                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


JAMES ERIN MCKINNEY,                   No. 09-99018
           Petitioner-Appellant,
                                          D.C. No.
               v.                   2:03-cv-00774-DGC

CHARLES L. RYAN,
          Respondent-Appellee.           OPINION


      Appeal from the United States District Court
               for the District of Arizona
      David G. Campbell, District Judge, Presiding

           Argued and Submitted En Banc
       December 15, 2014—Pasadena, California

               Filed December 29, 2015

   Before: Sidney R. Thomas, Chief Judge, and Alex
 Kozinski, Kim McLane Wardlaw, William A. Fletcher,
Ronald M. Gould, Marsha S. Berzon, Richard C. Tallman,
 Consuelo M. Callahan, Carlos T. Bea, Morgan Christen
       and Jacqueline H. Nguyen, Circuit Judges.

             Opinion by Judge W. Fletcher;
                 Dissent by Judge Bea
2                      MCKINNEY V. RYAN

                           SUMMARY*


                          Habeas Corpus

    The en banc court reversed the district court’s judgment
denying Arizona state prisoner James McKinney’s petition
for a writ of habeas corpus, remanded with instructions to
grant the writ with respect to McKinney’s death sentence
unless the state, within a reasonable time, corrects the
constitutional error in his death sentence or vacates the
sentence and imposes a lesser sentence consistent with law.

    The en banc court overruled Schad v. Ryan, 671 F.3d 708
(9th Cir. 2011) (per curiam), which prohibited an assumption
of unconstitutionality under Eddings v. Oklahoma, 455 U.S.
104 (1982), absent a clear indication in the record that the
state court applied the wrong standard.

    The en banc court held that the Arizona Supreme Court
applied an unconstitutional causal nexus test to McKinney’s
post-traumatic stress disorder—refusing, as a matter of law,
to treat it as a relevant nonstatutory mitigating factor—
contrary to clearly established federal law as established in
Eddings.

    The en banc court held that Eddings error is not structural
error, but that the Eddings error in this case had a substantial
and injurious effect on McKinney’s sentence within the
meaning of Brecht v. Abrahamson, 507 U.S. 619 (1993).


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

    Judge Bea, joined by Judges Kozinski, Gould, Tallman,
and Callahan, dissented. He wrote that the majority ignores
Supreme Court precedent, implicitly overrules this court’s
precedent, replaces AEDPA’s deferential standard of review
with an impermissible de novo standard, misstates the record,
wrongly smears the Arizona Supreme Court, calls into
question every death sentence imposed in Arizona between
1989 and 2005 and this court’s cases that have denied habeas
relief as to those sentences, and brushes by the facts of
McKinney’s gruesome crimes to find that the error the
majority has manufactured was prejudicial.


                        COUNSEL

Ivan K. Mathew (argued) and Susan Turner Mathew, Mathew
and Associates, Phoenix, Arizona, for Petitioner-Appellant.

Jon Anderson (argued) and Jeffrey A. Zick, Assistant
Attorneys General, Terry Goddard, Attorney General, and
Kent Cattani, Chief Counsel, Arizona Attorney General’s
Office, Criminal Appeals/Capital Litigation Section, Phoenix,
Arizona, for Respondent-Appellee.

Michael L. Burke and Robin Konrad, Assistant Federal
Public Defenders, Jon M. Sands, Federal Public Defender,
Federal Public Defender’s Office, Phoenix, Arizona, for
Amicus Curiae Office of the Federal Public Defender.
4                   MCKINNEY V. RYAN

                         OPINION

W. FLETCHER, Circuit Judge:

    Petitioner James McKinney was sentenced to death, and
his sentence was affirmed by the Arizona Supreme Court on
de novo review in 1996. State v. McKinney, 917 P.2d 1214
(Ariz. 1996). A three-judge panel of this court denied
McKinney’s petition for a writ of habeas corpus. McKinney
v. Ryan, 730 F.3d 903 (9th Cir. 2013). We granted rehearing
en banc and withdrew our three-judge panel opinion.
McKinney v. Ryan, 745 F.3d 963 (9th Cir. 2014). In his
federal habeas petition, McKinney challenges both his
conviction and sentence. We agree with the decision of the
three-judge panel with respect to McKinney’s challenges to
his conviction, and to that extent we incorporate the decision
of the panel. We address in this opinion only McKinney’s
challenge to his death sentence. For the reasons that follow,
we grant the petition with respect to his sentence.

    In Eddings v. Oklahoma, 455 U.S. 104, 114 (1982), the
Supreme Court held under the Eighth and Fourteenth
Amendments that a sentencer in a capital case may not
“refuse to consider, as a matter of law, any relevant
mitigating evidence” offered by the defendant. (Emphasis in
original.) Oklahoma state courts had refused, as a matter of
law, to treat as relevant mitigating evidence a capital
defendant’s background of family violence, including
beatings by his father, on the ground that “it did not tend to
provide a legal excuse from criminal responsibility.” Id. at
113. The Supreme Court reversed. Recognizing the special
character of the death penalty, the Court held that evidence of
Eddings’s background of family violence had to be treated as
relevant evidence in determining whether to put him to death.
                    MCKINNEY V. RYAN                         5

The Court wrote, “The sentencer, and the Court of Criminal
Appeals on review, may determine the weight to be given
relevant mitigating evidence. But they may not give it no
weight by excluding such evidence from their consideration.”
Id. at 114–15.

    At all times relevant to this case, Arizona law provided
for two kinds of mitigation factors in capital sentencing —
statutory and nonstatutory. A nonexhaustive list of five
statutory mitigating factors was provided in Ariz. Rev. Stat.
Ann. § 13-703(G). Arizona case law applied, in addition,
nonstatutory mitigating factors, such as a difficult family
background or a mental condition not severe enough to
qualify as a statutory mitigating factor.

    For a period of a little over 15 years in capital cases, in
clear violation of Eddings, the Supreme Court of Arizona
articulated and applied a “causal nexus” test for nonstatutory
mitigation that forbade as a matter of law giving weight to
mitigating evidence, such as family background or mental
condition, unless the background or mental condition was
causally connected to the crime. In State v. Wallace,
773 P.2d 983, 986 (Ariz. 1989), decided seven years after
Eddings and four years before petitioner was sentenced, the
Arizona Supreme Court wrote, “A difficult family
background, in and of itself, is not a mitigating
circumstance. . . . A difficult family background is a relevant
mitigating circumstance if a defendant can show that
something in that background had an effect or impact on his
behavior that was beyond the defendant’s control.” In State
v. Ross, 886 P.2d 1354, 1363 (Ariz. 1994), decided one year
after petitioner was sentenced but before his sentence was
affirmed on appeal, the Arizona Supreme Court wrote, citing
the precise page in Wallace, “A difficult family background
6                   MCKINNEY V. RYAN

is not a relevant mitigating circumstance unless ‘a defendant
can show that something in that background had an effect or
impact on his behavior that was beyond the defendant’s
control.’ State v. Wallace, . . . 773 P.2d 983, 986 (1989).”

    Two years after its decision in Ross, the Arizona Supreme
Court affirmed McKinney’s death sentence. In addressing
the potential mitigating effect of his mental condition, the
Court wrote that McKinney’s PTSD had no causal nexus to
his crimes. If anything, the Court wrote, “the effects of [his]
childhood, specifically the diagnosis of post-traumatic stress
disorder (PTSD)” would have influenced him not to commit
the crimes. McKinney, 917 P.2d at 1234. The Court
concluded its analysis of McKinney’s PTSD, citing the
precise page in Ross on which it had articulated the causal
nexus test for nonstatutory mitigation: “[A] difficult family
background, including childhood abuse, does not necessarily
have substantial mitigating weight absent a showing that it
significantly affected or impacted the defendant’s ability to
perceive, comprehend, or control his actions. See State v.
Ross, . . . 886 P.2d 1354, 1363 (1994).” State v. McKinney,
917 P.2d 1214, 1234 (Ariz. 1996).

    For just over fifteen years, the Arizona Supreme Court
consistently articulated and applied its causal nexus test, in
accordance with its strong view of stare decisis. See Young
v. Beck, 251 P.3d 380, 385 (Ariz. 2011) (“[S]tare decisis
commands that ‘precedents of the court should not be lightly
overruled,’ and mere disagreement with those who preceded
us is not enough.” (quoting State v. Salazar, 173 Ariz. 399,
416 . . . (1992))); State ex re. Woods v. Cohen, 844 P.2d 1147,
1148 (Ariz. 1993) (referring to “a healthy respect for stare
decisis”); State v. Williker, 491 P.2d 465, 468 (Ariz. 1971)
(referring to “a proper respect for the theory of stare
                    MCKINNEY V. RYAN                         7

decisis”); White v. Bateman, 358 P.2d 712, 714 (Ariz. 1961)
(prior case law “should be adhered to unless the reasons of
the prior decisions have ceased to exist or the prior decision
was clearly erroneous or manifestly wrong”).

    The case before us is unusual. In federal habeas cases
under the Antiterrorism and Effective Death Penalty Act
(“AEDPA”), we apply a “presumption that state courts know
and follow the law” and accordingly give state-court
decisions “the benefit of the doubt.” Woodford v. Visciotti,
537 U.S. 19, 24 (2002). If the Arizona Supreme Court during
the relevant period had been inconsistent in its articulation
and application of its unconstitutional “causal nexus” test for
nonstatutory mitigation, we would give the Court the benefit
of the doubt and would accord it the presumption that it knew
and followed governing federal law. But the Arizona
Supreme Court’s consistent articulation and application of its
causal nexus test, and its citation in McKinney’s case to the
specific page of Ross on which it articulated the test, make
such a course impossible. While Visciotti’s presumption is
appropriate in the great majority of habeas cases, the
presumption is rebutted here where we know, based on its
own words, that the Arizona Supreme Court did not “know
and follow” federal law.

    The precise question before us is whether the Arizona
Supreme Court applied its unconstitutional “causal nexus”
test in affirming McKinney’s death sentence on de novo
review. We must decide whether, under AEDPA, the
Arizona Supreme Court refused to give weight, as a matter of
law, to McKinney’s nonstatutory mitigation evidence of
PTSD, “contrary to . . . clearly established Federal law, as
determined by the Supreme Court of the United States.”
28 U.S.C. § 2254(d)(1). For the reasons that follow, we
8                   MCKINNEY V. RYAN

conclude that it did. We therefore grant the writ with respect
to petitioner’s sentence.

     I. McKinney’s Crimes, Conviction, and Sentence

    James McKinney and his older half brother, Charles
Michael Hedlund, committed two burglaries in February and
March of 1991. One person was shot and killed during each
of the burglaries. At the time of the crimes, McKinney was
23 years old. Hedlund was 26 years old. McKinney and
Hedlund had learned about potential burglary targets from
their half brother, Christopher Morris, and a friend, Joe
Lemon, who had suggested Christine Mertens’s home as a
target. The four of them attempted to burglarize Ms.
Mertens’s home on February 28, 1991, but Ms. Mertens came
home and they left to avoid detection. The three half
brothers, McKinney, Hedlund, and Morris, then committed
two burglaries at other locations the following day.

    McKinney, Hedlund, and possibly Morris went back to
Ms. Mertens’s house a little over a week later, on March 9,
1991. This time, Ms. Mertens was already at home. She was
beaten and stabbed by one or more of the burglars. One of
the burglars held Ms. Mertens down on the floor and shot her
in the back of the head with a handgun, covering the gun with
a pillow. (Morris turned state’s evidence and testified against
McKinney and Hedlund. He testified that he was at work at
Burger King on the night of the Mertens murder, but Burger
King had no record of him working that night.) McKinney
and Hedlund later tried unsuccessfully to sell the gun. They
ultimately disposed of the gun by burying it in the desert.
Not quite two weeks later, on March 22, 1991, McKinney and
Hedlund burglarized the home of Jim McClain, from whom
Hedlund had bought a car several months earlier. Mr.
                    MCKINNEY V. RYAN                        9

McClain was asleep in the bedroom. He was shot in the back
of the head by either McKinney or Hedlund. The bullet was
consistent with having been fired from a sawed-off rifle
owned by Hedlund.

    McKinney and Hedlund were tried together before dual
juries for the burglaries and homicides. McKinney’s jury
found him guilty of two first degree murders. Hedlund’s jury
found him guilty of second degree murder of Ms. Mertens
and first degree murder of Mr. McClain. On July 23, 1993,
the trial judge sentenced McKinney to death. The Supreme
Court decision holding judge-sentencing in capital cases
unconstitutional was nine years in the future. See Ring v.
Arizona, 536 U.S. 584 (2002). In the last reasoned state court
decision, the Arizona Supreme Court, reviewing de novo,
affirmed McKinney’s conviction and sentence in 1996.
McKinney, 917 P.2d 1214. We describe the Arizona Supreme
Court’s sentencing decision at greater length below.
McKinney filed for state post-conviction relief. His petition
was denied by the trial court without an evidentiary hearing.
The Arizona Supreme Court then summarily denied his
petition for review.

            II. McKinney’s Family Background

    McKinney suffered a traumatic childhood characterized
by severe physical and psychological abuse, both by his
biological parents, James McKinney, Sr. (“James”) and
Bobbie Jean Morris, and by his stepmother, Shirley Crow
McKinney. At McKinney’s sentencing hearing, his aunt (his
father’s sister), Susan Sesate, and his younger sister, Diana
McKinney, described the abuse.
10                   MCKINNEY V. RYAN

    Susan and Diana both testified about the squalid
conditions in which McKinney lived as a child. Susan
testified that while McKinney’s parents, James and Bobbie,
were still married, their house was filthy. She testified,
“[W]hen you walked through the door, it wasn’t nothing to
see, you know, diapers full of — all around. . . . Everything
stunk.” James was an alcoholic, and Bobbie left him when
McKinney was about three years old.

    When Bobbie left James, she took with her their three
children, Diana, Donna, and McKinney. Susan testified, “She
ran with them. . . . She ran to a lot of different states. I know
she went to California first and Kansas twice. California
again. I know she went through Texas, New Mexico.” James
pursued and brought Bobbie and the children back to
Arizona, but “she would run again.” “As soon as he brought
her back, within a week she’d be gone again to Kansas. She
had the kids there.” James told McKinney’s presentence
investigator that Bobbie had “kidnapped” the children, and
that he took them back “after he found out they were being
physically abused and were being locked in closets, hungry
and sick.”

    Bobbie eventually left James for good, and he got
remarried. James got custody of the children and brought
them to Arizona to live with him and his new wife Shirley.
The conditions in the house with James and Shirley were
even worse than they had been with James and Bobbie.
Susan, a teenager at the time, lived with her mother (who was
also James’s mother) in a house nearby. She was at the
McKinney house frequently. Susan testified that the house
“was gross. It was gross. I mean, the house was filthy, the
kids were filthy, they never had clean clothes that I ever saw
                    MCKINNEY V. RYAN                        11

them in. If they had clothes, they were ill-fitting clothes. I
mean, it was disgusting.”

    McKinney, his two sisters, and his older half brother
Hedlund (Bobbie’s son by a different father) shared one small
bedroom. Shirley’s daughter had a bedroom to herself.
Susan testified that the floor of the four children’s bedroom
was always covered with dirty clothes because there were no
bureaus and no hangers for the closet. There were no sheets
on the beds. The children had to share their room with
animals Shirley brought home, including dogs, cats, a goat,
snakes, and a monkey. The animals regularly defecated and
urinated in the bedroom. Diana testified that the adults never
cleaned the bedroom.

    Diana was 18 months old when James took the children
from Bobbie and brought them to the Arizona house he
shared with his new wife Shirley. Donna was three,
McKinney was four or five, and Hedlund was seven. Diana
and Susan testified that the four children were responsible for
all general household cooking and cleaning, including
cleaning up the animal feces and urine that were “all over”
the house; feeding farm animals, including cows, pigs, and
goats; taking care of James’s hunting dogs; doing all of their
own laundry; and sometimes doing Shirley’s laundry. Diana
testified that she and the other children cleaned the house the
best they could, but “the house still smell[ed]” all the time.
Susan testified, “It was nothing to see James [Jr.] and Michael
[Hedlund] standing on chairs at the stove cooking or having
to stand on chairs to do the dishes” because they were too
small to reach the stove and the counters. Shirley’s daughter
did not have to do any chores. Shirley kept the children from
attending school as punishment for various supposed
infractions. Susan testified that on one occasion McKinney
12                  MCKINNEY V. RYAN

sat on the porch for three days while the others went to
school. When Susan’s mother (McKinney’s grandmother)
sent Susan over to investigate, McKinney told her that Shirley
would not allow him to go to school unless Bobbie bought
him a new pair of tennis shoes. Susan’s mother bought
McKinney shoes so he could return to school.

    The children never had regular baths and often had dirty
hair. When the children went to school, they wore dirty
clothes that reeked of urine from being on the bedroom floor
with the animals. The children’s school sent letters home
about their appearance and odor. They were regularly
harassed and teased by other children. McKinney was
frequently suspended for fighting on the school bus because
other children made fun of his appearance and odor.

     The four children suffered regular and extensive physical,
verbal, and emotional abuse. Minor infractions of Shirley’s
rules, such as not doing the dishes properly, resulted in
beatings. Diana testified that she could not recall a time when
none of the children had a welt or bruise inflicted by Shirley.
Susan testified, “They had bruises all the time. It was hard to
tell what were new bruises and what weren’t.” Shirley used
plastic switches, cords, belts, and a hose to hit them—
“anything she could get in her hands.” Diana estimated that
McKinney was beaten two to three times a week. Susan
testified to repeated serious beatings, including one particular
beating with

       [a] water hose. It was about a yard long like
       that (indicating), and she had like a pocket
       knife, and she snipped the hose and she went
       after him. She beat him on the back of the
       head, down his back, all over his legs, his
                    MCKINNEY V. RYAN                        13

       arms; anything that moved, she hit him. . . .
       He had bruises for weeks after that all over
       him. . . . Michael Hedlund tried to stop her.
       He grabbed her arm, and so she swung back
       and hit him across the side of the face and
       bruised his face.

    Hedlund left the house to live with his mother when he
was 14 years old. This left McKinney, approximately age 11,
as the only boy and the oldest of the three remaining children.
McKinney was too young to protect either himself or his
younger sisters. Diana, the younger of the two girls,
described their childhood experience as “horrible. It was
scary. It seems like we were all stressed out wondering when
the next time we were getting beat; wondering when we were
going to eat next.”

     Shirley’s physical abuse was accompanied by verbal and
emotional abuse. Diana testified that Shirley regularly yelled
at them, telling them that they were “[s]tupid, ugly, [and] not
worth anything.” Diana testified that Shirley showed
consistent favoritism toward her own daughter, while treating
her stepchildren as the “four bad kids.”

    Shirley often locked the children out of the house for
hours without food and, sometimes, water. There was a hose
in the yard, but Susan testified that if Shirley “was really
angry at them, they couldn’t turn the water faucet on outside
and even get a drink of water, and it would be 110 degrees
outside.” Susan remembered one occasion seeing the four
children outside on a hot Arizona summer day, clustered in
the shade of an eave of the house. None of the children had
shoes; the girls were wearing only underwear, and the boys
were wearing cutoff shorts with no shirts. When Susan and
14                  MCKINNEY V. RYAN

her mother returned to their house four hours later in the
middle of the afternoon, the children were still there, their
faces “beet red.” They told her that they were not allowed to
get any water and could not come back inside until their
father got home, when he would “punish them.” On another
occasion, Susan testified, Shirley “pick[ed] James [Jr.] up by
the scruff of the neck” and put him out on the porch with no
shoes or coat during the winter, when the frozen grass “would
crunch under your feet.”

    Shirley spent most of her time at home, while James was
generally absent. When he was home, James drank heavily.
Susan testified that James’s mother confronted him about
Shirley’s physical abuse of the children, but he told her to
“keep her nose out of his business.” Susan testified to an
incident in which McKinney, who was in first or second
grade at the time, had stolen a lunch at school because Shirley
and James had not given him any lunch money. McKinney
was suspended for several days. James told his son that “he
wasn’t going to punish him for stealing lunch; he was going
to punish him for getting caught.”

    By age nine or 10, McKinney had become distant, quiet
and withdrawn. He avoided other children. He began using
alcohol and marijuana at age 11. He dropped out of school in
the seventh grade. At about this time, he began running away
from home. Diana testified that McKinney ran away four or
five times. Susan remembered one incident in which, at age
11, McKinney showed up unannounced at her house in
Gilbert, Arizona after traveling alone from Oklahoma, where
the family had moved. McKinney had taken a bus as far as
Flagstaff, but did not have enough money to go farther. He
spent the next two days hitchhiking the rest of the way to
Susan’s house. McKinney’s arm, shoulder, and face were
                    MCKINNEY V. RYAN                        15

bruised; he told Susan he had gotten into a fight with Shirley.
Susan called his mother Bobbie on the telephone to tell her
that McKinney was at her house and that he was dirty and
tired, and hadn’t eaten in days. Bobbie did not come over to
pick him up. She called the sheriff instead, who picked up
McKinney and put him in juvenile detention.

      III. McKinney’s Post-traumatic Stress Disorder

    Dr. Mickey McMahon, a psychologist, made a formal
diagnosis of PTSD resulting from the horrific childhood
McKinney had suffered. Before arriving at his diagnosis, Dr.
McMahon had spent eight and a half hours with McKinney,
talking to him and administering a battery of tests. He had
also spoken with Susan for an hour and with Diana for half an
hour. Finally, Dr. McMahon had listened to Susan and
Diana’s testimony in court before providing his own
testimony. When asked, “[D]o you have any doubts about
your diagnosis of James McKinney having Post-traumatic
Stress Disorder?” Dr. McMahon answered, “No. None.”

    Dr. McMahon testified that his diagnosis of PTSD rested
not only on the abuse that McKinney himself had suffered.
He testified, “We know in research that witnessing can be
even more damaging than actually being the recipient of
abuse. . . . [T]here is a helplessness that is involved when
you’re witnessing . . . violence and you’re too small to do
anything about it.” When asked whether “violence upon his
sisters and brother would be . . . more traumatic to him
possibly than himself,” Dr. McMahon answered, “Yes.” Dr.
McMahon testified that his interview with McKinney “had
gone into great depth about him witnessing Dian[]a being
abused and beaten by her stepmother.”
16                   MCKINNEY V. RYAN

     Dr. McMahon testified that McKinney’s PTSD was
characterized by “flashbacks,” by “some sort of voidness,
numbing, withdrawing,” and by “substance abuse.” The
substances were “generally downers, opiates in prison,
alcohol, marijuana.” Dr. McMahon characterized McKinney
as “basically passive,” “quite submissive,” and “susceptible
to manipulation, exploitation.” “He can be emotionally
overwhelmed by environmental stress and act in poorly-
judged ways just to [re]duce the internal emotional turmoil.”
“He does not present [i]n the testing [as someone] who is . . .
manipulative, sensation- or thrill-seeking, and we know often
that people that get involved with violent kinds of crime are
thrill-seeking sociopaths. These results do not look like that.
It looks the opposite of that, since these tests are pretty much
consistent. He is a lo[]ner; depressed.”

      When asked whether someone with PTSD would “suffer
. . . constantly” from it, or whether it “may rear its head under
certain situations,” Dr. McMahon responded that for someone
with PTSD “there is the potential for the trauma to be re-
triggered, if things happen that are similar to what happened
when you’re originally traumatized.” When asked about the
Mertens burglary and murder, Dr. McMahon testified that if
an altercation had taken place between Ms. Mertens and
another person (not necessarily McKinney), it could “very
possib[ly]” have “re-triggered” McKinney’s trauma and could
have produced “diminished capacity.”

    When asked about the McClain burglary and murder, Dr.
McMahon testified that it would have been very
uncharacteristic of McKinney to have shot a sleeping person.
“Mr. McKinney’s test[] results, in the more than eight hours
I spent with him, did not indicate that he was that thrill-
seeking kind of, execution-kind of person. He’d rather
                   MCKINNEY V. RYAN                       17

withdraw from the situation.” Shooting a sleeping person
“would be the exact opposite of what I would expect from
Mr. McKinney.”

    Dr. Steven Gray, also a psychologist, testified for the
prosecution. In preparation for his testimony, Dr. Gray had
reviewed two presentence reports, a report prepared by Dr.
McMahon, the raw data and results of tests performed by Dr.
McMahon, and McKinney’s school records. He had also
interviewed McKinney in jail, in the company of one of his
lawyers, for “an hour, hour-and-a-half.” Dr. Gray had not
spoken with Susan, Diana, or other family members. Dr.
Gray testified, “I don’t think there’s enough evidence or
diagnostic materials or work that’s been done to conclusively
diagnose [McKinney] as having Post-traumatic Stress
Disorder.” Dr. Gray’s “tentative or provisional diagnosis”
was “Antisocial Personality Disorder.”

                      IV. Sentencing

    The verdict forms submitted to McKinney’s and
Hedlund’s juries asked only for general verdicts. The
prosecutor had argued to the juries that they could find
McKinney and Hedlund guilty of first degree murder either
because they were guilty of actually killing Ms. Mertens or
Mr. McClain, or because they were guilty of felony murder.
At McKinney’s sentencing hearing, the judge indicated that
he believed that McKinney had shot Ms. Mertens and that
Hedlund had shot Mr. McClain. But the judge recognized
that the jury had not specifically found that McKinney had
shot Ms. Mertens. The judge therefore relied on Enmund v.
Florida, 458 U.S. 782 (1982), and Tison v. Arizona, 481 U.S.
137 (1987), to conclude that even if McKinney had not killed
either Ms. Mertens or Mr. McClain, his involvement in the
18                   MCKINNEY V. RYAN

crimes leading up their murders nevertheless made him
death-eligible. He said with respect to the murder of Ms.
Mertens, “[E]ven if [Helund] had committed the homicide of
Mrs. Mertens, [McKinney] knew that [Hedlund] at the time
of entering the McClain residence was capable of killing.”

    When McKinney was sentenced, Arizona provided by
statute a nonexhaustive list of five specific mitigating factors.
See Ariz. Rev. Stat. Ann. § 13-703(G) (1993). Among the
statutory mitigators was a modified form of diminished
capacity, contained in § 13-703(G)(1): “The defendant’s
capacity to appreciate the wrongfulness of his conduct or to
conform his conduct to the requirements of the law was
significantly impaired, but not so impaired as to constitute a
defense to prosecution.”

    Arizona law also provided for nonstatutory mitigating
factors, such as family background or mental conditions that
did not rise to the level of impairment specified in § 13-
703(G)(1). For a little over fifteen years, from the late 1980s
until 2006, Arizona Supreme Court applied a “causal nexus”
test to nonstatutory mitigation factors. Under this test,
evidence of a difficult family background or mental disorder
was not in and of itself a relevant nonstatutory mitigating
factor. As a matter of Arizona law, such evidence was
relevant for nonstatutory mitigation only if it had a causal
effect on the defendant’s behavior in the commission of the
crime at issue. Application of the causal nexus test to
nonstatutory mitigation factors violated Eddings, for it
resulted in Arizona courts being entirely forbidden, as a
matter of state law, to treat as a mitigating factor a family
background or a mental condition that was not causally
connected to a defendant’s crime.
                    MCKINNEY V. RYAN                       19

     The trial judge sentenced McKinney to death. The judge
weighed what he concluded were legally relevant aggravating
and mitigating circumstances. He stated that “with respect to
mitigation” he “considered” the exhibits that were admitted
into evidence, and that he “did take . . . into consideration”
the testimony of Susan Sestate, Diana McKinney, and Dr.
McMahon. He stated as to McKinney’s family history, “I
agree that there was evidence of a difficult family history by
the defendant. However, as I’ve indicated, I do not find that
[it] is a substantial mitigating factor . . . .”

    The judge accepted Dr. McMahon’s PTSD diagnosis, but
concluded that it was not causally connected to McKinney’s
criminal behavior. Twice the judge specifically addressed the
relevance of McKinney’s PTSD as a potential mitigating
factor. Although the judge did not expressly so state, it
appears (and we are willing to assume) that he was speaking
both times in the context of statutory mitigation under § 13-
703(G)(1). The judge gave McKinney’s PTSD no weight as
a mitigating factor.

   The judge stated:

       But I think more importantly than that,
       certainly not trying to dispute him as an
       expert on what all that meant, it appeared to
       me that Dr. McMahon did not at any time
       suggest in his testimony nor did I find any
       credible evidence to suggest that, even if the
       diagnosis of Post-traumatic Stress Syndrome
       were accurate in Mr. McKinney’s case, that
       [it] in any way significantly impaired Mr.
       McKinney’s conduct.
20                  MCKINNEY V. RYAN

(Emphasis added.) He stated a short time (two transcript
paragraphs) later:

       [I]t appeared to me that based upon all these
       circumstances that there simply was no
       substantial reason to believe that even if the
       trauma that Mr. McKinney had suffered in
       childhood had contributed to an appropriate
       diagnosis of Post-traumatic Stress Syndrome
       that it in any way affected his conduct in this
       case.

(Emphasis added.) Nowhere else in his sentencing colloquy
did the judge specifically refer to McKinney’s PTSD and its
possible mitigating effect.

    The italicized language in two paragraphs just quoted
echoes the causal nexus test of the statutory mitigating factor
in § 13-703(G)(1). When applied solely in the context of
statutory mitigation under § 13-703(G)(1), the causal nexus
test does not violate Eddings. However, the italicized
language also echoes the restrictive language of Arizona’s
causal nexus test applicable to nonstatutory mitigation. When
applied in the context of nonstatutory mitigation, the causal
nexus test clearly violates Eddings.

    The Arizona Supreme Court reviews capital sentences de
novo, making its own determination of what constitute legally
relevant aggravating and mitigating factors, and then
independently weighing those factors. Ariz. Rev. Stat. Ann.
§ 13-755; see also McKinney, 917 P.2d at 1225. The Arizona
Supreme Court affirmed McKinney’s death sentence. The
Court addressed “the effects of [McKinney’s] childhood,
specifically the diagnosis of post-traumatic stress disorder
                    MCKINNEY V. RYAN                        21

(PTSD).” Id. at 1234. The Court agreed with the trial judge
that there was no causal nexus between McKinney’s PTSD
and his crimes. Indeed, the Court went further, finding that
McKinney’s PTSD would have influenced him not to commit
his crimes.

    In sentencing McKinney to death, the Arizona Supreme
Court gave no weight to McKinney’s PTSD. It made no
reference to statutory mitigation under § 13-703(G)(1).
Instead, the Court recited its unconstitutional causal nexus
test applicable to nonstatutory mitigation, citing the specific
page of Ross on which it had articulated that test two years
earlier. The Court wrote:

            [T]he record shows that the judge gave
       full consideration to McKinney’s childhood
       and the expert testimony regarding the effects
       of that childhood, specifically the diagnosis of
       post-traumatic stress disorder (PTSD).
       Assuming the diagnoses were correct, the
       judge found that none of the experts testified
       to, and none of the evidence showed, that such
       conditions in any way impaired McKinney’s
       ability to conform his conduct to the law. The
       judge noted that McKinney was competent
       enough to have engaged in extensive and
       detailed preplanning of the crimes.
       McKinney’s expert testified that persons with
       PTSD tended to avoid engaging in stressful
       situations, such as these burglaries and
       murders, which are likely to trigger symptoms
       of the syndrome. The judge observed that
       McKinney’s conduct in engaging in the
       crimes was counter to the behavior
22                  MCKINNEY V. RYAN

       McKinney’s expert described as expected for
       people with PTSD. . . . [A] difficult family
       background, including childhood abuse, does
       not necessarily have substantial mitigating
       weight absent a showing that it significantly
       affected or impacted the defendant’s ability to
       perceive, comprehend, or control his actions.
       See State v. Ross, 180 Ariz. 598, 607,
       886 P.2d 1354, 1363 (1994)[.]

McKinney, 917 P.2d at 1234 (emphasis added).

               V. Deference under AEDPA

   McKinney’s appeal is governed by AEDPA.
Accordingly, we will not grant his petition for a writ of
habeas corpus unless the state’s adjudication of his 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). We review de novo the district court’s
decision whether to grant McKinney’s habeas petition. Dyer
v. Hornbeck, 706 F.3d 1134, 1137 (9th Cir. 2013).

   Under the “contrary to” prong of § 2254(d)(1), a federal
court may grant habeas relief only “if the state court arrives
                     MCKINNEY V. RYAN                         23

at a conclusion opposite to that reached by [the Supreme]
Court on a question of law or if the state court decides a case
differently than [the Supreme] Court has on a set of
materially indistinguishable facts.” Williams v. Taylor,
529 U.S. 362, 413 (2000). Under the “unreasonable
application” prong, a federal court may grant relief only if
“the state court’s application of clearly established federal
law was objectively unreasonable,” id. at 409, such that
“fairminded jurists could [not] disagree that” the arguments
or theories that supported the state court’s decision were
“inconsistent with the holding in a prior decision of [the
Supreme] Court,” Harrington v. Richter, 562 U.S. 86, 102
(2011) (internal quotation marks omitted).

    For purposes of habeas review, we review the state
court’s “last reasoned decision.” Dyer, 706 F.3d at 1137. We
apply a “presumption that state courts know and follow the
law.” Visciotti, 537 U.S. at 24. “[Section] 2254(d)’s ‘highly
deferential standard for evaluating state-court rulings’ . . .
demands that state-court decisions be given the benefit of the
doubt.” Id. We “are not free to presume that a state court did
not comply with constitutional dictates on the basis of
nothing more than a lack of citation.” Bell v. Cone, 543 U.S.
447, 455 (2005); see also Early v. Packer, 537 U.S. 3, 8
(2002) (“[AEDPA] does not require citation of our
cases—indeed, it does not even require awareness of our
cases, so long as neither the reasoning nor the result of the
state-court decision contradicts them.”). We should neither
engage in hyper-technical analysis nor require “formulary
statement[s]” that ignore “the fair import of the [state court’s]
opinion.” Packer, 537 U.S. at 9. Our task is to determine
what standard the state court actually applied to resolve the
petitioner’s claim. See Lafler v. Cooper, 132 S. Ct. 1376,
1390 (2012).
24                  MCKINNEY V. RYAN

     VI. Clearly Established Law as Determined by the
                      Supreme Court

    The Supreme Court in Lockett v. Ohio, 438 U.S. 586
(1978), and in Eddings established a clear rule governing the
role of mitigating evidence in capital sentencing. In Lockett,
Chief Justice Burger wrote a plurality opinion concluding that
Ohio’s death penalty statute was invalid because it restricted
the mitigating circumstances that could be considered by the
sentencer. The plurality concluded that under the Eighth and
Fourteenth Amendments, “the sentencer . . . [must] not be
precluded from considering, as a mitigating factor, any aspect
of a defendant’s character or record and any of the
circumstances of the offense that the defendant proffers as a
basis for a sentence less than death” because a rule preventing
“the sentencer in all capital cases from giving independent
mitigating weight to aspects of the defendant’s character and
to circumstances of the offense proffered in mitigation creates
the risk that the death penalty will be imposed in spite of
factors which may call for a less severe penalty.” 438 U.S. at
604–05 (emphasis in original).

    Four years later, in Eddings, the Court applied the
principle articulated in Chief Justice Burger’s opinion in
Lockett. In Eddings, the sentencing judge had refused to
consider evidence that Eddings had been raised in turbulent
homes without supervision, had witnessed his mother’s
substance abuse, and had been beaten by his father. After
“weigh[ing] the evidence of aggravating and mitigating
circumstances,” the sentencing judge concluded that he could
not, “in following the law . . . consider the fact of this young
man’s violent background.” 455 U.S. at 108–09. Although
the state appeals court acknowledged Eddings’s family
history and psychological and emotional disorders, it upheld
                    MCKINNEY V. RYAN                        25

his conviction because “all the evidence tends to show that
[Eddings] knew the difference between right and wrong at the
time he pulled the trigger, and that is the test of criminal
responsibility in this State.” Id. at 109–10. The Supreme
Court endorsed the plurality opinion in Lockett and held that

       [j]ust as the State may not by statute preclude
       the sentencer from considering any mitigating
       factor, neither may the sentencer refuse to
       consider, as a matter of law, any relevant
       mitigating evidence. . . . The sentencer, and
       the Court of Criminal Appeals on review, may
       determine the weight to be given relevant
       mitigating evidence. But they may not give it
       no weight by excluding such evidence from
       their consideration.

Id. at 113–15 (emphasis in original).

     The United States Supreme Court interpreted and applied
the Lockett/Eddings rule in several other decisions prior to
McKinney’s sentencing in 1993 and the Arizona Supreme
Court’s affirmance in 1996. In those decisions, the Court
reiterated its holding that the admission of relevant evidence
is not enough to satisfy the Eighth and Fourteenth
Amendments if the sentencer is prevented by state law from
giving effect to that evidence. Because “full consideration of
evidence that mitigates against the death penalty is essential
if the [sentencer] is to give a ‘reasoned moral response to the
defendant’s background, character, and crime,’” Eddings
requires that “[t]he sentencer must also be able to consider
and give effect to that evidence in imposing sentence.” Penry
v. Lynaugh (Penry I), 492 U.S. 302, 319, 328 (1989),
abrogated on other grounds by Atkins v. Virginia, 536 U.S.
26                   MCKINNEY V. RYAN

304 (2002) (quoting Franklin v. Lynaugh, 487 U.S. 164, 184
(1988) (O’Connor, J., concurring in the judgment)). “[T]he
State cannot channel the sentencer’s discretion, but must
allow it to consider any relevant information offered by the
defendant.” McCleskey v. Kemp, 481 U.S. 279, 306 (1987);
see also Skipper v. South Carolina, 476 U.S. 1, 4–5 (1986)
(holding that even where mitigating evidence does “not relate
specifically to . . . [the defendant’s] culpability for the crime
he committed,” the defendant is entitled to offer any evidence
that “would be ‘mitigating’ in the sense that they might serve
‘as a basis for a sentence less than death’” (quoting Lockett,
438 U.S. at 604)).

     VII. The Causal Nexus Test and Its Application Here

                      A. Arizona’s Test

   The trial judge sentenced McKinney to death in 1993.
The Arizona Supreme Court affirmed Kinney’s conviction
and sentence in 1996.

    As briefly described above, Arizona capital sentencing
law included a statutorily specified nonexhaustive list of five
mitigating factors. See Ariz. Rev. Stat. Ann. § 13-703(G)
(1993). Among the statutory mitigating factors was a
modified form of diminished capacity, contained in § 13-
703(G)(1): “The defendant’s capacity to appreciate the
wrongfulness of his conduct or to conform his conduct to the
requirements of the law was significantly impaired, but not so
impaired as to constitute a defense to prosecution.”

    Arizona capital sentencing law also included nonstatutory
mitigating factors, such as family background or mental
conditions that did not rise to the level of impairment
                    MCKINNEY V. RYAN                        27

specified in § 13-703(G)(1). Beginning in the late 1980s,
Arizona Supreme Court developed a “causal nexus” test for
nonstatutory mitigation. Under this test, as we noted above,
evidence of a difficult family background or a mental
condition was not in and of itself relevant mitigating
evidence. As a matter of Arizona law, such evidence was
relevant for mitigation purposes only if it had some causal
effect contributing to the defendant’s behavior in the
commission of the crime at issue. Thus, while the defendant
could submit evidence of his difficult family background or
mental condition, the sentencing court was prohibited from
treating it as legally relevant mitigation evidence unless the
defendant proved a causal connection between his
background or disorder and the crime. In capital cases from
the late 1980s to the mid-2000s, the Arizona Supreme Court
repeatedly articulated this causal nexus test for nonstatutory
mitigation. The test was “contrary to . . . clearly established
Federal law, as determined by the Supreme Court of the
United States” in Eddings.

    In the immediate aftermath of Eddings, the Arizona
Supreme Court had not yet developed its causal nexus test for
nonstatutory mitigation. One year after Eddings, the Arizona
Supreme Court understood and applied Eddings and Lockett
correctly. In State v. McMurtrey, a capital case, the Court
wrote:

       [T]he sentencer may not refuse to consider, as
       a matter of law, relevant evidence presented in
       mitigation. Eddings v. Oklahoma, 455 U.S.
       104, 102 S.Ct. 869, 71 L.Ed.2d 1 (1982). . . .

           . . . If after considering the offered
       evidence, the court concludes that with
28                 MCKINNEY V. RYAN

       respect to the defendant’s mental condition, it
       merely establishes a character or personality
       disorder then the court may under [State v.]
       Richmond, [560 P.2d 41 (Ariz. 1976),]
       conclude that the mitigating circumstance in
       [Ariz. Rev. Stat. Ann.] § 13-703(G)(1) does
       not exist. In order to remain faithful to
       Lockett and [State v.] Watson, [586 P.2d 1253
       (Ariz. 1978),] however, the court’s inquiry
       may not end there. The court must consider
       the offered evidence further to determine
       whether it in some other way suggests that the
       defendant should be treated with leniency.

664 P.2d 637, 646 (Ariz. 1983); see also State v. Gretzler,
659 P.2d 1, 14 (Ariz. 1983).

   By the late 1980s, however, the Arizona Supreme Court
had begun to articulate and apply its causal nexus test to
nonstatutory mitigation. In Wallace, decided three years
before the trial judge sentenced McKinney, the Arizona
Supreme Court wrote in a capital case:

           A difficult family background, in and of
       itself, is not a mitigating circumstance. If it
       were, nearly every defendant could point to
       some circumstance in his or her background
       that would call for mitigation. A difficult
       family background is a relevant mitigating
       circumstance if a defendant can show that
       something in that background had an effect or
       impact on his behavior that was beyond the
       defendant’s control. . . . [Appellant’s] entire
       family background was before the court in the
                   MCKINNEY V. RYAN                       29

       pre-sentence report. Appellant, however,
       made no claim that his family background had
       anything to do with the murders he committed.

Wallace, 773 P.2d at 986 (1989) (emphasis added). The
Court could not have been clearer that, as a matter of law,
nonstatutory mitigation evidence not satisfying the causal
nexus test was irrelevant.     This test was in direct
contravention of Eddings and Lockett.

   In Ross, decided two years after the trial judge sentenced
McKinney, the Arizona Supreme Court wrote in another
capital case, with a pin citation to the precise page in
Wallace:

           A difficult family background is not a
       relevant mitigating circumstance unless “a
       defendant can show that something in that
       background had an effect or impact on his
       behavior that was beyond the defendant’s
       control.” State v. Wallace, 773 P.2d 983, 986
       (Ariz. 1989).

886 P.2d at 1363 (1994) (citation shortened) (emphasis
added). Again, the Court could not have been clearer that, as
a matter of law, nonstatutory mitigation evidence not
satisfying the causal nexus test was irrelevant. In affirming
McKinney’s death sentence in 1996, the Arizona Supreme
Court cited Ross, with a pin citation to this precise page.
McKinney, 917 P.2d at 1234.

   Two years after affirming McKinney’s death sentence, the
Arizona Supreme Court mentioned Eddings by name, in a
passage manifesting its continued misreading of Eddings and
30                   MCKINNEY V. RYAN

Lockett. In State v. Djerf, 959 P.2d 1274, 1289 (Ariz. 1998),
the Arizona Supreme Court explained that it read Eddings
and Lockett to require a sentencer to “consider” evidence
offered in mitigation. In the usage of the Arizona Court,
however, “considering” such evidence did not mean weighing
it to determine how much mitigating effect to give it. Rather,
it meant “considering” such evidence to determine whether it
satisfied the causal nexus test for nonstatutory mitigation. If
it satisfied the test, the sentencer was required to determine
how much weight, if any, to give it. If did not satisfy the test,
the sentencer was required, as a matter of law, to treat it as
irrelevant and to give it no weight. As the Court wrote in
Djerf:

        This court has held that Lockett and Eddings
        require only that the sentencer consider
        evidence proffered for mitigation. The
        sentencer, however, is entitled to give it the
        weight it deserves. Arizona law states that a
        difficult family background is not relevant
        unless the defendant can establish that his
        family experience is linked to his criminal
        behavior. Ross, 886 P.2d at 1362. The trial
        court considered the evidence but found it
        irrelevant and declined to give it weight
        because proof was lacking that his family
        background had any effect on the crimes.

Id. (emphasis added and some citations omitted).

   Two years later, in State v. Hoskins, the Arizona Supreme
Court reiterated what it had written in Djerf and explained the
Arizona causal nexus test and its two-step process for
                   MCKINNEY V. RYAN                       31

“consideration” of mitigating evidence. The Court wrote at
length:

           The trial court found that defendant had
       shown by a preponderance of the evidence
       that he suffered from antisocial or borderline
       personality disorder. But proof that such
       disorder exists does not of itself establish
       mitigation. For our purposes on review, it is
       essential not only that a personality disorder
       be shown to exist but that it be causally linked
       to the crime at the time the crime is
       committed.

          ...

           A dysfunctional family background or
       difficult childhood can be mitigating only if
       the defendant can establish that early
       experiences, however negative, affected later
       criminal behavior in ways that were beyond
       his control. Thus, family dysfunction, as with
       mental impairment under the (G)(1) statute,
       can be mitigating only when actual causation
       is demonstrated between early abuses suffered
       and the defendant’s subsequent acts. We
       reaffirm that doctrine here. . . .

           . . . If the defendant fails to prove
       causation, the circumstance will not be
       considered mitigating. However, if the
       defendant proves the causal link, the court
       will then determine what, if any, weight to
       accord the circumstance in mitigation.
32                  MCKINNEY V. RYAN

           ....

            The dissenting opinion expresses an
       impassioned description of the defendant’s
       “horrific” childhood. We are aware of the
       circumstances of defendant’s upbringing and
       have reviewed all aspects in minute detail.
       . . . Yet, it is clear that credible evidence in
       this record does not establish actual nexus
       with the crime, and our jurisprudence requires
       the nexus be proven. Wallace (II), 773 P.2d at
       985–86. Importantly, were we to hold
       otherwise, the family dysfunction factor and
       the impairment factor would become
       meaningless because virtually every homicide
       defendant can point to background
       dysfunction, abuse, or neglect as a basis for
       mitigation and leniency.

14 P.3d 997, 1021–22 (Ariz. 2000) (emphasis added and
some citations omitted).

     The decisions of the Arizona Supreme Court make clear
that family background or a mental condition could be given
weight as a nonstatutory mitigating factor, but only if
defendant established a causal connection between the
background or condition and his criminal behavior. For a
little over fifteen years, the Arizona Supreme Court routinely
articulated and insisted on its unconstitutional causal nexus
test, as seen in Wallace (1989), Ross (1994), Djerf (1998),
and Hoskins (2000), as just described, and in many other
cases. See, e.g., State v. White, 815 P.2d 869, 881 (Ariz.
1991) (“‘A difficult family background, in and of itself, is not
a mitigating circumstance.’” (quoting Wallace, 773 P.2d at
                    MCKINNEY V. RYAN                       33

986)); State v. Brewer, 826 P.2d 783, 802 (Ariz. 1992) (“The
evidence of defendant’s troubled background establishes only
that a personality disorder exists. It does not prove that, at
the time of the crime, the disorder controlled defendant’s
conduct or impaired his mental capacity to such a degree that
leniency is required.”); State v. Bible, 858 P.2d 1152, 1209
(Ariz. 1993) (holding that the defendant’s family history was
not mitigating in part because “Defendant made no showing
that any difficult family history had anything to do with the
murder” (citing Wallace, 773 P.2d at 986)); State v. Bolton,
896 P.2d 830, 854 (Ariz. 1995) (“A difficult family
background, however, is not always a mitigating
circumstance. If it were, many homicide defendants could
point to some circumstance in their background that would
call for mitigation. A difficult family background is a
mitigating circumstance if a defendant can show that
something in that background had an effect or impact on his
behavior that was beyond his control.” (citing Wallace,
773 P.2d at 986)); State v. Stokley, 898 P.2d 454, 473 (Ariz.
1995) (“A difficult family background alone is not a
mitigating circumstance.” (citing Wallace, 773 P.2d at 986));
State v. Jones, 917 P.2d 200, 219–20 (Ariz. 1996)
(defendant’s “chaotic and abusive childhood [was] not a
mitigating circumstance” because there was no causal nexus
to the crime); State v. Towery, 920 P.2d 290, 311 (Ariz. 1996)
(“We have held that a difficult family background is not
always entitled to great weight as a mitigating circumstance.
State v. Wallace, [773 P.2d at 985–86] (‘A difficult family
background is a relevant mitigating circumstance if a
defendant can show that something in that background had an
effect or impact on his behavior that was beyond the
defendant’s control.’)”); State v. Rienhardt, 951 P.2d 454,
467 (Ariz. 1997) (“[T]his court has rejected past drug and
alcohol use as a mitigating circumstance calling for leniency
34                  MCKINNEY V. RYAN

when there is no evidence of a causal connection between the
substance abuse and the crime.”); State v. Greene, 967 P.2d
106, 117 (Ariz. 1998) (“Greene’s mother may have
introduced him to drugs, but Greene failed to show how this
influenced his behavior on the night of the murder. Thus, we
do not find Greene’s dysfunctional family history to be a
mitigating circumstance.” (internal citation omitted)); State
v. Sharp, 973 P.2d 1171, 1182 (Ariz. 1999) (“[W]e require a
causal connection to justify considering evidence of a
defendant’s background as a mitigating circumstance.”); State
v. Kayer, 984 P.2d 31, 46 (Ariz. 1999) (holding that the
defendant’s mental impairment “was not established as a
nonstatutory mitigating factor” in part because “defendant
offered no evidence to show the requisite causal nexus that
mental impairment affected his judgment or his actions at the
time of the murder”); State v. Martinez, 999 P.2d 795, 809
(Ariz. 2000) (“There is simply no nexus between Martinez’
family history and his actions on the Beeline Highway. His
family history, though regrettable, is not entitled to weight as
a non-statutory mitigating factor.”); State v. Canez, 42 P.3d
564, 594 (Ariz. 2002) (“[A] causal nexus between the
intoxication and the offense is required to establish non-
statutory impairment mitigation.”); id. at 595 (“A defendant’s
difficult childhood is mitigating only where causally
connected to his offense.”).

    The Arizona Supreme Court articulated the causal nexus
test in various ways but always to the same effect: As a
matter of law, a difficult family background or mental
condition did not qualify as a nonstatutory mitigating factor
unless it had a causal effect on the defendant’s behavior in
committing the crime at issue. The Arizona Court frequently
stated categorically that, absent a causal nexus, would-be
nonstatutory mitigation was simply “not a mitigating
                    MCKINNEY V. RYAN                       35

circumstance.” Wallace, 773 P.2d at 986. Sometimes, the
court stated that evidence offered as nonstatutory mitigation
that did not have a causal connection to the crime should be
given no “weight.” For example, as it wrote in Djerf:

       Arizona law states that a difficult family
       background is not relevant unless the
       defendant can establish that his family
       experience is linked to his criminal behavior.
       The trial court considered the evidence but
       found it irrelevant and declined to give it
       weight because proof was lacking that his
       family background had any effect on the
       crimes.

Djerf, 959 P.2d at 1289 (citation omitted). Similarly, the
court wrote in Martinez, “There is simply no nexus between
Martinez’ family history and his actions on the Beeline
Highway. His family history, though regrettable, is not
entitled to weight as a non-statutory mitigating factor.”
Martinez, 999 P.2d at 809.

    Sometimes, the Arizona Supreme Court stated that
evidence of a difficult family background or mental illness
was “not necessarily” or not “usually” mitigating, and then
(often in the same paragraph) held as a matter of law that the
evidence in the specific case before the Court was not
mitigating because it had no causal connection to the crime.
For example, the Court wrote in Jones,

       A difficult family background is not
       necessarily a mitigating circumstance unless
       defendant can show that something in his
       background had an effect on his behavior that
36                  MCKINNEY V. RYAN

       was beyond his control. . . . [H]owever, the
       trial court did not find any connection
       between defendant’s family background and
       his conduct on the night of the murders, and
       our review of the record does not reveal any
       such connection.      Thus, we find that
       defendant’s chaotic and abusive childhood is
       not a mitigating circumstance.

Jones, 917 P.2d at 219–20 (emphasis added).

    Similarly, the Court wrote in Hoskins, quoting an earlier
case, “‘An abusive family background is usually given
significant weight as a mitigating factor only when the abuse
affected the defendant’s behavior at the time of the crime.’”
Hoskins, 14 P.3d at 1021 (emphasis added) (quoting State v.
Mann, 934 P.2d 784, 795 (Ariz. 1997)). The court in Hoskins
then went to state and apply the unconstitutional causal nexus
test as a matter of law to the evidence in the case before it,
writing,

       [I]t is essential not only that a personality
       disorder be shown to exist but that it be
       causally linked to the crime at the time the
       crime is committed. . . .

           . . . Because defendant has not connected
       his anti-social or personality disorder to the
       car-jacking and murder, it cannot be
       co nsidered a relevant m i t i gat i ng
       circumstance. . . .

           ....
                    MCKINNEY V. RYAN                       37

           . . . If the defendant fails to prove
       causation, the circumstance will not be
       considered mitigating. However, if the
       defendant proves the causal link, the court
       then will determine what, if any, weight to
       accord the circumstance in mitigation.

Id. at 1021–22 (emphasis added).

    In the mid-2000s, after the United States Supreme Court
emphatically reiterated the Eddings rule in Tennard v. Dretke,
542 U.S. 274 (2004), the Arizona Supreme Court finally
abandoned its unconstitutional causal nexus test for
nonstatutory mitigation. In its first post-Tennard case
addressing Eddings, the Arizona Supreme Court properly
stated the rule in a jury sentencing case:

       While Eddings and various other Supreme
       Court decisions dictate a liberal rule of
       admissibility for mitigating evidence, they
       still leave it to the sentencer to “determine the
       weight to be given to relevant mitigating
       evidence.” Eddings, 455 U.S. at 114–15, 102
       S.Ct. 869. Once the jury has heard all the
       defendant’s mitigation evidence, there is no
       constitutional prohibition against the State
       arguing that the evidence is not particularly
       relevant or that it is entitled to little weight.

State v. Anderson, 111 P.3d 369, 392 (Ariz. 2005). A year
later, in a judge-sentencing case, the Arizona Supreme Court,
relying on Anderson, again properly stated the rule:
38                 MCKINNEY V. RYAN

       We do not require that a nexus between the
       mitigating factors and the crime be
       established before we consider the mitigation
       evidence. See Tennard v. Dretke, 542 U.S.
       274, 287, 124 S.Ct. 2562, 159 L.Ed.2d 384
       (2004). But the failure to establish such a
       causal connection may be considered in
       assessing the quality and strength of the
       mitigation evidence.

State v. Newell, 132 P.3d 833, 849 (Ariz. 2006).

              B. Our “Clear Indication” Test

     Not counting the case now before us, we have decided
nine Arizona capital cases in which petitioners have alleged
that the Arizona Supreme Court, as a matter of law, treated
would-be mitigation evidence as legally irrelevant in
violation of Eddings. In two of these cases, we held that the
Arizona Supreme Court committed Eddings error. See
Williams v. Ryan, 623 F.3d 1258 (9th Cir. 2010); Styers v.
Schriro, 547 F.3d 1026 (9th Cir. 2008) (per curiam). In the
other seven, we held that the Arizona Court had not
committed Eddings error. In six of these, we applied a test
first articulated in Schad v. Ryan, 581 F.3d 1019, 1037 (9th
Cir. 2009) (per curiam) (unamended opinion), under which
we could not find Eddings error unless there was a “clear
indication in the record” that the Arizona Court had refused,
as a matter of law, to treat nonstatutory mitigation evidence
as relevant unless it had some effect on the petitioner’s
criminal behavior. See Hedlund v. Ryan, 750 F.3d 793, 818
(9th Cir. 2014); Murray v. Schriro, 746 F.3d 418, 455 (9th
Cir. 2014); Clabourne v. Ryan, 745 F.3d 362, 373 (9th Cir.
2014) (petition for panel rehearing and for rehearing en banc
                    MCKINNEY V. RYAN                         39

pending); Poyson v. Ryan, 743 F.3d 1185, 1188 (9th Cir.
2013); Lopez v. Ryan, 630 F.3d 1198, 1203 (9th Cir. 2011);
Schad v. Ryan, 671 F.3d 708, 724 (9th Cir. 2011) (per
curiam) (amended opinion). In the seventh, we did not apply
the “clear indication” test. See Towery v. Ryan, 673 F.3d 933
(9th Cir. 2012). In none of the cases in which we held that
there had been no Eddings error did we hold that the Arizona
Supreme Court had renounced its causal nexus test. Rather,
we held only that petitioners had not shown that the Court
had applied the test in such a way as to treat nonstatutory
mitigation evidence irrelevant as a matter of law.

    In our amended opinion in Schad, we stated the “clear
indication” test as follows:

           Absent a clear indication in the record
       that the state court applied the wrong
       standard, we cannot assume the courts
       violated Edding’s constitutional mandates.
       See Bell v. Cone, [543 U.S. 447, 455] (2005)
       (“Federal courts are not free to presume that a
       state court did not comply with constitutional
       dictates on the basis of nothing more than a
       lack of citation.”).

Schad, 671 F.3d at 724 (emphasis added). The language from
Bell, quoted in Schad in support of its “clear indication” rule,
states only that we may not presume that a state court failed
to follow federal constitutional law based on “nothing more
than a lack of citation.” But in Schad we broadened the
language from Bell and transformed it into a prohibition
against an “assumption” of unconstitutionality in the absence
of a “clear indication” to the contrary.
40                   MCKINNEY V. RYAN

    When used in Bell, the quoted language stated a rule that
is applicable in a narrow circumstance: a federal habeas court
should not presume, merely because a state court has failed
to cite a federal case, that the state court was unaware of or
failed to follow the rule established in that case. The Bell rule
is eminently sensible. A presumption of ignorance or
disregard of federal law based merely on a failure of citation
by a busy state court is both unrealistic and disrespectful. But
the Bell rule, as stated by the Supreme Court, has a relatively
narrow application. It is not a broad rule requiring federal
habeas courts to assume in all circumstances, including
Eddings cases, that absent a “clear indication” to the contrary,
a state understood and properly applied federal law.

    Congress knows how to limit federal collateral review by
requiring deference to state court decisions, and it has done
so in AEDPA. Under 28 U.S.C. § 2254(d), federal courts
shall not issue writs of habeas corpus on any claim
adjudicated in state court unless the adjudication “resulted in
a decision that was contrary to, or involved an unreasonable
application of, clearly established Federal law” or “that was
based on an unreasonable determination of the facts in light
of the evidence presented in the State court proceeding.”
Section 2254(d) is already a form of a clear statement or a
clear indication rule, which all federal courts are required to
follow. The “clear indication” rule stated by our circuit for
the first time in Schad, and applicable in our circuit only in
Eddings cases, is an inappropriate and unnecessary gloss on
the deference already required under § 2254(d). We therefore
overrule Schad, and the cases that have followed it, with
respect to the “clear indication” test.
                    MCKINNEY V. RYAN                         41

   C. Application of the Causal Nexus Test in This Case

    For the reasons that follow, we conclude that the Arizona
Supreme Court applied its unconstitutional causal nexus test
to McKinney’s PTSD, refusing, as a matter of law, to treat it
as a relevant nonstatutory mitigating factor. This was
contrary to clearly established federal law as established in
Eddings.

    We review the decision of the highest state court to have
provided a reasoned decision. Ylst v. Nunnemaker, 501 U.S.
797, 804–06 (1991). The Arizona Supreme Court reviews
capital sentences de novo, making its own determination of
what constitute legally relevant aggravating and mitigating
factors, and then weighing those factors independently. Ariz.
Rev. Stat. Ann. § 13-755. The Arizona Supreme Court
“conducts a thorough and independent review of the record
and of the aggravating and mitigating evidence to determine
whether the sentence is justified.” McKinney, 917 P.2d at
1225. The Court “considers the quality and strength, not
simply the number, of aggravating or mitigating factors.” Id.

    In reviewing the de novo sentencing decision of the
Arizona Supreme Court, we look only to the decision of that
Court. We look to the decision of the sentencing judge only
to the degree it was adopted or substantially incorporated by
the Arizona Supreme Court. See Barker v. Fleming, 423 F.3d
1085, 1903 (9th Cir. 2005) (holding that when “the last
reasoned decision adopted or substantially incorporated the
reasoning from a previous decision,” it is “reasonable for the
reviewing court to look at both decisions to fully ascertain the
reasoning of the last decision”). The sentencing judge
accepted the factual accuracy of Dr. McMahon’s diagnosis of
PTSD, saying that he was “certainly not trying to dispute him
42                  MCKINNEY V. RYAN

as an expert on what all that meant.” The judge then went on
to say that “Dr. McMahon did not at any time suggest in his
testimony nor did I find any credible evidence to suggest that,
even if the diagnosis of Post-traumatic Stress Syndrome were
accurate in Mr. McKinney’s case, that it in any way
significantly impaired Mr. McKinney’s conduct.” (Emphasis
added.) He further stated:

       [I]t appeared to me that based upon all these
       circumstances that there simply was no
       substantial reason to believe that even if the
       trauma that Mr. McKinney had suffered in
       childhood had contributed to an appropriate
       diagnosis of Post-traumatic Stress Syndrome
       that it in any way affected his conduct in this
       case.

(Emphasis added.) The italicized language echoes the
language of Arizona’s statutory mitigator under Ariz. Rev.
Stat. § 13-703(G)(1). It also echoes the language used by the
Arizona Supreme Court to articulate the unconstitutional
causal nexus test applied to nonstatutory mitigation. See, e.g.,
Wallace, 773 P.2d at 986 (“A difficult family background is
a relevant mitigating circumstance if a defendant can show
that something in that back ground had an effect or impact on
his behavior that was beyond his control.”) (emphasis added).

    The Arizona Supreme Court affirmed McKinney’s death
sentence in 1996, roughly in the middle of the fifteen-year-
plus period during which it insisted on its unconstitutional
nexus test for nonstatutory mitigation. The Court reviewed
in its opinion the death sentences of both Hedlund and
McKinney. The Court first affirmed Hedlund’s death
sentence, writing, “A difficult family background, including
                    MCKINNEY V. RYAN                         43

childhood abuse, does not necessarily have substantial
mitigating weight absent a showing that it significantly
affected or impacted a defendant’s ability to perceive, to
comprehend, or to control his actions. See State v. Ross, . . .
886 P.2d 1354, 1363 (1994).” McKinney, 917 P.2d at 1226.
As we pointed out above, the pin citation to Ross is a citation
to the precise page on which the Arizona Supreme Court had
two years earlier articulated its unconstitutional “causal
nexus” test for non-statutory mitigation.

    When the Arizona Supreme Court reviewed McKinney’s
death sentence, it again relied on Ross. The Court wrote that
the sentencing judge had given “full consideration” to
McKinney’s childhood and resulting PTSD, using the word
“consideration” in the sense of considering whether the
evidence was, or was not mitigating. See Djerf, 959 P.2d at
1289 (“This court has held that Lockett and Eddings require
only that the sentencer consider evidence proffered for
mitigation. The sentencer, however, is entitled to give it the
weight it deserves. Arizona law states that a difficult family
background is not relevant unless the defendant can establish
that his family experience is linked to his criminal behavior.”)
(emphasis added).

    Reviewing McKinney’s sentence de novo, the Arizona
Supreme Court addressed “the effects of [McKinney’s]
childhood, specifically the diagnosis of post-traumatic stress
disorder (PTSD).” McKinney, 917 P.2d at 1234. The Court
accepted the conclusion of the sentencing judge that, as a
factual matter, McKinney had not shown that his PTSD had
causally contributed to the murders of Mertens and McClain.
Indeed, the Arizona Supreme Court went further, pointing out
that McKinney’s PTSD, if anything, would have had the
opposite effect, influencing him not to have committed the
44                  MCKINNEY V. RYAN

murders. Because the Court concluded that McKinney’s
PTSD was not causally connected to his crimes, it refused, as
a matter of law, to treat his PTSD as a mitigating factor.
After describing McKinney’s PTSD evidence and assessing
de novo the effect of his PTSD on his behavior, the Court
recited its causal nexus test. The Court concluded with a pin
citation to the precise page in Ross on which, two years
earlier, it had articulated the causal nexus test for
nonstatutory mitigation.

     We quote in full the relevant paragraph:

            Here again, the record shows that the
        judge gave full consideration to McKinney’s
        childhood and the expert testimony regarding
        the effects of that childhood, specifically the
        diagnosis of post-traumatic stress disorder
        (PTSD). Assuming the diagnoses were
        correct, the judge found that none of the
        experts testified to, and none of the evidence
        showed, that such conditions in any way
        impaired McKinney’s ability to conform his
        conduct to the law. The judge noted that
        McKinney was competent enough to have
        engaged in extensive and detailed preplanning
        of the crimes. McKinney’s expert testified
        that persons with PTSD tended to avoid
        engaging in stressful situations, such as these
        burglaries and murders, which are likely to
        trigger symptoms of the syndrome. The judge
        observed that McKinney’s conduct in
        engaging in the crimes was counter to the
        behavior McKinney’s expert described as
        expected for people with PTSD. As we noted
                    MCKINNEY V. RYAN                         45

       in discussing Hedlund’s claim on this same
       issue, a difficult family background, including
       childhood abuse, does not necessarily have
       substantial mitigating weight absent a
       showing that it significantly affected or
       impacted the defendant’s ability to perceive,
       comprehend, or control his actions. See State
       v. Ross, . . . 886 P.2d 1354, 1363 (1994)[.]

Id. at 1234 (emphasis added).

    Based on (1) the factual conclusion by the sentencing
judge, which the Arizona Supreme Court accepted, that
McKinney’s PTSD did not “in any way affect[] his conduct
in this case,” (2) the Arizona Supreme Court’s additional
factual conclusion that, if anything, McKinney’s PTSD would
have influenced him not to commit the crimes, and (3) the
Arizona Supreme Court’s recital of the causal nexus test for
nonstatutory mitigation and its pin citation to the precise page
in Ross where it had previously articulated that test, we
conclude that the Arizona Supreme Court held, as a matter of
law, that McKinney’s PTSD was not a nonstatutory
mitigating factor, and that it therefore gave it no weight. This
holding was contrary to Eddings. We therefore hold that the
decision of the Arizona Supreme Court applied a rule that
was “contrary to . . . clearly established Federal law, as
determined by the Supreme Court of the United States.”
28 U.S.C. § 2254(d)(1).

              D. Structural or Harmless Error

     We have not heretofore decided whether an Eddings error
is structural error. We do so now and conclude that it is not.
46                   MCKINNEY V. RYAN

     The Supreme Court has consistently characterized
structural errors as “structural defects in the constitution of
the trial mechanism.” Brecht v. Abrahamson, 507 U.S. 619,
629 (1993). Because such errors go to the framework within
which judicial proceedings are conducted, they “infect the
entire trial process” and accordingly require “automatic
reversal of the conviction.” Id. at 629–30; see also Arizona
v. Fulminante, 499 U.S. 279, 310 (1991) (noting that
structural errors “affect[] the framework within which the
trial proceeds”).       Some structural errors produce a
fundamentally flawed record, so “any inquiry into [their]
effect[s] on the outcome of the case would be purely
speculative.” Satterwhite v. Texas, 486 U.S. 249, 256 (1988);
see also Rose v. Clark, 478 U.S. 570, 579 & n.7 (1986)
(holding that harmless-error analysis was appropriate because
“[u]nlike errors such as judicial bias or denial of counsel, the
error in this case did not affect the composition of the record.
Evaluation of whether the error prejudiced respondent thus
does not require any difficult inquiries concerning matters
that might have been, but were not, placed in evidence”).

    By contrast, harmless-error analysis applies to trial errors,
“which may . . . be quantitatively assessed in the context of
other evidence presented in order to determine whether its
admission was harmless.” Fulminante, 499 U.S. at 307–08.
Because “the error occurs at trial and its scope is readily
identifiable[,] . . . the reviewing court can undertake with
some confidence its relatively narrow task of assessing the
likelihood that the error materially affected the deliberations
of the jury.” Holloway v. Arkansas, 435 U.S. 475, 490
(1978). For example, in Satterwhite, the Court applied
harmless-error analysis to a Sixth Amendment error resulting
in the improper admission of testimony from a psychiatrist
who had examined Satterwhite without notifying his attorney.
                    MCKINNEY V. RYAN                         47

486 U.S. at 258. The Court noted that “the evaluation of the
consequences of an error in the sentencing phase of a capital
case may be more difficult because of the discretion that is
given to the sentencer.” Id. However, it held that the error at
issue was subject to harmless-error analysis because the
admission of testimony was an error of limited scope that was
ready identifiable and whose impact could be assessed by a
reviewing court. Id. at 257–58.

                      E. Harmless Error

    The harmless-error standard on habeas review provides
that “relief must be granted” if the error “‘had substantial and
injurious effect or influence in determining the jury’s
verdict.’” Brecht, 507 U.S. at 623 (quoting Kotteakos v.
United States, 328 U.S. 750, 776 (1946)). “Under this
standard, habeas petitioners may obtain plenary review of
their constitutional claims, but they are not entitled to habeas
relief based on trial error unless they can establish that it
resulted in actual prejudice.” Id. at 637 (internal quotation
marks omitted). But, as with the stricter Chapman standard,
the “risk of doubt” is placed “on the State.” O’Neal v.
McAninich, 513 U.S. 432, 439 (1995). On federal habeas, in
the absence of structural error that requires automatic
reversal, “relief is appropriate only if the prosecutor cannot
demonstrate harmless error.” Ayala v. Davis, 135 S. Ct.
2187, 2197 (2015).

   The Court explained in Kotteakos,

       [I]f one cannot say, with fair assurance, after
       pondering all that happened without stripping
       the erroneous action from the whole, that the
       judgment was not substantially swayed by the
48                  MCKINNEY V. RYAN

       error, it is impossible to conclude that
       substantial rights were not affected. The
       inquiry cannot be merely whether there was
       enough to support the result, apart from the
       phase affected by the error. It is rather, even
       so, whether the error itself had substantial
       influence. If so, or if one is left in grave
       doubt, the conviction cannot stand.

328 U.S. at 765. Accordingly, “[w]hen a federal judge in a
habeas proceeding is in grave doubt about whether a trial
error of federal law had ‘substantial and injurious effect or
influence in determining the jury’s verdict,’ that error is not
harmless. And, the petitioner must win.” O’Neal, 513 U.S.
at 436.

    We hold that the Eddings error committed by the Arizona
Supreme Court in this case had a “substantial and injurious
effect” on McKinney’s sentence within the meaning of
Brecht. McKinney presented evidence of severe, prolonged
childhood abuse that, in the words of the sentencing judge,
was “beyond the comprehension and understanding of most
people.” Dr. McMahon diagnosed McKinney as suffering
from PTSD as a result of his horrific childhood. McKinney’s
PTSD was important mitigating evidence, central to his plea
for leniency, but the Arizona Supreme Court, as a matter of
law, gave it no weight. See Coleman v. Calderon, 210 F.3d
1047, 1051 (9th Cir. 2000) (constitutionally infirm jury
instruction was not harmless because “it undermined the very
core of Coleman’s plea for life”). We hold here, as we did in
Styers, that PTSD is mitigating evidence under Eddings.
Styers, 547 F.3d at 1035–36 (granting the writ based on
Eddings error by the Arizona Supreme Court in treating
PTSD mitigation evidence irrelevant as a matter of law). We
                    MCKINNEY V. RYAN                         49

hold, further, as we also did in Styers, that the Arizona
Supreme Court’s refusal, as matter of law, to give weight to
petitioner’s PTSD, requires resentencing. Id.

    “[I]n capital cases the fundamental respect for humanity
underlying the Eighth Amendment . . . requires consideration
of the character and record of the individual offender and the
circumstances of the particular offense as a constitutionally
indispensable part of the process of inflicting the penalty of
death.” Woodson v. North Carolina, 428 U.S. 280, 304
(1976); see also Lockett, 438 U.S. at 605 (“Given that the
imposition of death by public authority is so profoundly
different from all other penalties, we cannot avoid the
conclusion that an individualized decision is essential in
capital cases.”). When a defendant’s life is at stake, the
Supreme Court has consistently emphasized the importance
of a properly informed, individualized sentencing
determination. See, e.g., Abdul-Kabir v. Quarterman,
550 U.S. 233, 264 (2007) (noting that Lockett and its progeny
“have made clear that when the jury is not permitted to give
meaningful effect or a ‘reasoned moral response’ to a
defendant’s mitigating evidence . . . the sentencing process is
fatally flawed”); Satterwhite, 486 U.S. at 258 (“It is important
to avoid error in capital sentencing proceedings.”);
McCleskey, 481 U.S. at 304; Lockett, 438 U.S. at 604 (“We
are satisfied that this qualitative difference between death and
other penalties calls for a greater degree of reliability when
the death sentence is imposed.”).

    We recognize that there were important aggravating
factors in this case. Although the jury had not found that
McKinney had himself killed either Ms. Mertens or Mr.
McClain, the sentencing judge concluded, based on
substantial evidence, that McKinney had killed Ms. Mertens,
50                   MCKINNEY V. RYAN

though not Mr. McClain. Further, McKinney had been
involved, as either the actual killer or as an accessory, in two
murders; the murders had been done for pecuniary gain; and
there had been cruelty to Mertens in the struggle preceding
her death. We do not give “short shrift” to, or minimize the
importance of, these aggravating factors. Bobby v. Van Hook,
558 U.S. 4, 13 (2009) (per curiam). But we conclude that
McKinney’s evidence of PTSD resulting from sustained,
severe childhood abuse would have had a substantial impact
on a capital sentencer who was permitted to evaluate and give
appropriate weight to it as a nonstatutory mitigating factor.
We conclude in this case that the Arizona Supreme Court’s
application of its causal nexus test to exclude, as a matter or
law, evidence of McKinney’s PTSD was “contrary to . . .
clearly established Federal law, as determined by the
Supreme Court of the United States,” and that its application
of the test had a “substantial and injurious effect or influence”
on its decision to sentence McKinney to death. Brecht,
507 U.S. at 623 (internal quotation marks omitted).

                  VIII. Response to Dissent

   The foregoing opinion speaks for itself, but we add a few
words to respond directly to two contentions in the dissent
with which we particularly disagree.

 A. Consistent Articulation and Application of the Causal
                       Nexus Test

    First, the dissent contends that during the relevant period
the Arizona Supreme Court was inconsistent in its articulation
and application of its unconstitutional causal nexus test for
nonstatutory mitigation. We disagree. As we discuss in the
body of our opinion, the Arizona Supreme Court, during a
                    MCKINNEY V. RYAN                        51

period of just over fifteen years, consistently insisted upon
and applied its causal nexus test to nonstatutory mitigation.
In no case during this period did the Court give any indication
that the causal nexus test was not the law in Arizona, or any
indication that it had the slightest doubt about the
constitutionality of the test.

   The dissent particularly relies on four Arizona Supreme
Court cases. Dissent at 89–96. Those cases are State v.
Towery, 920 P.2d 290 (Ariz. 1996), State v. Thornton,
929 P.2d 676 (Ariz. 1996), State v. Gonzales, 892 P.2d 838
(Ariz. 1995), and State v. Trostle, 951 P.2d 869 (Ariz. 1997).
None of the four cases even remotely supports the dissent’s
contention.

    Of the four cases, the dissent emphasizes Towery.
Dissent at 89–90. In Towery, however, the Arizona Supreme
Court clearly articulated and applied its causal nexus test.
The defendant in Towery had introduced, as a would-be
mitigating factor, evidence of his difficult family background.
The sentencing judge “rejected the evidence as a mitigating
factor because [Towery] failed to establish a nexus between
his family background and his crime.” Towery, 920 P.2d at
310. The Arizona Supreme Court, on de novo review,
affirmed the death sentence. It wrote:

           We have held that a difficult family
       background is not always entitled to great
       weight as a mitigating circumstance. State v.
       Wallace, . . . 773 P.2d 983, 985–86 (1989)
       (“A difficult family background is a relevant
       mitigating circumstance if a defendant can
       show that something in that background had
       an effect or impact on his behavior that was
52                  MCKINNEY V. RYAN

       beyond the defendant’s control.”)[.] We have
       since reaffirmed that family background may
       be a substantial mitigating circumstance when
       it is shown to have some connection with the
       defendant’s offense-related conduct. White,
       . . . 815 P.2d at 881–82.

          Defendant has failed to connect his family
       background to his criminal conduct.

Id. at 311 (citations shortened). The Court in Towery could
hardly have been clearer. It both articulated and applied its
unconstitutional causal nexus test to treat as irrelevant, as a
matter of law, nonstatutory mitigation evidence of the
defendant’s family background because he had “failed to
connect his family background to his criminal conduct.” Our
three-judge panel decision, reviewing Towery’s conviction
and sentence on federal habeas, held to the contrary, but it
was mistaken in so holding. See Towery v. Ryan, 673 F.3d
933 (9th Cir. 2012).

    The other three cases are of no greater help to the dissent.
In Thornton, the sentencing judge had given mitigating
weight to defendant’s “traumatic childhood, dysfunctional
family, and antisocial personality disorder,” as it was
permitted to do under Arizona law provided there was a
causal nexus to the crime. The Arizona Supreme Court
affirmed the judge on this point. It did not recite whether the
judge had found a causal nexus; it simply affirmed without
comment. The defendant contended that the sentencing judge
should also have given weight to four other nonstatutory
mitigating factors — mental illness, remorse, cooperation,
and character. The Arizona Supreme Court rejected the
contention that any of these factors were mitigating. It
                    MCKINNEY V. RYAN                        53

rejected three of them on the ground that they did not exist as
a factual matter. It rejected the fourth with a citation to the
precise page in Ross in which it had articulated its
unconstitutional causal nexus test. In Gonzales, defendant
contended his good character should have been given
mitigating weight. The Arizona Supreme Court rejected the
contention, holding as a factual matter that Gonzales did not
have good character. In Trostle, the Arizona Supreme Court
gave mitigating weight to the defendant’s mental impairment
because the causal nexus test was satisfied. The Court wrote,

       [W]eight to be given to mental impairment
       should be proportional to a defendant’s ability
       to conform or appreciate the wrongfulness of
       his conduct.

           The defendant here established . . . that he
       was affected in no small measure by an
       impaired ability to conform his conduct to the
       law’s requirements. . . . The trial court,
       therefore, should have given serious
       consideration to this evidence, either as
       statutory or nonstatutory mitigation.

951 P.2d at 886.

    The dissent also relies on two cases cited in Lopez v.
Ryan, 630 F.3d 1198, 1204 n.4 (9th Cir. 2011) — State v.
Mann, 934 P.2d 784 (Ariz. 1997); and State v. Medrano,
914 P.2d 225 (Ariz. 1996). Neither case supports the
dissent’s contention.

   In State v. Mann, the defendant had advanced four
proposed nonstatutory mitigators: (1) the possibility of
54                  MCKINNEY V. RYAN

consecutive life sentences rather than the death penalty;
(2) defendant’s relationship to his children; (3) a change in
defendant’s “lifestyle” after he committed the murders; and
(4) defendant’s difficult family background. 934 P.2d at 795.
The Arizona Supreme Court held as a matter of law that the
possibility of consecutive life sentences was “a sentencing
option” rather than a mitigating factor. Id. With respect to
defendant’s relationship with his children and his change in
lifestyle, the Court held that the defendant had not
“established mitigation of sufficient weight to call for
leniency.” Id. Finally, the Court held that defendant’s
difficult family background was irrelevant as a matter of law.
It recited its causal nexus test, citing the precise page in its
Wallace opinion on which it had articulated and applied the
test. The Court then wrote, “Defendant did not show any
connection.” Id.

    In State v. Medrano, the defendant contended that his
cocaine intoxication was both a statutory and nonstatutory
mitigating factor. The sentencing judge had found as a
factual matter that defendant’s cocaine intoxication had not
affected his behavior in committing the crime. The Arizona
Supreme Court applied the causal nexus test, writing that the
sentencing judge had found that the defendant had “not
proven by a preponderance of the evidence, either as a
statutory or nonstatutory mitigating factor, that cocaine
intoxication had contributed to his conduct on the night of the
murder.” 914 P.2d at 227. The Arizona Supreme Court
accepted the factual finding of the sentencing judge that there
had been no causal nexus. The Court wrote that defendant’s
evidence was “unpersuasive” and that his cocaine use
therefore “fail[ed] as a non-statutory mitigating
circumstance.” Id. at 229.
                    MCKINNEY V. RYAN                         55

    As we noted at the beginning of our opinion, the Arizona
Supreme Court has a strong view of stare decisis. The Court
wrote in White v. Bateman, 358 P.2d 712, 714 (Ariz. 1961),
for example, that its prior case law “should be adhered to
unless the reasons of the prior decisions have ceased to exist
or the prior decision was clearly erroneous or manifestly
wrong.” See also Young v. Beck, 251 P.3d 380, 385 (Ariz.
2011) (“[S]tare decisis commands that ‘precedents of the
court should not be lightly overruled,’ and mere disagreement
with those who preceded us is not enough.” (quoting State v.
Salazar, 173 Ariz. 399, 416 . . . (1992))); State ex re. Woods
v. Cohen, 844 P.2d 1147, 1148 (Ariz. 1993) (referring to “a
healthy respect for stare decisis”); State v. Williker, 491 P.2d
465, 468 (Ariz. 1971) (referring to “a proper respect for the
theory of stare decisis”).

    Consistent with its view of stare decisis, the Arizona
Supreme Court applied its unconstitutional causal nexus test
consistently throughout during the relevant period. We
would hardly expect the Court have done otherwise, given its
view of stare decisis and the causal nexus test. The test was,
of course, premised on a mistaken understanding of Eddings.
The Court corrected its mistake, consistent with its view of
stare decisis under Bateman (“the prior decision was clearly
erroneous or manifestly wrong”), after the United States
Supreme Court emphatically reiterated the Eddings rule in
2004 in Tennard v. Dretke. See State v. Anderson, 111 P.3d
369 (Ariz. 2005). But a mistake is only a mistake. All
courts, even very good courts, make mistakes. A good court,
however, does not apply an established rule erratically,
enforcing it arbitrarily in some cases but not in others. We
have great respect for the Supreme Court of Arizona, whose
institutional integrity is demonstrated, inter alia, by the
56                   MCKINNEY V. RYAN

consistent application of the causal nexus test during the
fifteen-year period it was in effect.

B. Appellate Review and “Unreasonable Determination of
                        Fact”

    Second, the dissent contends that the critical question
before us is whether the Arizona Supreme Court properly
concluded that the sentencing judge “fully considered
McKinney’s PTSD.” Dissent at 82. It further contends that
we must review whether the Court properly so concluded
under the “unreasonable determination of fact” standard of
AEDPA. 28 U.S.C. § 2254(d)(2). According to the dissent,
the Arizona Supreme Court did not unreasonably make the
factual determination that the sentencing judge had “fully
considered McKinney’s PTSD.” Therefore, according to the
dissent, we must uphold the sentencing decision of the
Arizona Supreme Court. The dissent misunderstands both the
significance of the Arizona Supreme Court’s de novo review
in capital cases, and the “unreasonable determination of fact”
standard of review under AEDPA.

    Contrary to the view of the dissent, the Arizona Supreme
Court in reviewing capital sentences does not base its
decision on whether the sentencing judge fully considered
aggravating and mitigating factors. Rather, as we indicated
above, the Arizona Supreme Court reviews capital sentences
de novo, making its own independent determination of what
constitute legally relevant aggravating and mitigating factors,
and then performing an independent weighing of those
factors. In its own words, the Arizona Supreme Court
“conducts a thorough and independent review of the record
and of the aggravating and mitigating evidence to determine
whether the sentence is justified, . . . consider[ing] the quality
                    MCKINNEY V. RYAN                        57

and strength, not simply the number, of aggravating or
mitigating factors.” McKinney, 917 P.2d at 1225.

    Further, and also contrary to the view of the dissent, the
question whether the sentencing judge “fully considered
McKinney’s PTSD” is not a question of “fact” under
§ 2254(d)(2). A “fact” under § 2254(d)(2) is an evidentiary
fact, such as whether a defendant had PTSD or whether a
defendant’s PTSD had a causal nexus to the crime. See, e.g.,
Wood v. Allen, 558 U.S. 290, 850 (2010) (analyzing
evidentiary facts under § 2254(d)(2)). Whether a sentencing
judge fully considered an evidentiary fact is not a “fact”
within the meaning of § 2254(d)(2).

                         Conclusion

    We review the decision of the Arizona Supreme Court, as
the last reasoned state court decision. The Arizona Supreme
Court reviewed McKinney’s death sentence de novo. That
Court accepted the factual conclusion of the trial judge that,
as an evidentiary matter, there was no causal nexus between
McKinney’s PTSD and his crimes. After accepting the
conclusion of the trial judge on this factual point, the Court
went further, noting that, far from contributing to his crimes,
McKinney’s PTSD would have influenced him not to commit
them. The Arizona Supreme Court then recited its
unconstitutional causal nexus test for nonstatutory mitigation,
followed by a pin citation to the page of Ross on which it had
articulated that test two years earlier, making clear that, as
matter of Arizona law, McKinney’s PTSD was not relevant
as a nonstatutory mitigating factor.

    We reverse the district court’s judgment denying the writ
of habeas corpus. We remand with instructions to grant the
58                       MCKINNEY V. RYAN

writ with respect to McKinney’s sentence unless the state,
within a reasonable period, either corrects the constitutional
error in his death sentence or vacates the sentence and
imposes a lesser sentence consistent with law.



BEA, Circuit Judge, dissenting, with whom KOZINSKI,
GOULD, TALLMAN, and CALLAHAN, Circuit Judges,
join:

    A state cannot impose the death penalty unless the
sentencer has considered all evidence submitted as to the
defendant’s condition, character, and background. Eddings v.
Oklahoma, 455 U.S. 104, 113–15 (1982) (explaining that a
sentencer may not “refuse to consider, as a matter of law, any
relevant mitigating evidence”). As a result, defendants so
sentenced usually and legitimately proffer mitigation
evidence provoking sympathy in the hope it will persuade the
sentencer to grant leniency and impose a life sentence instead
of the death penalty. Here, James McKinney submitted
evidence of his squalid, horrid childhood and expert
testimony that, as a result of that childhood, he developed
Post-Traumatic Stress Disorder (“PTSD”). He urged his
PTSD called for mercy for two reasons. First, he argued his
PTSD affected his mental capacity “to appreciate the
wrongfulness of his conduct” at the time of the murders. This
is a statutory mitigation factor under Arizona law.1 Second,
he argued his childhood and childhood-caused PTSD justified
leniency, separate from any effect it may have had on his
mental state at the time of the murders. That second argument


 1
     Ariz. Rev. Stat. § 13-751(G)(1).
                        MCKINNEY V. RYAN                               59

fits under Arizona’s nonstatutory catchall that requires
sentencers to consider all proffered mitigation evidence.2
McKinney admits the sentencing judge, Judge Sheldon,
considered his first argument. But McKinney contends Judge
Sheldon did not consider the mitigating value of his PTSD for
leniency purposes regardless its effect on him at the time of
the murders.

    McKinney pressed this same claim before the Arizona
Supreme Court on direct appeal from the sentence Judge
Sheldon imposed. That court correctly stated what Eddings
requires: “[T]he trial judge must consider any aspect of [a
defendant’s] character or record and any circumstance of the
offense relevant to determining whether a sentence less
severe than the death penalty is appropriate.”3 It then rejected
McKinney’s argument that Judge Sheldon had failed to
consider his PTSD separate from its effect on McKinney’s
mental capacity during the murders: “[T]he record shows that
the judge gave full consideration to McKinney’s childhood
and the expert testimony regarding the effects of that
childhood, specifically the diagnosis of post-traumatic stress
disorder.”4 That conclusion makes sense given Judge Sheldon
expressly stated at McKinney’s sentencing:




     2
     Ariz. Rev. Stat. § 13-751(G) (“The trier of fact shall consider as
mitigating circumstances any factors proffered by the defendant or the
state that are relevant in determining whether to impose a sentence less
than death, including any aspect of the defendant’s character, propensities
or record and any of the circumstances of the offense.”).
 3
     State v. McKinney, 917 P.2d 1214, 1226 (Ariz. 1996).
 4
     Id. at 1234 (emphasis added).
60                       MCKINNEY V. RYAN

          I have considered [McKinney’s arguments] at
          length, and after considering all of the
          mitigating circumstances, the mitigating
          evidence that was presented by the defense in
          this case as against the aggravating
          circumstances, and other matters which
          clearly are not set forth in the statute which
          should be considered by a court, I have
          determined . . . that the mitigating
          circumstances simply are not sufficiently
          substantial to call for leniency under all of the
          facts of this case.

(Emphasis added.)

    Our review of McKinney’s claim must proceed
differently than it did in the Arizona courts on direct appeal.
The Supreme Court has told us we must presume “state courts
know and follow the law.”5 And, in the Eddings context,
“[w]e must assume that the trial judge considered all [the]
evidence before passing sentence.”6 This appeal could be
resolved against McKinney, without the benefit of those
presumptions, simply based on the above quotations from the
record. This appeal presents even fewer problems to decide
under the standard provided by the Antiterrorism and
Effective Death Penalty Act of 1996 (“AEDPA”), which
prescribes “‘a difficult to meet’ and ‘highly deferential
standard for evaluating state-court rulings, [and] which
demands state-court decisions be given the benefit of the



 5
     Woodford v. Visciotti, 537 U.S. 19, 24 (2002).
 6
     Parker v. Dugger, 498 U.S. 308, 314 (1991).
                          MCKINNEY V. RYAN                               61

doubt.’”7 Yet the majority still somehow concludes that,
under the standard of review prescribed by AEDPA, there
was Eddings error in this case.

    The majority starts by incorrectly summarizing the
Arizona Supreme Court’s Eddings jurisprudence between
1989 and 2005 as constituting continuous and recurrent
Eddings error.8 Not so at all, as our own decisions have
repeatedly recognized.9 Based on its incorrect summary of the
Arizona decisions10 and a paean to stare decisis, the majority
then rejects our precedent11 and concludes that we should
never afford the Arizona Supreme Court the presumption that
“state courts know and follow the law” with respect to any of



 7
      Cullen v. Pinholster, 131 S. Ct. 1388, 1398 (2011) (citation omitted).
 8
      Slip op. at 5–7, 26–38.
  9
   See Lopez v. Ryan, 630 F.3d 1198, 1203–04 (9th Cir. 2011) (“Some
cases decided prior to Tennard applied a causal nexus requirement in an
impermissible manner. Other cases, however, properly looked to causal
nexus only as a factor in determining the weight or significance of
mitigating evidence.”); Poyson v. Ryan, 743 F.3d 1185, 1198 (9th Cir.
2013); Towery v. Ryan, 673 F.3d 933, 946 (9th Cir. 2012) (per curiam).
  10
    For a more accurate relation of the relevant Arizona Supreme Court
cases, see infra Section III.B.1.
  11
     See Lopez, 630 F.3d at 1203–04 (“In light of this backdrop, which
highlights a range of treatment of the nexus issue, there is no reason to
infer unconstitutional reasoning from judicial silence. Rather, we must
look to what the record actually says.”); Clabourne v. Ryan, 745 F.3d 362,
372–73 (9th Cir. 2014), petition for rehearing and rehearing en banc
pending, No. 09-99022 (9th Cir. Mar. 18, 2014); Poyson, 743 F.3d at 1198
n.7; Schad v. Ryan, 671 F.3d 708, 723–24 (9th Cir. 2011); Greenway v.
Schriro, 653 F.3d 790, 807–08 (9th Cir. 2011).
62                        MCKINNEY V. RYAN

that court’s Eddings cases.12 Rather, the majority creates a
new and contrary presumption—that the Arizona courts did
not know or follow Eddings between 1989 and 2005—and
finds this presumption is not rebutted even where the Arizona
courts have clearly complied with Eddings’s mandate.13 Of
course, this process is quite contrary to the deferential
standard of review the Supreme Court has told us to use.

     But the majority does not stop there. When the majority
turns to the record in this case, it misreads it. The majority
first suggests that when Judge Sheldon stated there was no
evidence that McKinney’s PTSD “in any way affected his
conduct in this case,” he applied an unconstitutional nexus
test to exclude the PTSD from consideration altogether.14 Not
so. At that portion of the hearing, Judge Sheldon was dealing
with, and rejecting, McKinney’s own argument that his PTSD
impaired his ability “to appreciate the wrongfulness of his
conduct” at the time of the murders. Next, the majority states
the Arizona Supreme Court “recited its unconstitutional
causal nexus test” when it decided McKinney’s appeal.15 The
court did no such thing; if it did state an unconstitutional
nexus test, this case would be simple. Finally, the majority
ignores the Arizona Supreme Court’s careful articulation of
Eddings’s requirements and focuses instead on a single case




 12
      Slip op. at 7.
 13
      See id.
 14
      Id. at 19–21, 42.
 15
      Id. at 21, 44–45, 57.
                         MCKINNEY V. RYAN                         63

citation in the Arizona opinion.16 None of this is permissible
under AEDPA.

    In short, the majority ignores Supreme Court precedent,17
implicitly overrules our own precedent,18 replaces AEDPA’s
deferential standard of review of state-court decisions with an
impermissible de novo standard, and misstates the record
when applying that standard. Also quite troubling, the
majority wrongly smears the Arizona Supreme Court and
calls into question every single death sentence imposed in
Arizona between 1989 and 2005 and our cases which have
denied habeas relief as to those sentences. Finally, the
majority brushes by the facts of McKinney’s gruesome
crimes to find that the error the majority has manufactured
was indeed prejudicial to the outcome of the sentencing,
rather than harmless, in contravention of the prejudice
standard stated in Brecht v. Abrahamson, 507 U.S. 619
(1993).

       I respectfully dissent.

                                    I.

   This case should come down to a review of only a few
pages of the transcript from McKinney’s sentencing, and a
few pages from the Arizona Supreme Court’s decision

 16
      Id.
 17
      Visciotti, 537 U.S. at 22–24; Parker, 498 U.S. at 314–16.
  18
     See Clabourne, 745 F.3d at 372–73, petition for rehearing and
rehearing en banc pending, No. 09-99022 (9th Cir. Mar. 18, 2014);
Poyson, 743 F.3d at 1198 & n.7; Schad, 671 F.3d at 723–24; Greenway,
653 F.3d at 807–08; Lopez, 630 F.3d at 1203–04.
64                      MCKINNEY V. RYAN

affirming his sentence. State v. McKinney, 917 P.2d 1214,
1225–27, 1233–34 (Ariz. 1996). A brief discussion of the
sentencing proceeding and Arizona’s statute governing the
application of the death penalty may help analyze these few
pages.

      A. The Statutory Scheme and McKinney’s Sentencing
                          Arguments

     Arizona law separates mitigating evidence into two
categories, statutory and nonstatutory. There are five statutory
mitigating factors under Arizona’s sentencing statute: mental
capacity, duress, minor participation, reasonable
foreseeability, and age. Ariz. Rev. Stat. § 13-751(G)(1)–(5).19
The nonstatutory category is a catchall that requires the
sentencer to consider “any factors proffered by the defendant
or the state that are relevant in determining whether to impose
a sentence less than death,” id. § 13-751(G), “including any
aspect of the defendant’s character or any circumstances of
the offense relevant to determining whether a capital sentence
is too severe.” State v. White, 982 P.2d 819, 824 (Ariz. 1999).

    McKinney’s sentencing memorandum included 11
separate parts; each argued for leniency for different reasons.
McKinney’s two primary arguments in support of leniency
were based on his troubled childhood and his claimed
resulting PTSD diagnosis. McKinney relied on his PTSD to
make two arguments in support of leniency. First, in Part VIII
of his sentencing memorandum, McKinney argued his PTSD


 19
    Arizona renumbered the statute in 2009, and it is now codified without
any changes at Ariz. Rev. Stat. § 13-751. See, e.g., Robinson v. Schriro,
595 F.3d 1086, 1111 (9th Cir. 2010). This dissent cites to the new location
of the statute.
                    MCKINNEY V. RYAN                        65

warranted leniency based on the statutory mitigation factor
§ 13-751(G)(1) (“Mental Capacity Factor”). The Mental
Capacity Factor requires the court to consider whether “[t]he
defendant’s capacity to appreciate the wrongfulness of his
conduct or to conform his conduct to the requirements of law
was significantly impaired, but not so impaired as to
constitute a defense to prosecution.” Ariz. Rev. Stat.
§ 13-751(G)(1). McKinney argued his PTSD diminished his
capacity to appreciate the wrongfulness of his conduct during
the murders of Christene Mertens and Jim McClain. It must
be kept in mind that it was McKinney who claimed a causal
nexus between his PTSD and his commission of the murders.
So the sentencing judge can hardly be faulted for considering
this as “nexus” evidence.

    Second, in Parts I and VII of his sentencing
memorandum, McKinney argued his PTSD warranted
leniency separate from any effect that PTSD may have had on
him at the time of the murders. This argument did not assert
McKinney’s PTSD played a role in the two murders. Thus, it
did not fall under the statutory Mental Capacity Factor, or any
other specific statutory mitigation factor. See id. § 13-751(G)
(duress, minor participation, reasonable foreseeability, and
age). Instead, it fit under the nonstatutory catchall, quoted
above.

                  B. The PTSD Testimony

     McKinney called Diana McKinney, his sister, Susan
Sesate, his aunt, and Dr. Mickey McMahon, a psychologist,
to testify. The state called Dr. Steven Gray in rebuttal to Dr.
McMahon’s testimony. McKinney’s sister and aunt testified
to the conditions of McKinney’s squalid, harsh childhood. Dr.
66                  MCKINNEY V. RYAN

McMahon opined McKinney’s childhood caused McKinney
to develop PTSD.

    Dr. McMahon testified that McKinney was a “loner” and
not the type of criminal who would engage in “thrill-seeking
behavior,” such as committing a crime for the sake of the
excitement the crime provided. Instead, McKinney’s PTSD
would lead him to avoid confrontations and stressful
situations; and McKinney “tries to respond to [stress] by
withdrawing.” Dr. McMahon agreed that McKinney would
leave a stressful situation to avoid a confrontation if he could
do so.

    Dr. McMahon testified there was a “high likelihood” that
McKinney’s PTSD was triggered during his confrontation
with his first victim, Christene Mertens, and McKinney’s
mental capacity was diminished as a result. With respect to
the McClain robbery and murder, Dr. McMahon admitted, “I
don’t have enough facts to say that [McKinney] was suffering
from diminished capacity.” Dr. McMahon testified that the
murder of McClain in his sleep “would be the exact opposite
of what I would expect from Mr. McKinney.” Those acts
were consistent with someone who seeks out stressful
situations rather than avoids them; it was a contra-indication
to the presence of PTSD.

    The prosecution’s expert, Dr. Gray, did not diagnose
McKinney with PTSD. He did not “think there’s enough
evidence or diagnostic materials or work that’s been done to
conclusively diagnose him as having [PTSD].” His tentative
diagnosis was that McKinney has antisocial personality
disorder. He explained that “[m]ost antisocial people have [a]
major disturbance in thinking, not to be confused with
schizophrenia or psychosis. They tend to, for example blame
                    MCKINNEY V. RYAN                         67

others for their situation.” Dr. Gray noted antisocial people
typically avoid being a victim. Instead, “they want to be an
offender, be in control, be in charge, be powerful even though
the manner in which they do that is self-defeating, unhealthy
and is abusive, harmful to others.” Which is why “people
with antisocial personality have a long history of conflict with
the law.”

    At the conclusion of the evidence, trial judge Sheldon
credited defense expert Dr. McMahon’s testimony that
McKinney had PTSD over Dr. Gray’s contrary opinion. He
found that Dr. McMahon’s opinion was entitled “to more
weight” than Dr. Gray’s testimony. He then adjourned for
three days to consider the evidence before ruling on
McKinney’s sentence.

 C. Judge Sheldon Considers McKinney’s PTSD Evidence

    Judge Sheldon imposed his sentence on July 23, 1993. At
the outset of that hearing, he found the prosecution proved
two aggravating factors for the Mertens murder: In the
language of the statute, McKinney (1) “committed the offense
as consideration for the receipt, or in expectation of the
receipt, of anything of pecuniary value”; and (2) “committed
the offense in an especially heinous, cruel or depraved
manner.” See Ariz. Rev. Stat. § 13-751(F)(5)–(6). No one
disputes the solid footing in the record evidence for finding
both of these aggravating factors. McKinney and Hedlund
killed to get Mertens’s money. And before dispatching
Mertens with a bullet to her head, McKinney and Hedlund
savagely injured her. Judge Sheldon also found the
government proved two aggravating factors for the murder of
Jim McClain: (1) the pecuniary-gain aggravating factor; and
(2) that McKinney was “convicted of another offense in the
68                      MCKINNEY V. RYAN

United States for which under Arizona law a sentence of life
imprisonment or death was imposable,” i.e., the earlier
Mertens murder. See Ariz. Rev. Stat. § 13-751(F)(1), (5).
Again, no one disputes the basis for these findings.
McKinney and Hedlund killed McClain to get McClain’s
money, and McKinney was convicted for the earlier murder
of Mertens.

    Judge Sheldon then addressed McKinney’s mitigation
evidence. Judge Sheldon started by crediting Dr. McMahon’s
testimony twice and accepting Dr. McMahon’s PTSD
diagnosis as true. Judge Sheldon then addressed McKinney’s
nexus argument for leniency under the statutory Mental
Capacity Factor, id. § 13-751(G)(1), which McKinney had
cited in his sentencing memorandum. Judge Sheldon stated
there was no evidence McKinney’s PTSD “in any way
significantly impaired Mr. McKinney’s conduct.” He
repeated that conclusion a second time moments later, where
he concluded there was no evidence that McKinney’s PTSD
“in any way affected his conduct in this case.”20 Judge
Sheldon reached that conclusion based on McKinney’s
planning of the burglaries and statements McKinney made to
witnesses before the burglaries that he would shoot a resident
if he encountered one during the burglaries. Judge Sheldon
noted Dr. McMahon testified that a person suffering from
PTSD would be withdrawn and would “avoid contacts which
would either exacerbate or recreate the trauma that would

 20
    Early in its opinion, the majority admits that this language is directed
to McKinney’s argument for leniency under the statutory Mental Capacity
Factor. Slip op. at 19. The majority nonetheless suggests these statements
also show Judge Sheldon applied an unconstitutional nexus test. Id. at 20,
42. As I discuss in detail below, at this point in the sentencing colloquy,
Judge Sheldon is addressing the statutory mitigating factors and only the
statutory mitigating factors. See infra Section III.A.2.
                      MCKINNEY V. RYAN                           69

bring on this type of stress from childhood.” But McKinney
sought out stressful situations by planning and executing the
burglaries that led to the two murders. Judge Sheldon
concluded leniency was not available based upon the
statutory Mental Capacity Factor, and repeated a third time
his belief that the PTSD did not “significantly impair[]”
McKinney’s conduct.

    This analysis of PTSD under the statutory mitigation
factors did not end Judge Sheldon’s consideration of
McKinney’s PTSD for purposes of mitigation. Judge Sheldon
next transitioned to address “the other mitigating factors
raised by the defense in their memorandum.”21 Those other
mitigation factors included, among others, McKinney’s Part
VII argument for leniency due to his difficult childhood and
his psychological history, including his PTSD. After finding
McKinney’s childhood did not support leniency, Judge
Sheldon concluded: “With respect to the other matters set out
in the [defendant’s sentencing] memorandum, I have
considered them at length, and after considering all of the
mitigating circumstances . . . I have determined that . . . the
mitigating circumstances simply are not sufficiently
substantial to call for a leniency under all of the facts of this
case.” (Emphasis added.) The court then sentenced
McKinney to death for both first-degree murder convictions.

   A week later, Judge Sheldon sentenced McKinney’s
co-defendant, Michael Hedlund, to death.




 21
    This was the 27-page, 11-part sentencing memorandum, which Judge
Sheldon specifically cited by date during his sentencing colloquy.
70                   MCKINNEY V. RYAN

     D. McKinney’s Direct Appeal to the Arizona Supreme
                           Court

    McKinney appealed his sentence. See McKinney,
917 P.2d at 1232–34. The Arizona Supreme Court addressed
both McKinney’s and Hedlund’s sentences together in the
same opinion, taking Hedlund’s first. As is common practice
when a court addresses similar claims in the same opinion,
the Arizona Supreme Court more fully articulated the legal
standard applicable to both when it first addressed Hedlund’s
arguments. Id. at 1225–27. For Hedlund’s Eddings error
argument, the court detailed what Eddings requires:

         Hedlund correctly observes that the trial judge
         must consider any aspect of his character or
         record and any circumstances of the offense
         relevant to determining whether a sentence
         less severe than death is appropriate. In
         considering such material, however, the judge
         has broad discretion to evaluate expert mental
         health evidence and to determine the weight
         and credibility given to it.

Id. at 1226. The court then rejected Hedlund’s argument that
Judge Sheldon failed to consider his mitigation evidence. Id.
at 1226–27.

    The court reached the same conclusion for McKinney’s
Eddings argument: “Here again, the record shows that the
judge gave full consideration to McKinney’s childhood and
the expert testimony regarding the effects of that childhood,
specifically the diagnosis of post-traumatic stress disorder.”
Id. at 1234. The court concluded: “The record clearly shows
that the judge considered McKinney’s abusive childhood and
                     MCKINNEY V. RYAN                         71

its impact on his behavior and ability to conform his conduct
and found it insufficiently mitigating to call for leniency.” Id.
The court held Judge Sheldon did not err and affirmed
McKinney’s sentence. Id.

                               II.

    A. What Eddings v. Oklahoma Requires and What It
                        Prohibits

    Eddings’s command is simple. In Eddings, the trial judge
stated that “in following the law” he could not “consider the
fact of this young man’s violent background” in determining
whether to sentence him to death. Eddings, 455 U.S. at
112–13. The Supreme Court held the trial judge’s refusal to
consider the evidence was unconstitutional under the Eighth
Amendment. Id. at 113–15. “Just as the State may not by
statute preclude the sentencer from considering any
mitigating factor, neither may the sentencer refuse to
consider, as a matter of law, any relevant mitigating
evidence.” Id. at 113–14. Yet the Court made clear that the
sentencer “may determine the weight to be given relevant
mitigating evidence. But [it] may not give it no weight by
excluding such evidence from [its] consideration.” Id. at
114–15. In later cases, the Supreme Court clarified that the
sentencer cannot refuse to consider evidence because that
evidence does not bear a causal nexus to the crime. See, e.g.,
Tennard v. Dretke, 542 U.S. 274, 287 (2004). We have
recognized that the sentencer may consider a “causal
nexus . . . as a factor in determining the weight or
significance of mitigating evidence.” Lopez v. Ryan, 630 F.3d
72                       MCKINNEY V. RYAN

1198, 1204 (9th Cir. 2011) (citing Eddings, 455 U.S. at
114–15).22

                B. The “Last Reasoned Decision”

    AEDPA governs when we review a state’s determination
whether a prisoner’s rights under the federal Constitution
have been violated. See 28 U.S.C. § 2254. Under AEDPA,
our review is confined to the “last reasoned decision” of the
state courts. See Ylst v. Nunnemaker, 501 U.S. 797, 803–04
(1991); Barker v. Fleming, 423 F.3d 1085, 1091 (9th Cir.
2005). The “last reasoned decision” is the most recent
“adjudication on the merits” that “finally resolve[s] the rights
of the parties on the substance of the claim, rather than on the
basis of a procedural or other rule precluding state review of
the merits.” Barker, 423 F.3d at 1092.

   I agree with the majority that the Arizona Supreme
Court’s opinion on direct review is the “last reasoned
decision.” Slip op. at 41. I do not agree with the majority’s


  22
     A sentencer is free to assign whatever weight, including no weight,
that mitigating evidence deserves under the facts of the case, as long as the
sentencer does not exclude from his consideration relevant mitigating
evidence as a matter of law. See, e.g., Towery, 673 F.3d at 945 (“One
could question the wisdom of the Arizona Supreme Court’s decision to
accord Towery’s evidence little or no weight. . . . However, the court’s
reasoned and individualized decision to give Towery’s evidence little or
no weight was not contrary to Supreme Court precedent.”); Allen v. Buss,
558 F.3d 657, 667 (7th Cir. 2009) (“The rule of Eddings is that a
sentencing court may not exclude relevant mitigating evidence. But of
course, a court may choose to give mitigating evidence little or no
weight.” (citation omitted)); United States v. Johnson, 495 F.3d 951, 965
(8th Cir. 2007) (“[J]urors are obliged to consider relevant mitigating
evidence, but are permitted to accord that evidence whatever weight they
choose, including no weight at all.”).
                     MCKINNEY V. RYAN                         73

understanding of that opinion. The majority repeatedly refers
to the Arizona Supreme Court’s review of McKinney’s
sentence as a “de novo review.” See, e.g., id. at 4, 7, 9, 20, 41,
43, 56–57. The Arizona Supreme Court does independently
review each death sentence. See Ariz. Rev. Stat. § 13-755.
But the way it does its “independent review” is first to
conduct a normal appellate review to determine whether the
trial court made any legal errors when it imposed the death
sentence. See id. § 13-755(a)–(b). We owe this finding double
deference under AEDPA. See, e.g., Lopez v. Schriro,
491 F.3d 1029, 1037–38 & n.2 (9th Cir. 2007). After the
Arizona Supreme Court reviews for legal errors, it then
decides whether the death sentence is justified. See Ariz. Rev.
Stat. § 13-755(a)–(b); State v. Roseberry, 353 P.3d 847,
849–50 (Ariz. 2015) (“[T]his Court reviews the entire record
and independently considers whether a capital sentence is not
only legally correct, but also appropriate.”). Based on its own
incorrect notion of what “independent review” means in
Arizona practice, the majority converts this appellate review
of death sentences into a new sentencing determination and
treats McKinney’s trial-court sentencing hearing as irrelevant,
except insofar as the Arizona Supreme Court accepted Judge
Sheldon’s factual findings as its own. Slip op. at 21, 41–45.

    Although at times we construe an appellate court’s
decision and a trial court’s decision together as the “last
reasoned decision,” we do so only when the appellate court
adopts the trial court’s decision. See, e.g., Barker, 423 F.3d
at 1093. That is not what occurred here. The Arizona
Supreme Court did not, as the majority posits, accept any of
Judge Sheldon’s factual findings as its own. See slip op. at 21,
41–45; McKinney, 917 P.2d at 1233–34. The court merely
reviewed McKinney’s argument that Judge Sheldon failed to
consider McKinney’s mitigation evidence and concluded,
74                     MCKINNEY V. RYAN

“On this record there was no error.” McKinney, 917 P.2d at
1234. It also “independently reviewed the record,” as it was
required to do under Arizona law, and affirmed McKinney’s
death sentence. Id.; see also id. at 1225 (explaining the
Arizona procedure for reviewing death sentences on direct
appeal). For that reason, the Arizona Supreme Court’s
opinion is the “last reasoned decision.” See Towery v. Ryan,
673 F.3d 933, 944 n.3 (9th Cir. 2012) (per curiam) (refusing
the petitioner’s suggestion to “review the decisions of the
sentencing court and the [Arizona Supreme Court]
together”).23

                C. AEDPA’s Deferential Review

    The standard by which federal courts must review
state-court decisions under AEDPA is well known, if not
always well followed. See 28 U.S.C. § 2254(d). Under
§ 2254(d)(1), a federal court can issue a writ of habeas corpus
only if the state court’s decision “was contrary to, or involved
an unreasonable application of, clearly established Federal
law, as determined by the Supreme Court of the United
States.” Id. § 2254(d)(1). Under § 2254(d)(2), a federal court
can issue the writ only if the state court’s decision “was based
on an unreasonable determination of the facts in light of the
evidence presented in the State court proceeding.” Id.
§ 2254(d)(2).




 23
    The majority’s error in reviewing Judge Sheldon’s colloquy as part of
the “last reasoned decision” makes no difference. To dispel any doubts,
as I explain below, the record shows both the Arizona Supreme Court and
Judge Sheldon complied with Eddings even under a de novo
review—which is the wrong standard under AEDPA. See infra Section III.
                        MCKINNEY V. RYAN                                75

    We apply the “contrary to” prong of § 2254(d)(1) where,
as here, the parties dispute whether a state appellate court
applied the correct standard. See Woodford v. Visciotti,
537 U.S. 19, 22–24 (2002) (applying § 2254(d)(1) where the
parties disputed whether the California Supreme Court
applied the correct standard under Strickland). In this case, I
apply § 2254(d)(1) when analyzing whether the Arizona
Supreme Court used an unconstitutional nexus test in its
review of McKinney’s sentence.

     The question whether a trial judge has considered all the
proffered mitigation evidence is a factual question, not a legal
one. See Lopez, 491 F.3d at 1037–38 & n.2. And a state
appellate court’s finding that the trial judge considered all the
proffered mitigation evidence is itself a factual finding. See
id.; see also Parker v. Dugger, 498 U.S. 308, 320 (1991). As
a result, I apply § 2254(d)(2) to the Arizona Supreme Court’s
finding that Judge Sheldon considered all of McKinney’s
mitigation evidence, which can be overturned only if it was
“unreasonable.” See Towery, 673 F.3d at 945 n.4; Lopez,
491 F.3d at 1037–38 & n.2. Judge Sheldon’s sentencing
colloquy is relevant only for making that determination.24



 24
    The majority’s faulty understanding of the Arizona Supreme Court’s
opinion leads it to conclude that I am wrong to apply § 2254(d)(2) in this
case. Slip op. at 56–57. We previously used § 2254(d)(2) in habeas review
of Arizona death sentences, see Towery, 673 F.3d at 945 n.4; Lopez,
491 F.3d at 1037–38 & n.2, as did Judge Wardlaw—who joins the
majority opinion—in her partial dissent to the original panel opinion in
this case, see McKinney v. Ryan, 730 F.3d 903, 925–27 (9th Cir. 2013)
(Wardlaw, J., dissenting in part). The majority’s disagreement on this
point creates a circuit split with at least two other circuits. See Corcoran
v. Neal, 783 F.3d 676, 685–87 (7th Cir. 2015); Quince v. Crosby, 360 F.3d
1259, 1267 (11th Cir. 2004).
76                       MCKINNEY V. RYAN

                                    III.

    I begin by evaluating McKinney’s appeal under the
correct standard.25 That standard requires that we first
determine whether the Arizona Supreme Court’s decision was
“contrary to . . . clearly established Federal law” under
§ 2254(d)(1). Applied here, we must determine whether the
Arizona Supreme Court treated McKinney’s PTSD as
irrelevant to consider whether leniency was justified, because
McKinney did not show the PTSD affected his conduct at the
time of the murders. If the Arizona Supreme Court treated the
PTSD as mitigation evidence relevant to whether leniency
was justified, we must then determine whether the Arizona
Supreme Court’s conclusion that Judge Sheldon fully
considered McKinney’s PTSD was an “unreasonable
determination of fact” under § 2254(d)(2).

 A. The Correct Analysis of the Arizona Supreme Court’s
                        Decision

                                     1.

    This case primarily boils down to what standard the
Arizona Supreme Court applied when addressing McKinney’s
Eddings claim. “A decision is contrary to clearly established
law if the state court ‘applies a rule that contradicts the
governing law set forth in [Supreme Court] cases.’” Lafler v.
Cooper, 132 S. Ct. 1376, 1390 (2012) (citation omitted);
Frantz v. Hazey, 533 F.3d 724, 734 (9th Cir. 2008) (en banc)
(“[U]se of the wrong legal rule or framework . . . constitute[s]
error under the ‘contrary to’ prong of § 2254(d)(1).”). The

  25
     The majority’s incorrect standard is dealt with later. See infra Section
III.B.
                       MCKINNEY V. RYAN                             77

state argues the Arizona Supreme Court correctly applied
Eddings; McKinney argues the Arizona Supreme Court
applied a “nexus” standard to exclude his PTSD from
consideration contrary to Eddings.

    The Supreme Court’s decision in Visciotti governs our
analysis under the “contrary to” prong of § 2254(d)(1). See
Visciotti, 537 U.S. at 22–24. In Visciotti, the petitioner argued
the California Supreme Court applied the wrong standard for
what constitutes prejudicial error under Strickland. Id. To
prove such prejudice under Strickland, “the defendant must
establish a ‘reasonable probability that, but for counsel’s
unprofessional errors, the result of the proceeding would have
been different.’” Id. at 22 (quoting Strickland v. Washington,
466 U.S. 668, 694 (1984)). In its opinion, the California
Supreme Court began its Strickland analysis by twice stating
the correct standard: “reasonable probability.” Id. at 22–23.
The opinion then misstated the “prejudice” standard four
times in other portions of the opinion because it used the term
“probable” instead of “reasonably probable.” Id. at 23.26
Relying on the misstatements, we found the California
Supreme Court applied the incorrect standard. Id. at 23–24.
The decision was therefore “contrary to” Strickland under
§ 2254(d)(1). Id.

    In a per curiam opinion, and without the benefit of merits
briefing or oral argument, the Supreme Court reversed our
judgment. Id. at 22–24. The Court chided us for
mischaracterizing the California Supreme Court’s decision,


  26
     Petitioner Visciotti made the point that the “reasonably probable”
standard was an easier standard of proof for him to meet than the plain
“probable.” Visciotti v. Woodford, 288 F.3d 1097, 1108–09 (9th Cir.
2002).
78                  MCKINNEY V. RYAN

“which expressed and applied the proper standard for
evaluating prejudice.” Id. at 22. Our “readiness to attribute
error [was] inconsistent with the presumption that state courts
know and follow the law.” Id. at 24 (citing Parker, 498 U.S.
at 314–16 (1991)). Our “readiness to attribute error” was
“also incompatible with § 2254(d)’s ‘highly deferential
standard for evaluating state-court rulings,’ which demands
that state-court decisions be given the benefit of the doubt.”
Id. (quoting Lindh v. Murphy, 521 U.S. 320, 333 n.7 (1997)).

    Visciotti’s teaching is not complicated. When we review
a state-appellate-court decision under the “contrary to” prong
of § 2254(d)(1), we must presume the state court knew and
followed federal constitutional law. Id. And we must give the
court the “benefit of the doubt.” Id. For that reason, we must
construe any ambiguity in language in the state court’s favor.
As applied to Eddings cases, when the state court identifies
and articulates the correct Eddings standard, we must
presume it applied that standard. That presumption can be
rebutted by any action by the state court that shows the state
court excluded the defendant’s mitigation evidence as a
matter of law. The easiest way to rebut the presumption
would be an express statement from the state court that it was
excluding evidence from consideration as a matter of law,
such as the trial judge’s statements in Eddings itself. See
Eddings, 455 U.S. at 112–13. However, that is not the only
way to rebut the presumption. If the state court’s reasoning
shows, without any ambiguity, that it did not consider
relevant mitigation evidence at all, that would suffice to rebut
the presumption. Any less deferential review rejects the
presumption that Visciotti requires. This is the analysis that
should replace our “clear indication” test for Eddings cases.
See, e.g., Schad v. Ryan, 671 F.3d 708, 724 (9th Cir. 2011)
(“Absent a clear indication in the record that the state court
                    MCKINNEY V. RYAN                        79

applied the wrong standard, we cannot assume the courts
violated Eddings’s constitutional mandates.”).

    Applying Visciotti to this case is quick work. At no point
did the Arizona Supreme Court state either that Judge
Sheldon had excluded McKinney’s PTSD evidence as a
matter of law, or that it would have been permissible to do so,
under Arizona’s nonstatutory catchall because the PTSD bore
no nexus to the crime. Nor did the Arizona Supreme Court
treat that evidence as if it had no weight as a matter of law.
That should be the end of the matter and of McKinney’s
appeal. All the majority and McKinney do is speculate that,
regardless what it stated, the Arizona Supreme Court applied
a nexus test to conclude the PTSD evidence was irrelevant
under the nonstatutory catchall. Visciotti prohibits such
speculation.

   But let us make a closer inquiry anyway to quell any
doubts raised by the majority’s flank attack on the Arizona
Supreme Court’s decision. That court first outlined the
Eddings standard when, in its combined review of Hedlund’s
and McKinney’s sentences, it stated:

       Hedlund correctly observes that the trial judge
       must consider any aspect of his character or
       record and any circumstance of the offense
       relevant to determining whether a sentence
       less severe than the death penalty is
       appropriate. In considering such material,
       however, the judge has broad discretion to
       evaluate expert mental health evidence and to
       determine the weight and credibility given to
       it.
80                  MCKINNEY V. RYAN

McKinney, 917 P.2d at 1226 (emphasis added). This is what
Eddings requires and all that it requires. See Harris v.
Alabama, 513 U.S. 504, 512 (1995) (“[T]he Constitution does
not require a State to ascribe any specific weight to particular
factors, either in aggravation or mitigation, to be considered
by the sentencer.”). The Arizona Supreme Court then
confirmed it knew the difference between excluding
mitigation evidence altogether as a matter of law (Eddings
error) and giving mitigation evidence little or no weight as a
matter of fact (permissible under Eddings and Harris). See
McKinney, 917 P.2d at 1231 (noting that Judge Sheldon “did
not improperly exclude mitigating evidence at sentencing and
the mitigating evidence is not of great weight”).

   The Arizona Supreme Court then found Judge Sheldon
complied with Eddings in McKinney’s case:

           Here again, the record shows that the
       judge gave full consideration to McKinney’s
       childhood and the expert testimony regarding
       the effects of that childhood, specifically the
       diagnosis of post-traumatic stress disorder
       (PTSD).

Id. at 1234 (emphasis added). The court continued:

       [A] difficult family background, including
       childhood abuse, does not necessarily have
       substantial mitigating weight absent a
       showing that it significantly affected or
       impacted the defendant’s ability to perceive,
       comprehend, or control his actions.
                    MCKINNEY V. RYAN                         81

Id. (emphasis added). In other words, when a difficult
background does affect the “defendant’s ability to perceive,
comprehend, or control his actions,” it has “substantial
mitigating weight.” When there is no such effect, the
evidence does not necessarily have substantial mitigating
weight, but it can have such weight. That is up to the
sentencer’s discretion.

    The best McKinney can do is point to the Arizona
Supreme Court’s citation to State v. Ross, 886 P.2d 1354
(Ariz. 1994), which is a case where that court did indeed
misapply Eddings. But that single citation is insufficient to
rebut the presumption that the court knew and followed
Eddings. In Visciotti, the California Supreme Court misstated
the Strickland prejudice standard four times after stating it
correctly. Visciotti, 537 U.S. at 22–24. If actually misstating
the standard four times is insufficient to rebut the
presumption that the state court applied the correct standard
(Visciotti), then the lesser sin of citing a suspect case cannot
overcome the court’s correct statement of the law and the
presumption it applied that law (McKinney). That is why we
have previously held a single citation cannot be a basis for
finding Eddings error on AEDPA review. See Towery,
673 F.3d at 946. Indeed, a prior en banc panel of this court
rejected this exact argument in the less deferential,
pre-AEDPA context. See Jeffers v. Lewis, 38 F.3d 411, 415
(9th Cir. 1994) (en banc). As a result, we must conclude the
Arizona Supreme Court’s decision was not “contrary to . . .
clearly established Federal law.”

                              2.

   I turn to the Arizona Supreme Court’s conclusion that
Judge Sheldon fully considered McKinney’s PTSD. That is
82                   MCKINNEY V. RYAN

a conclusion we review to determine whether it was an
“unreasonable determination of fact” under § 2254(d)(2). See
Lopez, 491 F.3d at 1037–38 & n.2. We are barred from
characterizing the Arizona Supreme Court’s “factual
determination[] as unreasonable ‘merely because we would
have reached a different conclusion in the first instance.’”
Brumfield v. Cain, 135 S. Ct. 2269, 2277 (2015) (citation
omitted). “Instead, § 2254(d)(2) requires that we accord the
state . . . court substantial deference.” Id. “State-court factual
findings . . . are presumed correct; the petitioner has the
burden of rebutting the presumption by ‘clear and convincing
evidence.’” Davis v. Ayala, 135 S. Ct. 2187, 2199–2200
(2015) (citation omitted). If “‘reasonable minds reviewing the
record might disagree’ about the finding in question, ‘on
habeas review that does not suffice to supersede the [state
court’s] determination.’” Brumfield, 135 S. Ct. at 2277
(citation omitted).

     It requires no strenuous effort to conclude that Judge
Sheldon fully considered McKinney’s PTSD. First, unlike the
trial court judge in Eddings, at no point did Judge Sheldon
state he was excluding the PTSD from consideration under
the nonstatutory catchall as a matter of law because the PTSD
had no effect on McKinney’s criminal conduct. Quite the
opposite. Before sentencing McKinney, Judge Sheldon stated
he “consider[ed] all of the mitigating circumstances.” That
alone should preclude us from concluding the Arizona
Supreme Court’s finding was an “unreasonable determination
of fact.”

    But even were we to indulge in de novo review of the
record, that review confirms that Judge Sheldon fully
considered McKinney’s PTSD. Judge Sheldon’s discussion
of McKinney’s mitigation arguments proceeded in three
                   MCKINNEY V. RYAN                       83

steps. First, at pages 26 to 28 of the sentencing transcript,
Judge Sheldon discussed the mitigation evidence McKinney
proffered, specifically citing McKinney’s sentencing
memorandum by date. Second, at pages 28 to 31, Judge
Sheldon addressed four statutory mitigating factors in Ariz.
Rev. Stat. § 13-751(G), including McKinney’s argument,
under § 13-751(G)(1), that his PTSD affected his mental state
at the time of the murders. Third, at pages 31 to 32, Judge
Sheldon addressed the nonstatutory mitigating factors
McKinney raised in his sentencing memorandum, including
McKinney’s argument for leniency under the nonstatutory
catchall due to his PTSD separate from its effect on his
mental state at the time of the murders.

   That chronology proceeded as follows:

   •   At the conclusion of the evidentiary hearing, Judge
       Sheldon credited Dr. McMahon’s testimony: “I do
       believe that for purposes of this hearing that some
       evidence of [McKinney’s] possible manifestations of
       Post-traumatic Stress Syndrome were demonstrated
       by the testimony of Dr. McMahon. And I’ll just—I
       don’t know that I find it an overwhelmingly
       persuasive mitigating factor, but I will tell you that
       I’m, more inclined to believe that than Dr. Gray’s
       determination that there is not enough evidence to
       assume that there is Post-traumatic Stress Syndrome.”
       Judge Sheldon later stated Dr. McMahon’s PTSD
       diagnosis was entitled “to more weight under the
       circumstances of this case.”

   •   Judge Sheldon began his discussion of McKinney’s
       mitigation evidence at the sentencing hearing by
       stating, “I have considered all the exhibits admitted
84                      MCKINNEY V. RYAN

         into evidence, Numbers 1 through 8.” At least one of
         those exhibits dealt with PTSD and its effects.27

     •   Judge Sheldon again credited defense witness Dr.
         McMahon’s testimony: “[I]t appears, and I believe
         that the statements made [about McKinney’s
         childhood], both by Dr. McMahon and made by the
         witnesses at the time they were testifying, were
         truthful, and I did take them into consideration in this
         case.” (Emphasis added.)

     •   Judge Sheldon then credited Dr. McMahon’s
         testimony that McKinney’s childhood led him to
         develop PTSD: “For whatever reasons, some of which
         I believe were due to the traumatic circumstances that
         he grew up in and the circumstances which were
         testified to by the witnesses during the mitigation
         hearing, the circumstances of child abuse, which I
         accept as true for purposes of this hearing, I think
         manifest the causal factors linked to Post-traumatic
         Stress Syndrome as testified to by Dr. McMahon.”

After discussing an exhibit the defense proffered, Judge
Sheldon turned to the statutory mitigation factors under Ariz.
Rev. Stat. § 13-751(G). He first addressed McKinney’s
primary argument, contained in Part VIII of his sentencing
memorandum, that McKinney was entitled to leniency under
the statutory Mental Capacity Factor, § 13-751(G)(1) because
his PTSD affected him at the time of the murders:




  27
     The exhibits are not in the parties’ excerpts of record, but they are
discussed during the sentencing hearing.
                   MCKINNEY V. RYAN                       85

   •   Judge Sheldon began: “[I]t appeared to me that Dr.
       McMahon did not at any time suggest in his
       testimony nor did I find any credible evidence to
       suggest that, even if the diagnosis of Post-traumatic
       Stress Syndrome were accurate in Mr. McKinney’s
       case, that in any way significantly impaired Mr.
       McKinney’s conduct.” Judge Sheldon repeated that
       conclusion a page later: “[A]nd it appeared to me that
       based upon all these circumstances that there simply
       was no substantial reason to believe that even if the
       trauma that Mr. McKinney had suffered in childhood
       had contributed to an appropriate diagnosis of
       Post-traumatic Stress Syndrome that it in any way
       affected his conduct in this case.”

   •   Judge Sheldon explained why he believed the PTSD
       did not affect McKinney’s state of mind at the time of
       the murders. Namely, McKinney’s pre-planning of
       the burglaries and homicides was inconsistent with
       Dr. McMahon’s testimony that PTSD would cause
       McKinney to avoid confrontation rather than seek it
       out.

   •   Judge Sheldon then concluded leniency was not
       available under the Mental Capacity Factor,
       § 13-751(G)(1), again repeating his belief that the
       PTSD did not “significantly impair[]” McKinney at
       the time of the murders.

Judge Sheldon then addressed, and rejected, the other
statutory mitigation factors.

   Finally, Judge Sheldon turned to McKinney’s
nonstatutory mitigation factors. McKinney’s sentencing
86                   MCKINNEY V. RYAN

memorandum argued in two separate parts (Parts I and VII)
that McKinney was entitled to leniency for his PTSD separate
from any effect the PTSD had on his state of mind during the
murders. Part I of the memorandum was titled: “Evidence of
a Difficult Family History: Eddings v. Oklahoma, supra.” In
Part I, McKinney mentioned the childhood-caused PTSD as
a mitigating factor along with his difficult childhood. The
title’s citation to Eddings v. Oklahoma brought front and
center the constitutional requirement that the PTSD diagnosis
be considered without restriction. Part VII of the
memorandum was titled: “Psychological History.” There,
McKinney explained Dr. McMahon’s PTSD diagnosis and
stated: “Defendant submits that his psychological background
is mitigating.” Judge Sheldon made clear he considered both
of these sections:

     •   Judge Sheldon started: “With respect to the other
         mitigating factors raised by the defense in their
         memorandum, defendant’s mitigating memorandum
         received by this Court July 15th, 1993, I have had an
         opportunity to review that memorandum.” Judge
         Sheldon then rejected the Part I argument that
         McKinney’s childhood warranted leniency.

     •   Judge Sheldon then addressed the remaining
         arguments McKinney made, which included Part
         VII’s argument that McKinney’s PTSD warranted
         leniency: “With respect to the other matters set out in
         the memorandum, I have considered them at length,
         and after considering all of the mitigating
         circumstances, the mitigating evidence that was
         presented by the defense in this case as against the
         aggravating circumstances, and other matters which
         clearly are not set forth in the statute which should be
                        MCKINNEY V. RYAN                                87

         considered by the court, I have determined that . . .
         the mitigating circumstances simply are not
         sufficiently substantial to call for leniency under all of
         the facts of this case.” (Emphasis added.)28

    As the sentencing transcript shows, Judge Sheldon
considered “at length” McKinney’s sentencing
memorandum’s arguments that his PTSD diagnosis warranted
leniency without any reference to PTSD’s possible effect on
his mental capacity during the murders. And Judge Sheldon
found the PTSD did not carry enough mitigating weight “to
call for leniency.” When combined with Judge Sheldon’s
prior crediting of Dr. McMahon’s testimony as to the PTSD
diagnosis, the only conclusion to reach is that Judge Sheldon
complied with Eddings. Even were there an ambiguity in
Judge Sheldon’s statements (there isn’t), the Supreme Court
has admonished that “[w]e must assume that the trial judge
considered all this evidence before passing sentence. For one
thing, he said he did.” Parker, 498 U.S. at 314.29



   28
      It was only in Part VIII of the sentencing memorandum that
McKinney argued the causal relationship—“nexus”—between his PTSD
and his criminal conduct.
  29
     Nor was McKinney entitled to a “specific listing and discussion of
each piece of mitigating evidence under federal constitutional law.” See
Jeffers, 38 F.3d at 418 (“While ‘it is important that the record on appeal
disclose to the reviewing court the considerations which motivated the
death sentence,’ ‘due process does not require that the sentencer
exhaustively document its analysis of each mitigating factor as long as a
reviewing federal court can discern from the record that the state court did
indeed consider all mitigating evidence offered by the defendant.’”
(citation omitted) (quoting Gardner v. Florida, 430 U.S. 349, 361 (1977)
(plurality opinion); Jeffries v. Blodgett, 5 F.3d 1180, 1197 (9th Cir.
1993))).
88                      MCKINNEY V. RYAN

    In short, the Arizona Supreme Court’s conclusion that
Judge Sheldon properly considered all of McKinney’s
mitigation evidence was not an “unreasonable determination
of fact.” In fact, it was the correct conclusion.30

               B. The Majority’s Flawed Analysis

    Perhaps because the Arizona Supreme Court was explicit
in its compliance with Eddings, the majority takes a very
different course to conclude McKinney’s death sentence is
invalid. The majority opinion proceeds in essentially two
steps. First, it falsely paints the Arizona Supreme Court as a
habitual violator of Eddings between 1989 and 2005. Based
on that false assertion, the majority concludes the Visciotti
presumption is automatically rebutted in this case and every
other Eddings case coming out of Arizona within that time
period. Slip op. at 7. In its place, the majority suggests the
presumption is flipped and engages in a sort of de novo


  30
     McKinney also argues the Arizona Supreme Court and Judge Sheldon
failed to consider his horrific childhood in violation of Eddings. The
majority does not address that claim, but the record makes clear that Judge
Sheldon considered that evidence too. He listened to lengthy testimony
about it; he mentioned it several times in his colloquy; and he expressly
stated: “I agree that there was evidence of a difficult family history by the
defendant. However, as I’ve indicated, I do not find that is a substantial
mitigating factor or that there was any evidence that linked that in any
way to demonstrate that . . . somehow significantly impaired the
defendant’s capacity to understand the wrongfulness of his conduct.”
(Emphasis added.) Just like the PTSD evidence, Judge Sheldon considered
McKinney’s childhood both as to its effect on McKinney at the time of the
crimes and independently from any effect it may have had. The Arizona
Supreme Court confirmed Judge Sheldon properly considered that
evidence: “[T]he record shows that the judge gave full consideration to
McKinney’s childhood and the expert testimony regarding the effects of
that childhood.” McKinney, 917 P.2d at 1234.
                    MCKINNEY V. RYAN                        89

review to see if Arizona has rebutted the presumption it
violated Eddings, with the burden of proof as to Eddings
compliance on the Arizona courts. Id. at 41–45, 50–54.
Second, the majority relies on a misreading of Judge
Sheldon’s sentencing colloquy and the Arizona Supreme
Court opinion to conclude the Arizona Supreme Court
violated Eddings despite that court’s correct articulation of
Eddings’s requirements. Id. I take each mistake in turn.

                              1.

    The majority begins by acknowledging we are required to
presume state courts know and follow the law. Id. at 7. But it
concludes we should not afford the presumption in any
Arizona Eddings case because the Arizona Supreme
Court—like common-law courts generally—adheres to the
principle of stare decisis and “applied its unconstitutional
causal nexus test consistently throughout . . . the relevant
period.” Id. at 6–7, 55–56. Though such a presumption is
“appropriate in the great majority of habeas cases,” the
majority posits, “the presumption is rebutted here where we
know, based on its own words, that the Arizona Supreme
Court did not ‘know and follow’ federal law.” Id. at 7. In
other words, the majority relies on other Arizona Supreme
Court cases to conclude the Arizona Supreme Court in this
case is afforded no deference under AEDPA. Even if AEDPA
permitted this type of analysis (it doesn’t, and the majority
cites no case in support of it), the analysis is based on a false
premise. The Arizona courts did not consistently misapply
Eddings.

    The majority asserts that Arizona cases show a uniform
error between 1989 and 2005. Id. at 26–38, 50–56. To see that
assertion is wrong, one need look no further than a case the
90                 MCKINNEY V. RYAN

Arizona Supreme Court decided a mere six weeks after it
decided McKinney’s appeal and squarely within that time
period. See State v. Towery, 920 P.2d 290 (Ariz. 1996).
There, the court cited to Eddings and its progeny for the
proposition that “[t]he sentencer . . . must consider the
defendant’s upbringing if proffered but is not required to give
it significant mitigating weight. How much weight should be
given proffered mitigating factors is a matter within the sound
discretion of the sentencing judge.” Id. at 311 (applying
Penry v. Lynaugh, 492 U.S. 302, 319 (1989) (emphasis
added)). The Arizona Supreme Court rejected defendant
Towery’s argument that the trial judge failed to comply with
Eddings when he considered Towery’s background and “gave
it little or no mitigating value.” Id. And, on habeas review of
Towery, we concluded the Arizona Supreme Court complied
with Eddings when it affirmed Towery’s sentence. Towery,
673 F.3d at 944–46. In another case decided the same year as
McKinney’s appeal, the Arizona Supreme Court found the
defendant’s diagnosis of antisocial personality disorder to be
a mitigating circumstance even though it did not find a nexus
between that mental illness and the defendant’s crime. State
v. Thornton, 929 P.2d 676, 685–86 (Ariz. 1996) (“We agree
with the trial court that Thornton’s childhood, dysfunctional
family, and personality disorder are mitigating factors.”).

    But Towery and Thornton are no outliers. A case decided
a year before McKinney’s appeal was decided, see State v.
Gonzales, 892 P.2d 838, 851 (Ariz. 1995) (applying Eddings),
and a case decided a year after it, see State v. Trostle,
951 P.2d 869, 885–86 (Ariz. 1997) (applying Lockett,
Eddings’s precursor), confirm the Arizona Supreme Court
knew how to apply Eddings correctly. Moreover, the Arizona
Supreme Court relied on non-nexus mitigation evidence to
vacate death sentences during the majority’s chosen time
                        MCKINNEY V. RYAN                                91

period, a fact our court has already recognized. See Lopez,
630 F.3d at 1203–04 (collecting cases for the proposition that
“the Arizona Supreme Court expressly took mitigating
evidence into consideration when reducing a death sentence
to life, regardless of any causal nexus to the crime”
(emphasis added)).

    Still, the majority would have us believe the Arizona
Supreme Court usually applied an unconstitutional nexus test.
It provides a long string citation in an attempt to prove its
point. Slip op. at 32–34. But the Arizona Supreme Court did
not even apply an invalid nexus test in many of the cases the
majority cites. The majority cites two cases where we have
already held on habeas review that the Arizona Supreme
Court did not commit Eddings error.31 Indeed, as the majority
recognizes, we have found there was no Eddings error in six
additional cases during the relevant time period.32 Id. at
38–39. The majority cites other cases where a federal district
court has held there was no Eddings error and appeal is




 31
   See State v. Towery, 920 P.2d 290, 310–11 (Ariz. 1996), habeas relief
denied in Towery, 673 F.3d at 944–47; State v. Stokley, 898 P.2d 454, 473
(Ariz. 1995), habeas relief denied in part in Stokley v. Ryan, 705 F.3d 401,
404 (9th Cir. 2012) (explaining that “on balance, the Arizona Supreme
Court’s opinion suggests that the court did weigh and consider all the
evidence presented in mitigation at sentencing”).
  32
     Hedlund v. Ryan, 750 F.3d 793, 818 (9th Cir. 2014); Murray v.
Schriro, 746 F.3d 418, 455 (9th Cir. 2014); Clabourne, 745 F.3d at
371–74, petition for rehearing and rehearing en banc pending, No. 09-
99022 (9th Cir. Mar. 18, 2014); Poyson, 743 F.3d at 1196–1200; Schad,
671 F.3d at 722–26; Lopez, 630 F.3d at 1203–04.
92                     MCKINNEY V. RYAN

pending.33 Id. at 33–34. The majority also cites cases as
examples of Eddings error where the Arizona Supreme Court
gave little weight to mitigation evidence because there was no
nexus between that evidence and the murder.34 Id. at 33. But
giving little or no weight to such evidence as a factual matter
is perfectly permissible under Eddings. See, e.g., Lopez, 630
F.3d at 1204. Finally, the two cases upon which the majority
most heavily relies, State v. Djerf, 959 P.2d 1274 (Ariz.
1998), and State v. Hoskins, 14 P.3d 997 (Ariz. 2000), came
years after the Arizona Supreme Court affirmed McKinney’s
sentence. See slip op. at 29–32.

    A close review of the majority’s string cite shows that, at
worst, the Arizona Supreme Court sometimes misapplied
Eddings in the years before that court affirmed McKinney’s
sentence. See, e.g., Ross, 886 P.2d at 1363; State v. Wallace,
773 P.2d 983, 986 (Ariz. 1989). It is for that reason that we
have always rejected the majority’s conclusion that the
Arizona Supreme Court consistently applied an




 33
   See State v. Martinez, 999 P.2d 795 (Ariz. 2000), habeas relief denied
in Martinez v. Schriro, No. CV-05-1561-PHX-EHC, 2008 WL 783355, at
*33 (D. Ariz. Mar. 20, 2008), appeal pending sub nom. Martinez v. Ryan,
No. 08-99009 (9th Cir. May 29, 2008); State v. Rienhardt, 951 P.2d 454
(Ariz. 1997), habeas relief denied in Rienhardt v. Ryan, 669 F. Supp. 2d
1038, 1059–60 (D. Ariz. 2009), appeal pending, No. 10-99000 (9th Cir.
Jan. 8, 2010).
  34
     State v. Jones, 917 P.2d 200, 219 (Ariz. 1996) (“A difficult family
background is not necessarily a mitigating circumstance unless defendant
can show that something in his background had an effect on his behavior
that was beyond his control.” (emphasis added)); State v. Bible, 858 P.2d
1152, 1209 (Ariz. 1993) (“In sum, our independent review of the record
shows no significant mitigating evidence.” (emphasis added)).
                        MCKINNEY V. RYAN                              93

unconstitutional nexus test during this time period.35 As a
result, we have always rejected the argument that the Arizona
Supreme Court’s prior mistakes in this area are relevant to the
decision before us.36 In fact, we have specifically rejected the
argument that the Arizona Supreme Court is not entitled to
the Visciotti presumption in Eddings cases. See Poyson v.
Ryan, 743 F.3d 1185, 1198 (9th Cir. 2013). The majority
today overrules these precedents sub silentio, and concludes
Arizona is not entitled to the Visciotti presumption because
Arizona has on occasion misapplied Eddings before.

    The majority’s response to the cases involving Eddings
compliance reveals its view of the Arizona courts: No matter
what the Arizona courts say, they never really considered all
of the mitigation evidence. See slip op. at 50–56. For
example, we previously held in Lopez that Arizona complied
with Eddings during this time period and relied in part on
three cases for that conclusion. See Lopez, 630 F.3d at 1204
n.4 (citing State v. Trostle, 951 P.2d 869 (Ariz. 1997); State
v. Mann, 934 P.2d 784 (Ariz. 1997); State v. Medrano,
914 P.2d 225 (Ariz. 1996)). The majority gets around those
cases by disregarding the parts of the cases that show the
Arizona Supreme Court quite understood and applied


  35
    See Poyson, 743 F.3d at 1198; Towery, 673 F.3d at 946; Lopez,
630 F.3d at 1203–04.
  36
     See Poyson, 743 F.3d at 1198 n.7 (“We reject the suggestion that
because other Arizona cases may have involved causal nexus error we
should presume that this case did as well.”); see also Clabourne, 745 F.3d
at 372–73, petition for rehearing and rehearing en banc pending, No. 09-
99022 (9th Cir. Mar. 18, 2014); Schad, 671 F.3d at 723–24 (finding the
Arizona Supreme Court did not apply an unconstitutional nexus test in an
opinion filed eight months after the court’s Wallace decision); Greenway,
653 F.3d at 807–08; Lopez, 630 F.3d at 1203–04.
94                      MCKINNEY V. RYAN

Eddings’s mandate.37 Slip op. at 53–54. The majority


 37
   These cases show the Arizona Supreme Court understood that Eddings
requires consideration of non-nexus mitigation evidence but that the
sentencing court retains discretion over how much weight, if any, to afford
such evidence. In Trostle, the Arizona Supreme Court explicitly discussed
Eddings’s mandate and concluded, “In considering evidence of mental
impairment, our primary task is to determine its mitigating weight, if any.”
951 P.2d at 885–86. The court expressly considered numerous pieces of
non-nexus mitigating evidence: Trostle’s cooperation with the police, past
drug and alcohol abuse, good conduct during trial, loving family
relationships, ability to function well in a structured environment, lack of
a prior felony conviction, and remorse. Id. at 887. The Arizona Supreme
Court noted that the trial court should have considered such evidence and
factored the evidence into its independent reweighing of the aggravating
and mitigating factors. Id. at 887–88. The court reduced Trostle’s death
sentence to life imprisonment. Id. at 888.

     In Mann, the Arizona Supreme Court reviewed four pieces of non-
nexus mitigating evidence and found Mann did not “establish[] mitigation
of sufficient weight to call for leniency.” 934 P.2d at 795. The majority
concedes that the Arizona Supreme Court considered, but gave little
weight to, two pieces of non-nexus mitigating evidence: Mann’s
relationship with his children and a change in Mann’s lifestyle post-dating
his crimes. Slip op. at 53–54. The majority contends, however, that the
court “held that defendant’s difficult family background was irrelevant as
a matter of law.” Id. at 54. The Arizona Supreme Court did no such thing.
It stated “[a]n abusive family background is usually given significant
weight as a mitigating factor only when the abuse affected the defendant’s
behavior at the time of the crime.” Mann, 934 P.2d at 795 (emphasis
added). This statement is entirely consistent with Eddings: It shows the
court understood it could ascribe Mann’s family background the
mitigating weight it deserves. Cf. supra Section III.A.1. The majority also
contends Mann’s citation to Wallace shows the Arizona Supreme Court
applied an unconstitutional causal-nexus test to Mann’s evidence of a
troubled family background. Slip op. at 54. However, the court also cited
a case in which it did not ascribe “much weight” to the defendant’s
“difficult family background,” which is entirely consistent with Eddings.
See Mann, 934 P.2d at 795 (citing State v. West, 862 P.2d 192, 211–12
                          MCKINNEY V. RYAN                                  95

similarly gives short shrift to State v. Thornton, 929 P.2d 676
(Ariz. 1996), and State v. Gonzales, 892 P.2d 838 (Ariz.
1995).38 Slip op. at 52–53.

    The majority is grasping at straws. First, the majority has
flipped the presumption to require us to presume the Arizona
courts violated Eddings. No law or case is cited for this
proposition. Second, those cases demonstrate compliance


(Ariz. 1993), overruled on other grounds by State v. Rodriguez, 961 P.2d
1006 (Ariz. 1998)).

     In Medrano, the Arizona Supreme Court reviewed Medrano’s cocaine
use both as a statutory mitigating factor and as a nonstatutory mitigating
factor. 914 P.2d at 227–29. The court found Medrano’s cocaine use did
not qualify as a statutory mitigating factor under Ariz. Rev. Stat. § 13-
751(G)(1) because Medrano failed to prove his cocaine use significantly
impaired his ability to conform his conduct to the law or appreciate the
wrongfulness of his actions. Id. at 228. The Arizona Supreme Court
acknowledged it was required to consider Medrano’s cocaine use
regardless any causal connection, but found Medrano’s cocaine use
unpersuasive as mitigating evidence. Id. at 229 (citing State v. Ramirez,
871 P.2d 237, 252 (Ariz. 1994) (“[A]lthough [courts] must consider all
evidence offered in mitigation, they are not bound to accept such evidence
as mitigating.” (alterations in original))). The court then noted that the trial
court, consistent with Eddings, rejected Medrano’s “claim that cocaine
intoxication, under these facts, is sufficiently mitigating to call for
leniency.” Id.; see also id. (“Judges are presumed to know and follow the
law and to consider all relevant sentencing information before them.”).
  38
    The majority takes issue with Thornton’s citation to Ross, slip op. at
53, but ignores that the citation to Ross is for a point that is irrelevant to
the majority’s analysis. See Thornton, 929 P.2d at 686 (“Thornton argues
that his cooperation with law enforcement is a mitigating factor.
Thornton’s admission of guilt after he was stopped and his offer to admit
guilt in exchange for the state withdrawing the request for the death
penalty furthered his own interest. Cooperation that is in the best interest
of the accused is not a mitigating circumstance. State v. Ross . . . .”).
96                   MCKINNEY V. RYAN

with Eddings sufficient to rebut this newly created flipped
presumption. Look at Gonzales. There, the Arizona Supreme
Court explained that “[i]n capital sentencing proceedings, the
trial court must consider the mitigating factors in [Ariz. Rev.
Stat.] § 13-703(G) as well as any aspect of the defendant’s
background or the offense relevant to determining whether
the death penalty is appropriate.” Gonzales, 892 P.2d at 850
(emphasis added). The court later noted:

            From the detailed special verdict, it is
        clear that the trial court considered all
        evidence offered in mitigation. He was
        required to do no more. See Eddings v.
        Oklahoma, 455 U.S. 104, 112 (1982)
        (applying the rule in Lockett v. Ohio that the
        “sentencer in capital punishment cases must
        be permitted to consider any relevant
        mitigating factor”).

Id. at 851. Does that not show the Arizona Supreme Court
here complied with Eddings? What else could the court have
done to overcome the majority’s flipped presumption?

    In short, the majority’s response to those cases showing
compliance with Eddings is nothing short of an act of
contortion. See slip op. at 50–56. It cannot escape the fact that
the Arizona Supreme Court applied Eddings correctly during
the relevant time period. As a result, there is no reason to
invert the presumption that the Arizona courts knew and
followed the law into a presumption they did not.
                    MCKINNEY V. RYAN                        97

                              2.

    After freeing itself from the presumption that state courts
know and follow the law, the majority engages in de novo
review and concludes the Arizona courts here applied an
unconstitutional nexus test. Id. at 41–45. As I have shown,
even a de novo review shows there was no Eddings error. The
majority reaches the opposite conclusion largely by
selectively reading—better said, misreading—the record.

     To start, the majority states that the Arizona Supreme
Court accepted Judge Sheldon’s conclusions, at pages 28 and
29 of the sentencing transcript, that McKinney’s PTSD did
not affect his state of mind at the time of the murders and, in
any event, would have influenced him not to commit the
murders. Id. at 41–45. The majority suggests this part of the
sentencing colloquy “echoes” the Arizona Supreme Court’s
nexus test and implies these statements show the court
applied a nexus test to exclude McKinney’s PTSD evidence
from consideration under the nonstatutory mitigation factor.
Id. at 19–22, 41–45. But the majority admits these statements
are directed to Judge Sheldon’s analysis of the statutory
mitigating factors, which, as I have explained, is the correct
understanding. Id. at 19–20. So, even if the Arizona Supreme
Court accepted Judge Sheldon’s conclusion that there was no
causal connection between McKinney’s PTSD and the
murders, there was no error.

    Moreover, the majority’s analysis rests on an assumption
that the Arizona Supreme Court accepted a single factual
finding by Judge Sheldon and ignored the rest of Judge
Sheldon’s sentencing colloquy. As I have already explained,
the Arizona Supreme Court did not rely on any of Judge
98                       MCKINNEY V. RYAN

Sheldon’s factual conclusions.39 But if the Arizona Supreme
Court did accept any of Judge Sheldon’s findings regarding
McKinney’s mitigation evidence, it accepted all of them. See
McKinney, 917 P.2d at 1234 (“[T]he record shows that the
judge gave full consideration to McKinney’s childhood and
the expert testimony regarding the effects of that childhood,
specifically the diagnosis of post-traumatic stress disorder.”
(emphasis added)); id. (“The record clearly shows that the
judge considered McKinney’s abusive childhood and its
impact on his behavior and ability to conform his conduct.”
(emphasis added)).40 The majority’s selective reading of


  39
     The Arizona Supreme Court merely reviewed whether Judge Sheldon
considered all of McKinney’s mitigation evidence, found “[t]he record
clearly shows that the judge considered McKinney’s” mitigation evidence,
and concluded, “On this record there was no error.” McKinney, 917 P.2d
at 1234. It did not accept Judge Sheldon’s factual findings as part of its
own review of McKinney’s sentence.
  40
       During Hedlund’s sentencing colloquy, Judge Sheldon specifically
cited to Eddings and Lockett v. Ohio, 438 U.S. 586 (1978), and explained
those cases required him to “weigh carefully, fairly, objectively, all of the
evidence offered at sentencing, recognizing that not everyone who
commits murder should be put to death.” Hedlund v. Ryan, 750 F.3d 793,
816 (9th Cir. 2014). Judge Sheldon then considered Hedlund’s alcohol
abuse: “The Court has concluded that although evidence of alcohol use [is
not] a mitigating circumstance under (G)(1), [it] nevertheless should be
considered as mitigating evidence.” (Emphasis added.) Judge Sheldon
later reiterated that point: “The defendant’s dependent personality traits,
his past drug and alcohol abuse, and child abuse have been considered by
the Court. If not demonstrating the existence of the mitigating factors
under (G)(1), they have nevertheless been given consideration by the
Court.” (Emphasis added.) He then concluded with a discussion of
Hedlund’s childhood evidence: “I have considered [that evidence]. I think
it is the court’s obligation to consider, whether or not it complies with the
requirements in (G)(1).” (Emphasis added.) The majority fails to explain
why the Arizona Supreme Court ignored this discussion even though the
                      MCKINNEY V. RYAN                          99

Judge Sheldon’s analysis is therefore wrong on multiple
levels. It is also irrelevant to the outcome of the case. That the
Arizona Supreme Court may have accepted Judge Sheldon’s
conclusion that the evidence showed McKinney’s PTSD did
not affect his conduct does not show Eddings error. To
violate Eddings the court must have excluded the evidence
from consideration altogether because of the lack of a nexus.

    The rest of the majority’s evaluation of the Arizona
Supreme Court’s decision is just as flawed. The majority first
asserts, citing Djerf for support, that the Arizona Supreme
Court did not really consider McKinney’s PTSD evidence
even though it used the word “considering.” Slip op. at
43–43. That is nonsense. The referenced case, Djerf, came
two years after McKinney’s appeal. See Djerf, 959 P.2d at
1274. It is irrelevant to the Arizona Supreme Court’s decision
in this case.

    Next, the majority conclusorily asserts that the Arizona
Supreme Court “recited its unconstitutional causal nexus
test.” Slip op. at 21, 44, 57. It did? If the Arizona Supreme
Court recited a causal-nexus test, then why would the
majority need so many pages to reach the conclusion that the
court did, in fact, apply a causal-nexus test? It appears the
majority believes the following to be an unconstitutional
nexus test:

        [A] difficult family background, including
        childhood abuse, does not necessarily have
        substantial mitigating weight absent a
        showing that it significantly affected or


court reviewed Hedlund’s and McKinney’s death sentences in the same
opinion.
100                   MCKINNEY V. RYAN

        impacted the defendant’s ability to perceive,
        comprehend, or control his actions.

McKinney, 917 P.2d at 1234 (emphasis added). Not so. As I
have noted, this statement means that when a difficult
background does affect the “defendant’s ability to perceive,
comprehend, or control his actions,” it has “substantial
mitigating weight.” But when there is no such effect, the
evidence does not necessarily have substantial mitigating
weight, but it can have such weight. For that reason, I am at
a loss to understand the majority’s conclusion that the
Arizona Supreme Court recited an unconstitutional nexus test.

    Finally, the majority relies on the Arizona Supreme
Court’s citation to Ross. See slip op. at 42–45; Ross, 886 P.2d
at 1363. Visciotti forecloses any reliance on the citation to
Ross to find Eddings error.41 But even if we looked at the
Arizona Supreme Court’s citation to Ross without the
Visciotti presumption, we should conclude that court applied
Eddings correctly. The court correctly stated Eddings’s
requirements several times. See McKinney, 917 P.2d at
1226–27, 1234. The majority’s reliance on that citation,
rather than the words the Arizona Supreme Court actually
used, demonstrates the majority is applying the flipped




  41
      To that end, the majority implicitly overrules our prior en banc
decision where we held a citation to a suspect case does not show the
Arizona court misapplied Eddings. See Jeffers, 38 F.3d at 415.
                        MCKINNEY V. RYAN                               101

presumption it references elsewhere in its opinion.42 See slip
op. at 7, 50–56.

    In short, none of the reasons the majority relies on support
its conclusion that the Arizona Supreme Court misapplied
Eddings.

                 IV. The Harmless-Error Analysis

   The majority’s final mistake comes in its harmless-error
analysis.43 Habeas petitioners “are not entitled to habeas relief

  42
      The majority claims that a single citation to Ross in the Arizona
Supreme Court’s opinion renders the court’s treatment of McKinney’s
mitigating evidence suspect. Slip op. at 42–45. By that logic, a citation to
Eddings, Lockett, Eddings’s precursor, or State v. McMurtrey, 664 P.2d
637 (Ariz. 1983), an Arizona Supreme Court case the majority
acknowledges applies Eddings correctly, should demonstrate compliance
with Eddings. See, e.g., State v. Canez, 42 P.3d 564, 593 (Ariz. 2002)
(citing Lockett and McMurtrey); State v. Sharp, 973 P.2d 1171, 1183
(Ariz. 1999) (citing Lockett); Trostle, 951 P.2d at 885–86 (citing Lockett
and McMurtrey); Towery, 920 P.2d at 311 n.2 (citing Eddings and
Lockett); Gonzales, 892 P.2d at 851 (citing Eddings, Lockett, and
McMurtrey); Bible, 858 P.2d at 1209 (citing McMurtrey); State v. Brewer,
826 P.2d 783, 802 (Ariz. 1992) (citing McMurtrey); State v. White,
815 P.2d 869, 889 (Ariz. 1991) (citing Lockett); State v. Walton, 769 P.2d
1017, 1034 (Ariz. 1989) (citing Lockett).
  43
     I agree that Eddings error is not structural and is instead subject to
harmless-error analysis, as we have already recognized. Henry v. Ryan,
720 F.3d 1073, 1089 (9th Cir. 2013). Indeed, most circuits have held
Eddings error is not structural. See Campbell v. Bradshaw, 674 F.3d 578,
596 (6th Cir. 2012); McGehee v. Norris, 588 F.3d 1185, 1197 (8th Cir.
2009); Ferguson v. Sec’y of Dep’t of Corr., 580 F.3d 1183, 1201 (11th
Cir. 2009); Martini v. Hendricks, 348 F.3d 360, 371 (3d Cir. 2003);
Bryson v. Ward, 187 F.3d 1193, 1205–06 (10th Cir. 1999); Boyd v.
French, 147 F.3d 319, 327–28 (4th Cir. 1998); Williams v. Chrans,
945 F.2d 926, 949 (7th Cir. 1991). But see Nelson v. Quarterman,
102                    MCKINNEY V. RYAN

based on trial error unless they can establish that it resulted in
‘actual prejudice.’” Brecht, 507 U.S. at 637 (citation omitted).
We can grant habeas relief only if we have “grave doubt
about whether a trial error of federal law had ‘substantial and
injurious effect or influence in determining the [sentencer’s]
verdict.’” O’Neal v. McAninch, 513 U.S. 432, 436 (1995)
(citation omitted). There must be more than a “reasonable
possibility” that an error was harmful. Brecht, 507 U.S. at
637. Anything less puts the state to the “arduous task [of
retrying a defendant] based on mere speculation that the
defendant was prejudiced by trial error.” Calderon v.
Coleman, 525 U.S. 141, 146 (1998) (per curiam). Here,
would lack of consideration of McKinney’s PTSD cause us
to have “grave doubt” that Judge Sheldon would have
imposed the death sentence? No.

    Judge Sheldon found the prosecution established four
aggravating factors, two as to each of the murders. See Ariz.
Rev. Stat. § 13-751(F)(1), (5)–(6). First, Judge Sheldon found
McKinney committed not one, but two murders, i.e., the
murders of Mertens and McClain. Second, he found Mertens
was murdered “in an especially heinous, cruel or depraved
manner.” For that finding, Judge Sheldon credited testimony
that McKinney admitted to his father that he shot Mertens.
Judge Sheldon then explained the evidence at trial “showed
that [Mertens] struggled violently to survive before being
killed by a shot to the head.” There were numerous “non-fatal
wounds” and a “substantial amount of blood over large areas
of [Mertens’s] body, and the house, the bottom of her shoes,
her slippers, which suggests that a struggle occurred while
she was conscious.” He concluded it was reasonable to


472 F.3d 287, 314 (5th Cir. 2006) (en banc) (finding Eddings error to be
structural).
                     MCKINNEY V. RYAN                       103

assume Mertens “suffered tremendous physical torment prior
to her death.” The murder was therefore “cruel.” At the very
least, Judge Sheldon found the “violence was gratuitous” and
“clearly” unnecessary, which supported a finding that
McKinney’s state of mind was “heinous and depraved.”
Finally, Judge Sheldon found McKinney committed both
murders with the expectation that they would lead to
pecuniary gain. The Arizona Supreme Court did not disturb
any of these findings on direct appeal. McKinney, 917 P.2d at
1233–34.

    The majority opinion treats these aggravating factors as
an afterthought. See slip op. at 49–50. It daintily elides a
description of the facts by which the murders were
committed. Yet the majority claims to have conducted a
harmless-error analysis without giving the aggravating factors
“short shrift.” See id. Properly considered, these factors show
the alleged failure to consider McKinney’s PTSD, had it
occurred, would have been harmless. As McKinney’s expert
admitted, there was no evidence that McKinney’s PTSD
affected McKinney’s state of mind at the time of the murders.
And Judge Sheldon found there was no link. Had Judge
Sheldon not considered the PTSD diagnosis, forcing him to
do so would not have altered the result. He would have given
the PTSD diagnosis little weight (indeed, he did give it little
weight).

    The evidence of McKinney’s childhood was much more
compelling than his PTSD. As the majority thoroughly
outlines, the evidence showed McKinney’s childhood was
horrible. Id. at 9–15. But that only bolsters the conclusion that
the Arizona courts’ alleged failure to consider McKinney’s
PTSD was harmless. If McKinney’s horrific childhood was
not enough to justify leniency, then why would McKinney’s
104                 MCKINNEY V. RYAN

resulting PTSD, which had no effect on McKinney at the time
of the murders, have changed anything? I suppose it is
possible that McKinney’s PTSD would have nudged Judge
Sheldon across the line to leniency on the supposition that
“anything is possible”; but that is not the test for harmless
error. “Possibility” does not mean “grave doubt” that the
failure to consider the PTSD had a “substantial and injurious
effect or influence in determining [his] verdict.” O’Neal,
513 U.S. at 436. The brutal nature of the Mertens murder, the
finding that McKinney committed the two murders for
pecuniary gain, and the fact that McKinney had committed
multiple murders all weigh heavily in favor of the death
penalty. The failure to consider the marginal mitigating
weight of McKinney’s PTSD could not have affected the
outcome. McKinney has not shown “actual prejudice,” and
thus any error in McKinney’s sentencing was harmless.

                         *    *   *

    The majority’s application of § 2254(d)(1) will have
far-reaching effects beyond this case. Most immediately, the
opinion potentially undermines every Arizona death sentence
between 1989 and 2005. If we cannot find the Arizona
Supreme Court complied with Eddings in this case, where it
stated the Eddings standard correctly and made explicit
findings that illustrate it observed Eddings to avoid error,
then I don’t quite see how future cases could come out
differently. The ineluctable effect from today’s majority is
that, no matter what they said or did during this time period,
Arizona courts violated Eddings. This is not idle speculation.
                        MCKINNEY V. RYAN                          105

The majority may have already passed judgment on two cases
that are currently pending appeal before our court.44

    Most importantly, the majority’s reliance on other
Arizona Supreme Court cases will spread to all § 2254(d)(1)
cases. Before today, we applied the correct standard under
§ 2254(d)(1). See, e.g., Elmore v. Sinclair, 781 F.3d 1160,
1168 (9th Cir. 2015). After today, three-judge panels must
abandon the correct standard and apply not the deference the
Supreme Court instructs, but the majority’s analysis. See
generally Miller v. Gammie, 335 F.3d 889 (9th Cir. 2003) (en
banc). We will be flooded with string citations claiming to
show how state appellate courts have misapplied the federal
Constitution in past cases. And petitioners will rely on those
cases to argue we cannot presume those courts applied the
law correctly. This cannot be how AEDPA operates, which
this court recognized when it previously rejected the
arguments the majority revives today.

    I conclude by noting that, today, we once again misapply
AEDPA. But we do so only in this case. In our future cases,
the Supreme Court should not presume we always misapply
AEDPA because of today’s decision or because of prior
reversals in this area. That is, one hopes the Supreme Court
will not apply a past performance test to us similar to that
which the majority opinion applies to the Arizona Supreme
Court.

       I respectfully dissent.


  44
     See Martinez, 2008 WL 783355, at *33, appeal pending sub nom.
Martinez v. Ryan, No. 08-99009 (9th Cir. May 29, 2008); Rienhardt,
669 F. Supp. 2d at 1059–60, appeal pending, No. 10-99000 (9th Cir. Jan.
8, 2010).
