                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


STEVEN LIVADITIS,                         No. 14-99011
              Petitioner-Appellant,
                                             D.C. No.
                 v.                       2:96-cv-02833-
                                               SVW
RON DAVIS, Warden,
             Respondent-Appellee.           OPINION

      Appeal from the United States District Court
          for the Central District of California
      Stephen V. Wilson, District Judge, Presiding

          Argued and Submitted May 9, 2019
              San Francisco, California

                 Filed August 9, 2019

     Before: Ronald M. Gould, Richard R. Clifton,
          and Carlos T. Bea, Circuit Judges.

               Opinion by Judge Clifton
2                      LIVADITIS V. DAVIS

                          SUMMARY *


               Habeas Corpus / Death Penalty

    The panel affirmed the district court’s denial of Steven
Livaditis’s habeas corpus petition challenging his capital
sentence.

    Applying Cullen v. Pinholster, 563 U.S. 170 (2011), the
panel considered only the record before the California
Supreme Court (including the trial court record), and did not
consider the evidence presented in the federal court
evidentiary hearing. Because the California Supreme Court
summarily denied Livaditis’s state habeas petition, the panel
considered whether there is any reasonable argument that
could have supported that decision under the deferential
AEDPA standard that applies in this context.

    The panel held that the California Supreme Court did not
unreasonably apply federal law or unreasonably determine
facts in denying Livaditis’s ineffective assistance of counsel
claim based on counsel’s failure to investigate and present in
mitigation evidence of the mental impairments and abusive
conduct of Livaditis’s mother.           The panel rejected
Livaditis’s argument that his counsel’s performance was
constitutionally deficient for failing to discover and present
this evidence, and concluded that the state court could
reasonably have concluded that Livaditis was not prejudiced
by counsel’s failure to do so.



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

    The panel held that the California Supreme Court could
have reasonably determined that Livaditis was not
prejudiced by counsel’s failure to investigate and present in
mitigation evidence that Livaditis suffered from mental
impairments prior to and through the time of his crimes. As
it was unnecessary, the panel did not address counsel’s
performance with regard to this evidence.


                        COUNSEL

Gary D. Sowards (argued), McBreen & Senior, Los Angeles,
California; Jan B. Norman, Altadena, California; for
Petitioner-Appellant.

Seth P. McCutcheon (argued), Deputy Attorney General;
Victoria B. Wilson and James William Bilderback II,
Supervising 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.


                        OPINION

CLIFTON, Circuit Judge:

    California state prisoner Steven Livaditis appeals the
district court’s denial of his habeas corpus petition
challenging his capital sentence. Livaditis pled guilty to
three counts of first degree murder, five counts of robbery,
three counts of kidnapping, and one count of second degree
burglary in connection with his armed robbery of a jewelry
store in Beverly Hills, California. The California Supreme
4                    LIVADITIS V. DAVIS

Court, which had previously affirmed his convictions and
sentence, denied his habeas petition. The federal district
court likewise denied his federal petition under 28 U.S.C.
§ 2254. On appeal from that denial, Livaditis argues that the
district court erred in denying two of his ineffective
assistance of counsel claims. In particular, he argues that his
trial counsel was ineffective for failing to investigate and
present two types of mitigation evidence: 1) evidence that
Livaditis’s mother was mentally ill and abusive during
Livaditis’s youth, and 2) evidence that Livaditis suffered
from mental impairments prior to and through the time of his
crimes. Under the deferential standard of review that applies,
we hold that the California Supreme Court could have
reasonably concluded that both claims lacked merit. We
therefore affirm.

I. Background

    On June 23, 1986, twenty-two-year-old Steven Livaditis
robbed the Van Cleef & Arpels jewelry store in Beverly
Hills. Shortly after the store opened, Livaditis entered
carrying a briefcase. A security guard (William Smith) and
three sales clerks (Ann Heilperin, Hugh Skinner, and Carol
Lambert) were in the main sales area at the time. Livaditis
and Heilperin entered the adjoining boutique after Livaditis
asked to look at some watches. A few minutes later,
Heilperin screamed. Livaditis, displaying a revolver, forced
Heilperin back into the main sales area. Although Smith
attempted to draw his weapon, Livaditis disarmed him. A
shipping clerk (Robert Taylor) ran into the sales room and
was also taken hostage. Everyone else in the building
escaped.

    The police quickly surrounded the store. Livaditis forced
the five hostages into the watch boutique and ordered Taylor
                     LIVADITIS V. DAVIS                      5

and Lambert to bind the other hostages’ ankles and hands.
He also ordered them to fill the briefcase with watches.

    Livaditis then attempted to leave the store but returned
when he saw the police. He ordered Lambert to bind Taylor
in a sitting position and then dial 911. On the phone,
Livaditis demanded that he be put on the news and provided
with a television set and that the police leave. He threatened
to “execute these people one at a time.”

    Smith was the first hostage to be killed. Livaditis stabbed
Smith in the back with a hunting knife after Smith said that
Livaditis thought he was a “big man with that gun.” Smith
bled to death in front of the other hostages. Livaditis then
covered Smith’s body, which was still bound and face down
on the ground, with a coat. He left the knife in Smith’s back.
Livaditis subsequently told a reporter that he stabbed Smith
because Smith did not follow orders and “kept talking.”
Livaditis said that he felt no remorse for the stabbing.

    Heilperin was next. Livaditis appeared angry at
Heilperin because she screamed at the beginning of the
robbery. He then ordered her to lie down next to Smith’s
body. While on the phone with a local media outlet, Livaditis
told the reporter to wait and then walked over to Heilperin
and shot her. She died instantly. Livaditis told the reporter
that his gun had misfired.

    Livaditis held the remaining hostages in the store for
approximately thirteen hours. Skinner eventually proposed
an escape plan. Skinner suggested that the three hostages and
Livaditis exit the store under a blanket so that the police
would not be able to tell which person was the gunman. They
would be tied together at the waist, with Livaditis in the
middle. They would then walk to a nearby car and escape.
After Livaditis agreed to this plan, Lambert spent a few
6                    LIVADITIS V. DAVIS

hours sewing a blanket from cloth used for jewelry displays.
While she was sewing, Livaditis put more jewelry into his
briefcase. Once Lambert finished, Livaditis and the hostages
practiced walking under the blanket for a couple of hours.

    At approximately 11:30 pm, Livaditis and the hostages
exited the store under the blanket. As they walked, Skinner
and Taylor yelled that they were hostages. Livaditis
threatened to kill the hostages if the police intervened. When
the police threw “flash-bangs” (explosive diversion devices)
as the group reached the car, the blast separated Skinner
from Livaditis and the other hostages. Skinner pointed to
Livaditis and yelled, “Here he is.” Unfortunately, a police
sharpshooter stationed on a nearby parking structure
mistakenly believed that both male hostages were black and
that only Livaditis was white. In fact, Skinner was also
white. When the sharpshooter saw Skinner, a white man who
resembled the general description the police had received of
the gunman, he believed that Skinner was the perpetrator.
The sharpshooter heard his spotter say “shiny object” and
heard someone else say “gun.” He then shot and killed
Skinner, believing that Skinner was the gunman and was
about to start killing one or more of the remaining hostages.

    At that point, the officers arrested Livaditis. Livaditis
told the police that he killed Smith because Smith had been
“uncooperative and antagonistic” and “to keep control of the
situation.” He said that he killed Heilperin because “he felt
that he had to kill another hostage in order to prove that his
demands should be taken seriously.” He said that he was
sorry and that his plan had only been to rob the store.

    Livaditis pled guilty to the first degree murders of Smith,
Heilperin, and Skinner; five counts of robbery; three counts
of kidnapping; and one count of second degree burglary. He
admitted several special circumstance allegations, including
                     LIVADITIS V. DAVIS                       7

murder during the commission of robbery and burglary,
multiple murder, and weapons enhancements. After jury
selection, the case proceeded to the penalty phase.

A. The Penalty Phase

    During the penalty phase, in addition to evidence about
the circumstances of the Van Cleef & Arpels robbery and
murders, the state presented evidence of prior crimes and bad
acts by Livaditis. That included evidence that he robbed a
jewelry store in Las Vegas at gunpoint in February 1986,
four months before the Beverly Hills crimes. During the Las
Vegas robbery, Livaditis forced two store employees to lie
bound on the floor, threatened to kill them, and kicked one
of them repeatedly. He escaped with jewelry worth over
$400,000 retail, or $177,555 wholesale. Livaditis also had
one prior felony conviction for burglary and one for
possession of stolen property. In addition, the state’s
evidence described three prior instances in which Livaditis
forcibly resisted arrest.

    In arguing for a sentence less than death, the defense
focused on several mitigation themes, including family
sympathy, pleas for mercy, and Livaditis’s acceptance of
responsibility for his crimes. Seven witnesses testified on
Livaditis’s behalf.

    Sophie Livaditis, Livaditis’s mother, explained the
circumstances of her arrival to the United States and
described her tumultuous marriage to Louis Livaditis,
Livaditis’s father. She testified that Louis abused her in front
of their children and abused their children as well. She
explained that due to her recurring illnesses, she had to send
Livaditis to St. Basil’s Academy, a Greek Orthodox
orphanage in upstate New York, for two years during his
childhood. According to Sophie, Livaditis was “never happy
8                   LIVADITIS V. DAVIS

there” because he was homesick. She also described the
severe appendicitis Livaditis suffered as a child and a head
injury that he received at St. Basil’s. She said that she “had
no problems” with her children and was “very close” with
Livaditis.

    Sophie believed that Livaditis’s problems began during
his time in the U.S. Army and became worse after he left the
service and moved to Las Vegas. She said that the move was
“his disaster” because “he enrolled himself with the bad
people.” She said that she was shocked when she found out
about his crimes because the family “never had problems”
and Livaditis had “good plans for the future.” She said that
her son “knows that he did a very bad thing” and that she
“was hurt, very ashamed” and was “grieving with the
victims’ family.”

    On cross-examination, Sophie testified that her ex-
husband hit and spanked each of her children and repeatedly
stated that all of her children had the same upbringing and
the same advantages and disadvantages. She reaffirmed that
she never had trouble with her children.

    Two of Livaditis’s aunts and one of his uncles also
testified on his behalf. Their statements were generally
similar to Sophie’s testimony. One aunt, Pauline Poulakos,
testified that Louis Livaditis was “like a monster in the
house” and that the children were afraid of him. She said that
Louis hit Sophie, including while she was pregnant. She
described Livaditis’s unhappiness at St. Basil’s and his
desire to return home. She said that Livaditis was a “normal
boy” who tried to help his mother and that he was “very, very
sorry” for what he did. She also rooted his problems in his
move to Las Vegas.
                     LIVADITIS V. DAVIS                      9

    Voula Boulari, the other aunt, testified about Livaditis’s
“delicate character” as a child. She said that she would not
imagine that he would commit such a crime and that she was
“ashamed of what he did.” She said that he “has completely
regretted what he did” and that he told her that he “went there
just to steal and not cause any other trouble and then he was
afraid.”

    Theofanis Thantzalos, Livaditis’s uncle, testified about
Livaditis’s time at St. Basil’s. He also said that Livaditis
“acted natural” when he lived with them in Greece as a
teenager. Like Sophie, Theofanis indicated that Livaditis’s
problems dated back to his time in the army. He recalled that
when Livaditis visited Greece on a leave of absence from the
army, “he acted kind of wild.”

    Father Angelo Gavalas, the family’s Greek Orthodox
priest, testified about Sophie’s challenges as a severely ill
single parent. He said that Livaditis had an excellent
relationship with Sophie. He also discussed Livaditis’s time
at St. Basil’s and said that Livaditis “managed to stay two
years under great duress” because he was very unhappy
there. Father Gavalas testified that the Livaditis family was
“close knit,” so that “if something happens to one of them, it
really happens to all of them.”

    Livaditis’s brother, George, testified next. He said that
he had “sort of blacked out” his younger years but that he
remembered that his parents’ relationship “wasn’t too nice.”
He said that life after his parents divorced was “kind of
tough” because his mother had to take care of four children
alone and struggled to make ends meet, to the point that she
was forced to sort through garbage cans to find food and
clothes. George said that Livaditis “was always the first to
try and do something” to help their mother. He also indicated
that Livaditis’s problems originated in Las Vegas. He
10                   LIVADITIS V. DAVIS

believed that when Livaditis moved to Las Vegas, he was
“more confused than ever before” and “really didn’t know
why he was born, basically, his purpose in life.” On cross-
examination, George testified that Livaditis was Sophie’s
favorite but said that Livaditis was not treated differently
than the other children, with the exception of traveling to
Greece with Sophie.

    Finally, Livaditis’s sister Fanny testified. She said that
Livaditis was very close to Sophie and spent more time with
her than the other children. Fanny testified that Livaditis
“wasn’t very talkative” and “looked very preoccupied and
sort of moody and depressed” after he left the military.
Livaditis told her that he felt confused and couldn’t find any
meaning in his life. Fanny said that she forgave Livaditis for
what he did and wanted him to live. Livaditis’s other sister
did not testify.

    In closing arguments, the state argued that Livaditis’s
prior crimes were the beginning of a pattern of criminality
that his family either did not see or did not want to see. The
state argued that all of the Livaditis children “basically had
the same background,” but “if anyone had more of an
advantage growing up than anyone else, it would be the
defendant” because he was “obviously the favorite of the
mother.” The state emphasized that Livaditis “had good
family” and “a good support network” but engaged in a
pattern of refusing to take responsibility for his bad choices.
The state then detailed the circumstances of the Van Cleef &
Arpels robbery and the murders of the three hostages and
placed particular emphasis on the fact that Livaditis made
the choice to commit these crimes and bore full
responsibility for the consequences.

    During the defense’s closing argument, Livaditis’s
attorney, Michael Demby, noted that Livaditis had accepted
                    LIVADITIS V. DAVIS                     11

responsibility for his crimes and admitted his guilt, even
though he knew that he would either get life in prison
without parole or the death penalty. He urged the jury to be
cautious in deciding on the death penalty and asked them to
look at Livaditis’s background. He said that Livaditis did not
have a lifetime record of criminality, unlike many other
defendants, and had not been planning to kill the hostages.
Demby repeatedly emphasized the effect of Livaditis’s
crimes and sentence on his family members, who knew a
“good” and “kind” side of Livaditis.

    The jury began its deliberations on June 16 and returned
a verdict of death on June 19, 1987. Livaditis was sentenced
to death on July 8, 1987.

B. Procedural History

    The California Supreme Court affirmed Livaditis’s death
sentence, without dissent, in a published opinion filed on
June 18, 1992. People v. Livaditis, 831 P.2d 297 (Cal. 1992).
The United States Supreme Court denied his petition for a
writ of certiorari on March 8, 1993. Livaditis v. California,
507 U.S. 975 (1993) (mem.).

    Livaditis successfully applied for a stay of execution and
appointment of counsel from the federal district court on
April 22, 1996. He filed his first federal habeas petition on
April 23, 1997. On August 20, 1997, he simultaneously filed
a habeas petition in the California Supreme Court and an
amended federal habeas petition in the district court. The
California Supreme Court summarily denied his state
petition for a writ of habeas corpus on the merits on
November 24, 1998.

   The district court granted Livaditis leave to file a second
amended habeas petition on August 12, 1999. After
12                      LIVADITIS V. DAVIS

substantial briefing and other litigation activity, the district
court, considering only the record before the California
Supreme Court, denied Livaditis’s habeas petition in a
lengthy written order filed on July 8, 2014. 1

    Livaditis appealed. He requested a certificate of
appealability on three claims. A motions panel of our court
granted a certificate of appealability on part of his claim that
he received ineffective assistance of counsel (“Claim 11”),
namely, whether “trial counsel was effective at the penalty
phase in failing to present any mitigating evidence
concerning: (i) Petitioner’s alleged mental health problems;
and (ii) Petitioner’s allegedly abusive and mentally unstable
mother.” Livaditis does not present any uncertified claims
on appeal.

II. Discussion

   We review the district court’s denial of habeas relief de
novo. Hurles v. Ryan, 752 F.3d 768, 777 (9th Cir. 2014).
Because Livaditis filed his petition after April 24, 1996, the
Antiterrorism and Effective Death Penalty Act (AEDPA)
governs our review of his habeas claims. Under AEDPA, we
may grant a writ of habeas corpus only if the state court’s

     1
       The district court had earlier issued an order granting an
evidentiary hearing on various claims in the petition, including the
claims that Livaditis raises on appeal. The evidentiary hearing took place
over four days in 2010. After the evidentiary hearing, the Supreme Court
issued its decision in Cullen v. Pinholster, 563 U.S. 170 (2011). In
Pinholster, the Court held that a federal habeas court conducting review
under AEDPA “is limited to the record that was before the state court
that adjudicated the claim on the merits.” Id. at 181. The parties filed
briefs with the district court addressing the impact of the decision on
Livaditis’s petition. The district court ultimately considered only the
record before the California Supreme Court in denying Livaditis’s
habeas petition.
                     LIVADITIS V. DAVIS                       13

adjudication of the merits of the claim: “(1) resulted in a
decision that was contrary to, or involved an unreasonable
application of, clearly established Federal law, as
determined by the Supreme Court of the United States; or
(2) resulted in a decision that was based on an unreasonable
determination of the facts in light of the evidence presented
in the State court proceeding.” 28 U.S.C. § 2254(d).

    This is a high bar, as “it was meant to be.” Harrington v.
Richter, 562 U.S. 86, 102 (2011). “A state court’s
determination that a claim lacks merit precludes federal
habeas relief so long as fairminded jurists could disagree on
the correctness of the state court’s decision.” Id. at 101
(quotation marks omitted).

    Where, as here, a state court summarily denies a claim, a
petitioner “can satisfy the ‘unreasonable application’ prong
of § 2254(d)(1) only by showing that ‘there was no
reasonable basis’ for the [state court’s] decision.” Cullen v.
Pinholster, 563 U.S. 170, 188 (2011) (quoting Richter,
562 U.S. at 98). We “must determine what arguments or
theories . . . could have supporte[d] the state court’s
decision; and then [we] must ask whether it is possible
fairminded jurists could disagree that those arguments or
theories are inconsistent with the holding in a prior decision
of [the Supreme Court].” Id. at 188 (some alterations in
original) (quoting Richter, 562 U.S. at 102). Our review is
“limited to the record that was before the state court that
adjudicated the claim on the merits.” Id. at 181.

    We evaluate a habeas claim de novo and consider
evidence presented for the first time in federal court only if
we find, “considering only the evidence before the state
court, that the adjudication of a claim on the merits resulted
in a decision contrary to or involving an unreasonable
application of clearly established federal law, or that the state
14                       LIVADITIS V. DAVIS

court’s decision was based on an unreasonable
determination of the facts.” Hurles, 752 F.3d at 778.

A. The Record on Appeal

    In Pinholster, a habeas case involving another California
murder conviction and capital sentence, the Supreme Court
held that a federal habeas court conducting review under
AEDPA “is limited to the record that was before the state
court that adjudicated the claim on the merits.” 563 U.S.
at 181. This rule applies even when the state court has
summarily denied the habeas claims. See id. at 181, 188.

     The district court correctly applied Pinholster. It based
its decision only on the record before the California Supreme
Court (including the trial court record 2) and did not consider
the evidence presented in the federal court evidentiary
hearing. We take the same approach.

B. Ineffective Assistance of Counsel Claims

    Livaditis raises two ineffective assistance of counsel
claims on appeal. He argues that his trial counsel was
deficient for failing to present two categories of mitigating

     2
       In Pinholster, the Supreme Court also explained that when the
California Supreme Court issues a summary denial of a habeas claim, it
“generally assumes the allegations in the petition to be true, but does not
accept wholly conclusory allegations, and will also ‘review the record of
the trial to assess the merits of the petitioner’s claims.’” 563 U.S. at 188
n.12 (alterations and citation omitted) (quoting In re Clark, 855 P.2d 729,
742 (Cal. 1993)).

     The record before the California Supreme Court in this case
included both the allegations in Livaditis’s habeas petition and the record
of the trial. See id. The California Supreme Court had previously
reviewed the trial record in connection with Livaditis’s direct appeal.
                    LIVADITIS V. DAVIS                   15

evidence: 1) additional information about Sophie Livaditis’s
abuse and mental illness; and 2) information about
Livaditis’s mental illness and brain damage.

    For our review under AEDPA of claims of ineffective
assistance of counsel, the law clearly established by
decisions of the U.S. Supreme Court is Strickland v.
Washington, 466 U.S. 668 (1984). See Ayala v. Chappell,
829 F.3d 1081, 1096 (9th Cir. 2016). Under Strickland, the
petitioner must satisfy a two-part test:

       First, the [petitioner] must show that
       counsel’s performance was deficient. This
       requires showing that counsel made errors so
       serious that counsel was not functioning as
       the “counsel” guaranteed the defendant by
       the Sixth Amendment. Second, the
       [petitioner] must show that the deficient
       performance prejudiced the defense. This
       requires showing that counsel’s errors were
       so serious as to deprive the [petitioner] of a
       fair trial, a trial whose result is reliable.

466 U.S. at 687.

    Our review “of counsel’s performance must be highly
deferential.” Id. at 689. We must “indulge a strong
presumption that counsel’s conduct falls within the wide
range of reasonable professional assistance.” Id. When
reviewing a state court’s decision on a Strickland claim
under AEDPA, the federal court’s review must be “doubly”
deferential, Richter, 562 U.S. at 105, because Strickland
provides courts with a general standard:

       Because judicial application of a general
       standard “can demand a substantial element
16                   LIVADITIS V. DAVIS

        of judgment,” the more general the rule
        provided by the Supreme Court, the more
        latitude the state courts have in reaching
        reasonable outcomes in case-by-case
        determinations. Yarborough v. Alvarado,
        541 U.S. 652, 664 (2004). In turn, the state
        courts’ greater leeway in reasonably applying
        a general rule translates to a narrower range
        of decisions that are objectively unreasonable
        under AEDPA. Accordingly, we review a
        state court’s decision applying Strickland’s
        general principles with increased, or double,
        deference.

Cheney v. Washington, 614 F.3d 987, 995 (9th Cir. 2010).

    The California Supreme Court denied Livaditis’s
petition summarily. Because it did not discuss its reasons for
denying the claims of ineffective assistance of counsel, the
question before us becomes “whether there is any reasonable
argument” that could have supported that decision under the
deferential standard that applies in this context. Richter,
562 U.S. at 105.

    After considering the record, we conclude that there
were reasonable grounds to support the denial of relief by
the California Supreme Court on Livaditis’s claims of
ineffective assistance of counsel. Put in terms of the relevant
standard under AEDPA, the decision by the California
Supreme Court was not based on an unreasonable
application of the law or determination of facts.

     1. The Defense Strategy

   Michael Demby, a deputy public defender, was
appointed to represent Livaditis shortly after his arrest. At
                    LIVADITIS V. DAVIS                    17

that point, Demby had more than seventeen years of
experience as a public defender. An investigator assisted
Demby on the case.

    Demby provided a declaration in Livaditis’s state habeas
proceedings explaining his strategy for the penalty phase. In
this declaration, Demby stated that he “knew early on that a
penalty phase investigation was of primary importance in
preparing for trial.” Demby stated that Livaditis cooperated
with preparations for trial and that he interviewed Livaditis
about his background multiple times. Demby also
interviewed several of Livaditis’s family members.
According to Demby, these interviews made it “obvious that
Mr. Livaditis came from a very dysfunctional family.” In
particular, he “knew from other members of the family that
[Livaditis’s mother] suffered from mental and physical
illnesses throughout Mr. Livaditis’s childhood.” According
to Demby, Livaditis’s mother initially refused to cooperate
meaningfully in Livaditis’s defense. Demby also knew that
Livaditis’s sister, Pauline, was mentally ill.

    Demby learned that Livaditis “had serious abandonment
issues” and that his father had been abusive. Livaditis was
placed at St. Basil’s when he was eight and stayed there for
almost two years, even though he was extremely unhappy.
The family only removed him when he began to starve
himself and became very ill. Demby learned that Livaditis
was then “shuffled to different family members, including
an aunt and uncle in Greece who physically and
psychologically abused him.” He also discovered that
Livaditis had other physical problems in his youth, including
at least two head injuries, nearly fatal appendicitis, and a
serious fall.
18                      LIVADITIS V. DAVIS

    Demby stated that did not obtain or review additional
records in preparing Livaditis’s defense because the trial
commenced before he was fully prepared:

         The trial prematurely ended my efforts to
         obtain medical records and other social
         history documents, and it prevented any
         attempts to obtain more information about
         the orphanage where Mr. Livaditis was so
         unhappy as a child as well as information
         regarding Mr. Livaditis’s training and service
         in the Army Reserves. Had I been given
         additional time, I would have done
         everything I could to obtain additional
         medical records and related social history
         documents. 3

    Demby stated that his initial strategy was to focus on the
physical abuse that Livaditis’s father and uncle inflicted on
him, as well as the detrimental effect of his family’s
abandonment. Ultimately, however, Demby decided to
present testimony from Livaditis’s family members instead.
He hoped that “the jury would like these family members
and would want to do something for them, even if they did
not want to do something for Mr. Livaditis.” He based this
decision on interviews that he conducted with various
members of the family in Greece, including Sophie
Livaditis.

    To that end, Demby’s mitigation strategy focused on the
closeness of the family and the fact that Livaditis only began

     3
       There is no claim before us that Livaditis’s trial counsel did not
have adequate time to prepare for the penalty phase of trial, or that the
trial court wrongly denied a motion to continue the trial.
                    LIVADITIS V. DAVIS                    19

to have problems as a young adult after leaving the army.
Demby also elicited testimony that Livaditis’s father was
abusive, but he did not probe into the abuse in depth.

   2. Mental Illness of and Abuse by Livaditis’s Mother

    Livaditis argues that Demby’s assistance was
constitutionally deficient because Demby was aware that
Livaditis’s mother, Sophie, suffered from severe mental
illness and had abused her children but failed to investigate
further or present any of this evidence in mitigation. The
information that Demby was aware of included statements
of family members and the family priest describing Sophie
as depressed, ill, emotionally and mentally unstable, and in
need of special therapy; a statement from a family member
that Sophie abused Livaditis; and statements from family
members and Livaditis describing his misery at St. Basil’s
and the rarity of Sophie’s visits.

     Based on this information, Livaditis now contends that
Demby should have pursued further investigation into
Sophie’s background and abuse. He argues that, had Demby
and his investigator performed proper interviews with family
members, they would have learned that Sophie and her
family experienced hardship in Greece; mental illness was
common in Sophie’s family; Sophie’s parents were mentally
ill; Sophie was “essentially sold” to relatives in the United
States who did not treat her well; Sophie’s marriage to Louis
Livaditis was difficult from the beginning; Sophie attempted
to self-induce abortions, including while pregnant with
Livaditis, because she did not want children; Sophie beat all
of her children; relatives described her as suffering from a
nervous breakdown and odd behavior after she and Louis
were divorced; Sophie prohibited her children from
contacting any member of the Livaditis family, including
Louis; she was referred for a psychiatric consultation
20                  LIVADITIS V. DAVIS

because of “bizarre behavior” during a hospital stay,
resulting in a diagnosis of a “hysterical personality with the
possibility of underlying ego pathology,” with a possible
dissociative disorder; and Sophie enlisted other relatives to
discipline and beat her children. Livaditis argues that
Demby’s performance as his attorney was constitutionally
deficient for failing to discover and present any of this
evidence in mitigation.

    We disagree. Under Strickland, “strategic choices made
after less than complete investigation are reasonable
precisely to the extent that reasonable professional judgment
supports the limitations on investigation. In other words,
counsel has a duty to make reasonable investigations or to
make a reasonable decision that makes particular
investigations unnecessary.” 466 U.S. at 690–91. Reviewing
courts must “apply[] a heavy measure of deference to
counsel’s judgments” about the decision not to investigate.
Id. at 691.

   The record reflects that Demby did perform an initial
investigation of Livaditis’s social background, including his
mother’s abuse and mental illness. Although Demby
apparently did not have all of the information that Livaditis
describes, he was aware that a focus on Sophie’s abuse and
mental illness was a possible mitigation strategy. Once he
became aware of an alternative strategy, namely, mercy
based on pleas from Sophie and other sympathetic family
members, he was in a position to make a reasonable decision
about how to proceed, and whether to continue to investigate
Sophie’s background.

   The additional evidence of Sophie’s mental illness and
abuse that Demby failed to discover did not differ
meaningfully from the evidence that Demby already had.
Rather, it primarily added details about issues of which
                    LIVADITIS V. DAVIS                    21

Demby was already aware. The California Supreme Court
could have reasonably concluded that this additional
evidence would not have altered Demby’s strategy. See
Bobby v. Van Hook, 558 U.S. 4, 11–12 (2009) (“[This] is . . .
a case, like Strickland itself, in which defense counsel’s
‘decision not to seek more’ mitigating evidence from the
defendant’s background ‘than was already in hand’ fell ‘well
within the range of professionally reasonable judgments.’”
(quoting Strickland, 466 U.S. at 699)).

    Likewise, the California Supreme Court could
reasonably have concluded that Demby did not select a
constitutionally deficient mitigation strategy. The U.S.
Supreme Court has recognized that a “mercy” or “family
sympathy” theme is a valid approach to mitigation. See
Pinholster, 563 U.S. at 191 (denying petitioner’s ineffective
assistance of counsel claim, in part because the “family
sympathy” mitigation strategy “was known to the defense
bar in California [in 1984] and had been used by other
attorneys”). And here, pleading for mercy on behalf of
Livaditis’s family was a legitimate strategy given its
closeness, which Demby understood after extensive
interviews with the family.

    Furthermore, as the district court correctly noted,
emphasizing Sophie’s abuse of Livaditis would have been
inconsistent with portraying her as a sympathetic witness
and would therefore have limited the efficacy of a family
sympathy approach. Indeed, in light of the challenges that
Demby had in convincing Sophie to cooperate with his
investigation and testify during the sentencing, portraying
Sophie as severely mentally ill could have had a detrimental
impact on her participation in the trial. In addition, this
evidence could have undercut the jury’s view of her
testimony.
22                  LIVADITIS V. DAVIS

    As for the second prong under Strickland, the state court
could also reasonably have concluded that Livaditis was not
prejudiced by Demby’s failure to present evidence of
Sophie’s mental illness and abuse. Demby did elicit some
testimony about Livaditis’s difficult upbringing during the
penalty phase. Although evidence of Sophie’s abuse would
have added to this testimony, much of the new evidence that
Livaditis cites was cumulative. The California Supreme
Court could reasonably have concluded that this evidence
would not have changed the outcome of Livaditis’s
sentencing. See Wong v. Belmontes, 558 U.S. 15, 22–23
(2009) (holding that the state court could reasonably have
concluded that the petitioner was not prejudiced when the
evidence that counsel failed to present was cumulative of the
“humanizing” evidence counsel used because the jury was
already “‘well acquainted’ with [the petitioner’s]
background and potential humanizing features” (quoting
Schriro v. Landrigan, 550 U.S. 465, 481 (2007))).

    We conclude that the California Supreme Court did not
unreasonably apply federal law or unreasonably determine
facts in denying the ineffective assistance of counsel claim
based on the mental impairments and abusive conduct of
Livaditis’s mother.

     3. Livaditis’s Mental Impairments

    Livaditis also argues that Demby was constitutionally
deficient because he was aware that Livaditis had signs of
possible mental illness but failed to investigate further or
present any of this evidence in mitigation.

    Livaditis correctly asserts Demby had information
suggesting that Livaditis may have been mentally ill. That
information included Livaditis’s own statements to Demby
that he was a little “unstable,” had not been “thinking like a
                     LIVADITIS V. DAVIS                     23

normal person,” and was “screwed up in the head”;
Livaditis’s statements to Demby that at the beginning of the
robbery, he was “high” and “excited” and felt “like he was
President of the United States,” but later he felt angry and
likened his feelings to a person who was at “a party having
a good time and somebody does something to ruin it”; a co-
worker’s statement that Livaditis was “a hyper person who
was given to abrupt mood swings”; a statement from
Livaditis to his cousin that he experienced “an inner rage that
left him confused”; a copy of the police hostage negotiator’s
notes that described Livaditis’s false assertions that he was a
Vietnam veteran, a college graduate with several degrees,
was fluent in four languages, was capable of “maxing”
aptitude tests, and was able to move water with telekinesis;
a transcript of Livaditis’s post-arrest interview indicating
that he was chuckling to himself and said that he killed one
of the hostages because something “kicked inside” and he
heard a voice telling him to kill the hostage; and an interview
with the media in which Livaditis described himself as a
Robin Hood figure. Demby also received Livaditis’s school
records, which indicated that Livaditis was a “below average
student” who had an “inability to read with comprehension”
and was recommended to repeat third grade; and the
transcript of a police interview in which Livaditis said that
he may not be able to keep up with their interview questions
because he did not have a lot of “understanding.”

    Demby’s trial notes indicate that he discussed the issue
of mental illness with Livaditis. Those notes reflect that
Livaditis told Demby that he was “not crazy,” although it
had “crossed his mind to act crazy” and he could “do a good
job” acting the part. The notes indicate that Livaditis
considered feigning mental illness because he had “heard
they could not execute an insane person.” Demby also
24                  LIVADITIS V. DAVIS

consulted a “mental health expert,” although the record is
silent regarding the results of that consultation.

    Livaditis argues that Demby should have investigated
Livaditis’s mental impairments further. Had he done so,
Livaditis contends that he could have discovered jail medical
records requesting toxicology testing, which a doctor
ordered after he observed “Abnormal Behavior,” with a
handwritten notation of “Drugs/vs/Psychosis”; the results of
that toxicology testing that showed no presence of drugs or
alcohol; jail records from a few days after Livaditis’s arrest
indicating that he told staff that he was “hearing voices” and
was “willing to see psych”; and a psychiatrist’s tentative
assessment that he had an “adjustment disorder” with
“mixed emotional features” and an antisocial personality
disorder.

    In the state post-conviction proceedings, Livaditis’s
new counsel retained three mental health experts to perform
an analysis of Livaditis’s mental health. Dr. Rosenberg, a
psychologist, prepared a report after interviewing Livaditis
for 18 ½ hours, Fanny Livaditis for 5 hours, and George
Livaditis for 5 hours. She also used a detailed social history
of Livaditis and related exhibits to prepare her evaluation.
She concluded that Livaditis’s childhood trauma “adversely
affected his subsequent psychological development,
including his behavioral, social, emotional, and cognitive
functioning.”

    Dr. Watson, a neuropsychologist, performed an
evaluation based on 17 hours of interviews and tests. Dr.
Watson also reviewed family declarations, Livaditis’s
hospital records from 1985 and 1986, his educational and
army records, other family medical records, his jail medical
records, and Dr. Rosenberg’s declaration. Dr. Watson
concluded that Livaditis had a “mild degree of
                       LIVADITIS V. DAVIS                          25

neuropsychological    impairment”     and     intellectual
functioning “below that expected based upon both
demographic and performance characteristics.”

    Dr. Foster, a neuropsychiatrist, provided an expert
declaration on the basis of four sets of examinations,
interviews, and tests that he conducted over 16 hours. He
also reviewed Dr. Rosenberg’s social history, the
declarations of family members and acquaintances, and Dr.
Watson’s report. Dr. Foster found that Livaditis suffered
from “severe psychiatric disorders, neuropsychological and
medical deficits which significantly compromised his ability
accurately to perceive and understand the world around him,
his ability to respond adequately to complex situations, and
his ability to function normally.” According to Dr. Foster,
Livaditis’s disorders included both post-traumatic stress
disorder and a “severe mood disorder with intermittent
psychotic features,” most likely bipolar disorder, but
possibly schizoaffective disorder. Dr. Foster also concluded
that Livaditis’s symptoms were “consistent with acquired
and, perhaps, congenital brain injury.”

    After reviewing that record, the district court held that
the California Supreme Court could have reasonably denied
Livaditis’s habeas petition under both prongs of Strickland.
With respect to prejudice, we agree. We conclude that the
California Supreme Court could have reasonably determined
that Livaditis was not prejudiced at the penalty phase. 4

   “Establishing prejudice in the death sentence context
requires a showing that there is a reasonable probability that,
absent the errors, the sentencer would have concluded that

    4
      As it is unnecessary, we do not address Demby’s performance. See
Pinholster, 563 U.S. at 202.
26                  LIVADITIS V. DAVIS

the balance of aggravating and mitigating circumstances did
not warrant death. The defendant bears the highly
demanding and heavy burden of establishing actual
prejudice.” Bible v. Ryan, 571 F.3d 860, 870 (9th Cir. 2009)
(quotations and punctuation omitted). For three reasons, we
conclude that the California Supreme Court could have
reasonably determined that Livaditis did not meet that
burden.

    First, several aggravating circumstances supported the
jury’s verdict. This was not the first time that Livaditis had
demonstrated ruthlessness during the commission of a
violent crime. As noted above, the state presented evidence
of Livaditis’s record of crimes and bad acts. In particular,
four months before the Beverly Hills robbery and murders,
Livaditis robbed a jewelry store in Las Vegas at gunpoint.
During that robbery, he tied up two of the store’s employees,
verbally abused them, threatened to kill them, and kicked
one of the bound employees repeatedly.

    Livaditis exhibited similar callousness during the
Beverly Hills robbery and murders when he killed Smith and
Heilperin. He stabbed Smith because Smith verbally defied
him and let him bleed to death in front of the other hostages.
He then killed Heilperin because he wanted to prove that his
demands were serious. He chose Heilperin because she had
screamed at the start of the robbery. As in the Las Vegas
robbery, both victims were helpless. Moreover, during press
interviews Livaditis indicated that he believed Smith’s
stabbing was “appropriate.” The cruelty Livaditis displayed
over the course of multiple crimes constituted a substantial
aggravating factor. See, e.g., Sully v. Ayers, 725 F.3d 1057,
1069 (9th Cir. 2013) (“staggering” aggravating evidence
weighed against a conclusion that defendant was
prejudiced); Bible, 571 F.3d at 870 (the “powerful
                    LIVADITIS V. DAVIS                    27

aggravating circumstances surrounding [the] murder”
weighed against a conclusion that defendant was
prejudiced).

    Second, the California Supreme Court could have
reasonably decided to accord the declarations submitted by
Livaditis’s mental health experts little weight.         Dr.
Rosenberg focused on describing the psychological effects
of Livaditis’s abusive childhood. Because Demby elicited
testimony that demonstrated that Livaditis had been abused
as a child and the jury could have inferred negative effects
from that treatment, the California Supreme Court could
have considered Dr. Rosenberg’s testimony cumulative. See
Wong, 558 U.S. at 22–23. Moreover, Dr. Rosenberg did not
propose a clinical diagnosis. See Runningeagle v. Ryan, 825
F.3d 970, 987 (9th Cir. 2016) (discounting mental health
declaration that “gave no affirmative diagnosis”).

    Dr. Watson indicated only that Livaditis suffered from a
“mild degree of neuropsychological impairment.” The
California Supreme Court could have concluded that
mitigating effect of that statement was limited. See id.
at 987–88 (giving limited weight to mental health diagnosis
that “used qualifying language”).

    Dr. Foster discussed Livaditis’s history of trauma, child
abuse, and neglect. Although Dr. Foster proposed several
clinical diagnoses, those diagnoses were based on interviews
conducted nearly ten years after the murders. See id. at 988
(discounting diagnosis produced more than 20 years after the
crimes were committed). Moreover, on the crucial issue of
brain damage, Dr. Foster simply opined that Livaditis’s
symptoms were “consistent with” brain damage. See Leavitt
v. Arave, 646 F.3d 605, 614 (9th Cir. 2011) (holding, in pre-
AEDPA case, that mental health opinions that “couch results
28                  LIVADITIS V. DAVIS

in tentative language” are “simply not enough to show
prejudice”).

    The record also reflected that Livaditis had told Demby
that he was “not crazy” but that he had considered acting
crazy and could “do a good job” at that. The California court
may have decided as a result to treat with skepticism expert
statements based on interviews of Livaditis conducted years
after he had already been sentenced to death. That skepticism
could have been fueled by Demby’s own declaration, which
indicated that he had consulted his own mental health expert
at trial. It would not have been unreasonable for the
California Supreme Court to discount the testimony of these
mental health experts.

    Third, as discussed above, Demby put on extensive
mitigation evidence, including testimony from Livaditis’s
family. One of the key themes of Demby’s mitigation
strategy was the closeness of the family and the jurors’
potential sympathy for Livaditis’s mother, Sophie. The
mental health experts’ declarations discussed the abuse
Livaditis suffered at Sophie’s hands at length. All three
experts relied on that abuse in reaching their conclusions.
Any testimony along the lines suggested by the later
testimony from those experts would almost certainly have
touched on Sophie’s abuse. That testimony could have
rendered Sophie far less sympathetic in the jurors’ eyes.
Thus, if Demby had called on mental health experts during
mitigation, those experts may have undercut the mitigation
case that Demby did put on. Cf. Pinholster, 563 U.S. at 202
(no prejudice where, inter alia, “some of the new testimony
would likely have undercut the mitigating value of the
testimony by Pinholster’s mother”).

   After considering the aggravating evidence adduced, the
substantial mitigating evidence that Demby did present, and
                      LIVADITIS V. DAVIS                    29

the mitigation evidence he could have presented, the
California Supreme Court could have reasonably concluded
that further evidence concerning Livaditis’s mental health
would not have made a difference. More precisely, in the
terms used in Strickland, the California Supreme Court
could have reasonably concluded that there was not a
“reasonable probability that . . . the result of the proceeding
would have been different.” Strickland, 466 U.S. at 694.

III.     Conclusion

    We affirm the district court’s denial of Livaditis’s
petition for a writ of habeas corpus. Under de novo review,
we might reach a different conclusion. Especially under the
double deference that applies to our review, however, we
cannot say that the inferred conclusions by the California
Supreme Court constituted unreasonable applications of
federal law or unreasonable determinations of the facts. See
Richter, 562 U.S. at 105.

       AFFIRMED.
