5 Cal.5th 186, we addressed whether 
the trial court’s failure to instruct on second degree murder (and 
various other lesser forms of homicide) in a felony murder case 
had been rendered harmless by the jury’s true finding on a 
special circumstance allegation that the murder was committed 
during a robbery.  In deciding that question, we applied 
Breverman’s rule that “[t]he failure to instruct on lesser 
included offenses supported by substantial evidence [is] state 
law error.”  (Gonzalez, at p. 196.)  We did not address, nor did 
the defendant raise, the theory of federal constitutional error 
that Justice Kennard discussed (and that the majority left open) 
in Breverman.  Indeed, it does not appear that theory would 
have had any relevance to the type of error at issue in Gonzalez 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
23 
 
because the omitted instructions in that case — lesser forms of 
homicide — did not operate to negate or otherwise modify the 
elements of the charged offense of felony murder, which does not 
require a showing of malice.  (See People v. Dillon (1983) 
34 Cal.3d 441, 475 [“malice is not an element of felony 
murder”].)  Accordingly, we find nothing in Gonzalez that 
forecloses us from finally addressing the theory of error that 
Schuller raises here. 
The People argue that even if Breverman and Gonzalez do 
not foreclose us from considering Schuller’s argument regarding 
constitutional error, we should nevertheless reject that 
argument on the merits.  While acknowledging that Chapman 
review applies to a trial court’s failure to properly instruct on an 
element of the charged offense, the Attorney General contends 
the absence of imperfect self-defense is not an element of 
murder, but rather amounts only to “an exculpatory theory  . . . 
similar to a defense.”  (See, e.g., People v. Martinez (2003) 
31 Cal.4th 673, 685 [for purposes of deciding whether foreign 
conviction satisfies prior murder special circumstance (see 
§ 190.2, subd. (a)(2)), the absence of imperfect self-defense does 
not qualify as an element of murder].)  Thus, the Attorney 
General 
reasons, 
cases 
applying 
Chapman 
review 
to 
instructions that relate to an element of the offense are 
inapplicable.   
The Attorney General overlooks that Chapman review 
applies not only to instructions that omit an element of the 
offense, but also to instructions that provide an incomplete or 
misleading description of what is necessary to establish an 
element of the offense.  (See Hendrix, supra, 13 Cal.5th at 
p. 942; Wilkins, supra, 56 Cal.4th at p. 349.)  And as discussed 
above, it is well established that when imperfect self-defense is 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
24 
 
at issue, the prosecution cannot establish malice without 
proving the absence of that circumstance beyond a reasonable 
doubt.  Because of that requirement, without an instruction on 
imperfect self-defense, the jury is left unable to properly 
evaluate whether the prosecution has sustained its burden to 
prove malice.  More specifically, the jury is left unaware that 
even if the prosecution has proven that the defendant intended 
to kill — a circumstance that generally demonstrates express 
malice — the jury cannot find malice if it has a reasonable doubt 
whether the defendant killed in imperfect self-defense.  Thus, 
the failure to instruct on that issue rendered the description of 
malice —which is unquestionably an element of murder — 
incomplete.  
Finally, the Attorney General disagrees with our 
conclusion that under Mullaney, supra, 421 U.S. 684, the State 
has a constitutional duty to disprove imperfect self-defense 
beyond a reasonable doubt when that theory is presented in a 
murder case.  (See ante, at pp. 17–18.)  He contends that two 
subsequent high court decisions, Patterson v. New York (1977) 
432 U.S. 197 (Patterson) and Engle v. Isaac (1982) 456 U.S. 107 
(Engle), have clarified that while states may choose to “task[] 
the prosecution with proving [the] absence [of imperfect self-
defense] beyond a reasonable doubt,” they nonetheless retain 
the authority to allocate the burden of proof on that issue to the 
defendant.  In the Attorney General’s view, because these cases 
show California is not constitutionally required to disprove 
imperfect self-defense, any error associated with failing to 
instruct on that theory is necessarily grounded in state law and 
thus subject to Watson review. 
Contrary to the Attorney General’s assertions, nothing in 
Patterson, supra, 432 U.S. 197, or Engle, supra, 456 U.S. 107, 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
25 
 
supplants Mullaney’s rule that when a state chooses to recognize 
a defensive theory that operates to negate an element of the 
charged offense, and the defendant presents evidence placing 
that theory at issue, the due process clause requires the state to 
prove the absence of that circumstance beyond a reasonable 
doubt.  (See Mullaney, supra, 421 U.S. at p. 704; Smith, supra, 
568 U.S. at p. 110 [when a defensive theory “ ‘negate[s] an 
element of the crime’. . . the Government has [a] constitutional 
duty to overcome the defense beyond a reasonable doubt”].)  
In Patterson, supra, 432 U.S. 197, the court held only that 
the principles of Mullaney do not require states to “disprove 
beyond a reasonable doubt every fact constituting any and all 
affirmative defenses related to the culpability of an accused.”  
(Patterson, at p. 210.)  Patterson involved a New York law that 
defined murder differently from California.  The New York law 
defined the crime of murder as “causing the death of another 
person with intent to do so.”  (Id. at p. 205.)  Thus, unlike 
California or Maine, the New York law crucially did not define 
murder by using the term “malice.”  Instead, the sole elements 
of the offense were the death of a person, the intent to kill and 
causation.  New York also provided an affirmative defense of 
“extreme emotional disturbance” that, if proved by the 
defendant by a preponderance of the evidence, would reduce the 
crime to manslaughter.   
In upholding the constitutionality of this legal structure, 
the court noted that unlike the homicide laws at issue in 
Mullaney, New York’s emotional disturbance defense did “not 
serve to negative any facts of the crime which the State is to 
prove in order to convict of murder” (Patterson, supra, 432 U.S. 
at p. 207), but rather related to “a separate issue” (ibid.) distinct 
from the elements of the offense.  Thus, Patterson merely stands 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
26 
 
for the proposition that states are permitted to place the burden 
of proving some forms of affirmative defenses on the defendant, 
namely those that do not serve to “negative any facts” (ibid.) 
necessary to prove the charged offense. 
In Engle, supra, 456 U.S. 107, habeas petitioners raised 
multiple arguments challenging the constitutionality of a state 
law that shifted the burden of proving self-defense to 
defendants.  In the section of the decision the Attorney General 
cites, the court reiterated Patterson’s holding that states are 
constitutionally permitted to assign defendants the burden of 
proving some forms of affirmative defenses.  (Engle, at p. 121.)  
However, in a separate section of the decision that the Attorney 
General does not discuss, the Engle court evaluated petitioners’ 
alternative contention that because the homicide offenses they 
had been charged with required a showing of “purposeful or 
knowing behavior” (id. at p. 121), the presence of self-defense 
served to “negate” (ibid.) an element of the crime, thus requiring 
the State to “disprove that defense as part of its task of 
establishing guilty mens rea . . . .”  (Id. at p. 122.)  Noting that 
several federal and state courts had interpreted Mullaney and 
Patterson as creating a constitutional duty to “prove absence of 
self-defense if that defense negates an element . . .  of the 
charged crime” (Engle, at p. 122), the court found that the 
petitioners’ argument stated a “colorable constitutional claim.”  
(Ibid.)  The court went on to conclude, however, that for 
purposes of federal habeas relief, petitioners had procedurally 
defaulted this claim by failing to raise it in the state court 
proceedings.  As a result, the court declined to address the claim 
on the merits. 
More recently, in Smith, supra, 568 U.S. 106, the high 
court adopted the argument left unaddressed in Engle, 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
27 
 
clarifying that under the Mullaney/Patterson framework, “[t]he 
State is foreclosed from shifting the burden of proof to the 
defendant . . . ‘when an affirmative defense . . . negate[s] an 
element of the crime.’  [Citation.]  Where instead it ‘excuse[s] 
conduct that would otherwise be punishable,’ but ‘does not 
controvert any of the elements of the offense itself,’ the 
Government has no constitutional duty to overcome the defense 
beyond a reasonable doubt.”  (Smith, at p. 110; cf. People v. 
Thomas (2023) 14 Cal.5th 327, 384 [Mullaney’s principles are 
inapplicable to provocation in the context of first degree murder 
because provocation is merely a factor the jury can consider 
when evaluating premeditation and deliberation].)  Smith thus 
reaffirms that because California has structured its homicide 
laws so that imperfect self-defense operates to negate the 
element of malice, the State is constitutionally required to 
disprove such a theory in cases where the issue is presented.5    
 
5  
The People argue that language in People v. Babbitt (1988) 
45 Cal.3d 660 (Babbitt), supports the view that the prosecution 
does not have a constitutional duty to disprove defensive 
theories that negate an element of the crime.  The defendant in 
Babbitt argued that an instruction on the affirmative defense of 
unconsciousness violated the due process clause by placing the 
burden of proof on that issue on the defense.  The defendant 
posited that because unconsciousness operated to negate intent, 
the People could not shift the burden of proof on that issue, but 
instead were required to prove the absence of that circumstance 
beyond a reasonable doubt.   
While Babbitt contains language that could be read to 
suggest the People are not constitutionally required to disprove 
defensive theories that negate an element of the crime (see 
Babbitt, supra, 45 Cal.3d at pp. 693–694), we ultimately held 
that the challenged instructions did not shift the burden on the 
question of unconsciousness and therefore did not implicate the 
constitutional issues addressed in Mullaney and Patterson.  
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
28 
 
In sum, while states retain flexibility in choosing how to 
define criminal offenses, our high court’s decisions make clear 
that if a state chooses to recognize a defensive theory that 
operates to negate an element of the charged offense, the due 
process clause requires the prosecution to prove the absence of 
that circumstance beyond a reasonable doubt.6  Applying those 
principles here, we hold that when there is substantial evidence 
of imperfect self-defense in a murder case, the trial court’s 
failure to instruct on that theory precludes the jury from making 
a factual finding that is necessary to prove the malice element 
of murder.  The error therefore amounts to a violation of the 
federal Constitution and is subject to Chapman’s “beyond a 
reasonable doubt” standard for evaluating prejudice.    
We emphasize that our conclusion is predicated on the 
“unique” 
relationship 
between 
murder 
and 
voluntary 
 
Moreover, Babbitt was decided before Smith, supra, 568 U.S. 
106, and Rios, supra, 23 Cal.4th 450, which make clear that 
because imperfect self-defense negates the malice element of 
murder, the People have a constitutional duty to prove the 
absence of that circumstance beyond a reasonable doubt.  (Rios, 
at p. 462; Smith, at p. 110.)  
6 
As our high court has acknowledged, under the approach 
adopted in the Mullaney and Patterson line of cases, “the 
prosecution’s constitutional duty to negate affirmative defenses 
may depend, at least in part, on the manner in which the State 
defines the charged crime.”  (Engle, supra, 456 U.S. at p. 120.)  
While the court’s due process jurisprudence in this area does 
appear to allow states considerable flexibility in defining 
offenses in such a way as to reallocate the burden of proving 
certain defensive issues (see Patterson, supra, 432 U.S. at 
p. 210), those cases nonetheless make clear the structure 
California has adopted with respect to homicide trigger a 
constitutional duty to disprove imperfect self-defense beyond a 
reasonable doubt. 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
29 
 
manslaughter (see ante, at pp. 15–18), and does not otherwise 
modify the general rule that the failure to instruct on other 
forms of lesser included offenses in noncapital cases is an error 
of state law.  (See Breverman, supra, 19 Cal.4th at p. 165.)7  We 
also express no opinion on the appropriate standard of review 
for instructional errors related to other forms of defensive 
theories, including affirmative defenses.  (See Gonzalez, supra, 
5 Cal.5th at p. 199 [this court “ha[s] yet to determine whether a 
trial court’s failure to instruct on a requested affirmative 
defense instruction supported by substantial evidence is federal 
constitutional error or state law error”]; cf. People v. Rogers 
(2006) 39 Cal.4th 826, 872 [discussing federal authorities 
concluding that trial court’s failure to give a requested 
instruction embodying the defense’s theory of the case “violate[s] 
the defendant’s due process right to present a complete 
defense”].)  
 
7  
Our holding does of course apply to other forms of 
voluntary manslaughter, i.e., heat of passion and imperfect 
defense of others, which operate identically to imperfect self-
defense by negating the malice element of murder.  (See Rios, 
supra, 23 Cal.4th at p. 461; People v. Randle (2005) 35 Cal.4th 
987, 997 [as with imperfect self-defense, one who kills in 
imperfect defense of others is “guilty of manslaughter, not 
murder, because he lacks the malice required for murder” 
(italics omitted)].)  Thus, when the record contains substantial 
evidence of heat of passion or imperfect defense of others, the 
failure to instruct on those theories is likewise subject to review 
under the Chapman standard.  We disapprove People v. 
Breverman, supra, 19 Cal.4th 162, and People v. Randle, supra, 
35 Cal.4th 987, to the extent those cases could be read to hold 
otherwise. 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
30 
 
B. The Court of Appeal’s Prejudice Analysis Did 
Not Comport with Chapman   
Having concluded that the trial court’s misinstruction (or 
more precisely the court’s assumed misinstruction, see ante, at 
p. 13, fn. 2) qualified as a violation of the federal Constitution, 
we must next assess the Court of Appeal’s conclusion that the 
error was harmless.  Although the court found that the 
misinstruction amounted to an error of state law only (a 
conclusion we have now rejected), it went on to hold that the 
error was harmless even under Chapman’s stricter standard for 
constitutional violations, which requires reversal unless it 
appears “ ‘beyond a reasonable doubt that the error complained 
of did not contribute to the verdict obtained.’ ”  (People v. Brown 
(2023) 14 Cal.5th 453, 473.) 
Our recent decision in Lopez, supra, 14 Cal.5th 562, 
clarified the Chapman standard in the context of instructional 
errors that “ ‘misdescri[be] . . . the elements’ ” of the charged 
offense.  (Lopez, at p. 568.)  We explained that the “test is 
exacting” (id. at p. 581), requiring reversal unless the reviewing 
court is persuaded that “ ‘ “[n]o reasonable jury” ’ would have 
found in favor of the defendant on the missing fact, given the 
jury’s actual verdict and the state of the evidence” (id. at p. 580). 
When making this evaluation, the reviewing court “ ‘does not . . . 
“become in effect a second jury to determine whether the 
defendant is guilty.”  [Citation.]  Rather a court, in typical 
appellate-court fashion, asks whether the record contains 
evidence that could rationally lead to a contrary finding with 
respect to the omitted element.’ ”  (Id. at p. 581.)  As stated by 
our high court, “safeguarding the jury guarantee will often 
require that a reviewing court conduct a thorough examination 
of the record.  If, at the end of that examination, the court cannot 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
31 
 
conclude beyond a reasonable doubt that the jury verdict would 
have been the same absent the error — for example, where the 
defendant contested the omitted element and raised evidence 
sufficient to support a contrary finding — it should not find the 
error harmless.”  (Neder, supra, 527 U.S. at p. 19.)   
In this case, the Court of Appeal’s harmless error analysis 
focused solely on what it characterized as “overwhelming 
evidence that [Schuller] was not acting in any form of self-
defense.”  (Schuller, supra, 72 Cal.App.5th at p. 238.)  In the 
court’s 
view, 
several 
categories 
of 
evidence 
“undercut 
[Schuller’s] claim of self-defense” (id. at p. 239) or “did not 
entirely align with his story” (id. at p. 240), including (among 
other things):  (1) “[his] account of the killing radically changed 
leading up to trial” (id. at p. 238); (2) two psychologists testified 
that Schuller appeared to be malingering (id. at p. 239); (3) his 
conduct immediately after the killing (setting fire to the body, 
shooting the victim’s phone and fleeing from the scene) belied 
his claim that he had tried to contact police (id. at pp. 239–240); 
(4) many “aspects of [Schuller’s] testimony” were inconsistent, 
thereby “undercut[ting] his credibility” (id. at p. 239); (5) the 
physical evidence at the scene of the crime did not support 
Schuller’s claim, in particular the fact that the knife was found 
“on the table — not on the floor . . . [a]nd unlike the surrounding 
area, . . . had no blood on it” (id. at p. 239); and (6) Schuller shot 
the victim nine times in the head, suggesting “a personal motive, 
rather than panicked self-defense” (id. at p. 240).  The court 
believed that, considered together, this evidence showed “there 
was no reasonable possibility the error contributed to the 
verdict.”  (Ibid.) 
The court’s discussion suggests that rather than assess 
whether any reasonable jury could have credited Schuller’s 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
32 
 
claim of imperfect self-defense “given the . . .  actual verdict and 
the state of the evidence” (Lopez, supra, 14 Cal.5th at p. 580), 
the court performed its own weighing of the evidence and its own 
assessment of witness credibility.  It was not the court’s role, for 
example, to decide whether Schuller’s failure to raise the issue 
of self-defense in his initial conversations with police 
demonstrated that his trial testimony was not true or credit the 
psychologists’ 
disputed 
conclusion 
that 
Schuller 
was 
malingering.  While much of the trial evidence certainly casts 
doubt on Schuller’s claim of imperfect self-defense, it was 
ultimately the jury’s role, not that of the reviewing court, to 
assess whether such evidence showed beyond a reasonable 
doubt that Schuller did not “kill[] with an actual but 
unreasonable belief in the need for self-defense against 
imminent death or great bodily injury.”  (In re Christian S. 
(1994) 7 Cal.4th 768, 778.) 
The court’s findings on the merits of Schuller’s 
instructional claim — i.e., that he was entitled to an instruction 
on imperfect self-defense — further confirm that the court’s 
evaluation of prejudice did not comport with the standards of 
Chapman.  When assessing the merits of Schuller’s claim, the 
court correctly explained that an instruction on imperfect self-
defense must be given when there is “substantial evidence” to 
support such a theory.  (Schuller, supra, 72 Cal.App.5th at 
p. 231; see Breverman, supra, 19 Cal.4th at p. 162.)  It further 
observed — again correctly — that “substantial evidence [in this 
context] is ‘ “ ‘evidence from which a jury composed of 
reasonable [persons] could’ ” ’ ” find in the defendant’s favor on 
the issue.  (Schuller, at p. 231; see Breverman, at p. 162.)  
Applying those standards, the court found that the record did 
contain sufficient evidence to require an instruction on 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
33 
 
imperfect self-defense, citing Schuller’s testimony that W.T. had 
threatened him with a knife and citing evidence demonstrating 
that a knife was found at the scene of the crime.  (Schuller, at 
p. 236.)  Despite that finding, the court went on to conclude that 
the instructional error was harmless because the evidence 
weighing against Schuller’s claim of imperfect self-defense was 
“overwhelming.”  (Id. at p. 238.)   
Had the court properly applied the standards required 
under Chapman, it could not have found both that Schuller 
presented sufficient evidence to support an instruction on 
imperfect self-defense and that the error was harmless based 
solely on the conclusion that the evidence was so overwhelming 
as to compel a finding against him on that theory.  (See Neder, 
supra, 527 U.S. at p. 9.)  In other words, if the court believed an 
instruction was warranted because there was sufficient 
evidence from which a reasonable jury could find in Schuller’s 
favor on the question of imperfect self-defense, the court could 
not then, consistent with Chapman, go on to find that the error 
was nonetheless harmless simply because the evidence against 
imperfect self-defense was so overwhelming that no reasonable 
jury could have possibly found in Schuller’s favor on that issue.  
(See ibid.)8 
 
8  
In Breverman, we rejected the defendant’s argument that 
“an erroneous failure to instruct on a lesser included offense is 
necessarily prejudicial, on the premise that if the evidence was 
substantial enough to warrant lesser offense instructions in the 
first place, it must have been strong enough to affect the 
outcome had the instructions not been omitted.”  (Breverman, 
supra, 19 Cal.4th at p. 177.)  We explained that the “standard[] 
of evidentiary review” used to evaluate whether an instruction 
on a lesser included offense should have been provided is 
“distinct” from the standard of “[a]ppellate review under 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
34 
 
Because the Court of Appeal’s harmless error analysis 
demonstrates that it misapprehended the standard that 
Chapman requires, we remand the matter to allow the court to 
reconsider whether the failure to instruct on self-defense was 
harmless beyond a reasonable doubt under the appropriate 
standard.  (See Lopez, supra, 14 Cal.5th at pp. 580–592 
[clarifying Chapman standard and remanding question of 
prejudice where the reviewing court’s analysis indicated it 
“misapprehended” the appropriate standard]; cf. Yamaha Corp. 
of America v. State Bd. of Equalization (1998) 19 Cal.4th 1, 15, 
[where the Court of Appeal applied an erroneous standard, 
“regard for the structure of appellate decisionmaking suggests 
the case should be returned to the Court of Appeal”].)9 
 
Watson.”  (Ibid.)  That analysis, however, involved an 
application of the Watson harmless error standard.  (Ibid.)  It 
does not apply to the higher standard of prejudice applicable 
under Chapman review. 
9  
The Attorney General argues that even if the Court of 
Appeal’s approach to evaluating prejudice did not comport with 
Chapman, there is nonetheless a separate basis to support a 
finding of harmlessness:   the jury’s “first degree murder verdict, 
and rejection of second degree murder, shows that the jury 
necessarily rejected Schuller’s testimony that he acted in self-
defense, leaving no doubt the jury would have returned the same 
verdict had it been instructed regarding imperfect self-defense.”  
In support, the Attorney General cites People v. Manriquez 
(2005) 37 Cal.4th 547.  (See id. at p. 582 [jury’s first degree 
murder verdict “le[ft] no doubt the jury would have returned the 
same verdict had it been instructed regarding imperfect self-
defense”].)  The defendant and the concurrence disagree, 
arguing that the first degree murder finding does not render the 
instructional error harmless because “the requirements of self-
defense are consistent with a killing undertaken with 
premeditation and deliberation.”  (Conc. opn. of Liu, J., post, at 
p. 2, citing CALCRIM No. 571.) 
PEOPLE v. SCHULLER 
Opinion of the Court by Groban, J. 
 
35 
 
III. CONCLUSION 
 
The judgment is reversed and the matter is remanded for 
further proceedings consistent with this opinion. 
 
GROBAN, J. 
We Concur: 
GUERRERO, C. J. 
CORRIGAN, J. 
LIU, J. 
KRUGER, J. 
JENKINS, J. 
EVANS, J. 
 
The Attorney General did not rely on this alternative 
theory below and the Court of Appeal did not address it.  (See 
People v. Maya (2020) 9 Cal.5th 239, 243 [declining to address 
“alternative ground” raised in support of the judgment and 
remanding to allow the Court of Appeal to “consider [the issue] 
in the first instance”]; Central Coast Forest Assn. v. Fish & 
Game Com. (2017) 2 Cal.5th 594, 606 [“it is appropriate to 
remand . . . for the Court of Appeal to consider . . . unresolved 
issues in the first instance”].) 
1 
PEOPLE v. SCHULLER 
S272237 
 
Concurring Opinion by Justice Liu 
 
 
I agree that “when the record contains substantial 
evidence of imperfect self-defense, the trial court’s failure to 
instruct on that theory amounts to constitutional error and is 
thus subject to review under the federal Chapman standard.”  
(Maj. opn., ante, at p. 2; see Chapman v. California (1967) 386 
U.S. 18, 24.)  I further agree that where the Court of Appeal 
“believed an instruction was warranted because there was 
sufficient evidence from which a reasonable jury could find in 
Schuller’s favor on the question of imperfect self-defense” (maj. 
opn., ante, at p. 33), the court could not then “perform[] its own 
weighing of the evidence” to hold such error harmless (id. at 
p. 32).  I write separately to address two issues. 
First, while I agree with today’s opinion as far as it goes, I 
would hold that reversible error occurred here.  The Court of 
Appeal determined that instructional error occurred; the 
Attorney General does not challenge that determination; and 
our clarification that Chapman review applies does not 
implicate it.  (Maj. opn., ante, at pp. 1, 13, fn. 2.)  The Court of 
Appeal “could not have found both that Schuller presented 
sufficient evidence to support an instruction on imperfect self-
defense and that the [instructional] error was harmless based 
solely on the conclusion that the evidence was so overwhelming 
as to compel a finding against him on that theory.”  (Id. at p. 33.)  
Because the Court of Appeal found the former, and because our 
decision presents no grounds to disturb that finding, logic 
PEOPLE v. SCHULLER 
Liu, J., concurring 
 
2 
 
dictates that the error cannot be held harmless based on the 
weight of the evidence. 
This conclusion comports with our precedent.  In 
evaluating the harmlessness of an instructional error under 
Chapman, a court is limited to determining whether “it would 
be impossible, based on the evidence, for a jury to make the 
findings reflected in its verdict without also finding the missing 
fact as well.”  (In re Lopez (2023) 14 Cal.5th 562, 568.)  Unless 
the jury’s findings in this case precluded any possibility of also 
finding that Schuller acted in imperfect self-defense, the 
instructional error cannot be held harmless. 
Because the jury’s findings that Schuller acted with 
premeditation and deliberation do not preclude a finding that he 
honestly but unreasonably believed he needed to act in self-
defense, the instructional error is not harmless.  While 
voluntary manslaughter based on heat of passion is “manifestly 
inconsistent” with premeditation and deliberation  (People v. 
Wharton (1991) 53 Cal.3d 522, 572), voluntary manslaughter 
based on imperfect self-defense is not.  Imperfect self-defense 
does not require a rash or impulsive killing.  Rather, the 
requirements of self-defense are consistent with a killing 
undertaken with premeditation and deliberation.  A defendant 
who acts in self-defense must honestly believe that he or she is 
“in imminent danger of being killed or suffering great bodily 
injury” and that “the immediate use of deadly force [is] 
necessary to defend against the danger.”  (CALCRIM No. 571.)  
These requirements imply that a defendant has evaluated both 
the danger present and alternate options for escape or de-
escalation and has concluded that “ ‘imminent danger to life or 
great bodily injury’ ” requires the use of deadly force.  (People v. 
Trujeque (2015) 61 Cal.4th 227, 270, italics omitted.) 
PEOPLE v. SCHULLER 
Liu, J., concurring 
 
3 
 
Schuller’s 
self-defense 
claim 
aligns 
with 
these 
requirements.  He testified that after unsuccessfully attempting 
to flee W.T.’s apartment and then seeing W.T. reach for a gun 
and attempt to attack with a knife, he determined that 
responding with deadly force was necessary.  (Maj. opn., ante, at 
p. 10.)  Schuller’s testimony supports a conclusion that he 
premeditated — that is, he “decided to kill before completing the 
act[] that caused death,” a decision that “can be reached 
quickly” — and that he deliberated by “carefully weigh[ing] the 
considerations for and against” his decision to kill.  (CALCRIM 
No. 521.)  A juror who credited his testimony could rationally 
conclude both that he acted with premeditation and deliberation 
and that he honestly though unreasonably believed he needed 
to act in self-defense.  Because the instructional error in this 
case did not allow a juror to express both of those conclusions, it 
cannot be found harmless. 
Second, if Schuller’s conviction is reversed, a new trial is 
likely to again raise the question of whether his belief in the 
need for self-defense was “entirely delusional” or was instead 
supported by an “objective correlate.”  (People v. Elmore (2014) 
59 Cal.4th 121, 137 (Elmore).)  I continue to disagree with our 
determination in Elmore, a closely divided decision, that a 
defendant may not argue imperfect self-defense based on a 
“purely delusional belief in the need to act in self-defense.”  (Id. 
at p. 130; see id. at p. 154 (conc. & dis. opn. of Kennard, J., joined 
by Werdegar & Liu, JJ.).) 
Elmore held that “unreasonable self-defense is ‘a species 
of mistake of fact . . . predicated upon a negligent perception of 
facts, not, as in the case of a delusion, a perception of facts not 
grounded in reality.’ ”  (Elmore, supra, 59 Cal.4th at p. 136.)  
Defendants may argue imperfect self-defense where an objective 
PEOPLE v. SCHULLER 
Liu, J., concurring 
 
4 
 
correlate — that is, evidence demonstrating “a motivation 
arising from objective facts, not delusions” (id. at p. 138) — 
supports their “mistaken[] belie[f] that actual circumstances 
required their defensive act” (id. at p. 146).  By contrast, Elmore 
said, “[a] claim of self-defense based solely on delusion is . . . a 
claim of legal insanity” and is therefore “reserved for the [trial’s] 
sanity phase.”  (Id. at p. 145.)   
But there is no reason to preclude a claim of imperfect self-
defense because of the origin of a defendant’s honest belief.  
Because “California has structured its homicide laws so that 
imperfect self-defense operates to negate the element of malice” 
(maj. opn., ante, at p. 27), “that most culpable of mental states 
‘cannot coexist’ with an actual belief that the lethal act was 
necessary to avoid one’s own death or serious injury at the 
victim’s hand” (People v. Rios (2000) 23 Cal.4th 450, 461).  As 
discussed above, self-defense requires a defendant to genuinely 
believe that he or she is “in imminent danger of being killed or 
suffering great bodily injury” and that “the immediate use of 
deadly force [is] necessary to defend against the danger.”  
(CALCRIM No. 571.)  But because a “purely delusional” belief in 
the need for self-defense may be just as genuine as a belief based 
on an “objective correlate,” it is not clear what supports Elmore’s 
conclusion that a defendant’s claim of imperfect self-defense 
must be grounded in objective reality.  Such an assessment goes 
to the reasonableness of a defendant’s belief — a consideration 
necessary to perfect self-defense but irrelevant to imperfect self-
defense, which is by definition unreasonable.  (Elmore, supra, 59 
Cal.4th at pp. 133–134.) 
Moreover, this case demonstrates that Elmore’s holding 
requires highly subjective line drawing.  Under Elmore, “[a] 
person who sees a stick and thinks it is a snake” is entitled to 
PEOPLE v. SCHULLER 
Liu, J., concurring 
 
5 
 
assert imperfect self-defense, but someone “who sees a snake 
where there is nothing snakelike” is not.  (Elmore, supra, 59 
Cal.4th at p. 137.)  This distinction, in addition to lacking a 
principled basis in the law of murder, comes with no guidance 
for determining what qualifies as an “objective correlate.”  Here, 
the Court of Appeal held that the “large knife . . . found on the 
kitchen table” and the “gun case . . . on the table” provided 
objective correlates sufficient to conclude that Schuller’s belief 
was not purely delusional.  (People v. Schuller (2021) 72 
Cal.App.5th 221, 236.)  But would the mere presence of a knife 
in the same room as Schuller have been sufficient, even if 
Schuller only imagined that W.T. lunged for it?  What if W.T. 
had looked at the knife in a way that Schuller interpreted as 
presaging an imminent attack?  What if W.T. had walked 
toward the side of the kitchen where the knife was located, and 
Schuller honestly believed W.T. was going to grab the knife and 
attack? 
There are no easy answers to such questions, yet courts 
applying Elmore must answer them.  (See, e.g., People v. 
Ocegueda (2016) 247 Cal.App.4th 1393, 1409–1410 [defendant’s 
uncorroborated testimony that he saw victim pull a metallic 
object from his waistband provided a sufficient objective 
correlate to necessitate an imperfect self-defense instruction]; 
People v. Leeds (2015) 240 Cal.App.4th 822, 833 [father’s kicking 
down of office door provided an objective correlate for 
defendant’s fatal shooting despite defendant’s fear resulting 
from delusional beliefs about father].)  Elmore foists on trial 
courts and juries “[t]he unenviable task of distinguishing such 
partly delusional beliefs having some objective basis from those 
that are ‘purely’ or ‘entirely’ delusional.”  (Elmore, supra, 59 
Cal.4th at p. 152 (conc. & dis. opn. of Kennard, J.).)  This 
PEOPLE v. SCHULLER 
Liu, J., concurring 
 
6 
 
unguided inquiry is compounded by the equally subjective 
challenge of determining, in the chain of events leading a 
defendant to have an unreasonable belief in the need for self-
defense, at what temporal or causal point an objective correlate 
must be found. 
All of this is unnecessarily confusing and complicated.  
Requiring an “objective correlate” in order to assert imperfect 
self-defense is inconsistent with the requirement of malice to 
prove murder.  Because “[t]he unreasonable belief in the need 
for self-defense may stem from mental illness, negligence, 
subaverage intelligence, or a variety of other causes . . . [,] it 
should not matter why the killer perceived a need for self-
defense.”  (Elmore, supra, 59 Cal.4th at p. 150 (conc. & dis. opn. 
of Kennard, J.).)  Where substantial evidence supports an 
imperfect self-defense instruction, “the jury at the guilt phase 
need not decide whether [a defendant’s] belief was delusional, 
but [need] only decide[] whether that belief was genuine.”  (Id. 
at p. 152 (conc. & dis. opn. of Kennard, J.).)  I suggest we 
reconsider Elmore in an appropriate case. 
 
LIU, J. 
 
I Concur: 
EVANS, J. 
 
 
 
See next page for addresses and telephone numbers for counsel who 
argued in Supreme Court. 
 
Name of Opinion  People v. Schuller 
__________________________________________________________  
 
Procedural Posture (see XX below) 
Original Appeal  
Original Proceeding 
Review Granted (published) XX 72 Cal.App.5th 221 
Review Granted (unpublished)  
Rehearing Granted 
__________________________________________________________  
 
Opinion No. S272237 
Date Filed:  August 17, 2023 
__________________________________________________________  
 
Court:  Superior  
County:  Nevada 
Judge:  Candace S. Heidelberger 
__________________________________________________________   
 
Counsel: 
 
David L. Polsky, under appointment by the Supreme Court, for 
Defendant and Appellant. 
 
Mary K. McComb, State Public Defender, Anne W. Lackey and William 
Whaley, Deputy State Public Defenders, and Jessie Peterson for the 
Office of the State Public Defender as Amicus Curiae on behalf of 
Defendant and Appellant. 
 
Kamala Harris, Xavier Becerra and Rob Bonta, Attorneys General, 
Lance E. Winters, Chief Assistant Attorney General, Michael P. 
Farrell, Assistant Attorney General, Ivan P. Marrs, Christopher J. 
Rench, Eric L. Christoffersen, Jennifer M. Poe, Daniel B. Bernstein 
and Peter H. Smith, Deputy Attorneys General, for Plaintiff and 
Respondent.
 
 
Counsel who argued in Supreme Court (not intended for 
publication with opinion): 
 
David L. Polsky 
Attorney at Law 
P.O. Box 118 
Ashford, CT 06278 
(860) 429-5556 
 
Jennifer M. Poe 
Deputy Attorney General 
1300 I Street 
Sacramento, CA 95814 
(916) 210-7692