                  FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


RICHARD KENNETH DJERF,                   No. 08-99027
        Petitioner-Appellant,
                                         D.C. No.
             v.                     2:02-cv-00358-JAT

CHARLES L. RYAN,
        Respondent-Appellee.              OPINION

     Appeal from the United States District Court
              for the District of Arizona
     James A. Teilborg, District Judge, Presiding

        Argued and Submitted March 26, 2019
             San Francisco, California

                   Filed July 24, 2019

  Before: M. Margaret McKeown, Ronald M. Gould,
          and Sandra S. Ikuta, Circuit Judges.

             Opinion by Judge McKeown
2                         DJERF V. RYAN

                          SUMMARY *


               Habeas Corpus / Death Penalty

    The panel affirmed the district court’s dismissal of an
Arizona state prisoner’s 28 U.S.C. § 2254 habeas corpus
petition challenging his conviction by guilty plea for four
counts of first-degree murder and his capital sentence.

    Following a period of appointed representation,
petitioner waived counsel and represented himself. He
entered guilty pleas, and counsel resumed representation for
sentencing.

     The panel held that counsel did not provide
constitutionally ineffective pre-trial assistance by failing
adequately to communicate with petitioner or visit him in
jail, or to diligently interview witnesses, review discovery,
and examine evidence. The panel concluded that, under any
standard of review, counsel’s conduct was not objectively
unreasonable.        Accordingly, petitioner’s claims of
involuntary waiver of counsel and invalid guilty pleas,
premised on ineffective pre-trial assistance, failed. Further,
petitioner’s procedural default of the ineffective assistance
claims was not excused.

    The panel affirmed the district court’s denial of
petitioner’s claim that counsel provided ineffective
assistance during sentencing by failing to investigate,
develop, and present additional mitigation evidence related

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

to his family background and mental health. The panel
concluded that the state post-conviction court did not
unreasonably apply Supreme Court precedent in holding that
there was no ineffective assistance of counsel during
sentencing, and the district court did not abuse its discretion
in denying petitioner’s request for an evidentiary hearing on
that claim.

   Finally, any error in the Arizona court’s impermissibly
ignoring mitigating evidence of petitioner’s family
background because it lacked a causal nexus to his crimes
was harmless.


                         COUNSEL

Therese Michelle Day (argued) and Michael L. Burke,
Assistant Federal Public Defenders; Jon M. Sands, Federal
Public Defender; Office of the Federal Public Defender,
Phoenix, Arizona; for Petitioner-Appellant.

Ginger Jarvis (argued), Assistant Attorney General; Lacey
Stover Gard, Chief Counsel; Mark Brnovich, Attorney
General; Office of the Attorney General, Phoenix, Arizona;
for Respondent-Appellee.
4                        DJERF V. RYAN

                           OPINION

McKEOWN, Circuit Judge:

    Richard K. Djerf killed the mother, father, brother, and
sister of a former friend to avenge a petty theft. He was
promptly arrested and charged with numerous crimes. After
a year and a half of appointed representation, he waived
counsel and represented himself. Djerf pleaded guilty to
four counts of first-degree murder, and counsel resumed
representation for sentencing. The trial judge imposed a
capital sentence for each of the murder convictions. The
Arizona Supreme Court did the same on de novo review.
Arizona courts denied Djerf’s requests for post-conviction
relief, and the district court dismissed his federal habeas
petition. We affirm.

                   FACTUAL BACKGROUND 1

    Djerf and Albert Luna, Jr. were friends from their job at
the local supermarket, but in early 1993 Albert stole several
electronics and a firearm from Djerf’s apartment. Djerf
reported the incident and his suspicions about Albert’s
involvement to the police, who took no action. Djerf sought
revenge several months later. Late one morning, Djerf
arrived at the Luna family home with a handgun, knife, latex
gloves, handcuffs, and fuse cord, using a vase with fake
flowers as a ruse to gain entry. Albert’s mother and five-
year-old brother were home; Djerf bound them and asked the
mother whether she or her young son should die first and
whether she knew Albert’s whereabouts. Djerf briefly

    1
      The following account of Djerf’s crimes was set forth by the
Arizona Supreme Court on direct review. See State v. Djerf, 959 P.2d
1274, 1279–80 (Ariz. 1998) (en banc).
                      DJERF V. RYAN                        5

untied the mother, forcing her to load electronics and other
valuables from the home into the family car.

   Several hours later, Albert’s eighteen-year-old sister
came home. Djerf bound and gagged her, cut off her clothes,
and raped her before repeatedly stabbing her in the chest and
head and slitting her throat. Djerf then told Albert’s mother
what he had done to her daughter.

    Shortly after, Albert’s father came home. Djerf
handcuffed him and forced him to crawl on all fours and lay
face down on his bed. Djerf struck him in the head several
times with a baseball bat, removed his handcuffs, bound his
hands with tape, and left him for dead. Djerf told the mother
that he had killed her husband.

    Djerf then attempted, but failed, to snap the boy’s neck
and to electrocute him with a stripped electrical wire. The
father, who had survived the earlier beating, charged and
stabbed Djerf with a pocketknife. During the ensuing
struggle, Djerf stabbed the father and then fatally shot him
six times in front of the mother and boy. Djerf asked the
mother whether she wanted to watch the boy die, or for him
to watch her die, before shooting both in the head. He
covered the bodies and the house with gasoline, turned on
two stove burners, and placed cardboard and a rag on the
stove, before fleeing the house in the family’s car. The
cardboard and rag never ignited. When Albert returned to
the house, he discovered the gruesome scene and notified the
police.

    Over the next several days, Djerf described the murders
to his girlfriend and two other friends. Djerf was arrested
shortly after.
6                      DJERF V. RYAN

               PROCEDURAL BACKGROUND

    A grand jury charged Djerf with four counts of first-
degree murder, as well as first-degree burglary, kidnapping,
sexual assault, aggravated assault, attempted arson, theft,
and unlawful use of a prohibited weapon. Michael Vaughn
and Alan Simpson were appointed as counsel, and they
represented Djerf at numerous hearings over the next year
and a half. In February 1995, Djerf wrote to the trial judge
to express his displeasure with the frequency of counsel’s
communication, their responsiveness, and their efforts to
keep him apprised of trial strategy. Djerf requested that
Vaughn and Simpson be withdrawn as counsel and asked to
represent himself.

    At a hearing several days later, the judge questioned
Djerf at length to ensure he understood the disadvantages of
self-representation and the severity of the potential penalties
he faced. Counsel expressed their belief that Djerf was
competent, but strongly advised against self-representation.
The judge reiterated this advice, but nonetheless concluded
Djerf knowingly, intelligently, and voluntarily waived his
right to counsel, accepted the waiver of counsel, and
appointed Vaughn and Simpson in an advisory capacity.

    A few weeks later, the State requested an evaluation of
Djerf’s competence. In a prescreening report, Dr. Jack Potts
concluded that Djerf understood the nature of the charges
and possible penalties, the pending proceedings, his
constitutional rights, and the necessary waiver of those rights
if he entered a guilty plea. According to the report, Djerf
understood he faced a “far greater burden” if he represented
himself, but believed he had “very little to lose” given that
the case against him was so strong. The report concluded
that Djerf was competent to represent himself and that
                       DJERF V. RYAN                         7

further evaluation of his competency was unnecessary. The
trial judge agreed.

    Several months later, Djerf sent a letter to the prosecutor
offering to accept the maximum non-capital sentences on all
charges in exchange for an agreement not to pursue the death
penalty, though he admitted he had little negotiating
leverage. The prosecutor declined, affirming the State’s
intention to pursue death sentences on the murder charges.
The prosecutor offered to dismiss all other charges if Djerf
would plead guilty to the murder charges “with no
agreements as to sentence.” Djerf consulted with Vaughn
and decided to accept the offer. During the change of plea
hearing, the judge conducted a thorough canvass and
accepted Djerf’s guilty pleas.

    Several weeks later, in September 1995, Djerf asked to
remove Vaughn and Simpson as advisory counsel in light of
their purported lack of attention and failure to communicate,
and to appoint “effective” and “experienced” counsel for
sentencing. Djerf stated that he “would prefer that counsel
represent me for sentencing, but . . . I have pretty much lost
trust in Mr. Vaughn and Mr. Simpson.” The trial judge
denied the motion, noting the substantial work counsel had
performed on Djerf’s case and their considerable experience
in serious criminal cases. The judge concluded that
“appoint[ing] some new attorney now at this stage would . . .
not be in the interest of justice” because it would cause
further delay and Djerf might have the same complaints
about different lawyers.

    Djerf ultimately withdrew his waiver of counsel, and the
court reappointed Vaughn and Simpson.              The State
presented its aggravation case over the course of five days in
October 1995.
8                         DJERF V. RYAN

    After obtaining several continuances, Simpson presented
Djerf’s mitigation case in February 1996. 2 A jail guard
testified to Djerf’s conduct in detention, referencing several
minor disciplinary infractions but indicating he was not an
especially problematic inmate. Arthur Hanratty, a court-
appointed investigator, testified about Djerf’s upbringing,
based on interviews with Djerf’s parents and sister and a
review of background records, school documents, and other
materials. Counsel also introduced a recorded interview
with Djerf corroborating much of Hanratty’s testimony. The
court then granted continuances for counsel’s ongoing
development of potential mental health expert evidence.
Counsel ultimately opted not to present any such evidence.

     In late spring 1996, counsel filed a presentence
memorandum, and the mitigation hearing resumed, with
another jail guard testifying to Djerf’s respectful behavior
and duties as a jail trustee serving meals. At the final
sentencing hearing several weeks later, Djerf declined
multiple offers to address the court before a sentence was
rendered. The judge concluded that the State had proven
three statutory aggravating factors for each murder and a
fourth for the murder of the five-year-old boy. See Ariz.
Rev. Stat. § 13-703(F)(5), (6), (8), (9) (1996). According to
the judge, Djerf failed to prove any statutory or non-statutory
mitigating factors: he “failed to show his difficult family
background is a mitigating circumstance” because “[t]here
is no evidence that any alleged difficult family background
had any effect on the defendant’s behavior during these
killings that was beyond the defendant’s control.” The judge



    2
      Vaughn was unable to attend the hearing because he “had to attend
to matters in another court.”
                        DJERF V. RYAN                          9

entered capital sentences for each of the four murder
convictions.

    In May 1998, the Arizona Supreme Court affirmed the
convictions and, on de novo review, imposed the same
capital sentences. Djerf, 959 P.2d at 1281–90. The court
decided that Djerf’s pre-trial waiver of counsel was valid and
that the trial judge did not abuse his discretion by declining
to conduct a competency hearing. Id. at 1281–84. The court
also concluded that three aggravating factors had been
proven for all four of the murders, a fourth aggravating
factor applied to the murder of the boy, and Djerf failed to
prove any mitigating factors. Id. at 1286–90. According to
the Arizona Supreme Court, Djerf’s difficult family
background was not mitigating because such evidence “is
not relevant unless the defendant can establish that his
family experience is linked to his criminal behavior.” Id. at
1289 (citing State v. Ross, 886 P.2d 1354, 1363 (Ariz.
1994)). The U.S. Supreme Court denied Djerf’s petition for
writ of certiorari. Djerf v. Arizona, 525 U.S. 1024 (1998)
(mem.).

    In February 2000, the Arizona Supreme Court appointed
Jamie McAlister as counsel for Djerf’s state post-conviction
proceedings. A year and a half later, a different trial judge
dismissed Djerf’s petition for post-conviction relief. In early
2002, the Arizona Supreme Court summarily denied a
petition for review.

    Djerf then filed a federal habeas petition in district court.
See 28 U.S.C. § 2254. In September 2004, Djerf requested
discovery and an evidentiary hearing. A year later, the
district court denied Djerf’s request and dismissed several
claims as either procedurally barred or non-cognizable. In
September 2008, the district court denied the remaining
claims, but granted a certificate of appealability for two of
10                     DJERF V. RYAN

them: (i) whether Djerf’s pre-trial waiver of counsel was
involuntary because he was forced to decide between self-
representation and incompetent counsel, and (ii) whether
Simpson and Vaughn provided ineffective assistance of
counsel during sentencing by failing to investigate and
present further mitigation evidence related to Djerf’s family
background and mental health. Djerf appealed.

    In March 2009, Djerf filed another petition for post-
conviction relief in state court claiming his guilty pleas were
not knowing, intelligent, or voluntary and that McAlister
provided ineffective assistance during the initial post-
conviction proceedings. The state court rejected the first
claim as precluded because it was denied by the Arizona
Supreme Court on direct appeal. The court then dismissed
the second claim on the grounds that Djerf did not have a
constitutional right to counsel in post-conviction
proceedings. A few months later, the Arizona Supreme
Court summarily dismissed the petition.

     In 2012, the U.S. Supreme Court decided Martinez v.
Ryan, which held that “[i]nadequate assistance of counsel at
initial-review collateral proceedings may establish cause for
a prisoner’s procedural default of a claim of ineffective
assistance at trial.” 566 U.S. 1, 9 (2012). We granted Djerf’s
motion for a partial remand to permit him to pursue several
claims, including whether McAlister’s allegedly inadequate
representation excused Djerf’s failure to exhaust certain
claims in the initial state post-conviction proceedings.

    In April 2017, the district court denied all remaining
claims, holding that Djerf did not establish cause and
prejudice to set aside the procedural default of his pre-trial
ineffective assistance claim. On appeal to this court, Djerf
argued that the Arizona courts impermissibly ignored his
family background mitigation evidence by employing an
                       DJERF V. RYAN                        11

unconstitutional “causal nexus” test. See generally Eddings
v. Oklahoma, 455 U.S. 104 (1982). We expanded the
certificate of appealability to include the causal nexus claim
and the claims denied by the district court on partial remand.

        JURISDICTION AND STANDARDS OF REVIEW

    We have jurisdiction under 28 U.S.C. §§ 1291 and
2253(a). We review de novo the district court’s denial of a
writ of habeas corpus and for clear error its findings of fact.
Stanley v. Schriro, 598 F.3d 612, 617 (9th Cir. 2010).
Because Djerf’s federal habeas petition was filed after April
24, 1996, he must satisfy the standards set forth in the
Antiterrorism and Effective Death Penalty Act (“AEDPA”).
Under AEDPA, we may not grant relief unless a state court’s
ruling “was contrary to . . . clearly established Federal law[]
as determined by the Supreme Court,” “involved an
unreasonable application of” such law, or “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). In conducting this review, we look to the last
reasoned state court decision for each claim. White v. Ryan,
895 F.3d 641, 665 (9th Cir. 2018).

                          ANALYSIS

    Djerf contends that Simpson and Vaughn provided
ineffective assistance during their pre-trial representation.
He acknowledges that he failed to raise, and therefore
procedurally defaulted, this claim in the initial state post-
conviction proceedings. However, he argues that Martinez
excuses the procedural default, because McAlister’s
ineffective assistance during post-conviction proceedings
was the reason he failed to raise the claim. Djerf advances
two other claims premised on Simpson and Vaughn’s
purportedly deficient pre-trial representation: his waiver of
12                    DJERF V. RYAN

counsel was involuntary because he was forced to decide
between ineffective counsel and self-representation, and his
guilty pleas were invalid because the trial judge failed to
disclose that he was forfeiting his right to proceed with
competent counsel. Because the record does not establish
that Simpson and Vaughn’s pre-trial representation was
constitutionally deficient, the procedural default is not
excused, and the waiver of counsel and guilty pleas claims
fail.

    Djerf advances two other claims on appeal. He contends
that Simpson and Vaughn provided ineffective assistance
during sentencing by failing to investigate and present
further evidence of his difficult family background and
mental health issues. Affording the necessary deference to
the state court’s denial of this claim under AEDPA, we
affirm. Finally, Djerf contends that the Arizona courts
impermissibly ignored mitigating evidence of his family
background because it lacked a causal nexus to his crimes.
We conclude any such error was harmless.

I. Claims   Premised        on     Ineffective   Pre-Trial
   Representation

    As noted, several of Djerf’s claims are premised on
ineffective pre-trial assistance by Vaughn and Simpson.
Specifically, Djerf contends that they failed to adequately
communicate with or visit him in jail, or to diligently
interview witnesses, review discovery, and examine
evidence. The record belies these complaints. Jail visitor
logs and Djerf’s own correspondence demonstrate that
counsel visited him in the months preceding his request for
self-representation and communicated with him regularly
over the telephone and at court. The record likewise
establishes that counsel performed significant work during
this time: they interviewed more than fifty witnesses, with
                      DJERF V. RYAN                      13

some interviews lasting several days; they initiated
negotiations for a plea deal; they filed various motions on
Djerf’s behalf and attended regular hearings; they prepared
for parallel, consolidated proceedings involving use and
treatment of DNA evidence; and they spent nearly an entire
day reviewing the physical evidence in police custody.
During his waiver of counsel hearing, and again in a hearing
at the onset of sentencing proceedings, Djerf acknowledged
that Vaughn and Simpson had done considerable work on
his behalf during their months of representation. The record
demonstrates that brief continuances sought by counsel were
reasonably necessary to permit the continued preparation for
trial and accommodate health issues and other case
responsibilities, not, as Djerf asserts, because counsel had
failed to start any serious work on his case.

    We see no indication that Simpson and Vaughn’s
“representation fell below an objective standard of
reasonableness.” Strickland v. Washington, 466 U.S. 668,
688 (1984). They satisfied their “duty to make reasonable
investigations” by interviewing dozens of witnesses and
seeking out and reviewing evidence. Id. at 691. The record
rebuts Djerf’s conclusory allegations that counsel “did
nothing at all to prepare a defense.” Crandell v. Bunnell,
25 F.3d 754, 755 (9th Cir. 1994) (per curiam). At no point
was there a “complete breakdown in communication,”
Daniels v. Woodford, 428 F.3d 1181, 1201 (9th Cir. 2005),
nor did counsel ever fail to “consult with the defendant on
important decisions [or] to keep the defendant informed of
important developments in the course of the prosecution.”
Strickland, 466 U.S. at 688. Again, despite Djerf’s
suggestions to the contrary, the record does not reveal any
significant periods of time during which counsel failed to
communicate with or respond to him. See Crandell, 25 F.3d
at 755 (suggesting that complete silence for the first two
14                           DJERF V. RYAN

months of representation raised questions about competence
of counsel). Under any standard of review, Simpson and
Vaughn’s conduct was not objectively unreasonable.

    Because the record fails to establish that Vaughn and
Simpson provided constitutionally inadequate pre-trial
assistance, it also fails to establish that Djerf was forced to
choose between self-representation and incompetent
counsel. As a result, his claim that his waiver of counsel was
involuntary fails. So does his related argument that the trial
judge erred by failing to further investigate his motivation
for removing counsel and therefore discover the purportedly
ineffective representation. 3 Djerf’s challenge to the validity
of his guilty pleas also fails—the record does not establish
that counsel were incompetent, so Djerf did not forfeit any
right to proceed with competent counsel. No clearly
established Supreme Court precedent entitles Djerf to relief
on his waiver of counsel and guilty plea claims, and the
Arizona courts reasonably applied the facts in the record to
deny them.

    For the same reasons, we conclude that the procedural
default of the underlying ineffective assistance claim is not
excused. To excuse a procedural default, a habeas petitioner
must establish both “cause” and “prejudice.” Coleman v.
Thompson, 501 U.S. 722, 750 (1991). Typically, ineffective

     3
       Djerf also argues that his waiver of counsel and request for self-
representation in February 1995 should have been construed as a request
to substitute counsel and that the trial court erred by failing to do so. This
argument is not consistent with the record; Djerf several times expressly
stated his desire to represent himself, despite strong discouragement
from the judge and counsel. At no point prior to or during the February
1995 hearing did Djerf intimate a desire for other counsel. In view of
this record, the Arizona Supreme Court’s denial of this claim was not an
unreasonable application of Supreme Court precedent. See Djerf,
959 P.2d at 1283–84.
                       DJERF V. RYAN                         15

assistance of post-conviction counsel cannot excuse a
procedural default. See Martinez, 566 U.S. at 9, 13–14.
However, Martinez created a narrow exception in Arizona
and other states that bar ineffective assistance claims on
direct appeal; in those states, the initial collateral
proceedings are the first opportunity to bring such claims.
Id. The Supreme Court subsequently expanded this
exception, holding that where a “state procedural
framework, by reason of its design and operation, makes it
highly unlikely in a typical case that a defendant will have a
meaningful opportunity to raise a claim of ineffective
assistance of trial counsel on direct appeal, our holding in
Martinez applies.” Trevino v. Thaler, 569 U.S. 413, 429
(2013). To satisfy “cause” in this context, Djerf must show
that McAlister was ineffective under Strickland—that is,
McAlister’s post-conviction representation was deficient
because she failed to bring the pre-trial ineffective assistance
claim, and there is a “reasonable probability” that, had the
claim been raised, “the result of the post-conviction
proceedings would have been different.” Clabourne v.
Ryan, 745 F.3d 362, 377 (9th Cir. 2014), overruled on other
grounds by McKinney v. Ryan, 813 F.3d 798, 819 (9th Cir.
2015) (en banc). To satisfy “prejudice,” Djerf must show
that the underlying claim is “substantial”—that is, that it has
“some merit.” Id. There is considerable overlap between
these requirements, since each considers the strength and
validity of the underlying ineffective assistance claim. See
id.

    Even if we were to assume that Djerf’s pre-trial
ineffective assistance claim was substantial (which would be
a stretch in light of the record and the service performed by
counsel), there is no reasonable probability that advancing
that claim during initial post-conviction proceedings would
have altered the result. See Rodney v. Filson, 916 F.3d 1254,
16                     DJERF V. RYAN

1260 (9th Cir. 2019) (clarifying that a petitioner represented
by counsel in post-conviction proceedings must satisfy both
Strickland prongs). Djerf’s post-hoc criticisms of counsel’s
pace of preparation were contradicted by his statements at
the time, as well as those of the prosecutor and trial judge.
The record shows regular visits and communication between
counsel and Djerf, and Djerf has not identified any authority,
existing then or now, suggesting that the frequency and
nature of communication was constitutionally infirm. Even
if Djerf had been able to show that the representation was
constitutionally deficient, he would have struggled to show
that the purported deficiencies resulted in sufficient
prejudice to warrant overturning his four murder
convictions. We cannot excuse the procedural default of this
claim under these circumstances.

II. Ineffective Representation During Sentencing

    We next turn to Djerf’s claim that Simpson and Vaughn
rendered ineffective assistance during sentencing by failing
to further investigate, develop, and present additional
mitigation evidence related to his family background and
mental health. The trial judge’s post-conviction denial of
this claim was the last reasoned state court decision, so we
review that ruling under AEDPA. See Hibbler v. Benedetti,
693 F.3d 1140, 1146 (9th Cir. 2012). In the district court,
Djerf requested an evidentiary hearing in connection with
this claim. As explained below, the state post-conviction
court did not unreasonably apply Supreme Court precedent
in holding there was no ineffective assistance of counsel
during sentencing and the district court did not err in denying
Djerf’s request to expand the record.
                       DJERF V. RYAN                       17

   A. Family Background

    Djerf’s argument that counsel provided ineffective
assistance by failing to obtain more background records and
conduct more interviews was rejected by the post-conviction
judge because Djerf failed to present any supporting
evidence, and instead merely “speculate[d] that if his
childhood was investigated, some mitigating evidence might
have been discovered.” We review the post-conviction
judge’s determination under AEDPA and determine it was
not an unreasonable application of Supreme Court
precedent.

    Throughout the entirety of his state post-conviction and
federal habeas proceedings, Djerf has failed to identify any
evidence related to his childhood that counsel should have,
but did not, uncover. Crucially, Djerf did not point the post-
conviction judge to any evidence sentencing counsel failed
to present that was meaningfully different from what was
introduced at mitigation. It was Djerf’s burden to establish
a reasonable probability that the result of the proceedings
would have been different but for counsel’s purported errors.
Strickland, 466 U.S. at 694. Strickland prejudice is not
established by mere speculation that witness testimony
“might have given information helpful to” the defense.
Bragg v. Galaza, 242 F.3d 1082, 1088 (9th Cir. 2001).
Under the significant deference required by AEDPA, the
post-conviction judge’s denial of this claim was neither an
unreasonable application of clearly established law nor an
unreasonable determination of the facts in light of the
evidence in the record at that time.

   B. Mental Health

    Djerf’s argument that counsel provided ineffective
assistance by failing to investigate and develop additional
18                     DJERF V. RYAN

mental health mitigating evidence was rejected by the post-
conviction judge for a similar reason: Djerf merely relied on
expert reports prepared prior to sentencing to speculate that
“there might be other mitigating information that should
have been presented.” Under AEDPA, the state court’s
ruling that Djerf did not suffer ineffective assistance of
counsel due to the alleged failure to develop additional
mental health mitigating evidence was not an unreasonable
application of Supreme Court precedent.

    In his initial post-conviction proceedings, Djerf’s
appointed mental health expert conducted extensive
neurological testing. However, Djerf did not introduce any
reports or other evidence from this expert in support of his
petition. Instead, he submitted Dr. Potts’s prescreening
report from April 1995 and reports prepared by Dr.
McMahon, Dr. Walter, and Dr. Duane prior to sentencing.

    In the winter of 1995–96, Dr. McMahon conducted
several hours of psychological testing and prepared a report,
noting that Djerf’s results were suggestive of “learning
disabilities and/or some diffuse neuropsychological
dysfunction.” He recommended further evaluation. Dr.
Walter then completed neuropsychological testing; he
reported that Djerf performed “relatively well in [a] number
of areas,” though there were indications that he might have
a “focal cerebral deficit in the right temporal area.” To better
understand the possible “right temporal disturbance,” Dr.
Walter recommended further neuropsychiatric evaluation to
seek out possible “abnormal electrical activity.” Dr. Duane
then conducted an electro-encephalogram and advanced
brain-mapping.         Dr. Duane summarized Djerf’s
developmental history, noting that as an infant, Djerf “fell
over and hit his head with a large knot” and reportedly fell
often in the subsequent years. Dr. Duane concluded that the
                           DJERF V. RYAN                             19

test results were consistent with a personality disorder, not
brain dysfunction. Dr. McMahon compiled the results of all
these findings and conclusions into a final report. Dr.
McMahon intimated that the test results are consistent with
an antisocial personality disorder, not a delusional disorder
or schizophrenia. Dr. McMahon acknowledged that Djerf
likely has “some learning disabilities that . . . affect his
ability to organize a situation and make effective decisions,”
but concluded “there is an absence of a sufficiently severe
mental defect that it would have precluded his appreciating
the wrongfulness of his acts, or resulted in an inability to
conform his behavior to the requirement of the law.”
Counsel received each report, and, several days after
receiving Dr. McMahon’s final report, notified the court they
would not be submitting any expert mental health evidence
in mitigation.

    The post-conviction judge considered and rejected
Djerf’s argument that sentencing counsel provided
ineffective assistance because they failed to adequately
investigate and develop evidence of “a serious brain-related
injury” that Djerf experienced as a child. 4 At least two of

    4
      Djerf argues that AEDPA deference does not apply here because
the post-conviction judge made a factual error. Indeed, the judge
incorrectly stated that the reports prepared by Dr. McMahon, Dr. Walter,
and Dr. Duane had been “considered by the court prior to sentencing.”
Counsel did not submit the reports to the court. However, this minor
error does not unlock de novo review. See 28 U.S.C. § 2254(d). The
judge rejected this claim because Djerf failed to show there was helpful
mental evidence that sentencing counsel could have, but failed to,
develop. Djerf’s speculation that such evidence might have existed was
insufficient. Whether the sentencing court reviewed certain reports prior
to sentencing had no bearing on this holding. De novo review is
authorized when a “decision . . . was based on an unreasonable
determination of the facts,” not every time an order or opinion includes
an incorrect factual finding. 28 U.S.C. § 2254(d) (emphasis added).
20                     DJERF V. RYAN

the experts who evaluated Djerf prior to sentencing were
aware of his alleged childhood head injury. Djerf does not
specify what further information counsel should have but
failed to uncover and provide to the experts to assist in their
evaluations: Djerf’s mother admitted she did not seek
medical attention for her son, and no other family member
recalled the injury or any side effects. The McMahon,
Walter, and Duane reports could reasonably be read to rule
out schizophrenia or any other comparably mitigating
disorder. Djerf asked the post-conviction judge to deduce
from these reports that unidentified background evidence
would have changed the diagnosis or that other experts,
equipped with such information, might have diagnosed him
with schizophrenia. It was not unreasonable for the judge to
decline the invitation to make this speculative leap. That
Djerf later found experts who might nominally disagree with
the earlier findings, see infra p.23–24, does not render the
state court’s ruling unreasonable, as no evidence establishing
a diagnosis helpful to the defense was in the state post-
conviction record. See Murray v. Schriro, 745 F.3d 984,
1000 (9th Cir. 2014) (AEPDA review limited to evidence in
state court record). Any argument that sentencing counsel
erred by failing to present reports or testimony from Dr.
McMahon, Dr. Walter, or Dr. Duane during mitigation is
equally unavailing. “When counsel focuses on some issues
to the exclusion of others, there is a strong presumption that
[they] did so for tactical reasons . . . .” Yarborough v.
Gentry, 540 U.S. 1, 8 (2003) (per curiam). Given that many
aspects of their reports were harmful to Djerf’s mitigation
case, that presumption remains unrebutted here. For all of
these reasons, we hold that the post-conviction judge
                           DJERF V. RYAN                              21

reasonably applied Strickland in concluding that sentencing
counsel did not provide ineffective assistance. 5

    We need not reach the second prong of Strickland, but if
we did, we would conclude that the sentencing counsel’s
failure to investigate, develop, and present additional mental
health evidence was not prejudicial. Again, it is not clear
what evidence counsel would have uncovered had they more
vigorously investigated the purported head injury, or that the
discovery of such evidence would have resulted in expert
evidence supporting a schizophrenia diagnosis. Such
speculation rarely creates a “reasonable probability” that a
different result would have occurred absent the purportedly
deficient representation. Strickland, 466 U.S. at 694. The
prejudice inquiry also requires consideration of the State’s
aggravation case, which was remarkably strong: at least
three aggravating factors applied for each victim, including
undisputed, vivid details of gruesome physical, sexual, and
emotional abuse preceding the killings. The post-conviction
judge reasonably concluded that any deficient performance
by sentencing counsel was harmless under Strickland.



    5
       Djerf claims that the post-conviction judge never reached the
question of deficient performance and instead ruled only on prejudice.
Accordingly, he insists we review Strickland performance de novo. See
Porter v. McCollum, 558 U.S. 30, 39 (2009) (per curiam). We disagree;
read fairly, the judge’s ruling addresses both prongs of the analysis. But
even if we agreed with Djerf’s take on the ruling, we would reach the
same ultimate conclusion under de novo review. Counsel conducted a
“thorough investigation of law and facts relevant to [Djerf’s] plausible
options” for mitigation, and we must therefore afford significant
deference to their tactical decisions. Hernandez v. Chappell, 923 F.3d
544, 550 (9th Cir. 2019) (quoting Strickland, 466 U.S. at 690). Their
investigation of possible mental health mitigation evidence was not
unreasonable under prevailing professional norms. Strickland, 466 U.S.
at 688.
22                     DJERF V. RYAN

     C. Evidentiary Hearing

    In the district court, Djerf requested an evidentiary
hearing in connection with his ineffective assistance of
sentencing counsel claim, and he now seeks a remand to
permit expansion of the record and reconsideration of this
claim. The district court denied the request because Djerf
had not been diligent in developing the proffered factual
basis in state court. For the following reasons, we affirm.

    Under Cullen v. Pinholster, when a claim is subject to
AEDPA review, a district court is limited to the record that
was before the state court that adjudicated the claim on the
merits. 563 U.S. 170, 185 (2011). The entirety of the
ineffective sentencing counsel claim is subject to AEDPA
deference, so no evidentiary expansion is permitted. Even if
we granted a remand, Pinholster would prohibit the
introduction of new evidence.

    However, Pinholster was issued several years after Djerf
requested and the district court denied an evidentiary
hearing. Lacking Pinholster’s guidance, the district court
considered whether Djerf satisfied the exception for
evidentiary expansion under 28 U.S.C. § 2254(e)(2)(A)(ii),
which requires that “a factual predicate that could not have
been previously discovered through the exercise of due
diligence.” See Dickens v. Ryan, 740 F.3d 1302, 1321 (9th
Cir. 2014) (en banc) (expansion of the record is “severely
restrict[ed]” when lack of diligence prevented factual
development in post-conviction proceedings). Pinholster
clarified that this statutory exception applies only to claims
reviewed de novo; evidentiary expansion is prohibited for a
claim subject to AEDPA review, regardless of diligence.
563 U.S. at 185–86.
                       DJERF V. RYAN                       23

    Even if we assume, as the district court did, that Djerf’s
claim was covered by § 2254(e)(A)(2)—because we
reviewed the ineffective assistance of sentencing counsel
claim de novo—we conclude that the district court did not
abuse its discretion by declining to expand the record. See
West v. Ryan, 608 F.3d 477, 484 (9th Cir. 2010) (reviewing
decision to expand record for abuse of discretion).

    As a threshold matter, Djerf’s request for an evidentiary
hearing in the initial post-conviction proceedings was not
sufficient to demonstrate diligence. Cf. Baja v. Ducharme,
187 F.3d 1075, 1078–79 (9th Cir. 1999); see also Dowthitt
v. Johnson, 230 F.3d 733, 758 (5th Cir. 2000) (“Mere
requests for evidentiary hearings will not suffice; the
petitioner must be diligent in pursuing the factual
development of his claim.”). Moreover, Djerf fails to
identify any new evidence that he presented to the state court
in support of that request or any proffer he made to
demonstrate why an evidentiary hearing at that time would
have been worthwhile.

    In the district court, Djerf sought a hearing to present
testimony from his sister, his mother, Simpson, and
Hanratty. A short declaration from his sister offered a few
new, minor details about Djerf’s upbringing—e.g., their
father spanked him as a child—but otherwise only
corroborated the family background evidence originally
presented in mitigation. Djerf fails to explain how the
testimony from the other witnesses would vary meaningfully
from the family background evidence presented in
mitigation, or why such evidence could not have been
procured through the exercise of diligence during the initial
post-conviction proceedings.

   Djerf also seeks to present testimony from new medical
experts who will testify in support of his theory that he
24                     DJERF V. RYAN

suffered from schizophrenia at the time of his crimes. Djerf
and post-conviction counsel knew that brain dysfunction and
schizophrenia had been investigated by sentencing counsel
and several experts. Yet, despite having an appointed expert
in the post-conviction proceedings, Djerf did not present any
new medical, psychological, or neurological evidence at that
time. Djerf fails to explain why the factual basis for this
claim would have evaded discovery if he and his post-
conviction counsel had been diligent. In sum, Djerf did little
to show that an evidentiary hearing was warranted as to his
family background or mental health, and the district court
did not abuse its discretion by refusing to hold one.

III.   Causal Nexus

     Finally, we turn to Djerf’s claim that the Arizona courts
impermissibly refused to consider mitigating evidence of his
difficult family background because it lacked a causal
connection to his crimes. We focus on the Arizona Supreme
Court’s de novo review of Djerf’s sentence and consider the
trial judge’s rulings only to the extent that they were
“adopted or substantially incorporated” by the higher court.
McKinney, 813 F.3d at 819. We have addressed many causal
nexus appeals in recent years and need not repeat the history
and nuance of this doctrine, which is extensively detailed in
other decisions. See, e.g., id. at 811–24. In short, the
Supreme Court has clearly established that a sentencing
court must consider all mitigating evidence; state law may
not, for example, impose a threshold requirement that a
defendant demonstrate a causal connection to the offense.
See Smith v. Texas, 543 U.S. 37, 43–49 (2004) (per curiam);
Tennard v. Dretke, 542 U.S. 274, 283–88 (2004); Penry v.
Lynaugh, 492 U.S. 302, 319–28 (1989), abrogated on other
grounds by Atkins v. Virginia, 536 U.S. 304 (2002); Eddings,
455 U.S. at 110–17; Lockett v. Ohio, 438 U.S. 586, 597–609
                       DJERF V. RYAN                         25

(1978). Of course, the sentencing court is free to assign little
weight to mitigating evidence, but such evidence may not be
stripped of all weight as a matter of law. See Harris v.
Alabama, 513 U.S. 504, 512 (1995). However, relief is only
available when a causal nexus error was prejudicial—that is,
when it was not harmless. McKinney, 813 F.3d at 821–22.
We assume, without deciding, that the Arizona Supreme
Court committed a causal nexus error here and move directly
to the harmlessness inquiry.

    The question is whether the Arizona Supreme Court’s
refusal to consider Djerf’s family background evidence “had
substantial and injurious effect or influence in determining”
his sentence. Id. at 822 (quoting Brecht v. Abrahamson,
507 U.S. 619, 623 (1993)). We review aggravating factors
proven by the State and other mitigating evidence presented
to the sentencing court, then we ask whether consideration
of the improperly ignored evidence “would have had a
substantial impact on a capital sentencer who was permitted
to evaluate and give appropriate weight to it.” Id. at 823.
We conclude here it would not—any error was harmless.

    The State established three aggravating factors for each
of the victims: Djerf committed each murder expecting
receipt of something of pecuniary value; the murders were
committed “in an especially heinous, cruel or depraved
manner”; and the murders were committed in tandem. Ariz.
Rev. Stat. § 13-703(F)(5), (6), (8) (1996). Because one of
the victims was under eighteen, the State established another
aggravating factor for his murder. Id. § 13-703(F)(9). Each
of these factors is significant, but the undisputed facts
substantiating the “heinous, cruel, or depraved” finding are
especially powerful: with clear premeditation and
preparation, Djerf imposed appalling psychological and
physical suffering upon four strangers from a single family
26                     DJERF V. RYAN

before killing them in cold blood. The State’s aggravation
case stands out as one of, if not the, strongest we have
reviewed in recent years.

     On the other hand, Djerf’s mitigation case was, as he
admits on appeal, quite meager. Djerf was twenty-three
years old at the time of the crimes, did not resist arrest, was
mostly well-behaved for the duration of his post-arrest
detention, and purported to accept responsibility and feel
remorse for his conduct. The trial judge concluded that
Djerf’s relative youth was not a mitigating factor because
there was no indication that he lacked substantial judgment
or an ability to appreciate the consequences of his actions.
Djerf’s compliance with arresting officers was likewise not
mitigating because, by that time, his friends were
cooperating with the police and he had no other option.
Subsequent statements by Djerf blaming Albert Luna for the
crime and indicating that he could envision himself killing
again undermined his purported acceptance of responsibility
and remorse. So did the tactical justifications for his guilty
plea. The trial judge found that Djerf had adjusted to
confinement since his arrest, but several disciplinary
infractions kept that factor from warranting leniency. The
trial judge also concluded that Djerf did not suffer from any
psychological disorders, noting that he expressly disclaimed
any such problems. None of these considerations warranted
leniency.

    On direct appeal, Djerf challenged the court’s findings
regarding age, remorse, and acceptance of responsibility.
Djerf, 959 P.2d at 1288–90. The Arizona Supreme Court
largely reiterated the trial judge’s reasoning and reached the
same conclusions, finding that these considerations did not
warrant leniency. Id.
                       DJERF V. RYAN                        27

    That brings us to the evidence of a difficult family
background—evidence that we assume the Arizona courts
improperly ignored. Djerf’s mother experienced some
complications during pregnancy and childbirth. She recalled
her son falling on his head as a toddler, though Djerf’s father
does not recall any injuries. Neither parent was especially
affectionate or doting with their son, and they divorced when
he was approximately six years old; Djerf maintained
relationships and alternately lived with each parent in the
subsequent years. Both parents raised their voice on
occasion, and the mother’s new husband once pushed Djerf
up against a wall. However, there is no evidence that Djerf
experienced physical or emotional abuse throughout his
childhood. His mother recalled him rarely interacting with
friends, while his father thought he had “normal”
relationships until high school. At that point, his father
thought Djerf became “more of a loner,” although he
regularly spent time with friends. Djerf’s mother and sister
insisted that Djerf’s father drank heavily, though Djerf did
not recall ever seeing him intoxicated. His sister also
remembered their father as “loving” and a “good provider.”
She recalled a time from their childhood when Djerf
handcuffed her, but she did not recall anything else notable
about the incident. Djerf dropped out of high school, but
later obtained his diploma.

    We have previously found a causal nexus error to be
harmless when there is “overwhelming” evidence of
aggravating circumstances and proffered mitigation
evidence is “limited” or “relatively minor.” Murray v.
Schriro, 882 F.3d 778, 815–16 (9th Cir. 2018); Apelt v.
Ryan, 878 F.3d 800, 840 (9th Cir. 2017); Greenway v. Ryan,
866 F.3d 1094, 1100 (9th Cir. 2017) (per curiam). That is
precisely the case here. This is not an instance where
improperly ignored mitigation evidence addressed
28                     DJERF V. RYAN

“sustained, severe childhood abuse” “beyond the
comprehension and understanding of most people.”
McKinney, 813 F.3d at 823. In Poyson v. Ryan, there was
evidence of repeated physical and emotional childhood
abuse, sexual assault, coerced alcohol and drug use,
developmental delays, the sudden death of a close parental
figure, and severe head injuries resulting in headaches and
loss of consciousness. 879 F.3d 875, 892–93 (9th Cir. 2018).
Despite significant aggravating factors, we concluded that
exclusion of this “particularly compelling” mitigation
evidence was prejudicial because it may have persuaded the
sentencing court to impose a non-capital sentence. Id. The
mitigating evidence here is categorically less compelling,
and the aggravating circumstances are more severe.

    This is also not a situation where the evidence was
objectively “important” and “interlinked” with other
theories of mitigation, such that improperly excluding that
evidence deprived all other mitigation evidence of
persuasive force. See Spreitz v. Ryan, 916 F.3d 1262, 1279–
80 (9th Cir. 2019). We do not mean to suggest that Djerf
experienced an idyllic childhood. Rather, there was no
evidence of severe abuse, trauma, or other troubling
experiences that might warrant leniency in light of
overwhelming aggravating circumstances. We have no
choice but to conclude that any causal nexus error committed
by the Arizona Supreme Court was harmless.

                        CONCLUSION

    The record fails to establish that Djerf’s pre-trial counsel
were incompetent or provided constitutionally deficient
representation. This conclusion defeats Djerf’s challenges
to his waiver of counsel and guilty pleas, as both claims are
premised on constitutionally inadequate representation.
Because there is not a reasonable probability that state post-
                          DJERF V. RYAN                             29

conviction proceedings would have turned out differently if
Djerf had advanced a pre-trial ineffective assistance of
counsel claim, we cannot excuse the procedural default of
that claim. The state court reasonably concluded that
sentencing counsel was not ineffective, and the district court
did not abuse its discretion by denying Djerf’s request for an
evidentiary hearing on that claim. Finally, we conclude any
causal nexus error during Djerf’s sentencing was harmless.

    AFFIRMED. 6




    6
       After oral argument, the Supreme Court granted certiorari in
McKinney v. Arizona, No. 18-1109, 2019 WL 936074 (June 10, 2019),
to address the appropriate procedures for resentencing after a capital
sentence is vacated in light of a prejudicial Eddings error. Djerf moved
to stay these proceedings pending resolution of that case. Dkt. 119.
Because no resentencing is warranted here, the motion is DENIED.
