                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


JOSE L. ECHAVARRIA,                     Nos. 15-99001
               Petitioner-Appellee/          17-15560
              Petitioner-Appellant,
                                           D.C. No.
                v.                      3:98-cv-00202-
                                          MMD-VPC
TIMOTHY FILSON, Warden; ADAM
PAUL LAXALT, Attorney General,
          Respondents-Appellants/           OPINION
           Respondents/Appellees.


      Appeal from the United States District Court
               for the District of Nevada
       Miranda M. Du, District Judge, Presiding

       Argued and Submitted December 6, 2017
                Pasadena, California

                  Filed July 25, 2018

    Before: William A. Fletcher, Marsha S. Berzon,
      and Jacqueline H. Nguyen, Circuit Judges.

             Opinion by Judge W. Fletcher
2                     ECHAVARRIA V. FILSON

                            SUMMARY*


                           Criminal Law

    The panel affirmed the district court’s grant of habeas
corpus relief to Jose Echavarria, who was convicted and
sentenced to death for killing FBI Special Agent John Bailey.

    Echavarria claimed that there was a constitutionally
intolerable risk of bias, based on the fact that several years
earlier Agent Bailey had investigated for possible criminal
prosecution Nevada District Judge Jack Lehman, who
presided over Echavarria’s trial.

    The panel reviewed the Nevada Supreme Court’s decision
de novo, rather than with AEDPA deference, because the
Nevada Supreme Court adjudicated only Echavarria’s claim
of actual bias, not his distinct claim of risk of bias.

    The panel held that Echavarria’s right to due process was
violated because for an average judge in Judge Lehman’s
position there would have been a constitutionally intolerable
risk of bias.




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

                         COUNSEL

Jeffrey Morgan Conner (argued), Deputy Attorney General;
Adam Paul Laxalt, Attorney General; Carson City, Nevada,
for Respondents-Appellants/Appellees.

Randolph Fiedler (argued), Sylvia A. Irvin, and Michael
Pescetta, Assistant Federal Public Defenders; Rene
Valladares, Federal Public Defender; Office of the Federal
Public Defender, Las Vegas, Nevada; for Petitioner-
Appellee/Appellant.


                         OPINION

W. FLETCHER, Circuit Judge:

    In this capital case, the State of Nevada appeals from a
grant of habeas corpus to Petitioner Jose Echavarria.
Echavarria was convicted and sentenced to death for killing
an agent of the Federal Bureau of Investigation (“FBI”).
Several years earlier, that same FBI agent had investigated for
possible criminal prosecution the judge who presided over
Echavarria’s trial. Echavarria was never told of the
connection between the FBI agent and the judge. The district
court held that this unrevealed connection violated due
process by creating a constitutionally intolerable risk of
judicial bias. We agree.

                   I. Factual Background

    According to the evidence presented at trial, Echavarria
attempted to rob a Las Vegas bank on June 25, 1990. FBI
Special Agent John Bailey was at the bank on unrelated FBI
4                  ECHAVARRIA V. FILSON

business. Echavarria tried to rob a teller at gunpoint. The
teller screamed, and Echavarria abandoned the robbery
attempt. As Echavarria walked toward the bank’s front door,
Agent Bailey drew his gun, identified himself as an FBI
agent, and ordered Echavarria to stop. Echavarria continued
walking. Agent Bailey fired a shot that shattered the glass in
the door. Echavarria stopped and, at Agent Bailey’s orders,
dropped his gun. Agent Bailey frisked Echavarria and asked
a bank employee to retrieve handcuffs from Agent Bailey’s
car.

    Before Echavarria could be handcuffed, he knocked
Agent Bailey to the ground. Echavarria retrieved his gun and
shot Agent Bailey three times. Echavarria then ran out of the
bank and got into a car in which his getaway driver, Carlos
Gurry, was waiting. Gurry was apprehended by Las Vegas
police that afternoon. Echavarria drove the getaway car to
Juarez, Mexico, arriving there early the next morning.

            A. FBI Assistance to the Prosecution

    The FBI immediately launched an investigation. FBI
Agent Alvaro Cruz testified at a suppression hearing in state
court that he agreed that the case was of “great importance”
to his office “because of the fact that it was a special agent of
the FBI, who was a victim of this homicide.”

    On the morning of June 26, the FBI contacted Jose
Rubalcava, Commandante of the Chihuahua State Judicial
Police in Juarez, Mexico, to ask for his assistance in locating
and arresting Echavarria. Commandante Rubalcava, who had
a long-standing cooperative arrangement with the FBI,
assigned twenty-eight agents to the task. Mexican authorities
arrested Echavarria that night at about 8:30 pm at the Juarez
                  ECHAVARRIA V. FILSON                      5

airport and took him to the Juarez police station. After
learning of Echavarria’s arrest, four agents from the FBI’s El
Paso office, including Agent Cruz, drove across the border,
arriving at the Juarez police station at about 11:00 pm.

     Echavarria signed a confession the next morning. Before
trial, he moved for suppression of his confession, alleging
that it was obtained by torture.

   Oren Gordon, a former employee of the Drug
Enforcement Administration with experience working along
the U.S.-Mexico border, testified at the hearing on
Echavarria’s suppression motion:

       Q: And what was the general reputation of
          law enforcement agents in Mexico, for the
          use of physical abuse and torture, to
          obtain statements from suspects and
          witnesses?

       A: It was a common occurrence. It was a
          regular technique used to entice the person
          or induce the person to say what they
          wanted him to say . . . .

Gordon testified further that Mexican authorities used
electrical devices to administer shocks during interrogations.
He testified that devices with transformers, characterized by
a humming sound when turned on, generally did not leave
marks.

   Agent Manuel Marquez, one of the four FBI agents who
drove to Juarez, denied knowing this general reputation.
When asked whether Mexican law enforcement authorities
6                  ECHAVARRIA V. FILSON

have a “reputation among law enforcement agents, with
whom you interface, as obtaining statements through torture
or physical abuse,” he responded, “Within the law
enforcement community, no.” When asked about the
reputation “within the community in Juarez and El Paso,”
Agent Marquez responded, “Yes.”

    Echavarria testified at the suppression hearing that he was
tortured by the Mexican police. According to Echavarria,
police officers hit him while he was in the car on the way
from the airport to the police station. When they arrived at
the station, he was taken to the “Commandante,” who advised
him to cooperate, or else Maria, Echavarria’s former
girlfriend who had helped him when he arrived in Juarez,
“would be paying the consequences.” When Echavarria
refused to cooperate, he was taken to the second floor of the
police station, where his clothes were taken off. He was told
to spread his legs. The Mexican police beat him in the face,
using an open hand to avoid leaving marks, and between the
legs. After about an hour or an hour and a half, Echavarria
was clothed and taken back down to the first floor. He was
put in a room with the Commandante and two FBI agents,
one of whom spoke Spanish. The agents “asked me then if I
was ready to make a confession.” When Echavarria refused,
the Commandante “told his agent to take [Echavarria]
upstairs to the second floor again.”

    Once back on the second floor, Echavarria was again
stripped. This time, he was blindfolded. He was again beaten
in the face and between the legs. He heard someone cock a
gun next to his ear, and then felt the gun pressed against his
head. Echavarria was told he would be shot and thrown in
the river. Next, he heard what sounded like a welding
machine being turned on, and the officers shocked
                   ECHAVARRIA V. FILSON                       7

Echavarria’s “private parts.” They kept asking “[i]f I was
ready to make a confession.”

    Echavarria was then taken down to the first floor, where
“there was a tall white hair man who was a FBI of the United
States . . . [who] would ask me again whether I was going to
cooperate with them.” Echavarria was also taken to the
basement, where his former girlfriend Maria and her sister
were being held. Police officers threatened to beat Maria and
“tighten her nipples, the breast nipples,” and do other
“obscene things” to her.

      Having been brought “up to the second floor twice and
. . . once down to the cell downstairs,” Echavarria signed a
confession. He testified that he did so because “I had no
alternative.”

    The prosecution called as witnesses at the suppression
hearing two of the four FBI agents who had driven together
to Juarez. Agent Cruz testified that he and the other agents
met with Commandante Rubalcava and several other
Mexican police officers, and that Echavarria was brought into
the room. Agent Cruz testified that they interviewed
Echavarria for about thirty minutes. He also testified that
none of the four FBI agents who went to Juarez had white
hair. Agent Marquez estimated that the interview took thirty
to forty minutes. He testified that he gave Miranda warnings
to Echavarria orally, but that Echavarria did not sign the usual
FBI form acknowledging the warnings because the FBI
agents did not have the form with them.

   Agents Cruz and Marquez both testified that they saw no
marks on Echavarria or other indications of physical abuse,
and that they never saw Echavarria again that night. Agent
8                  ECHAVARRIA V. FILSON

Cruz testified, “I believe that we just went back to our car and
came back to El Paso.”

   Echavarria’s confession, signed at about 11:00 am the
next morning, stated:

             He then walked and entered the bank and
        went towards the tellers booths of the bank, he
        approached one of them which was being
        tended by a woman whom he knows was
        named CANY VELAZQUEZ and once in
        front of her, the declarant took the pistol and
        showed it to the teller already mentioned
        telling her in English “I have a gun in the
        hand, give me the money” . . . .

            [T]he FBI agent approached him with his
        pistol on the hand ordering the declarant to
        leave his weapon on the floor of the bank and
        declarant put his pistol on the floor so that
        afterwards, the FBI agent proceeded to put his
        pistol in the holster.

            He ordered the declarant to sit on a chair
        and declarant complied and when the FBI
        agent proceeded to handcuff both his hands,
        declarant threw himself against the FBI agent
        managing to throw him down on the floor and
        declarant managed to set himself loose and
        then grabbed his Rohm .38 special caliber
        pistol that was on the floor. With this, he shot
        three rounds at the FBI agent named JOHN
        BAILEY from a distance of one and a half
        meters while he was still lying on the floor.
                  ECHAVARRIA V. FILSON                    9

Echavarria did not independently know the names of the FBI
agent he had shot or of the bank teller he had attempted to
rob. This information was supplied by the FBI.

    Echavarria was formally turned over to the FBI at the
U.S.-Mexico border later in the day on June 27. He was
processed at the FBI’s office in El Paso. FBI agents then
accompanied Echavarria on a flight from El Paso to Las
Vegas. They were met at the airport by the Las Vegas
Metropolitan Police, who took custody of Echavarria and
booked him. FBI agents remained with Echavarria through
the booking process.

   Ten days after he was captured in Juarez, Echavarria was
charged in Nevada with capital murder.

    The FBI was deeply involved in developing witness
testimony. FBI agents interviewed about a dozen witnesses,
including the bank teller whom Echavarria had attempted to
rob. An FBI agent was present when the teller was shown a
photographic lineup.      FBI agents interviewed Maria,
Echavarria’s former girlfriend. They also interviewed
Maria’s brother, who had disposed of two guns for Echavarria
and had driven him to the Juarez airport.

    The FBI also actively developed physical evidence. FBI
agents executed a search warrant on the car that Gurry had
driven as the getaway vehicle from the bank and that
Echavarria had driven from Las Vegas to Juarez. Glass
fragments and fingerprints recovered from the car were sent
to the FBI laboratory in Washington, D.C., for analysis. An
FBI fingerprint specialist matched Echavarria’s prints to
those found in the car. An FBI forensic geologist examined
the glass fragments and matched them to glass from the
10                 ECHAVARRIA V. FILSON

shattered door of the bank. An FBI ballistics expert analyzed
a recovered .38 caliber revolver and matched it to bullets
removed from Agent Bailey’s body. An FBI language
specialist translated Echavarria’s confession from Spanish to
English. FBI agents took the bank’s camera film to have it
developed at a lab. About half a dozen FBI agents were
involved in the development of the film. FBI agents
contacted officials at the First Interstate Bank of Nevada,
where Gurry had an account. The agents were led to the bank
by a deposit slip an FBI agent had found in Echavarria’s
wallet.

      B. FBI Investigation of the Nevada Trial Judge

    Echavarria’s case was assigned to Nevada District Judge
Jack Lehman. Judge Lehman had been investigated several
years earlier by Agent Bailey for corruption, fraud, and
perjury. FBI documents describing the investigation were
sealed by the federal district court. After soliciting the views
of the parties and of the United States, we unsealed the
documents in this court. The narrative that follows is based
in part on the contents of the previously sealed documents.

    According to the FBI documents, Agent Bailey received
information in 1985 “that the state of Nevada was losing
millions of dollars on low cost housing land being sold . . . by
the Colorado River Commission (CRC).” The CRC was
allegedly selling state-owned land for a fraction of its actual
value, allowing the buyers to resell at substantial profits.
Lehman was the Chairman of the CRC during the relevant
time.

   Agent Bailey opened a formal FBI investigation in 1986.
Agent Bailey learned during the course of his investigation
                  ECHAVARRIA V. FILSON                    11

that the CRC had sold a 120-acre parcel of land in Laughlin,
Nevada, (the “Laughlin property”) to developer John H.
Midby in late 1983 or early 1984. Midby had bought the
Laughlin property from the CRC for $2,500 per acre. At
about the same time, another developer had paid $45,000 per
acre for land immediately adjacent to the Laughlin property.
The CRC had five commissioners. Lehman and Robert
Bugbee were the two CRC commissioners who had supported
Midby’s bid for the Laughlin property from the beginning
and whose view eventually prevailed in the CRC.

      From 1980 to 1982, before making a bid on the Laughlin
property, Midby had negotiated with the American Bank of
Commerce for a lease of 5,000 square feet of commercial
space that Midby owned and into which the bank wished to
expand. Lehman and Bugbee were members of the bank’s
Board of Directors. Bugbee volunteered to lead the bank’s
lease negotiations with Midby. After being at a “standstill”
over Midby’s asking price of $1.05 to $1.15 per square foot,
plus $165,000 in improvements to be paid for by the bank,
Midby agreed to drop the price to $0.85 per square foot, plus
only $80,000 to $90,000 to be paid for the improvements.
Midby also provided an additional 1,000 square feet of space
that would be rent-free for a year. The other board members
at the bank were “pleasantly surprised at [Bugbee’s] ability
to negotiate with [Midby].” One of the bank’s co-founders
later “realized that something may very well have been amiss
. . . .”

    The FBI file compiled by Agent Bailey contained
evidence that Lehman may have committed perjury in 1986
while testifying before the Nevada Gaming Control Board
about the Midby lease. Lehman had testified under oath
before the Board that he had “‘[a]bsolutely nothing’ to do
12                ECHAVARRIA V. FILSON

with negotiating the lease” between Midby and the bank.
However, the FBI file contained three letters signed by
Lehman—one in December 1980 and two in January
1981—in which Lehman discussed and negotiated terms of
the Midby lease.

    On August 31, 1987, after reviewing the FBI’s file, the
U.S. Attorney’s Office for the District of Nevada declined to
prosecute Lehman either for federal Hobbs Act violations or
for perjury. It deemed the perjury charge to be “a matter for
state prosecution.” The next day, James Weller, the FBI
Special Agent in Charge, wrote to William Maddox, the U.S.
Attorney, concerning the documents showing that Lehman
may have committed perjury. He wrote, “This office feels
strongly that State officials should have access to these
documents inasmuch as the alleged perjury took place before
the Nevada Gaming Control Board.” He wrote further, “This
office intends to turn [the documents] over to the chairman of
the Gaming Control Board who has expressed an intense
interest in any information indicating a witness may have lied
before the Gaming Control Board.” Weller indicated that he
would not make “[s]uch disclosure . . . until such time as you
concur with this proposal and until such time as, pursuant to
[Fed. R. of Crim. Proc.] 6(e), a United States District Court
Judge so orders.” In a handwritten internal FBI memorandum
to the Special Agent in Charge, dated December 5, 1987,
Agent Bailey wrote, “Following discussion with AUSA
Meyer, it is recommended this matter be maintained as –
Pending – until such time as the USA’s office receives
authority from D of J to present to a USDC Judge in Las
Vegas to present state officials with evidence of perjury
committed in state court with respect to Lehman and
[redacted].”
                  ECHAVARRIA V. FILSON                   13

    On June 23, 1988, federal District Judge Lloyd George
authorized the release of the documents to the Gaming
Control Board and the Nevada Attorney General’s Office. So
far as the record reveals, no state charges were ever filed
against Lehman. On October 5, 1990, Ronald Asher of the
Gaming Control Board advised the FBI that “a review of their
files failed to disclose any reference to Jack Lehman.”

                   C. Failure to Recuse

   On September 17, 1990, before Echavarria’s trial began,
Judge Lehman held a conference call with the lead
prosecutor, Chief Deputy District Attorney William Henry,
and Gurry’s counsel, David Wall. Wall stated in a sworn
declaration:

            During my representation of Mr. Gurry, I
       learned that the FBI had conducted an
       investigation of the Colorado River
       Commission at a time when Judge Lehman
       was a member of the Commission. Prior to
       trial, I participated in a telephone conference
       call with Judge Lehman and one of the
       prosecutors, either Mr. Henry or Mr. Harmon.
            ...

           Judge Lehman indicated during the
       conference call that a reporter had asked him
       whether he would recuse himself in the trial of
       Mr. Gurry and Mr. Echavarria due to Judge
       Lehman having been a member of the
       Colorado River Commission at the time it was
       investigated by the FBI. Judge Lehman asked
14                ECHAVARRIA V. FILSON

       if either party wanted to move to have the
       judge recuse himself.

          Neither I nor the prosecution asked that
       Judge Lehman recuse himself.

In an internal memorandum, Wall also noted that Judge
Lehman said that “his wife had been approached on 9/17/90
and told that Judge Lehman ought not to be presiding over the
case since it was Agent Bailey who had investigated actions
of Lehman on the Colorado River Commission prior to
Lehman’s appointment as a District Judge.” According to the
memorandum, “[B]oth Bill Henry and [Wall] indicated that
they did not believe that it was in any way harmful or
prejudicial.” It appears from Wall’s declaration and
memorandum that Judge Lehman did not fully explain to him
the nature and extent of the FBI’s investigation.

    On October 9, 1990, FBI agents met with Clark County
District Attorney Rex Bell and Chief Deputy DA Henry.
According to an FBI memorandum describing the meeting,
the agents provided information about the FBI’s investigation
of Judge Lehman. The memorandum noted that “[t]he
purpose of providing this information was to advise the DA
and the prosecuting ADA of its existence [so] that they could
evaluate its impact for use by the defense counsel in court
and/or appeal motions based on due process and equal
protection considerations and claiming judicial bias.” The
memorandum went on:

       ADA HENRY advised that defense counsel
       for CARLOS GURRY was aware of Judge
       LEHMAN’s involvement with SA BAILEY
       on official business but he did not believe that
                  ECHAVARRIA V. FILSON                     15

       counsel for JOSE ECHAVARRIA had that
       information. ADA HENRY said that he would
       suggest a chambers meeting to discuss this
       with all counsel present at the next court
       appearance.

(Emphasis added.)

    On October 17, the FBI wrote a follow-up memorandum
summarizing the information it had compiled about Judge
Lehman. In addition to information about the CRC, the bank,
and Lehman’s testimony before the Gaming Control Board,
the memorandum described an allegedly fraudulent land sale
to a group that included Lehman: The buying group did not
participate in the fraud, but it allegedly “did not inform
anyone of the fraud” and stood to “collect on title insurance
as an innocent buyer once the fraud was divulged.” The
memorandum also described a complaint alleging that
Lehman, acting for the CRC, extended a time limit for an
airport project “so that another firm with whom Lehman had
an interest could obtain the contract.”

    No “chambers meeting to discuss this with all counsel
present,” as contemplated in the memorandum describing the
meeting between the FBI and the state prosecutors, ever took
place. It is undisputed that Echavarria and his defense
attorneys did not learn about the FBI’s investigation of Judge
Lehman until well after trial and sentencing.

                    II. Procedural History

   Echavarria and Gurry were indicted on five
counts—murder with use of a deadly weapon, conspiracy to
commit robbery, burglary with intent to commit robbery,
16                 ECHAVARRIA V. FILSON

attempted robbery with use of a deadly weapon, and escape
with a dangerous weapon. They were tried together. After
the hearing described above, Judge Lehman denied
Echavarria’s motion to suppress his confession. Echavarria
was convicted on all five counts and was sentenced to death.
Gurry was convicted on all counts except escape and was
sentenced to life with the possibility of parole.

     Before entry of judgment, Echavarria moved for a new
trial based on, inter alia, juror misconduct. Judge Lehman
threatened to file a bar complaint against Echavarria’s
counsel for interviewing jury members in connection with the
motion. Judge Lehman then recused himself from hearing the
motion. After a different judge denied the motion, Judge
Lehman entered judgment sentencing Echavarria to death.

    Echavarria appealed his conviction and sentence to the
Nevada Supreme Court. He asserted a claim of actual
judicial bias based on Judge Lehman’s hostility to his counsel
during trial. Echavarria argued that he was “deprive[d] . . . of
a fundamentally fair trial” by “comments of the Court [that]
went far beyond legal admonishments on points of law and
took the form of enraged rebukes to counsel.” Echavarria did
not yet know of any connection between Judge Lehman and
Agent Bailey.

    The Nevada Supreme Court affirmed Echavarria’s
conviction and sentence. The Court did not specifically
address Echavarria’s actual judicial bias claim. After
addressing a number of other claims in detail, it wrote at the
end of its opinion, “We have carefully examined appellants’
numerous other assignments of error and determine that they
lack merit.” The United States Supreme Court denied
certiorari.
                   ECHAVARRIA V. FILSON                        17

    Echavarria’s first state habeas petition was denied by
Judge Lehman. The Nevada Supreme Court dismissed
Echavarria’s appeal and denied rehearing. Echavarria then
filed a federal habeas petition pro se. After counsel was
appointed and filed an amended petition, the federal district
court allowed Echavarria to subpoena the FBI to obtain
information about Agent Bailey’s investigation. The district
court then stayed Echavarria’s federal habeas proceedings to
allow him to present to the state court the evidence he
discovered about the investigation.

    Based on “the law of the case doctrine,” the state district
court denied Echavarria’s second state habeas petition, in
which he claimed “judicial bias” and “tortured confession.”
Echavarria then filed a third state habeas petition, which was
also denied. Echavarria appealed the denial of both petitions
to the Nevada Supreme Court. In his appeal, Echavarria
distinguished his claim that “Judge Lehman’s conduct
evidences an actual bias” from a separate claim that
Echavarria called “compensatory bias.” In support of his
“compensatory bias” claim, Echavarria cited a Fifth Circuit
case that explained that “[p]resumptive bias occurs when a
judge may not actually be biased, but has the appearance of
bias such that the probability of actual bias . . . is too high to
be constitutionally tolerable.”          See Richardson v.
Quarterman, 537 F.3d 466, 475 (5th Cir. 2008) (internal
quotation marks and citation omitted). He also cited a
Seventh Circuit case that explained that due process “may
sometimes bar trial by judges who have no actual bias and
who would do their very best to weigh the scales of justice
equally between contending parties. . . . [T]o perform its high
function in the best way justice must satisfy the appearance
of justice.” See Bracy v. Schomig, 286 F.3d 406, 410–11 (7th
Cir. 2002) (quoting Offut v. United States, 348 U.S. 11, 14
18                 ECHAVARRIA V. FILSON

(1954)) (internal quotation marks omitted). Echavarria
argued, “Judge Lehman’s in court rulings in Mr. Echavarria’s
case can best be explained by a desire to appear as a law and
order judge to Agent Bailey’s employer.” Echavarria’s two
trial counsel filed declarations stating that they would have
moved to disqualify Judge Lehman if they had known about
the investigation.

    The Nevada Supreme Court denied Echavarria’s appeal
of the denial of his second and third state habeas petitions.
The Court wrote, “Although it appears that Echavarria did not
learn of Agent Bailey’s investigation until well after trial, the
incidents he identifies as evidence of judicial bias were
largely raised on direct appeal and rejected summarily by this
court.” The Court characterized the information about Agent
Bailey’s investigation of Judge Lehman as “[n]ew
information as to the source of the alleged bias.” The court
concluded that the new evidence was “not so significant as to
persuade us to abandon the doctrine of the law of the case.”
The United States Supreme Court denied certiorari.

    Echavarria returned to federal district court and filed a
second amended habeas petition. In a written order, the
district court denied claims based on allegedly invalid
aggravating factors (Claim 2), allegedly improper jury
instructions (Claims 7 and 12), an allegedly improper denial
of an opportunity to investigate allegations of juror
misconduct (Claim 9), alleged prosecutorial misconduct
(Claim 11), and alleged cumulative error (Claim 15).

    The federal district court granted relief based on
Echavarria’s claim of judicial bias (Claim 4). The court held
that the Nevada Supreme Court had adjudicated Echavarria’s
claim of actual judicial bias on the merits, and had not
                   ECHAVARRIA V. FILSON                       19

unreasonably applied United States Supreme Court case law
in holding that Echavarria had not shown actual bias.
However, the district court held that the Nevada Supreme
Court had not adjudicated on the merits Echavarria’s claim
that there was an intolerable risk of judicial bias that “might
lead” the “average man as a judge” to be biased. See Tumey
v. Ohio, 273 U.S. 510, 532 (1927). The district court wrote:

        The Nevada Supreme Court did not consider
        whether there was unconstitutional implied
        judicial bias.    Specifically, the Nevada
        Supreme Court did not consider whether the
        relationship between the trial judge, the FBI
        and the murdered FBI agent, and the FBI’s
        involvement in the case would give rise to a
        possible temptation to the average judge to
        not hold the balance nice, clear and true.

    Ruling de novo on what it called Echavarria’s “implied
judicial bias” claim, the district court held that Echavarria had
established a violation of his right to due process. The court
wrote:

            Four years before Echavarria’s trial, the
        murder victim, FBI Agent Bailey, had
        conducted an investigation of serious fraud
        allegations concerning the trial judge. The
        trial judge was aware of that FBI
        investigation, as was the prosecution (and
        even counsel for Echavarria’s co-defendant),
        but Echavarria was not informed of it. The
        FBI played an important part in investigating
        Agent Bailey’s murder and in apprehending
        Echavarria. There was an issue in the case
20              ECHAVARRIA V. FILSON

     regarding the treatment of Echavarria in
     Juarez, after his arrest was made through
     cooperation between the FBI and the police in
     Juarez. Several FBI agents testified, both at
     the evidentiary hearing regarding the
     admissibility of the statement given by
     Echavarria after his arrest in Juarez, and at
     trial. Under these circumstances, this Court
     concludes that there was a significant risk that
     an average judge would possibly be tempted
     to lean in favor of the prosecution or to
     potentially have an interest in the outcome of
     the case. For example, an average judge in
     this judge’s position might be tempted to
     d emo nstrate a lack of bias by
     overcompensating and ruling in a manner to
     avoid any suggestion that the judge harbored
     ill will against the FBI, or against the FBI
     agent murder victim, for having conducted the
     investigation.       Or, to give another
     example—keeping in mind that the inquiry is
     to be made “under a realistic appraisal of
     psychological tendencies and human
     weakness,” [Caperton v. A.T. Massey Coal
     Co., 556 U.S. 868, 883–84 (2009)]—an
     average judge in this judge’s position might
     be tempted to avoid rulings unfavorable to the
     FBI, or to the prosecution of the FBI agent’s
     alleged murderer, in order to appease the FBI
     and avoid any further investigation. Either of
     these inclinations would have tended to lend
     bias and tip the scales against Echavarria.
                   ECHAVARRIA V. FILSON                    21

           In this Court’s view, it is an inescapable
       conclusion that the risk of bias on the part of
       the trial judge in this case was too high to
       allow confidence that the case was
       adjudicated fairly, by a neutral and detached
       arbiter, consistent with the Due Process
       Clause of the Federal Constitution.

(Internal citations omitted.)

    The district court examined, but did not decide,
Echavarria’s claim that his confession had been obtained by
torture and was therefore improperly admitted (Claim 3). The
district court analyzed Claim 3 in detail, suggesting that it
would have credited Echavarria’s testimony that his
confession had been obtained by torture, but the court
“refrain[ed]” from deciding “whether Echavarria’s Juarez
confession was voluntarily given.” The court wrote that it
took this approach

       out of sensitivity to the interests of comity and
       federalism, and also considering the interest
       of judicial economy. . . . [T]his Court expects
       that the issue of the admissibility of
       Echavarria’s Juarez confession may be
       revisited in state court, before Echavarria’s
       retrial, in light of this Court’s ruling that the
       trial judge, who previously ruled upon the
       admissibility of the Juarez confession, had an
       unconstitutional implied bias. Under these
       circumstances, the Court will abstain from
       ruling on Claim 3, and will, instead, deny the
       claim, without prejudice, as moot.
22                  ECHAVARRIA V. FILSON

    The district court granted habeas based on its ruling that
Echavarria had shown that there was a constitutionally
intolerable risk of judicial bias. It ordered that Nevada
release or retry Echavarria, but stayed its judgment pending
appeal. This appeal followed.

                    III. Standard of Review

    We review the district court’s decision to grant the
petition for habeas corpus de novo. Crittenden v. Chappell,
804 F.3d 998, 1006 (9th Cir. 2015). We review the district
court’s factual findings for clear error. Id.

                        IV. Discussion

     “A fair trial in a fair tribunal is a basic requirement of due
process.” In re Murchison, 349 U.S. 133, 136 (1955).
“Fairness of course requires an absence of actual bias in the
trial of cases. But our system of law has always endeavored
to prevent even the probability of unfairness.” Id. (emphasis
added).

    “[T]he Due Process Clause has been implemented by
objective standards that do not require proof of actual bias.
In defining these standards the Court has asked whether,
‘under a realistic appraisal of psychological tendencies and
human weakness,’ the interest ‘poses such a risk of actual
bias or prejudgment that the practice must be forbidden if the
guarantee of due process is to be adequately implemented.’”
Caperton v. A.T. Massey Coal Co., 556 U.S. 868, 883–84
(2009) (quoting Withrow v. Larkin, 421 U.S. 35, 47 (1975))
(internal citations omitted). The test does not require a
showing of actual judicial bias, “though actual bias, if
disclosed, no doubt would be grounds for appropriate relief.”
                  ECHAVARRIA V. FILSON                     23

Id. at 883. Rather, the test requires only a showing of an
undue risk of bias, based on the psychological temptations
affecting an “average judge.” Id. at 881. For example, in
concluding that there had been an undue risk of bias, the
Supreme Court wrote:

            We conclude that Justice Embry’s
       participation in this case violated appellant’s
       due process rights . . . . We make clear that we
       are not required to decide whether in fact
       Justice Embry was influenced, but only
       whether sitting on the case then before the
       Supreme Court of Alabama “would offer a
       possible temptation to the average . . . judge to
       . . . lead him not to hold the balance nice,
       clear and true.” The Due Process Clause
       “may sometimes bar trial by judges who have
       no actual bias and who would do their very
       best to weigh the scales of justice equally
       between the contending parties. But to
       perform its high function in the best way,
       ‘justice must satisfy the appearance of
       justice.’”

Aetna Life Ins. Co. v. Lavoie, 475 U.S. 813, 825 (1986) (first
elision added) (internal citations omitted). “The Constitution
requires recusal where ‘the probability of actual bias on the
part of the judge or decisionmaker is too high to be
constitutionally tolerable.’” Hurles v. Ryan, 752 F.3d 768,
788 (9th Cir. 2014) (quoting Withrow, 421 U.S. at 47).

    Echavarria claims that there was a constitutionally
intolerable risk of bias, based on FBI Agent Bailey’s criminal
investigation of Judge Lehman.
24                ECHAVARRIA V. FILSON

    The Antiterrorism and Effective Death Penalty Act
(“AEDPA”) requires us to give significant deference to the
state court’s last reasoned decision—here, the Nevada
Supreme Court’s decision on appeal from the denial of
Echavarria’s second and third state habeas petitions. See
28 U.S.C. § 2254(d). AEDPA deference applies to claims
that were “adjudicated on the merits in State court
proceedings.” Id.; see Lambert v. Blodgett, 393 F.3d 943,
966 (9th Cir. 2004). An adjudication on the merits is a
“decision finally resolving the parties’ claims . . . that is
based on the substance of the claim advanced, rather than on
a procedural, or other, ground.” Lambert, 393 F.3d at 969
(quoting Sellan v. Kuhlman, 261 F.3d 303, 311 (2d Cir.
2001)). “Any federally reviewable claim that was not
adjudicated on the merits in state court is reviewed de novo.”
Runningeagle v. Ryan, 825 F.3d 970, 978 (9th Cir. 2016). If
a state court denies a federal claim without giving any
explanation, we presume that the decision was an
adjudication on the merits. See Amado v. Gonzalez, 758 F.3d
1119, 1131 (9th Cir. 2014). But if a state court gives an
“explicit explanation of its own decision,” we take the state
court at its word. James v. Ryan, 733 F.3d 911, 916 (9th Cir.
2013). “[W]hen it is clear that a state court has not reached
the merits of a properly raised issue, we must review it de
novo.” Pirtle v. Morgan, 313 F.3d 1160, 1167 (9th Cir. 2002)
(footnote omitted).

    Here, the Nevada Supreme Court’s explanation of its
decision on state habeas shows that it adjudicated only
Echavarria’s claim of actual bias. It did not adjudicate his
distinct claim of risk of bias. When the Nevada Supreme
Court was presented with Echavarria’s claim of actual bias on
direct appeal, there was no evidence in the record of Agent
Bailey’s criminal investigation of Judge Lehman. Later,
                   ECHAVARRIA V. FILSON                     25

when presented in state habeas proceedings with evidence of
Agent Bailey’s investigation, the Nevada Supreme Court
wrote:

       Echavarria raised a claim of judicial bias on
       direct appeal, arguing that the trial judge
       made numerous disparaging and embarrassing
       comments about counsel. Although it appears
       that Echavarria did not learn of Agent
       Bailey’s investigation until well after trial, the
       incidents he identifies as evidence of judicial
       bias were largely raised on direct appeal and
       rejected summarily by this court. In his post-
       conviction petition, Echavarria merely refined
       this claim, contending that the genesis of the
       trial judge’s bias was related to Agent
       Bailey’s investigation of him.              New
       information as to the source of the alleged
       bias is not so significant as to persuade us to
       abandon the doctrine of the law of the case.

(Internal citations omitted.)

    By invoking the “law of the case” as the basis for its
denial of state habeas, the Nevada Supreme Court made clear
that it treated its prior decision as “decid[ing] the issue” of
bias “explicitly or by necessary implication.” Dictor v.
Creative Mgmt. Servs., LLC, 223 P.3d 332, 334 (Nev. 2010).
But on direct appeal, the Nevada Supreme Court had
addressed only a claim of actual bias based on Judge
Lehman’s hostility in court towards Echavarria’s counsel.
The Nevada Supreme Court could not have addressed
Echavarria’s distinct and later-raised claim of risk of bias,
based on Agent Bailey’s investigation, because Echavarria
26                 ECHAVARRIA V. FILSON

had made no such claim on direct appeal. Indeed, at the time
of his direct appeal, Echavarria had no knowledge of the
investigation.

    The Nevada Supreme Court’s reasoning in denying
Echavarria’s second and third habeas petitions makes clear
that it decided only “whether the judge [was] actually,
subjectively biased.” Caperton, 556 U.S. at 881. Reviewing
the denial of state habeas, the Nevada Supreme Court
described the evidence of Agent Bailey’s investigation as
“[n]ew information as to the source of the alleged bias.” The
Court deemed the new information insufficient because it did
not convince the Court that Judge Lehman was actually
biased. But actual bias was not the issue in Echavarria’s risk-
of-bias claim. A showing of a constitutionally intolerable
risk of bias does not require proof of actual bias. Id. at 883;
see also Williams v. Pennsylvania, 136 S. Ct. 1899, 1905
(2016) (“[T]he Court’s precedents apply an objective
standard that, in the usual case, avoids having to determine
whether actual bias is present.”). Indeed, due process “may
sometimes require recusal of judges who have no actual bias
and who would do their very best to weigh the scales of
justice equally.” Hurles, 752 F.3d at 789 (internal quotation
marks and citation omitted).

    The Nevada Supreme Court has made a similar error
before. In Rippo v. Baker, 137 S. Ct. 905 (2017) (per
curiam), the Supreme Court “vacate[d] the Nevada Supreme
Court’s judgment because it applied the wrong legal
standard” for a post-conviction claim of judicial bias. Id. at
907. The petitioner alleged that his trial judge was biased
because the judge was the subject of an investigation
involving the local district attorney’s office and Las Vegas
police department. Rippo v. State, 368 P.3d 729, 743 (Nev.
                   ECHAVARRIA V. FILSON                      27

2016) (per curiam), vacated, Rippo v. Baker, 137 S. Ct. 905
(2017) (per curiam). The Nevada Supreme Court had
concluded, “Taking Rippo’s allegations as true, there
remains [n]o factual basis . . . for Rippo’s argument that [the
trial judge] was under pressure to accommodate the State or
treat criminal defendants in state proceedings less favorably
or that he was biased against Rippo because of the
investigation and indictment.” Id. at 744 (internal quotation
marks omitted) (alterations in original). The United States
Supreme Court explained that “[t]he Nevada Supreme Court
did not ask the question our precedents require: whether,
considering all the circumstances alleged, the risk of bias was
too high to be constitutionally tolerable.” Rippo, 137 S. Ct.
at 907.

    Here, rather than applying the wrong legal standard to a
risk-of-bias claim, the Nevada Supreme Court never decided
the claim. The district court was therefore correct to review
the claim de novo. We, too, review it de novo. We must
determine “whether the average judge in [Judge Lehman’s]
position is ‘likely’ to be neutral, or whether there is an
unconstitutional ‘potential for bias.’” Caperton, 556 U.S. at
881. The rule is “stringent.” Hurles, 752 F.3d at 789
(quoting Murchison, 359 U.S. at 136). It reaches “[e]very
procedure which would offer a possible temptation to the
average . . . judge to forget the burden of proof . . . or which
might lead him not to hold the balance nice, clear and true
between the State and the accused.” Id. (quoting Tumey,
273 U.S. at 532). It also requires “a realistic appraisal of
psychological tendencies and human weakness.” Id. (quoting
Caperton, 556 U.S. at 883–84).

   Judge Lehman was well aware of the FBI’s efforts to
ensure Echavarria’s conviction. The average judge in his
28                 ECHAVARRIA V. FILSON

position would have understood the risk entailed in making
rulings favorable to Echavarria. As detailed above, the FBI
marshaled agents and resources from multiple offices and
enlisted the assistance of the Mexican police. The FBI sent
four agents to Echavarria’s interrogation in Mexico. The FBI
provided information used in the confession that Echavarria
signed the next morning. FBI personnel later translated the
confession into English for the prosecution. The FBI’s
involvement in the operation was so deep that Commandante
Rubalcava, the deputy chief of the Mexican police in Juarez,
later believed that he needed to “have a clearance” from the
FBI in order to speak with Echavarria’s counsel. After
Echavarria confessed, FBI agents gathered and analyzed
critical evidence to be used at trial—witnesses, fingerprints,
ballistics, and even glass fragments evaluated by an FBI
forensic geologist.

    FBI agents testified at the suppression hearing in state
court. At the conclusion of that hearing, Judge Lehman was
required to choose between the FBI agents’ account of the
interrogation and Echavarria’s. In all, twenty employees of
the FBI testified during proceedings before Judge Lehman,
many of them stressing the fact that Agent Bailey was an FBI
agent.

    During voir dire, the prosecution emphasized that “[t]he
murder victim was a special agent with the Federal Bureau of
Investigation.” At trial, the prosecution began its opening
statement the same way: “On[] the 25th of June, 1990, at
about eleven forty-nine a.m., Special Agent John Bailey of
the Federal Bureau of Investigation was inside the Security
Pacific National Bank . . . . He was there on official
business.” In its closing argument, the prosecution reiterated,
“It would be easy enough to, after all this time, . . . to forget
                  ECHAVARRIA V. FILSON                     29

perhaps the very real reason we are all here and we’re all
doing this. The very real reason we’re all here and we’re all
doing this is shown in State’s exhibit number one, the
photograph of Special Agent John Bailey of the Federal
Bureau of Investigation.”

    Based on our de novo review, we hold that Echavarria’s
right to due process was violated. Indeed, on the facts before
us, we would so hold even if we were addressing the question
under the deferential standard of AEDPA. For an average
judge in Judge Lehman’s position there would have been a
constitutionally intolerable risk of bias. An average judge in
that position would have feared that rulings favoring
Echavarria, tipping the outcome towards acquittal or a
sentence less than death, could cost him his reputation, his
judgeship, and possibly his liberty.

    The State argues that there was no risk of bias because
federal and state authorities had previously declined to
prosecute Judge Lehman. But the question before us is not
whether, a few years before Echavarria’s trial, Judge Lehman
had escaped prosecution. The question is whether an average
judge in Judge Lehman’s position would have feared that the
FBI might reopen its investigation or renew its advocacy for
state prosecution if he made rulings favorable to Echavarria.

    The State also argues that Judge Lehman’s risk of bias
was no different from that of “judges at all levels of the
judicial system [who] are constantly asked to make rulings
that could cut against the interests of state and federal law
enforcement agencies.” That is plainly incorrect. Judge
Lehman was no ordinary judge, and Echavarria was no
ordinary defendant. Rather, Judge Lehman personally had
been criminally investigated by the very FBI agent that
30                ECHAVARRIA V. FILSON

Echavarria was accused of killing, and the case required
Judge Lehman to determine, inter alia, whether FBI agents
had known about or been involved in the use of torture in
obtaining Echavarria’s confession.

     In the circumstances of this case, the risk of bias was
extraordinary in both its nature and severity. The risk was
obvious to all who had complete information about Agent
Bailey’s investigation. The FBI met with the prosecutors
specifically to brief them on Agent Bailey’s investigation and
prepare them for “in court and/or appeal motions based on
due process and equal protection considerations and claiming
judicial bias.” (Emphasis added.) Based on what was
revealed in that meeting, the prosecutors appear to have
recognized the importance of informing Echavarria of the
investigation. Indeed, Chief Deputy District Attorney Henry
promised to “suggest a chambers meeting to discuss this with
all counsel present.” But that meeting never took place, and
Echavarria never had the opportunity to request that Judge
Lehman recuse.

                         Conclusion

    The risk of bias in this case deprived Echavarria of the
fair tribunal to which he was constitutionally entitled. We
therefore affirm the district court’s grant of habeas relief.
Because we affirm the district court on this ground, we do not
reach the other questions presented in this appeal.

     AFFIRMED.
