                   FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


CARLOS J. AVENA,                          No. 14-99004
          Petitioner-Appellant,
                                          D.C. No.
              v.                    2:96-cv-08034-GHK

KEVIN CHAPPELL, Warden,
        Respondent-Appellee.               OPINION


      Appeal from the United States District Court
         for the Central District of California
       George H. King, District Judge, Presiding

        Argued and Submitted October 17, 2018
        Submission Vacated November 5, 2018
             Resubmitted August 8, 2019
              San Francisco, California

                   Filed August 8, 2019

 Before: Sidney R. Thomas, Chief Judge, and Susan P.
    Graber and Milan D. Smith, Jr., Circuit Judges.

            Opinion by Chief Judge Thomas
2                       AVENA V. CHAPPELL

                            SUMMARY*


                Habeas Corpus / Death Penalty

    The panel reversed the district court’s judgment denying
habeas relief on a certified claim of ineffective assistance of
counsel at the penalty phase, in a case in which Carlos Avena
was convicted and sentenced to death by a California jury on
two counts of first-degree murder for killings he committed
during a carjacking.

    Because the California Supreme Court did not address
whether Avena’s counsel performed deficiently at the penalty
phase, the panel reviewed counsel’s performance de novo.
The panel held that Avena’s counsel rendered deficient
performance by failing adequately to investigate Avena’s
good character and social history, and had no reasoned or
tactical excuse for doing so. The panel held that Avena’s
counsel also rendered deficient performance by not
investigating Avena’s claim of self-defense in a jail homicide
to counter the State’s use of it as aggravation evidence, and
had no reasonable or tactical excuse for not doing so.

    Because the California Supreme Court concluded that
Avena was not prejudiced by his counsel’s performance, the
panel reviewed the California Supreme Court’s decision
regarding prejudice under AEDPA’s deferential standard.
The panel held that the California Supreme Court’s
conclusion that Avena failed to show prejudice was
objectively unreasonable because the complete lack of

    *
      This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                    AVENA V. CHAPPELL                        3

mitigation evidence during the penalty phase all but ensured
Avena’s fate, as the jury was given no reason to consider
whether he deserved anything less than death. The panel
wrote that it does not suggest that a state court’s conclusion
of no prejudice is always unreasonable when defense counsel
does not present any mitigation evidence, but that the
mitigation evidence here was humanizing, painting Avena’s
crimes in a different light and providing an explanation for
the jail homicide. When weighing the totality of this
mitigation evidence against the aggravation evidence, the
panel concluded there remains a reasonable probability that
at least one juror would have determined the circumstances
did not warrant death, and that in the unusual circumstances
of this case, no fairminded jurist could disagree.

    The panel remanded for the district court to grant the writ
unless the state court resentences Avena within a reasonable
time to be determined by the district court.


                         COUNSEL

Sean K. Kennedy (argued), Los Angeles, California; Michael
J. Lightfoot, Of Counsel; Mark R. Krozdowski, Deputy
Federal Public Defender; Hilary Potashner, Federal Public
Defender; Office of the Federal Public Defender, Los
Angeles, California; for Petitioner-Appellant.

Michael Katz (argued) and A. Scott Hayward, Deputy
Attorneys General; Lance E. Winters, Senior Assistant
Attorney General; Gerald A. Engler, Chief Assistant Attorney
General; Xavier Becerra, Attorney General; Office of the
Attorney General, Los Angeles, California; for Respondent-
Appellee.
4                   AVENA V. CHAPPELL

                         OPINION

THOMAS, Chief Judge:

     Carlos Avena was convicted and sentenced to death by a
California jury on two counts of first-degree murder for
killings he committed during a carjacking in 1980. The
district court denied his habeas corpus petition raising claims
of ineffective assistance of counsel at the guilt and penalty
phases of his trial, but the court granted a certificate of
appealability on the penalty-phase claim.            We have
jurisdiction under 28 U.S.C. § 1291 and 28 U.S.C. § 2253.

    Because the California Supreme Court unreasonably
applied clearly established federal law in denying Avena’s
claim for ineffective assistance of counsel at the penalty
phase, we reverse the judgment of the district court.

                               I

                              A

    Avena was convicted of two counts of first-degree murder
and sentenced to the death penalty. The facts of his crimes
are detailed in the California Supreme Court’s opinion
denying him habeas relief. See In re Avena, 909 P.2d 1017,
1022–23 (Cal. 1996).

    In September 1980, Avena and brothers Victor and Arturo
Padua were driving on the streets of Los Angeles, California,
after drinking beer earlier that night. Avena sat in the
backseat with a .22-caliber rifle. When stopped at an
intersection, a car pulled up next to theirs and occupants in
each car exchanged insults. One person in the other car threw
                    AVENA V. CHAPPELL                         5

a beer bottle, hitting the car door closest to Avena. Avena
shot at the other car a few times in retaliation. As the car
drove away, Avena and the Padua brothers followed it and
eventually crashed their car into the rear end of the other car,
leaving their own car inoperable.

    After the crash, Avena and the Padua brothers approached
a nearby Chevrolet Camaro occupied by Manual Solis and
Miquel Vasquez. They demanded that the driver hand over
his money and the car keys. Arturo Padua struck the driver
with a piece of wood. Avena shot the passenger and then
shot the driver. Both men died from their injuries.

    Now driving the Camaro, Avena and the Padua brothers
went to Avena’s house to get more ammunition. Afterward,
they drove to an empty parking lot and set the Camaro on
fire. The three men, now on foot, made their way to a nearby
intersection, which was next to a freeway off-ramp. After
some time, a woman pulled up to the stop light at the
intersection in her car. Avena and Arturo Padua approached
the car and attempted to open the doors. Avena shot at the
car, but the woman escaped by driving through the red light.

     Two police officers in an unmarked police car were
driving on the freeway off-ramp when they saw the car drive
through the red light and saw Avena standing nearby with his
rifle. Avena shot at the officers, and they fired back in
response. Avena and Arturo Padua then fled on foot. Victor
Padua hid in the bushes and was discovered by police later
that evening. After first providing a false story to the police,
Victor eventually revealed his connection to Avena and
Arturo Padua. On September 15, 1980, Avena was arrested
and charged with the carjacking homicides.
6                   AVENA V. CHAPPELL

                              B

    Avena’s trial began in November 1981. The evidence
implicating him was overwhelming. Victor Padua testified
against him. The police introduced a secretly recorded
interrogation tape of Avena that largely tracked Victor’s
account. A law enforcement expert further confirmed
Avena’s involvement that night when he testified about the
type of firearm used in the shooting and the shell casings
recovered at the scene.

    Avena’s trial counsel, Marvin Part, hardly mounted a
defense. Part waived Avena’s right to appear in civilian
clothes during the trial and his own right to make an opening
statement. He presented no defense evidence, called no
defense witnesses, and eventually conceded Avena’s guilt.
During his closing argument, Part remarked, “[t]he tape is
right in front of you, literally confessing to shooting down a
couple of people . . . cold-blooded on the streets in Los
Angeles County.” After deliberating for a day and a half, the
jury convicted Avena of nearly all charges against him—two
counts of first-degree murder, two counts of assault with a
deadly weapon, one count of intent to commit murder, one
count of robbery, and one count of attempted robbery.

                              C

    At the penalty phase of Avena’s trial, the prosecution
argued vociferously that Avena deserved the death penalty.
They characterized him as a “deadly killing machine” that
had “no conscience.” They likened him to an animal—Avena
could not “live outside the cage” with the general public but
“liv[ing] inside the cage amongst the other tigers” also would
not stop him from killing again. Indeed, in the prosecution’s
                    AVENA V. CHAPPELL                       7

view, Avena was worse than an animal, which may “only
kill[] when [it] has to,” because Avena “doesn’t kill to live,
he kills for things like a ride home to get bullets.”

    To support this characterization of Avena, the prosecution
introduced aggravating evidence of other violent crimes in
which Avena was implicated. A former member of a rival
gang testified that in January 1978, he was standing on a
street corner with three friends when a man jumped out of a
car and fired two shots at them from a shotgun. A detective,
who investigated the shooting for the Los Angeles Police
Department, then testified that he arrested Avena in
connection with the incident, explaining that Avena admitted
to the shooting.

    Two deputies testified that, while Avena was in jail
awaiting trial for the carjacking homicides, he was implicated
in the homicide of another inmate. One deputy testified that
he saw Avena stab the inmate three or four times while the
victim was lying on the floor. The other deputy, who later
apprehended Avena, testified that Avena was “wearing a
towel wrapped around his midsection, a known protective
tactic used by jail inmates who anticipate participating in a
knife fight.” Id. at 1040–41. The inmate eventually died as a
result of his injuries.

    Finally, a third deputy testified that Avena had once
assaulted him while he was processing inmates who had just
returned from a medical visit. According to his testimony,
Avena “took a swing” at the deputy’s face with “clenched
hands” and a physical altercation ensued. During the
struggle, Avena attempted to bite him before the deputy
detained him.
8                       AVENA V. CHAPPELL

    Over and over, with this strong aggravating evidence and
passionate argument, the prosecution painted a picture of
Avena as something less than a “human being”—a “killing
machine” with a “malignant heart, if he has a heart at all,” a
wild animal that could not be caged, and a “cancer” that must
be “remove[d] [] before it kills you.”

    Avena’s trial counsel left this portrayal of Avena entirely
unchecked and unrebutted. Part presented no mitigation
evidence and called no witnesses to testify on Avena’s behalf.
He presented nothing about Avena’s childhood, good
character, social history, or extensive drug use. He called
only two witnesses to testify about the homicide in the jail,
neither of whom was present during the incident.1

    Instead, Part commended the jury on returning the
“correct verdict.” Part explained that he “couldn’t bring
[him]self to the level to tell [the jurors] that the defendant
didn’t kill those people that night.” There was “no question
he did it.” And “[t]here [wa]s no way in the world” the jurors
could like Avena or have sympathy for him. Avena was “a
bad person. There’s no question about that.”

    Part’s only argument that Avena should be spared from
the death penalty was that, “in [his] opinion,” Avena’s crimes
were not “so heinous, . . . so terrible, . . . so bad, that the
public vengeance cries out for” the death penalty. In Part’s


    1
       One witness, a jail deputy, testified that Avena had approached him
a few days before the homicide with “several puncture-type wounds on his
left temple, neck, and chest” and had said that “an unidentified ‘black guy’
had tried to get him.” Another deputy testified that he had handcuffed
another inmate also allegedly involved in the homicide and found a shank
lying on the floor near the victim.
                    AVENA V. CHAPPELL                       9

view, only serial killers should get the death penalty.
Someone like Avena, who has a “violent nature,” but whose
crimes had no “professionalism” or “sophistication,” should
not. He concluded by noting that when “people are young
they do rash things,” and he urged the jury to “put this man
away for the rest of his natural life.”

    Part’s performance led the prosecutor to comment
numerous times throughout sentencing that there was
“absolutely no mitigation evidence,” closing out the State’s
case against Avena by saying, “all of the evidence, all of the
inferences, all of the facts in this case are aggravating
circumstance . . . [e]very bit of it. There is no mitigation
whatsoever.” On December 17, 1981, after deliberating for
two days, the jury sentenced Avena to death.

                              D

    Avena filed his first state habeas petition in 1986.
Relevant to his claim of ineffective assistance at the penalty
phase, Avena alleged that Part was constitutionally
ineffective for failing to conduct an adequate investigation,
interview witnesses, present mitigating evidence, and argue
effectively. Id. at 1023. In support of his claim, Avena
attached several declarations.

    In his own declaration, Avena stated that he smoked
“sherms”—which are cigarettes dipped in PCP—on a regular
basis for six months to a year before the night of the
carjacking homicides and that he smoked one in the car with
the Padua brothers that day. Avena further testified that he
had informed Part about smoking PCP on the day of the
crimes and had requested to see a “shrink.” He also gave Part
the names of people in jail who had witnessed the homicide
10                  AVENA V. CHAPPELL

of the inmate and would testify that Avena acted in self-
defense. Avena testified that Part said he “did not have
anything to do with that and was not getting paid to
investigate it.”

     Avena also submitted declarations from two lawyers
representing him in other cases regarding interactions they
had with Part. Eleanor Kraft, Avena’s counsel handling his
direct appeal and state habeas proceeding, met with Part in
November 1982. Part told her that he had Avena wear jail
attire throughout the trial because “[y]ou know how those
Blacks and Mexicans are—they don’t know how to dress
right. They dress too loud and with the wrong colors and that
would make things worse.” Part also explained to Kraft that
he did not call any family members during the penalty phase
because “he did not think they would help,” and he did not
call Avena’s girlfriend because “she was ‘dumb’ and had a
‘bad record.’”

     Finally, Part also stated that he did not have a file for
Avena’s carjacking homicide case because he provided it to
the lawyer representing Avena in the homicide of the jail
inmate. But Roger Potash, Avena’s counsel for this jail
homicide, stated that he did not receive a case file from Part.
Potash also testified that he had interviewed witnesses to the
jail homicide who supported Avena’s contention that he acted
in self-defense.

    Various family members and friends also submitted
declarations. Avena’s mother discussed a so-called “chair
incident,” which Part gave as the only reason why he did not
present any mitigation evidence during the penalty phase of
Avena’s trial. Avena’s mother explained that Avena once
threw a chair at his father, but that he did so to protect his
                    AVENA V. CHAPPELL                       11

mother, whom his father was in the midst of physically
abusing. She and Avena’s sister also described Avena as a
loving son and brother. They both knew that Avena used
PCP in the time preceding the carjacking homicides. Avena’s
mother, sister, and girlfriend all stated that they were never
contacted to testify at Avena’s trial. Finally, Arturo Padua
stated that he regularly smoked PCP with Avena and, on the
evening of the carjacking homicides, he said that he, Avena,
and Victor Padua smoked “sherms.”

    Two expert witnesses submitted declarations regarding
the symptoms and effects of PCP use. Philip Berger, a
psychiatrist, stated that “the negative aspects of PCP
intoxication syndrome are reported to include disorientation,
mental confusion, anxiety, irritability, paranoia, and violent,
aggressive or assaultive behavior.” After reviewing various
case materials related to the carjacking homicides, Berger
concluded that “Avena’s behavior and mental state,” as
Avena described it, were “consistent with PCP intoxication.”
Edward Sanchez, a private investigator to Avena’s habeas
counsel and a former police officer, stated that the potency
and effects of PCP can be “unpredictable.” Long-term PCP
users “may also suffer a flash back and exhibit all the
symptoms of being under the influence, even if the person has
not used for a period of time.”

    Sanchez also submitted a declaration explaining what he
learned from William Stenberg, Part’s investigator, whom he
interviewed about Part’s representation of Avena. Stenberg
said he had interviewed Avena and four other persons after
Avena had already been sentenced to death for the carjacking
homicides. Stenberg also told Sanchez that “Part did not
request that he investigate the [carjacking homicides] case at
12                  AVENA V. CHAPPELL

the guilt or penalty phases.” Nor did Part “inform him of any
PCP use by Avena.”

     In another declaration, Paul Mansfield, an experienced
capital defense attorney, stated that in a case like Avena’s, he
would have requested funds to secure investigators and
experts, hired a psychologist or psychiatrist to examine the
defendant, investigated the defendant’s history of drug use
and use of drugs at the time of the crime, presented expert
testimony regarding the effects of PCP, presented mitigating
evidence regarding the defendant’s history in all relevant
respects, and investigated any other alleged acts of violence
in the defendant’s history. Mansfield concluded that the
fifty-three hours Part spent preparing before the trial and the
forty-one hours spent during the trial were “inadequate to
properly prepare a capital case without the assistance of some
very thorough and professional investigative help and expert
assistance as well.”

                               E

    The California Supreme Court referred Avena’s habeas
petition for an evidentiary hearing that began in February
1990. Avena’s habeas counsel called Part, Victor Padua, a
social historian, two psychiatrists, two capital defense
lawyers, and various family members and friends as
witnesses.

    The evidence presented at the hearing in support of
Avena’s ineffective assistance of counsel claim at the penalty
phase largely mirrored what Avena submitted in his petition:
(1) Avena had a long, documented history of drug use that
negatively affected his personality and behavior; (2) Avena’s
social history contained mitigating evidence that could have
                        AVENA V. CHAPPELL                             13

been discovered and presented during the penalty phase of his
trial, including that he endured an abusive childhood; and
(3) according to legal experts in the field, this evidence
should have been discovered and presented by his trial
counsel during the penalty phase.

                                    1

    Avena’s habeas counsel documented Avena’s history of
drug use and presented expert and lay witness testimony
indicating that Avena used PCP on the night of the carjacking
homicides. Habeas counsel submitted juvenile records dating
back to 1978 indicating Avena used marijuana and PCP
nearly every weekend. His friends and family testified that
Avena smoked PCP on a regular basis. Victor Padua
specifically witnessed Avena use “Angel dust,” a form of
PCP, at least twice a week in the period leading up to the
carjacking homicides. The sentencing report from the
carjacking homicides corroborated Avena’s declaration that
he smoked PCP on the night of the crimes.2 And according
to Victor Padua, Avena acted like “he was on PCP” the night
of the crimes but Victor could not specifically recall whether
he and Avena had smoked PCP that evening.

    When Avena smoked PCP, “he wasn’t the same person.”
“He wouldn’t talk very much, [h]e’d hold his face a lot,
[h]e’d touch his face a lot, [a]nd he couldn’t speak very
well.” He was sometimes in a “zombie”-like state—his eyes
would get puffy, he would mumble, and he would have


    2
     According to the report, Avena told a probation officer that “he had
been drinking a beer and smoking a sherm [i.e., a cigarette dipped in PCP]
before his two companions came to pick him up and he can hardly
remember anything that he did now.”
14                  AVENA V. CHAPPELL

difficulty walking and talking. Other times, he “c[ould] not
be still” and would get “aggressive.” When Avena smoked
PCP, he would say things like “me siento loco”—“I feel
crazy” or “I’m real high.”

    Two psychiatrists, Fred Rosenthal and Orm Analine, who
had experience treating PCP users, also testified about the
drug’s harmful and long-lasting effects. Together, their
testimonies explained that symptoms of PCP intoxication
vary across individuals and over time for a single person.
People on PCP can be “out of control, agitated, [and]
impulsive,” “may be hallucinating,” “may have delusional
thoughts,” and “often [become] extremely violent and
aggressive for what looks like apparently no reasons or mild
annoyances.” Chronic PCP users also “have a problem in
controlling their impulsive emotional behavior once it’s
started.”    “Very commonly memory is affected and
sometimes after an event or after something happens while a
person is intoxicated with PCP their memory of that event is
very distorted or non-existent.” PCP use can also have “long-
lasting effect[s],” beyond the time period in which the person
is under the influence, including “flash backs” that are “like
the period that they had when they were using the drugs.”

    Rosenthal concluded that “there was little doubt that
[Avena] was under the influence of PCP on that night.”
Analine concluded that Avena was a chronic PCP user before
the carjacking homicides and that the carjacking homicides
were affected by the ingestion of PCP.

                              2

    Expert and lay witnesses also testified about Avena’s
difficult and abusive childhood. Social historian Vincent
                    AVENA V. CHAPPELL                      15

Schiraldi testified that Avena’s father abused his wife and
children, and Avena “took the larger brunt of the beatings
because he was the oldest.” When Avena’s father left the
family, Avena’s mother moved with the children to Los
Angeles. Shortly after the family arrived there, Avena’s
father found the family and would occasionally live with
them between 1971 and 1980. Avena’s father beat Avena
during this time period, leading Avena to run away from the
house. Avena did not speak English when he first moved to
Los Angeles, so he struggled academically. He was often
teased in school, with other children calling him a “wetback.”
He began to experiment with drugs at age eleven or twelve
and became affiliated with a gang at age fifteen.

    In 1977, Avena was committed to a juvenile facility at
Camp Fennell for approximately eight months. Then, in
1978, he was committed to the California Youth Authority
(“CYA”). The “chair incident” was the impetus for his
committal to the CYA. After Avena threw a chair at his
father to protect his mother, Avena’s father called the police
and reported him for assault with a deadly weapon. Avena
was sent to the CYA after he was found guilty of the assault.

    Family members and friends testified to having loving
relationships with Avena. Avena was protective of his
siblings; was sweet to his mother, helping to support her
financially; and was described as a “wonderful” son.

                              3

    Finally, Avena’s habeas counsel presented evidence that
Part’s representation of Avena was woefully deficient.
Although Part had explained that he left case investigation to
his investigator, William Stenberg, record evidence and
16                  AVENA V. CHAPPELL

Stenberg contradicted this assertion. Stenberg told Sanchez
that Part never requested he investigate the carjacking
homicides case at either the guilt or penalty phases. Further,
only one bill exists documenting Stenberg’s work and it was
from his investigation of the jail homicide, which occurred
after Avena was sentenced for the carjacking homicides.

    Two experienced capital defense attorneys testified that
Part’s performance was inadequate. Howard Gillingham
explained that Avena’s history of abuse, school problems,
poverty, drug use, and gang activity could have been
mitigating factors at the penalty phase. Charles Gessler
testified that Avena’s PCP use and difficult childhood also
could have been mitigating factors, and that he would have
spoken to family members and friends about any alleged drug
use.

    Finally, Avena testified that Part asked him whether he
had used drugs the night of the carjacking homicides, and
Avena responded that “I drank beer, cognac, and smoked
sherms, PCP and marijuana.” Avena also testified that he
informed the police that he used PCP and marijuana.

    In 1996, the California Supreme Court issued an opinion,
denying Avena’s habeas petition in its entirety. In re Avena,
909 P.2d at 1021. In rejecting Avena’s ineffective assistance
of counsel claim at the penalty phase, the court focused on
Part’s failure to present evidence of Avena’s good character
and social history as well as a potential self-defense argument
for the jail homicide. Id. at 1040–43. The court determined
that it did not have to decide whether Part’s failures to
investigate or call witnesses constituted deficient
performance because Avena “fail[ed] to allege sufficient facts
to demonstrate prejudice.” Id. at 1041. According to the
                      AVENA V. CHAPPELL                           17

court, “the sheer number of potential witnesses is small,” the
character declarations Avena submitted were “not particularly
detailed” and “fail[ed] to portray [Avena] as an individual,”
and the evidence in general provided little detail of Avena’s
childhood that “would have engendered sympathy in a jury.”
Id. at 1043. The court also believed that Avena’s argument
that he could show self-defense in the jail homicide was a
“dubious proposition” because Avena was not wounded, the
victim was wounded multiple times, and deputies saw Avena
stab the inmate. Id. at 1041, 1043. Moreover, deputies
discovered him “wearing a towel wrapped around his
midsection, a known protective tactic used by jail inmates
who anticipate participating in a knife fight.” Id. at 1040–41.

    The court ultimately concluded that, after comparing the
“extremely serious nature of the crimes petitioner committed”
with the “relatively meager mitigating evidence petitioner has
uncovered,” it was “not reasonably probable the penalty
phase verdict would have been different had the jury heard
this mitigating evidence.” Id. at 1041–42. Two justices
dissented. Id. at 1045–73 (Mosk, J., dissenting); id. at
1073–74 (Kennard, J., dissenting).

                                 F

     Avena filed a federal habeas petition in 1998. He filed his
first amended federal habeas petition—the operative
petition—in 2005.3 The petition asserts ineffective assistance


    3
      Avena filed a second state habeas petition with the California
Supreme Court in 1999. The federal district court held this case in
abeyance pending the state court’s resolution of Avena’s petition. In
2005, the state court denied Avena’s petition. Following this ruling,
Avena amended his federal habeas petition.
18                  AVENA V. CHAPPELL

of counsel claims at both the guilt and penalty phases of trial.
The district court held an evidentiary hearing in 2009 on
Part’s failure to present mitigation evidence or counter the
State’s aggravation evidence at the penalty phase. The
district court denied Avena’s habeas petition but issued a
certificate of appealability on Avena’s claim of ineffective
assistance of counsel claim at the penalty phase.

                               II

    We review a district court’s denial of habeas relief de
novo. Earp v. Davis, 881 F.3d 1135, 1142 (9th Cir.), cert.
denied, 139 S. Ct. 566 (2018). Because Avena’s federal
petition was filed after April 24, 1996, we review it under the
standards detailed in the Antiterrorism and Effective Death
Penalty Act of 1996 (“AEDPA”). Murray v. Schriro,
745 F.3d 984, 996 (9th Cir. 2014) (citing Valerio v.
Crawford, 306 F.3d 742, 763 (9th Cir. 2002) (en banc)).
Under AEDPA, we must defer to the state court’s decision on
any claim adjudicated on the merits unless the decision was
“contrary to, or involved an unreasonable application” of
“clearly established Federal law” or was “based on an
unreasonable determination of the facts in light of the
evidence presented.” 28 U.S.C. § 2254(d). Avena argues that
the California Supreme Court decision unreasonably applied
the Supreme Court’s holding in Strickland v. Washington,
466 U.S. 668 (1984).

   “[C]learly established [federal law] . . . refers to the
holdings, as opposed to the dicta, of [Supreme Court]
decisions as of the time of the relevant state-court decision.”
Lockyer v. Andrade, 538 U.S. 63, 71 (2003) (quoting
Williams v. Taylor, 529 U.S. 362, 412 (2000)). “A state-court
decision is an ‘unreasonable application’ of Supreme Court
                     AVENA V. CHAPPELL                         19

precedent if ‘the state court identifies the correct governing
legal rule from th[e Supreme] Court’s cases but unreasonably
applies it to the facts of the particular state prisoner’s case.’”
Murray, 745 F.3d at 997 (quoting Williams, 529 U.S. at 407).
We consider only the evidence that was before the state court
at the time of its ruling. Cullen v. Pinholster, 563 U.S. 170,
182 (2011).

    Strickland v. Washington, 466 U.S. 668 (1984),
constitutes clearly established federal law governing a claim
for ineffective of assistance of counsel. Pinholster, 563 U.S.
at 189. Capital defendants have a constitutional right to the
effective assistance of counsel at the guilt and penalty phases
of trial. Strickland, 466 U.S. at 684–87. To establish that
counsel was ineffective under Strickland, a petitioner must
demonstrate that “counsel’s performance was deficient, and
that the deficiency prejudiced the defense.” Wiggins v. Smith,
539 U.S. 510, 521 (2003) (citing Strickland, 466 U.S. at 687).

                               III

    Under the performance prong of Strickland, counsel’s
performance was deficient if it “fell below an objective
standard of reasonableness.” Strickland, 466 U.S. at 688.
“[P]revailing professional norms” at the time of the
representation serve as the objective standard of
reasonableness under which counsel’s performance is
measured. Id. We apply a “‘strong presumption’ that
counsel’s representation was within the ‘wide range’ of
reasonable professional assistance.” Harrington v. Richter,
562 U.S. 86, 104 (2011) (quoting Strickland, 466 U.S. at
689). When assessing trial counsel’s conduct, “hindsight is
discounted by pegging adequacy to ‘counsel’s perspective at
the time’ [that] investigative decisions are made and by
20                  AVENA V. CHAPPELL

giving a ‘heavy measure of deference to counsel’s
judgment.’” Rompilla v. Beard, 545 U.S. 374, 381 (2005)
(quoting Strickland, 466 U.S. at 689, 691).

      At the time of Avena’s trial, the prevailing professional
norms demanded that trial counsel conduct a thorough
investigation of a defendant’s background in order to develop
a strategy for the penalty phase of trial. See, e.g., Williams,
529 U.S. at 396. Indeed, the duty to investigate is a
“substantial and important” one. Wiggins, 539 U.S.
at 524–25. “‘[S]trategic choices made after less than
complete investigation are reasonable’ only to the extent that
‘reasonable professional judgments support the limitations on
investigation.’” Id. at 528 (quoting Strickland, 466 U.S. at
690–91). Accordingly, when a petitioner challenges trial
counsel’s conduct in not presenting mitigation evidence at the
penalty phase, our “principal concern . . . is not whether
counsel should have presented a mitigation case[, but instead]
. . . whether the investigation supporting counsel’s decision
not to introduce mitigating evidence . . . was itself
reasonable.” Id. at 522–23.

    In denying Avena’s first habeas petition, the California
Supreme Court did not address whether Avena’s counsel
performed deficiently at the penalty phase because it
concluded that, regardless of any alleged deficiency, Avena
failed to demonstrate prejudice. In re Avena, 909 P.2d at
1040–41. Accordingly, we review de novo counsel’s
performance. See Porter v. McCollum, 558 U.S. 30, 39
(2009) (per curiam).
                    AVENA V. CHAPPELL                        21

                               A

    Part rendered deficient performance by failing adequately
to investigate Avena’s good character and social history, and
he has no reasoned or tactical excuse for not doing so.

    Up through jury selection, Part billed only fifty-three
hours in preparation time for Avena’s trial, less than a week’s
work for most attorneys. From jury selection through the end
of the sentencing phase, he billed another forty-one hours.
The small number of hours that counsel expended in
preparation for Avena’s capital trial is a striking initial
indication of his deficient investigation for the penalty phase.

    Avena’s family members also confirm counsel’s failure
to investigate Avena’s background and social history.
Avena’s mother stated that Part never contacted her before,
during, or after Avena’s trial. Avena’s sister also stated that
she was never contacted to testify at Avena’s trial. Avena’s
girlfriend at the time of the carjacking homicides stated that
she received a single call after the crimes but was not
contacted again.

    Statements and testimony from three experienced capital
defense attorneys establish that Part’s failure to contact
family members or investigate Avena’s background and
social history fell below prevailing professional norms. For
instance, Paul Mansfield stated that he would have presented
a comprehensive mitigation case of Avena’s “history,
background, character, mental and emotional conditions,
social history, family, employment, interests, friends, past
criminal history, and any other area of mitigation.” Howard
Gillingham testified that Avena’s history of abuse at the
hands of his father, school problems, poverty, drug use, and
22                  AVENA V. CHAPPELL

even his gang activity could be mitigating factors at the
penalty phase. Similarly, Charles Gessler testified that
Avena’s difficult and abusive childhood certainly could have
been a mitigating factor.

     Additionally, neither of the State’s arguments excuses
Part’s failure to investigate Avena’s social history and good
character. First, the State contends that counsel did not call
Avena’s relatives to testify because he worried that doing so
would open the door to further aggravating evidence of the
alleged “chair incident” with Avena’s father. However,
Part’s reliance on this incident as an excuse for not presenting
mitigation evidence remains unreasonable given his lack of
investigation into the circumstances surrounding it.
Conducting an adequate investigation to uncover potential
mitigation evidence is a prerequisite for determining the
strategic benefit of presenting any of it at the penalty phase.
Wiggins, 539 U.S. at 523. And foreclosing the option of
calling any family members as character witnesses because of
a single alleged incident, without further exploration into it,
is not a coherent strategy—it is entirely unreasonable. See id.
at 534. This is especially true when we consider that
testimony by character witnesses and the presentation of a
defendant’s social history and background play a fundamental
role in securing confidence in the outcome of the penalty
phase. See, e.g., Penry v. Lynaugh, 492 U.S. 302, 328 (1989)
(“In order to ensure reliability in the determination that death
is the appropriate punishment in a specific case, the jury must
be able to consider and give effect to any mitigating evidence
relevant to a defendant’s background and character or the
circumstances of the crime.” (internal citations and quotation
marks omitted)), abrogated on other grounds by Atkins v.
Virginia, 526 U.S. 304 (2002); Caldwell v. Mississippi,
472 U.S. 320, 330–31 (1985) (“When we held that a
                    AVENA V. CHAPPELL                       23

defendant has a constitutional right to the consideration of
[mitigating] factors . . . we clearly envisioned that that
consideration would occur among sentencers who were
present to hear the evidence and arguments and see the
witnesses.” (internal citations omitted)). Had he conducted
any investigation into this incident, Part would have
discovered substantial evidence that Avena acted to protect
his mother from his father’s abuse.

    Second, the State argues that Part cannot be faulted
entirely for his failure to present character witnesses because
Avena’s mother “admitted that she had not been forthcoming
with trial counsel at the time of trial.” This assertion is not
supported by any of the cited testimony. Avena’s mother
testified only that Part never contacted her and that she never
told anyone about her son’s PCP use.                Competent
representation requires counsel proactively to reach out to a
defendant’s family members and friends to develop an
understanding of the defendant’s background. See Wiggins,
539 U.S. at 522–23; see also Apelt v. Ryan, 878 F.3d 800,
830–31 (9th Cir. 2017) (finding deficient performance where
counsel did not pursue background information from family
members because they lived out of the country and did not
speak English), cert. denied, 2019 WL 1172280 (U.S. June
17, 2019) (No. 18-836).

                              B

    Part also rendered deficient performance by not
investigating Avena’s claim of self-defense in the jail
homicide to counter the State’s use of it as aggravation
evidence.
24                  AVENA V. CHAPPELL

    Part admitted that he did not investigate a potential self-
defense claim and asserted that he left that task to his
investigator. His investigator and the record evidence belie
Part’s assertion. There is no evidence that Part requested any
investigation of the jail homicide in preparation for the
penalty phase of the carjacking homicides case.

    The State’s argument that “reasonable trial counsel could
have decided to forgo an unbelievable self-defense argument
to avoid alienating the jury” does not excuse Part’s
performance. Again, our “principal concern . . . is not
whether counsel should have presented a mitigation case.”
Wiggins, 539 U.S. at 522–23. “Rather, we focus on whether
the investigation supporting counsel’s decision not to
introduce” evidence to counter the state’s aggravating
evidence “was itself reasonable.” Id. at 523. Part conducted
no such investigation, and his failure to do so was
unreasonable. Part’s “uninformed strategy [wa]s not a
reasoned strategy. It [wa]s, in fact, no strategy at all.”
Correll v. Ryan, 539 F.3d 938, 949 (9th Cir. 2008) (citing
Strickland, 466 U.S. at 690–91).

    Thus, Part also rendered deficient performance by failing
to investigate or present any mitigation evidence regarding
self-defense in the jail homicide, and he had no reasonable or
tactical excuse for not doing so.

                              IV

                              A

    Turning next to the prejudice prong of Strickland, we
determine whether a petitioner suffered prejudice at the
penalty phase by “reweigh[ing] the evidence in aggravation
                     AVENA V. CHAPPELL                        25

against the totality of available mitigating evidence” and
asking whether “there is a reasonable probability” that “at
least one juror would have struck a different balance.”
Wiggins, 539 U.S. at 534–37; see also Wong v. Belmontes,
558 U.S. 15, 26 (2009) (per curiam) (courts “must consider
all the evidence—the good and the bad—when evaluating
prejudice”). “A reasonable probability [of a different result]
is a probability sufficient to undermine confidence in the
outcome” of the penalty phase. Strickland, 466 U.S. at 694.
Counsel’s deficient performance must have been “so serious
as to deprive the defendant of a fair trial, a trial whose result
is reliable.” Apelt, 878 F.3d at 831 (internal citations
omitted).

    Avena’s task is more difficult still because the California
Supreme Court concluded that he was not prejudiced by
Part’s performance. In re Avena, 909 P.2d at 1040–41.
AEDPA’s deferential standard thus governs our review of the
California Supreme Court’s decision. Murray, 745 F.3d at
996. Accordingly, the question before us is not whether we
believe Avena suffered prejudice and the California Supreme
Court was “incorrect” in finding none; instead, we must ask
whether the California Supreme Court’s determination of no
prejudice was “unreasonable—a substantially higher
threshold.” Apelt, 878 F.3d at 832. Yet, “[e]ven in the
context of federal habeas, deference does not imply
abandonment or abdication of judicial review.” Miller-El v.
Cockrell, 537 U.S. 322, 340 (2003).

    At the conclusion of the penalty phase, the jury knew
almost nothing about Avena except what the prosecution said
of him: Avena was a dangerous, subhuman killer. He had
killed strangers for no apparent reason. No one, not even
family members, testified on his behalf.
26                  AVENA V. CHAPPELL

    In contrast to what was actually presented, a wealth of
mitigation evidence could have been presented had Avena’s
counsel conducted a constitutionally adequate investigation.
Mitigation evidence in capital sentencing is “constitutionally
indispensable.” Eddings v. Oklahoma, 455 U.S. 104, 112
(1982); see also Woodson v. North Carolina, 428 U.S. 280,
304 (1976) (plurality opinion) (“[I]n capital cases[,] the
fundamental respect for humanity underlying the Eighth
Amendment requires consideration of the character and
record of the individual offender and the circumstances of the
particular offense as a constitutionally indispensable part of
the process of inflicting the penalty of death.” (internal
citations omitted)). “[F]ull consideration of evidence that
mitigates against the death penalty is essential . . . .” Penry,
492 U.S. at 328.

    This is not a case in which mitigation evidence would
have “largely duplicated” that which was already presented
or would otherwise have little effect on the jury’s perception
of the defendant. See Pinholster, 563 U.S. at 200–01. On the
contrary, Avena’s good character and social history evidence
consists of more than just a few people who knew him saying
that he was “generally a good person.” Strickland, 466 U.S.
at 700; see also Allen v. Woodford, 395 F.3d 979, 1005 (9th
Cir. 2004) (finding no prejudice where mitigating evidence
only indicated defendant “could be pleasant”). The evidence
“paints a very different picture of [Avena’s] background and
character than was presented at sentencing.” Apelt, 878 F.3d
at 832.

    The testimony of Avena’s family members and
friends—that Avena was loving and sweet—would have
countered the prosecution’s characterization of Avena as
nothing more than a “killing machine” with a “malignant
                    AVENA V. CHAPPELL                      27

heart.” Along with social history experts, Avena’s family
members and friends also would have testified that Avena
suffered substantial and continual abuse as a child at the
hands of his father. This is exactly the kind of evidence that
could have led a jury member—by “reasoned moral
judgment”—to show Avena mercy. Doe v. Ayers, 782 F.3d
425, 462 (9th Cir. 2015); see also Williams, 529 U.S. at 398
(discussing the effect a defendant’s social history and
background evidence can have on a jury’s “appraisal of his
moral culpability” even where it does not undermine the
prosecution’s evidence of the defendant’s “dangerousness”).
Indeed, “evidence about [a] defendant’s background and
character is relevant [at sentencing] because of the belief,
long held by this society, that defendants who commit
criminal acts that are attributable to a disadvantaged
background, or to emotional or mental problems, may be less
culpable than defendants who have no such excuse.” Boyde
v. California, 494 U.S. 370, 382 (1990) (internal citations
omitted).

    The extensive evidence of Avena’s habitual PCP use, as
well as the effects the drug had on his demeanor, also could
have aided his defense. Whether or not this evidence was
compelling enough to support an actual defense at the guilt
phase of Avena’s trial, there remained considerable potential
for Part to argue during the penalty phase that Avena’s
habitual PCP use contributed to his violent and erratic
behavior on the night of the carjacking homicides.
Specifically, had Avena’s good character and social history
evidence been evaluated alongside the compelling expert
testimony about the harmful and long-term effects of PCP,
the jury could have “humanize[d]” Avena and evaluated his
behavior in the context in which it manifested. See Mayfield
v. Woodford, 270 F.3d 915, 931–32 (9th Cir. 2001) (en banc)
28                  AVENA V. CHAPPELL

(finding a death sentence unreliable, in part, because available
testimony from friends and family that a defendant’s
personality changed as a result of his drug and alcohol abuse
was never presented at sentencing).

    In addition to character evidence and evidence about PCP
use, competent counsel also could have presented evidence of
self-defense in the jail homicide. This was certainly the most
compelling aggravation evidence against Avena. The
prosecutor dramatically advanced the argument that Avena
was a danger to society even if he remained imprisoned,
arguing that Avena “cannot live outside the cage amongst us,
and he can’t live inside the cage amongst the other tigers.”
Rather than leaving that forceful assertion unchecked,
competent counsel would have presented evidence that, in
fact, Avena acted in self-defense. Not only could witnesses
to the jail homicide have testified that Avena acted in self-
defense, but Avena also presented to a deputy a few days
before the incident with wounds on various parts of his body
and claimed that someone was out to get him.

                               B

    In sum, the aggravating circumstances presented to the
jury were certainly strong: Avena committed two brazen
murders during a night of malicious criminal activity; while
awaiting trial for these murders, he was implicated in the
violent death of another inmate; and, during this same period,
he assaulted a police officer. But it would be difficult to find
a capital case at the sentencing phase that does not have
strong aggravating circumstances. Worse for Avena, the
prosecution’s case was all the jury knew of him.
                        AVENA V. CHAPPELL                              29

    On the other hand, the mitigation evidence the jury could
have learned was extensive and varied: Avena was loving to
and protective of his mother and sister; his father abused
everyone in the family, but Avena received the brunt of the
abuse; he eventually ran away from home and started using
harmful drugs like PCP at a young age; Avena’s drug use
changed his personality and behavior tremendously and for
the worse; the effects of drugs like PCP are long-lasting and
detrimental; witnesses to the homicide in the jail would
testify that Avena acted in self-defense; and Avena also
presented to a deputy a few days before the incident with
wounds on various parts of his body and claimed that
someone was out to get him.4

    The complete lack of mitigation evidence during the
penalty phase all but ensured Avena’s fate because the jury
was given no reason to consider whether he deserved
anything less than death. See Williams, 529 U.S. at 368–69
(reversing a death sentence for ineffective assistance of
counsel at the penalty phase despite strong aggravating
evidence).

    We do not suggest that a state court’s conclusion of no
prejudice is always unreasonable when defense counsel did
not present any mitigation evidence. But the mitigation
evidence here was humanizing, painting Avena’s crimes in a
different light and providing an explanation for the jail
homicide. When weighing the totality of this mitigation
evidence against the aggravation evidence, there remains a


    4
      The only potential rebuttal aggravating evidence concerned the so-
called “chair incident.” But the prospective harm that it could have caused
Avena was slight, particularly in light of the testimony that Avena was
protecting his mother from physical abuse by his father.
30                  AVENA V. CHAPPELL

reasonable probability that at least one juror would have
determined the circumstances did not warrant death.
Moreover, in the unusual circumstances of this case, we hold
that no “fairminded jurist[] could disagree.” Harrington, 562
U.S. at 101.

     In assessing prejudice at the penalty phase, the California
Supreme Court primarily emphasized the aggravating
circumstances. In re Avena, 909 P.2d at 1043. With respect
to the mitigating evidence, the court (a) concluded that the
character evidence was “no[t] very persuasive ” because it
lacked some detail and because the number of character
witnesses—three—was “small ” compared to other cases;
(b) did not mention the evidence pertaining to Avena’s PCP
use; and (c) found the self-defense theory pertaining to the
jail homicide “dubious” because of the evidence implicating
Avena. Id.

    The number and detail of the character witnesses may not
have been expansive, but it was qualitatively distinct from
what the jury heard on the subject: nothing. As described
above, the PCP evidence potentially humanized Avena and
his horrible crimes, yet the state court did not mention this
evidence in assessing prejudice. Finally, despite the evidence
implicating Avena in the jail homicide, the jury may have
found Avena’s alleged involvement in the incident less
damning, had the jury heard from witnesses that Avena acted
in self-defense in jail. Cf. Apelt, 878 F.3d at 834 (finding no
prejudice, in part, because mitigation evidence did not offer
an explanation for a brutal murder or reduce the defendant’s
responsibility for carrying it out).

   For all of the foregoing reasons, the California Supreme
Court was objectively unreasonable in concluding that Avena
                    AVENA V. CHAPPELL                       31

failed to show prejudice and denying Avena’s claim for
ineffective assistance of counsel at the penalty phase.

                              V

    In sum, we reverse the judgment of the district court on
the certified claim of ineffective assistance of counsel at the
penalty phase. We instruct the district court to grant the Writ
of Habeas Corpus as to Avena’s sentence unless the state
court resentences Avena within a reasonable time to be
determined by the district court. We do not reach non-
certified issues raised in the briefing.

   REVERSED            AND        RE MANDED           WI TH
INSTRUCTIONS.
