FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

WALTER JOSEPH COOK III,

Petitioner-Appellant,

v.

SCOTT KERNAN,

Respondent-Appellee.

No. 17-17257

D.C. No.

3:15-cv-06343-

WHA

OPINION

Appeal from the United States District Court

for the Northern District of California

William Alsup, District Judge, Presiding

Argued and Submitted March 27, 2019

San Francisco, California

Filed January 21, 2020

Before: Consuelo M. Callahan, N. Randy Smith,

and Mary H. Murguia, Circuit Judges.

Opinion by Judge Callahan;

Concurrence by Judge Callahan;

Dissent by Judge Murguia
2 COOK V. KERNAN

SUMMARY*

Habeas Corpus

The panel affirmed the district court’s denial of Walter 

Joseph Cook, III,’s 28 U.S.C. § 2254 habeas corpus petition 

challenging his California state conviction for three counts 

of first-degree murder, in an appeal in which Cook claimed, 

inter alia, that the state’s reliance on his confession 

prejudicially violated his constitutional rights.

Cook asserted that his statements to police were 

unlawfully obtained in two ways: that he was unable to 

understand his Miranda rights from the outset of his 

interrogation and thus did not knowingly and intelligently 

waive them, and that his confessions were coerced based on 

the totality of the circumstances as established by the 

existing record.

Applying AEDPA deference, the panel held that:

• based on the facts that Cook was repeatedly warned 

of his Miranda rights, expressly acknowledged the 

warnings, and offered coherent and knowing answers 

to the officers’ questions, the California Supreme 

Court had a reasonable basis to reject Cook’s 

challenge to the validity of his Miranda waiver.

• the California Supreme Court had a reasonable basis 

to conclude that Cook’s confession was voluntary 

* This summary constitutes no part of the opinion of the court. It 

has been prepared by court staff for the convenience of the reader.
COOK V. KERNAN 3

because Cook fails to show how this conclusion 

under the totality of the circumstances is 

“inconsistent with the holding in a prior decision of 

the [United States] Supreme Court.”

The panel held that Cook is not entitled under AEDPA 

to an evidentiary hearing into his allegation that an officer 

threatened him at gunpoint during his interview, and that the 

district court did not abuse its discretion in denying his 

request for one, because his failure to develop the factual 

basis for the claim in state court proceedings was due to his 

own lack of diligence.

The panel addressed remaining claims in a concurrently 

filed memorandum disposition.

In a concurring opinion, Judge Callahan wrote that if the 

panel had needed to reach the question of whether Cook was 

prejudiced by the admission of his statements, she would 

agree with the district court that the California Supreme 

Court could have reasonably denied Cook’s claim on the 

ground that any error was harmless.

Dissenting, Judge Murguia disagreed with the majority’s 

conclusion that the California Supreme Court could have 

reasonably denied habeas relief on the basis that Cook 

(1) knowingly and intelligently waived his Miranda rights; 

and (2) suffered no prejudice from the improper admission 

of his unlawfully obtained confession and other 

incriminating statements.
4 COOK V. KERNAN

COUNSEL

Cormac Early (argued), Jones Day, Washington, D.C.; Craig 

Stewart and Kelsey Israel-Trummel, Jones Day, San 

Francisco, California; for Petitioner-Appellant.

Sarah J. Farhat (argued), Deputy Attorney General; Peggy S. 

Ruffra, Supervising Deputy Attorney General; Jeffrey M. 

Laurence, Senior Assistant Attorney General; Xavier 

Becerra, Attorney General; Office of the Attorney General,

San Francisco, California; for Respondent-Appellee.

OPINION

CALLAHAN, Circuit Judge:

In 1994, a California jury convicted petitioner, Walter 

Joseph Cook, III, of three counts of first-degree murder, 

along with a special circumstance of multiple murders under 

California law, and sentenced him to death. Following his 

state habeas proceeding over a decade later, Cook’s sentence 

was reduced to life without the possibility of parole on the 

ground that he was intellectually disabled within the 

meaning of Atkins v. Virginia, 536 U.S. 304 (2002). Cook 

subsequently sought federal habeas relief from his 

conviction on multiple grounds. The district court denied his 

habeas petition but granted a certificate of appealability as to 

four issues, only one of which we address in this opinion: 

whether the state’s reliance on Cook’s taped confession 
COOK V. KERNAN 5

resulted in a prejudicial violation of his constitutional 

rights.1

Cook’s claim is subject to review under the 

Antiterrorism and Effective Death Penalty Act of 1996 

(“AEDPA”), 28 U.S.C. § 2254(d). Applying the AEDPA 

standard of review, we deny relief because the state habeas 

court could have reasonably concluded that Cook’s 

confession was not obtained in violation of his constitutional 

rights.

I.

A.

Cook’s convictions emerge from three murders that 

occurred over the span of four months in 1992 in East Palo 

Alto, California, where Cook was a local dealer of crack 

cocaine.2

The murder of Earnest Sadler occurred in the early 

morning of February 9, 1992. Around 4:00 a.m., police 

found Sadler’s body lying on the pavement in a residential 

neighborhood in East Palo Alto. Sadler’s head was severely 

battered, and three bloodstained and broken pieces of 

wooden board were found nearby. Sadler’s distinctive shoe 

prints were also visible on the damp soil in the front yard of 

a nearby house. When officers initially interviewed the 

1 We address Cook’s remaining claims in a concurrently filed 

memorandum disposition.

2 The facts and evidence presented at trial in support of Cook’s 

convictions are detailed at length in the California Supreme Court’s 

opinion on direct review, People v. Cook, 139 P.3d 492 (Cal. 2006).
6 COOK V. KERNAN

eleven occupants of the residence, none admitted to having 

seen Sadler killed.

It was only months later that several occupants of the 

house and other witnesses admitted that they knew Cook had 

beaten Sadler to death. Shawnte Early (who had been 

Cook’s girlfriend at one point) told police that she saw Cook 

beating Sadler with a stick while Sadler was on the ground, 

and that she tried to intervene by coaxing Cook into her car 

and driving him around the corner, only to have Cook jump 

out of her car and resume his brutal attack on Sadler. At trial, 

Early repudiated her taped interview, which was played for 

the jury. Earnest Woodward, a resident of 2250 Menalto, 

testified that he woke up that night to see Cook engaged in a 

fistfight with Sadler, and Woodward told the combatants to 

move down the street. Velisha Sorooshian testified that she 

was sitting with Leonard Holt in her car, smoking a pipe of 

crack cocaine, near 2250 Menalto that night when Cook 

pulled alongside her and laughingly asked her to see if the 

man lying in the street was all right. Shannon Senegal 

(Cook’s cousin) testified that, the day after Sadler’s death, 

Cook told him he had “beat someone down last night” and 

identified his victim as Sadler. Woodward and Senegal were 

either in custody or serving prison sentences at the time of 

trial, and Sorooshian also had a criminal record.

The murder of Michael Bettencourt occurred sometime 

between midnight and 1:00 a.m. on February 14, 1992. A 

group of drug dealers and friends was gathered on a

residential street in East Palo Alto, which was known as a 

site for illegal drug sales. Bettencourt, an outsider 

apparently wanting to buy drugs, arrived in the middle of the 

street in his gold Thunderbird car and was immediately 

surrounded by potential sellers, including Cook. Steven 

Sims (another seller) stuck his arm through the open driver-
COOK V. KERNAN 7

side window, but was jostled, causing him to drop his rock 

of cocaine inside Bettencourt’s car. When Sims opened the 

driver’s door to look for the fallen rock, he heard Cook—

who was standing behind him, holding a nine-millimeter 

automatic pistol—tell Bettencourt to return the rock or pay 

for it. Sims then heard Cook yell, “Get back, get back,” and 

when Sims stepped away, he saw Cook shoot Bettencourt 

once in the leg, pause, then unload the “clip in the nine,” 

shooting Bettencourt repeatedly.

Once he stopped shooting, Cook jumped into Nathan 

Gardner’s car and rode for a few blocks before he got out. 

During the short ride, Gardner asked Cook why he shot 

Bettencourt, and Cook said it was because Bettencourt had 

tried to “gaffle”—meaning to steal from—him. The next 

day or so, when Sims encountered Cook again and asked 

about the shooting, Cook replied that Bettencourt “should 

have give[n] me my money or my rock back.” Bettencourt 

was found by police, dead in his car, with the driver’s door 

open. The responding officer was unable to obtain 

information from anyone in the neighborhood about the 

shooting. Numerous shell casings were found in the street 

next to the car door, and a later forensic examination 

determined that eleven of the shell casings had come from a 

single gun.

The murder of Ronald Morris occurred on the afternoon 

of May 21, 1992. Cook, Senegal, and Lavert Branner were 

hurriedly leaving the parking lot of University Liquors in a 

Nova car (driven by Senegal) when they passed Sharoon 

Reed and three of her friends, who were also leaving the 

parking lot in their car. One of the men in the Nova told the 

women to “hurry up and move,” and as the women slowed 

their car to let the Nova pass, Cook displayed a gun to them. 

The women followed the Nova at a distance as they headed 
8 COOK V. KERNAN

to a birthday party on East O’Keefe Street in honor of their 

friend, Morris, also known as “Fat Man.”

When the cars arrived on East O’Keefe, Morris had just 

parked his car and hailed down the Nova. Senegal made a 

U-turn and pulled the Nova next to Morris. As Senegal 

began talking to Morris, Cook (who was in the front 

passenger seat) suddenly leaned across Senegal and fired 

multiple shots at Morris, announcing, “I told you I will get 

your punk ass back.” According to Senegal, Cook harbored 

a grudge against Morris based on an incident about a week 

earlier, when an armed Morris had mocked Cook for being 

unarmed. Reed testified that, from her viewpoint in the 

women’s car, she overheard Morris say, “Damn, you all 

strapped,” as he looked into the Nova, and then saw him 

suddenly turn away just before multiple shots were fired.

According to a pathologist at trial, Morris had five bullet 

wounds in his heart and lungs, any one of which was 

“potentially fatal.” Various nine-millimeter cartridge 

casings were recovered from the pavement where Morris 

fell, and were later compared to the nine-millimeter casings 

recovered from the Bettencourt murder. A San Mateo 

County Sheriff's criminalist testified that he could not 

determine with certainty whether both sets of casings had 

come from the same weapon, possibly because those from 

the earlier killing were aluminum while those from the later 

killing were brass. A day after the Morris murder, Cook 

threw his gun off the Dumbarton bridge and subsequently 

left the area.

B.

On June 26, 1992, Cook was arrested at his mother’s 

home in Lawton, Oklahoma, on a California warrant. He 

was transported to the local jail, where he was interviewed 
COOK V. KERNAN 9

by East Palo Alto Police Sergeant Gregory Eatmon and 

Inspector Bruce Sabin of the San Mateo District Attorney’s 

Office. The interview lasted approximately seven hours, 

from around 7:00 p.m. that night to around 2:00 a.m. the next 

morning.

At the beginning of the interview, Inspector Sabin read 

Cook his Miranda rights and then asked, “Do you 

understand that Walter?” Cook responded, “Yeah.” Sabin 

then asked, “Okay. Do you have any questions about that? 

That’s a yes or no,” to which Cook responded, “No.” After 

this confirmation from Cook, the investigators proceeded to 

question Cook about his background, his family, and, 

eventually, his whereabouts on the day of the Morris murder. 

During these first few hours of his videotaped interview, 

Cook generally appeared calm, even conversational at times, 

as he answered the investigators’ questions; at other times, 

he also seemed slightly confused, and his responses seemed 

unfocused and difficult to follow.3

 When the investigators 

began to question Cook about Morris, Cook initially 

maintained that he was at his cousin’s house the night of the 

murder and only heard about it after the fact.

Almost two hours into the interview, around 8:57 p.m., 

the investigators shifted their approach to a more direct 

verbal confrontation about the Morris murder. They told 

3 When asked for his date of birth and age at the start of the 

investigation, Cook stated that his birthdate was September 25, 1971 

(which would have made him twenty years old), but then stated he was 

nineteen years old when asked for his age. When Sabin pointed out the 

inconsistency between his responses, Cook responded with, “that’s what, 

what my mother told me, so.” The district court interpreted this colloquy 

as one of the first “signs that Cook was either seriously confused, or 

otherwise mentally incompetent.” Cook was actually eighteen years old 

at the time of his interview.
10 COOK V. KERNAN

Cook, “[E]verything you been giving us up till now has been 

bullshit,” and claimed they had multiple witnesses, 

fingerprint evidence, and shell casings all pinning him to the 

murder. In an effort to persuade Cook to confess, the 

investigators made statements such as: “[N]ow’s the time for 

you to tell the truth son, the absolute truth”; “If Fat Man did 

something to you that made you shoot him, we want to hear 

that”; and, “[N]ot only you’re going to look like a killer, but 

you’re going to look like a liar on top of it.” Cook responded 

to these statements with mostly one-word responses, 

eventually telling the investigators, “I really can’t say too 

much about it ‘cause um, I’m not going to endanger my 

family’s life.” The investigators continued to insist that 

Cook “tell the truth,” until Cook finally stated:

I don’t, anything I say would endanger my 

family life, I’d rather just, whatever’s going 

to happen to me is going to happen anyway. 

I’m either being . . . you know what I’m 

saying, if you got all this evidence on me, 

either way, I’d say whatever, yes or no, yes 

or no, I’ll either get the electric chair, 25 to 

life, so, you know what I’m saying, it didn’t, 

it really shouldn’t even matter what I say.

At this point, Cook had not explicitly admitted to 

shooting Morris, but the investigators continued to ask him 

why he killed Morris and whether it was because Morris had 

threatened him. Their questioning led Cook to discuss 

various incidents where he had felt threatened by or 

experienced conflict with Morris. Around 9:34 p.m., in 

response to the investigator’s prompting, “[N]ot only is 

[Morris] disrespecting you, but he’s threatening you for no 

reason, you didn’t do anything to him, did you? Did you 

ever do anything to him?,” Cook began to cry, replying, “No, 
COOK V. KERNAN 11

I never do nothing to nobody, I try to be everybody friend. I 

can’t work ‘cause I live on another part.” As Sabin 

continued to question Cook about the Morris shooting, Cook 

tearfully reiterated his fears about endangering his family, 

making statements such as: “I’m in for it regards if I say 

something or not . . . if I tell you something, then, put my 

family life in danger, I’d rather something just happen to 

me”; “It shouldn’t really matter, whatever I say now, you 

said I’m guilty . . . you got all this stuff that I’m in it, so . . .

regardless of what I say, you know what I’m saying, it’s not 

going to happen . . . if you all plan on killing me or whatever 

. . . I’m doing electric chair or 25 to life . . . it just don’t 

matter now”; “And then, after I tell you all the truth, 

whatever it is, who, you know what I’m saying, I got to face 

the consequences of what happened to, what if somebody 

kill my father and them.”

At one point, Sabin asked Cook, “[A]re you telling us 

you didn’t shoot this guy, is that what you’re saying?,” and 

Cook answered, “I didn’t say I did or I didn’t.” Sabin and 

Eatmon emphasized again all the evidence they had linking 

Cook to the murder, and told Cook he only needed to explain 

his motive. Cook finally responded, “The only thing I can 

tell you, what the truth is, I remember, the last thing I 

remember, he came up to the car and he, I forgot what he 

said, and last thing I just like blanked out, that’s the last thing 

I remember.” As the investigators pressed Cook for 

additional detail, Cook admitted that he was in the car with 

Branner and Senegal and had a gun with him, but continued 

to maintain that he could not remember what happened after 

Morris approached the car because he “blank[ed] out.”

Cook did not provide substantially more information 

after this admission, despite continued questioning over the 

next two hours. At one point, Sabin expressed frustration 
12 COOK V. KERNAN

with Cook’s responses, stating, “I hate to say this Walter, I 

really do, because we’ve come a long way . . . since when 

you were totally telling us bullshit, okay . . . . But, if you 

were sitting over here, being me, would you believe that?” 

Cook responded, “That’s, that’s what happened, I’m telling 

you, I’m telling you everything that I remember.”

Around 11:13 p.m., in response to a question about why 

he went to therapy as a child, Cook suddenly began to sob 

loudly and talk about the physical abuse of his mother by his 

father when he was younger. Faced with an increasingly 

emotional Cook, Sabin and Eatmon offered him a drink and 

unsuccessfully tried to reengage him in questions about 

Morris. Instead of responding to questions about Morris, 

however, Cook continued to discuss his abusive childhood, 

while still crying and making statements such as: “I don’t 

care, they can kill me, do whatever they want, I don’t care 

no more”; “I hope they kill me or whatever, I don’t want to 

worry about waking up every night, just thinking about got 

to help my mother, and I can’t do nothing to stop it . . . let 

them kill me, I don’t care, I have nothing to live for, nobody 

even care about me anyway so, I mean, it’s better if I’m 

gone”; “I don’t care what happens to me, kill me, I’d be more 

of a big heavy burden.” By 11:38 p.m., the investigators 

decided to take a break to allow Cook to calm down and 

escorted him back to his cell.4

4 In his state habeas petition, Cook alleged for the first time that, 

during this half-hour break in his interview, Sergeant Eatmon threatened 

him at gunpoint. According to Cook, as Eatmon escorted Cook from his 

cell to the interrogation room, Eatmon pulled Cook into a restroom, held 

a gun to Cook’s head, and threatened to harm him if he did not confess 

to killing Bettencourt. Cook did not offer a sworn affidavit personally 

attesting to this allegation in either his state or federal habeas petition, 

nor do the affidavits from trial counsel in response to his ineffective 
COOK V. KERNAN 13

The taped interview resumed around 12:10 a.m. Sabin 

reminded Cook again of his Miranda rights:

SABIN: Okay, Walter, when we initially 

started this interview we read you your 

Miranda rights, do you remember those?

COOK: Uh-hum.

SABIN: Okay. And you still want to talk to 

us is that correct?

COOK: Yeah, it don’t matter.

SABIN: Okay. I want you to understand 

that, if at some point in time you don’t want 

to talk to us anymore, say so, okay? 

Understand?

COOK: Yes.

SABIN: Okay. If you want us to stop at 

some point in time and take a break, say so 

with [sic] that alright?

COOK: Uh-hum.

SABIN: I want you to be totally comfortable 

with this, okay?

assistance of counsel claims mention this allegation. The California 

Supreme Court denied Cook’s petition without granting his request for 

an evidentiary hearing on this claim.
14 COOK V. KERNAN

COOK: Uh-hum.

Sabin then began questioning on the Bettencourt murder, 

which led to a somewhat abrupt confession from Cook:

SABIN: Alright. What we want to talk to 

you about Walter is an incident that happened 

on February 14th, 1992, on Alberni Street. 

Alberni near Jervis, do you have any idea 

what I’m talking about?

COOK: Uh-hum.

SABIN: Okay. Do you want to tell me what 

you know about it?

COOK: Yeah, I did it, I actually don’t know 

why. And that’s all you need to know. Well, 

I don’t care.

Sabin pressed for more information, but Cook declined to 

provide additional detail, asserting that he could not 

remember or did not know what happened, but knew that he 

committed the shooting.5 The questioning continued until 

about 1:42 a.m., when Eatmon gave Cook a glass of water 

and aspirin at Cook’s request, and Sabin left to use the 

restroom. Around 1:50 a.m., after Cook began coughing up 

5 Cook’s responses to various questions included: “Well, the whole 

plan is, everyone know that I did it or not, I did it so, you all can just 

shoot me or whatever, it don’t matter.”; “Well, I don’t really know. The 

only thing I know that I, I shot the dude, that’s all I know.”; “I don’t, I 

don’t know what happened. Last thing I remember, I know I shot the 

guy, that’s all I remember happening.”; “No, I don’t remember nothing. 

The only thing, the only thing I remember, I know I shot the dude, that’s 

all I remember.”
COOK V. KERNAN 15

his aspirin, the investigators decided to terminate the 

interrogation for the night.

The interview resumed the next day around 12:49 p.m. 

Sabin again asked Cook if he remembered “the Miranda

rights I read to you yesterday when we first met?” Cook 

answered, “Um, not really.” Sabin then reread the Miranda

rights to Cook and asked if he had any questions. Cook 

responded, “So, therefore that um, like, when you all talk to 

me I’m supposed to have an attorney here or something?” 

Sabin answered, “No, you have the right to have one here if 

you want,” which prompted this exchange:

COOK: Is that the only time you could have 

an attorney to be able, when you go to court?

SABIN: You can have an attorney present 

any time during these, these proceedings.

COOK: I didn’t know that.

SABIN: Okay, well, do you remember me 

reading that off to you yesterday?

COOK: Not really, but I remember you was 

reading something about my rights.

Cook then told the investigators he wanted to talk to his 

mother before he continued speaking with them. Sabin 

asked Cook a few more questions as to whether he 

understood his rights the day before. Cook answered, “No, 

I, I didn’t know that . . . you could have a lawyer . . . while 

you guys talk to me. I didn’t know that,” “I remember you 

telling me that I didn’t, like to remain silent,” and “Yeah, I 

thought I did [understand], but I guess I didn’t, I didn’t know 
16 COOK V. KERNAN

that like, when you guys talked to me that, I could have a 

lawyer here.”

After Cook was given an opportunity to talk to his 

mother, he returned to the interview at 6:20 p.m. and 

informed the investigators he did not want to talk to them 

because his mother “told me I should wait till I get back to 

California, we got to talk to my lawyer.” The officers 

subsequently ended the interview.6

C.

At the time of his arrest and interview, Cook was 

eighteen years old. According to Dr. William Lynch, a 

neuropsychologist who evaluated Cook prior to trial, Cook’s 

“full scale” IQ was 89 and his intelligence was “low average 

overall . . . with verbal and performance abilities falling at 

the extreme low end of the average range.” Dr. Zakee 

Matthews, a clinical psychologist who also evaluated Cook 

prior to trial, opined that Cook suffered from PTSD. Neither 

Dr. Lynch nor Dr. Matthews reviewed the transcripts or 

videotape of Cook’s interrogation as part of their pre-trial 

evaluations.

Over a decade later, at the request of Cook’s state habeas 

counsel, Dr. Matthews reviewed Cook’s videotaped 

interview and opined that “it was extremely unlikely 

Mr. Cook could have meaningfully understood the 

admonition regarding his legal rights as expressed in the 

language and manner used by the interrogating officers.” 

6 On June 30, 1992, Cook submitted to another interview with two 

different detectives from the San Mateo County Sheriffs’ Office, during 

which he confessed to killing Earnest Sadler. Cook was not read his 

Miranda warnings at this interview, and these statements pertaining to 

Earnest Sadler were not used at trial.
COOK V. KERNAN 17

According to Dr. Matthews, “Cook’s spontaneous questions 

and comments . . . confirm that he did not have an adequate 

comprehension of his rights necessary to make a knowing 

and intelligent waiver.”

In 1992, Dr. George Wilkinson was retained by the 

defense team to perform a forensic pretrial evaluation of 

Cook, which included a review of the audiotaped recordings 

and “a half-hour videotape” of the interrogation. In his 

pretrial evaluation, Dr. Wilkinson concluded that Cook “had 

life-long attentional and learning disabilities that reduced his 

performance even below his measured intelligence level of 

borderline to low average.” He also noted “a pattern of 

deficits affecting memory and information-processing that 

rendered Mr. Cook vulnerable, particularly when under 

stress, to becoming overwhelmed and confused. Individuals 

with such impairments are dependent upon cues and 

guidance from others to maintain a useful and functional 

organization of information.” In 2005, at the request of state 

habeas counsel, Dr. Wilkinson reviewed additional material 

and rendered an updated opinion that, had he been asked to 

do so at trial, he would have opined that “the circumstances 

of the interrogation, including Mr. Cook’s 

neuropsychological and intellectual impairments and the 

effects of his trauma-based symptoms, prevented him from 

knowingly and intelligently understanding and waiving his 

right to remain silent.”

Two other mental health experts also evaluated Cook 

years after trial and provided declarations in support of his 

2005 state habeas petition. Dr. Myla Young concluded that 

Cook’s full scale IQ was 83 with a “level of performance . . .

similar to that demonstrated by most children with an age 

equivalence of 9.9 years.” Based on her testing, Dr. Young 

concluded that “the impairments that Mr. Cook 
18 COOK V. KERNAN

demonstrates in 2004 would have been present at the time of 

the offenses and his trial,” and noted that her conclusions 

were “consistent with those reported by Dr. Lynch in 1994.”

Dr. George Woods provided an extensive report in 2005, 

stating that

[Cook] is easily distracted by external stimuli 

and internal dialogue, cannot inhibit 

impulsive response selection or retrieve 

information accurately, and readily 

incorporates cues, prompting and direction 

from others into his strategies for recalling 

information. Under the best of circumstances 

these cognitive deficits render Mr. Cook 

vulnerable to suggestibility and 

confabulation, i.e., adopting a created or 

suggested memory to fill a void where only 

partial or no memory exists.

Dr. Woods further opined that “Cook’s repeated inability 

spontaneously to offer details of events, to confidently 

confirm or deny suggested details or to indicate other than a 

lack of memory for events are strong indications that 

independent recollection was not accessible to him.” 

According to Dr. Woods, “The methods of interrogation and 

Mr. Cook’s evolving acquiescence in acknowledging 

possible, probable, or even actual involvement in the 

offenses are accompanied by so many symptomatic signs of 

dissociation and confabulation, the videotape could serve as 

a didactic instrument for permitting clinicians to observe the 

psychological dynamics that might lead to a false 

confession.”
COOK V. KERNAN 19

D.

At Cook’s trial in 1994, the prosecution presented 

multiple witnesses linking Cook to each murder, ballistics 

evidence, and medical evidence, as well as Cook’s taped 

confession to the Bettencourt and Morris murders. The jury 

convicted Cook of three counts of first-degree murder in 

violation of California Penal Code § 187, with a special 

allegation of multiple murders under California Penal Code 

§ 190.2(a)(3), amongst other offenses. A month later, the 

jury returned a death verdict. In August 2006, the California 

Supreme Court issued its opinion on direct appeal and 

affirmed Cook’s convictions and death sentence in full. 

People v. Cook, 139 P.3d 492 (Cal. 2006).

In August 2005, while his appeal was still pending 

review, Cook filed a habeas petition with the California 

Supreme Court, raising seventeen claims, which included his 

claim that the state’s reliance on his confession violated his 

constitutional rights. The petition also raised a number of 

new factual allegations, including the allegation that 

Sergeant Eatmon had threatened Cook at gunpoint during the 

interview, and requested an evidentiary hearing into the 

allegations.

On December 15, 2010, the California Supreme Court 

issued its one-page decision on Cook’s habeas petition. The 

California Supreme Court first ordered the Director of the 

Department of Corrections and Rehabilitation to “show 

cause in the San Mateo County Superior Court . . . why 

petitioner’s death sentence should not be vacated and 

petitioner sentenced to life without the possibility of parole 

on the ground that he is mentally retarded within the 

meaning of Atkins v. Virginia . . . .” It then summarily 

denied “[a]ll of the remaining claims in the petition . . . on 

the merits.” The California Supreme Court also invoked 
20 COOK V. KERNAN

procedural bars for a number of Cook’s claims, including the 

claim that “his statements to police were obtained in 

violation of his constitutional rights.”

In November 2014, the San Mateo County Superior 

Court found that Cook met diagnostic criteria for intellectual 

disability within the meaning of Atkins, 536 U.S. 304, 

vacated the death sentence, and resentenced Cook to life in 

prison without the possibility of parole.

In December 2015, Cook filed his federal habeas petition 

with the district court, raising seven claims, each of which 

had been previously raised in his state habeas petition. Cook 

also moved the district court for an evidentiary hearing to 

look “into all disputed issues of fact material to his Petition 

for Habeas Corpus,” including his claim that Sergeant 

Eatmon threatened him at gunpoint into confessing to the 

Bettencourt murder.

The district court denied Cook’s habeas petition. It 

denied Cook’s motion for an evidentiary hearing because 

“[a]ll issues presented by his petition can be resolved on the 

record” and “[o]ther allegations would not entitle Cook to 

relief even if proven true. . . .” In regard to Cook’s claims 

pertaining to his statements to police, the district court 

concluded that Cook’s Miranda waiver was not knowing and 

intelligent,7 but the admission of the confession at trial was 

7 According to the district court, “[g]iven substantial evidence of 

[Cook’s] inability to comprehend his rights, including his youth, low IQ, 

psychological deficiencies, inability to follow verbal instructions, 

dissociation, and his statements to interrogators that he did not 

understand he had the right to have a lawyer present at his interrogation, 

a contrary conclusion is unreasonable.”
COOK V. KERNAN 21

not prejudicial because the remaining evidence still 

supported the Morris and Bettencourt murder convictions.8

II.

This court reviews de novo the district court’s denial of 

habeas relief. Murray v. Schriro, 882 F.3d 778, 801 (9th Cir. 

2018).

As amended by AEDPA, 28 U.S.C. § 2254(d) requires 

“highly deferential” review of state court adjudications, 

“demand[ing] that state-court decisions be given the benefit 

of the doubt.” Woodford v. Visciotti, 537 U.S. 19, 24 (2002) 

(per curiam) (quoting Lindh v. Murphy, 521 U.S. 320, 333 

n.7 (1997)). A federal court’s authority to grant habeas relief 

is limited to instances where the state court’s ruling was 

(1) “contrary to, or involved an unreasonable application of, 

clearly established Federal law, as determined by the 

Supreme Court of the United States” at the time the state 

court adjudicated the claim on the merits, 28 U.S.C. 

§ 2254(d)(1), or (2) “based on an unreasonable 

determination of the facts in light of the evidence presented 

at the State court proceeding.” Id. § 2254(d)(2).

The “contrary to” and “unreasonable application” 

clauses of § 2254(d)(1) have independent meaning. 

Williams v. Taylor, 529 U.S. 362, 405 (2000). A state 

court’s decision is “contrary to” clearly established federal 

law if it “applies a rule that contradicts the governing law set 

forth in [Supreme Court] cases” or if it “confronts a set of 

facts that are materially indistinguishable from a decision of 

8 Having found a Miranda violation, but no prejudice, the district 

court declined to reach the question of whether Cook’s confession was 

involuntary.
22 COOK V. KERNAN

[the Supreme] Court and nevertheless arrives at a result 

different from [this] precedent.” Id. at 405–06.

A state court’s decision is an “unreasonable application” 

of clearly established federal law if it “correctly identifies 

the governing legal rule but applies it unreasonably to the 

facts of a particular prisoner’s case.” Id. at 407–08. “The 

‘unreasonable application’ clause requires the state court 

decision to be more than incorrect or erroneous”; it must be 

“objectively unreasonable.” Lockyer v. Andrade, 538 U.S. 

63, 75 (2003) (quoting Williams, 529 U.S. at 410); see also 

Schriro v. Landrigan, 550 U.S. 465, 473 (2007) (“The 

question under AEDPA is not whether a federal court 

believes the state court’s determination was incorrect but 

whether that determination was unreasonable—a 

substantially higher threshold.”) (citing Williams, 529 U.S. 

at 410). In other words, “[a]s a condition for obtaining 

habeas corpus [relief] from a federal court, a state prisoner 

must show that the state court’s ruling on the claim being 

presented in federal court was so lacking in justification that 

there was an error well understood and comprehended in 

existing law beyond any possibility for fairminded 

disagreement.” Harrington v. Richter, 562 U.S. 86, 103 

(2011).

Similarly, in regard to claims under § 2254(d)(2), a state 

court’s factual determination is not “unreasonable merely 

because the federal habeas court would have reached a 

different conclusion in the first instance.” Wood v. Allen,

558 U.S. 290, 301 (2010). Even if “[r]easonable minds 

reviewing the record might disagree” about a factual finding, 

“on habeas review that does not suffice to supersede” the 

state court’s determination. Rice v. Collins, 546 U.S. 333, 

341–42 (2006).
COOK V. KERNAN 23

III.

Cook claims that the state’s reliance on his confession 

prejudicially violated his constitutional rights, because his 

statements to police were unlawfully obtained in two ways. 

First, Cook asserts he was unable to understand his Miranda 

rights from the outset of his interrogation and thus did not 

knowingly and intelligently waive them. Second, Cook 

alleges that his confessions were coerced based on the 

totality of the circumstances as established by the existing 

record.

The California Supreme Court summarily denied this 

claim “on the merits.”9 Despite the state court’s lack of 

explanation for its denial of relief, our review is still subject 

to AEDPA. See Cullen v. Pinholster, 563 U.S. 170, 187 

(2011) (“Section 2254(d) applies even where there has been 

a summary denial.”).

Where a state court’s decision is 

unaccompanied by an explanation, the 

habeas petitioner’s burden still must be met 

by showing there was no reasonable basis for 

the state court to deny relief. This is so 

whether or not the state court reveals which 

9 The California Supreme Court also found this claim procedurally 

barred under In re Seaton, 95 P.3d 896 (Cal. 2004). While this court has 

not yet squarely addressed whether In re Seaton provides an “adequate 

and independent” state procedural rule that bars federal habeas review, 

we need not decide this question given the state’s failure to plead the 

existence of such a bar to Cook’s claim. See Bennett v. Mueller, 322 F.3d 

573, 586 (9th Cir. 2003). In fact, at oral argument, the state expressly 

asserted that no procedural bar applies to this claim. Accordingly, we 

consider any procedural bar waived and proceed to review the merits of 

Cook’s claims regarding the validity of his Miranda waiver and the 

voluntariness of his confession under the AEDPA standard.
24 COOK V. KERNAN

of the elements in a multipart claim it found 

insufficient, for § 2254(d) applies when a 

‘claim,’ not a component of one, has been 

adjudicated.

Richter, 562 U.S. at 98. Thus, in reviewing the California 

Supreme Court’s summary denial of Cook’s claim, we must 

determine: (1) “what arguments or theories supported or . . .

could have supported . . . the state court’s decision”; and 

(2) “whether it is possible fairminded jurists could disagree 

that those arguments or theories are inconsistent with the 

holding in a prior decision of [the Supreme] Court.” Id. 

at 102. Given this deferential standard, Cook is not entitled 

to federal habeas relief on his claim because fairminded 

jurists could disagree as to whether Cook’s confession was 

obtained in violation of his constitutional rights.

A.

Before proceeding with a custodial interrogation, a 

suspect must be advised of his Miranda rights: that he “‘has 

the right to remain silent, that anything he says can be used 

against him in a court of law, that he has the right to the 

presence of an attorney, and that if he cannot afford an 

attorney one will be appointed for him prior to any 

questioning if he so desires.’” Dickerson v. United States, 

530 U.S. 428, 435 (2000) (quoting Miranda v. Arizona, 

384 U.S. 436, 479 (1966)); see also Berghuis v. Thompkins, 

560 U.S. 370, 380 (2010). A suspect’s waiver of these rights 

is valid only if it is “voluntary, knowing and intelligent.” 

Miranda, 384 U.S. at 479. Thus, the waiver inquiry “has two 

distinct dimensions”—first, it must be “voluntary in the 

sense that it was the product of a free and deliberate choice 

rather than intimidation, coercion, or deception,” and 

second, it must be “made with a full awareness of both the 
COOK V. KERNAN 25

nature of the right being abandoned and the consequences of 

the decision to abandon it.” Thompkins, 560 U.S. at 382–83 

(quoting Moran v. Burbine, 475 U.S. 412, 421 (1986)). A 

waiver satisfies this two-part standard only “if the ‘totality 

of the circumstances surrounding the interrogation’ reveal 

both an uncoerced choice and the requisite level of 

comprehension.” Burbine, 475 U.S. at 421 (quoting Fare v. 

Michael C., 442 U.S. 707, 725 (1979)).

On the night of Cook’s arrest and initial interview, he 

was advised by police of his Miranda rights—three times in 

fact. Each time, Cook readily affirmed that he understood 

his rights and wanted to speak anyway, and did so without 

any apparent form of intimidation, coercion, or deception 

from the investigators providing the warnings. Each time 

the investigators read or reminded Cook of his Miranda 

rights during the interview, they also followed up with 

additional questions to ensure that Cook understood the 

rights he was read and wanted to waive them and proceed 

with the questioning, which—from at least an objective 

vantage point—Cook did. In that respect, the record 

supports the conclusion that Cook’s Miranda waiver was 

voluntary.

However, the mere fact “that a Miranda warning was 

given and the accused made an uncoerced statement, . . .

standing alone, is insufficient to demonstrate ‘a valid 

waiver’ of Miranda rights.” Thompkins, 560 U.S. at 384 

(quoting Miranda, 384 U.S. at 475). “The prosecution must 

make the additional showing that the accused understood 

these rights[,]” id., meaning that his waiver was also 

knowing and intelligent. “The determination of whether 

there has been an intelligent waiver . . . must depend, in each 

case, upon the particular facts and circumstances 

surrounding that case, including the background, experience, 
26 COOK V. KERNAN

and conduct of the accused.” Johnson v. Zerbst, 304 U.S. 

458, 464 (1938). Here, the record evidence contains some 

indication that Cook did not understand his right to have an 

attorney present during his interrogation—and thus did not 

knowingly and intelligently waive this particular right. 

These factors include: the weight of the mental health 

evidence regarding his cognitive inability to understand the 

rights warnings; the occasional indications of his confusion 

or lack of comprehension during the interview; and the 

statements he made on the second day of his interview, when 

he questioned whether he could have a lawyer present and 

asserted that he did not previously understand this right.

At the same time, “[t]he Constitution does not require 

that a criminal suspect know and understand every possible 

consequence of a waiver of the Fifth Amendment privilege. 

The Fifth Amendment’s guarantee is both simpler and more 

fundamental: A defendant may not be compelled to be a 

witness against himself in any respect.” Colorado v. Spring, 

479 U.S. 564, 574 (1987). The totality of Cook’s conduct, 

particularly on the first day of his interview, as well as his 

background and experience, support the conclusion that 

Cook fundamentally understood his Fifth Amendment 

rights. Cook had been arrested and been provided Miranda 

warnings on several occasions in the past, which the 

investigators confirmed at the beginning of the interview. 

And throughout much of the interview, Cook was able to 

respond coherently to the investigators’ questions. Based on 

these factors, the government’s alternative interpretation of 

the circumstances is reasonable: Cook “understood his rights 

and agreed to speak with police without counsel but then 

changed his mind the next day, proffering the self-serving 
COOK V. KERNAN 27

excuse that he had not earlier understood his right to 

counsel.”10

Under AEDPA’s deferential standard of review, we must 

keep in mind that review of Cook’s habeas action is “not a 

substitute for ordinary error correction through appeal.” 

Richter, 562 U.S. at 102–03. In order to grant relief, we are 

required to find that no fairminded jurist could conclude that 

Cook knowingly and voluntarily waived his Miranda rights. 

Although there are certain facts in the record that may 

support a finding that Cook did not fully and completely 

understand his right to have an attorney present at his 

interrogation, we must give even greater deference under 

AEDPA when determining whether the case-specific 

application of a general standard, such as the “totality of the 

circumstances” test, provides a reasonable basis for a state 

court decision. Based on the facts that Cook was repeatedly 

warned of his Miranda rights, expressly acknowledged the 

warnings, and offered coherent and knowing answers to the 

officers’ questions, the California Supreme Court had a 

reasonable basis to reject Cook’s challenge to the validity of 

his Miranda waiver.11

10 Given these circumstances, the dissent’s assertion that we find 

“one-word verbal affirmations” sufficient to establish that Cook 

understood the rights he was waiving obviously mischaracterizes our 

decision. See Dissent at 48.

11 The dissent arrives at a contrary conclusion after conducting what 

appears to be its “own independent inquiry into whether the state court 

was correct as a de novo matter” under the guise of AEDPA review. 

Yarborough v. Alvarado, 541 U.S. 652, 665 (2004). It is emphatically 

not the role of a federal habeas court to “issue the writ simply because 

that court concludes in its independent judgment that the state-court 

decision applied [the law] incorrectly.” Id. (quoting Woodford v. 

Visciotti, 537 U.S. 19, 24–25 (2002) (per curiam)).
28 COOK V. KERNAN

B.

We next address the voluntariness of Cook’s confession. 

An involuntary or coerced confession is inadmissible at trial, 

Lego v. Twomey, 404 U.S. 477, 478 (1972), because its 

admission is a violation of a defendant’s right to due process 

under the Fourteenth Amendment, Jackson v. Denno, 

378 U.S. 368, 385–86 (1964). A confession is involuntary 

if it is not “‘the product of a rational intellect and a free 

will.’” Medeiros v. Shimoda, 889 F.2d 819, 823 (9th Cir. 

1989) (citation omitted). A “necessary predicate” to finding 

a confession involuntary is that it was produced through 

“coercive police activity.” Colorado v. Connelly, 479 U.S. 

157, 167 (1986). Coercive police activity can be the result 

of either “physical intimidation or psychological pressure.” 

Townsend v. Sain, 372 U.S. 293, 307 (1963). Whether a 

confession is involuntary must be analyzed within the 

“totality of [the] circumstances.” Withrow v. Williams, 

507 U.S. 680, 693 (1993). “The factors to be considered 

include the degree of police coercion; the length, location 

and continuity of the interrogation; and the defendant’s 

maturity, education, physical condition, mental health, and 

age.” Brown v. Horell, 644 F.3d 969, 979 (9th Cir. 2011) 

(citations omitted).

Cook argues that the evidence in the existing record 

establishes coercion, highlighting the expert opinions that 

his statements to police were not voluntary based on his 

mental capabilities at the time. Cook likens his situation to 

United States v. Preston, 751 F.3d 1008 (9th Cir. 2014) (en 

banc), where we held that the 38-minute noncustodial 

interview of an eighteen-year old with an IQ of 65 was 

coercive and rendered his confession involuntary. Cook’s 

IQ at the time of his interview ranged between 83 to 89, 

which is notably higher than Preston’s. However, other 
COOK V. KERNAN 29

aspects of Cook’s interrogation are comparable to Preston’s, 

such as their similar age and some of the descriptions of their 

mental attributes—i.e., “easily confused” and “highly 

suggestible and easy to manipulate.” Id. at 1022. Cook’s 

investigators also employed some of the same interrogation 

techniques that we noted “would be hard for a person of 

Preston’s impaired intelligence to withstand or rationally 

evaluate”—such as “alternative questioning, providing 

suggestive details, and repetitious and insistent questions.” 

Id. at 1025–26. Moreover, Cook’s custodial interrogation 

also lasted around seven hours—far longer than the 

noncustodial interview in Preston—during which Cook 

became emotional at times and appeared physically 

exhausted by the end. These factors, on de novo review, 

could support the same conclusion we reached in Preston: 

that the “subtle forms of psychological persuasion” 

employed by the investigators were sufficiently coercive to 

overcome Cook’s will. See id. at 1023 (quoting Connelly, 

479 U.S. at 164).

However, our opinion in Preston is not “clearly 

established” Supreme Court precedent and thus not 

controlling under AEDPA review. See Williams, 529 U.S. 

at 412 (stating that the phrase “clearly established Federal 

law” in § 2254(d)(1) “refers to the holdings, as opposed to 

the dicta, of [the Supreme] Court’s decisions as of the time 

of the relevant state-court decision”). Moreover, none of the 

Supreme Court cases cited by Cook provide us with a 

“materially indistinguishable” set of facts by which we can 

determine whether the state court’s decision to deny relief in 

Cook’s case ran contrary to clearly established federal law. 

See id. at 405. Nor do we find that the state court’s 

conclusion would be an unreasonable application of clearly 

established federal law to the facts of Cook’s case. Indeed, 

the “totality of the circumstances” test for voluntariness as 
30 COOK V. KERNAN

established by the Supreme Court is a fact-based analysis 

that inherently allows for a wide range of reasonable 

application. Since “[a]pplying a general standard to a 

specific case can demand a substantial element of 

judgment,” federal courts must provide even “more leeway” 

under AEDPA in “evaluating whether a rule application was 

unreasonable . . . in case-by-case determinations.” 

Yarborough v. Alvarado, 541 U.S. 652, 664 (2004); see also 

Richter, 562 U.S. at 101 (applying this greater degree of 

deference in a case where the state court denied habeas relief 

in a one-sentence summary order).

Given this, Cook utterly fails to show how the conclusion 

that his confession was voluntary under the totality of the 

circumstances is “inconsistent with the holding in a prior 

decision of the Supreme Court.” Richter, 562 U.S. at 102. 

Cook’s case presents several circumstances that, taken 

together, could reasonably support the finding that his 

confession was voluntary. First, there is the apparent lack of 

blatantly coercive police activity from the videotaped 

interview. Aside from some of the suggestive or “repetitious 

and insistent” questioning we earlier noted, the entire 

interview contains little indication of coercion. In fact, the 

investigators’ interactions with Cook throughout the 

interview appear professional, calm, and even affable at 

times. They did not raise their voices or threaten Cook or 

make explicit promises of leniency for his confession, and 

they offered him breaks, food, and water throughout the 

interview. Second, Cook’s responses, taken as a whole, 

could be reasonably viewed as a deliberate—and largely 

successful—effort on his part to resist the officers’ 

interrogation tactics. Throughout the interview, Cook 

manages to evade the officers’ repeated and varied attempts 

to elicit specific admissions and inculpating details about the 

crimes, often by providing non-responsive, diversionary 
COOK V. KERNAN 31

answers to their questions. When he does finally “confess,” 

he makes only vague admissions to facts that minimize his 

culpability for the crimes—for instance, his repeated claims 

that he “blanked” out and does not remember actually 

committing the murders. Third, the circumstances 

surrounding the crimes and Cook’s personal history—such 

as his disposal of the murder weapon and flight to Oklahoma 

after the Morris shooting, as well as his previous arrests and 

experience with law enforcement—suggest that he could 

appreciate the gravity of his situation and his actions and 

could take affirmative measures to minimize or mask his 

guilt.

In light of the state court record, the California Supreme 

Court had a reasonable basis to conclude that Cook’s 

confession was voluntary.

C.

We finally address Cook’s request for an evidentiary 

hearing into his allegation that Sergeant Eatmon threatened 

him at gunpoint during his interview. As evidentiary support 

for his factual claim, Cook cites to the videotaped 

confession, in which he claims he makes indirect references 

to Eatmon’s gunpoint threat,12 and to his proffered evidence 

“that Eatmon had a reputation for sadistic violence, and a 

documented history of lying and lacking integrity.” 

Although Cook presented this evidence along with a request 

for an evidentiary hearing in his state habeas petition, the 

California Supreme Court summarily denied his petition 

12 Specifically, Cook points out that, minutes after Eatmon allegedly 

threatened him and the interrogation resumed, he states, “[E]veryone 

know that I did it or not, I did it so, you all can just shoot me or whatever 

it don’t matter.”
32 COOK V. KERNAN

without granting a hearing on this issue. According to Cook, 

because the state court never afforded him an evidentiary 

hearing to develop his claim, its fact-finding process was 

deficient, and this court should review Cook’s claims de 

novo. Alternatively, Cook asks us to “remand to the district 

court for an evidentiary hearing on the allegation against 

Eatmon.” Cook’s arguments essentially raise two separate 

claims: (1) the state habeas court’s failure to make any 

factual findings regarding the alleged gunpoint threat by 

Sergeant Eatmon was, in itself, an “unreasonable 

determination of the facts” under § 2254(d)(2), and (2) Cook 

is otherwise entitled to a federal evidentiary hearing under 

§ 2254(e)(2).

To determine whether a petitioner is entitled to an 

evidentiary hearing under § 2254(e)(2), a court must first 

determine whether a factual basis exists in the record to 

support the petitioner’s claim. Insyxiengmay v. Morgan, 

403 F.3d 657, 669–70 (9th Cir. 2005) (quoting Baja v. 

Ducharme, 187 F.3d 1075, 1078 (9th Cir. 1999)). If the 

record contains a sufficient factual basis that “refutes the 

applicant’s factual allegations or otherwise precludes habeas 

relief, a district court is not required to hold an evidentiary 

hearing.” Landrigan, 550 U.S. at 474; see Pinholster,

563 U.S. at 171 (“[A] federal habeas court is ‘not required to 

hold an evidentiary hearing’ when the state-court record 

‘precludes habeas relief’ under § 2254(d)’s limitations.”) 

(citation omitted). If the factual basis for a claim is 

undeveloped or absent, the next inquiry is whether petitioner 

“failed to develop” these facts in state court proceedings. 

Insyxiengmay, 403 F.3d at 669–70. Only when a petitioner 

demonstrates that he did not fail to develop the factual basis 

for his claim in state court may a federal court proceed to 

consider whether a hearing is appropriate or required under 

the framework set forth in Townsend v. Sain. Id.
COOK V. KERNAN 33

Under this analytical framework, Cook is not entitled to 

an evidentiary hearing. Cook’s failure to develop the factual 

basis for his claim in state court proceedings was due to his 

own lack of diligence. “Under the opening clause of 

§ 2254(e)(2), a failure to develop the factual basis of a claim 

is not established unless there is lack of diligence, or some 

greater fault, attributable to the prisoner or the prisoner’s 

counsel.” Williams, 529 U.S. at 432; see Baja, 187 F.3d 

at 1078. The standard for determining “diligence” is 

whether a petitioner “made a reasonable attempt, in light of 

the information available at the time, to investigate and 

pursue claims in state court.” Williams, 529 U.S. at 435. 

Absent unusual circumstances, diligence requires “that the 

prisoner, at a minimum, seek an evidentiary hearing in state 

court in the manner prescribed by state law.” Id. at 437. 

However, “a petitioner who ‘knew of the existence of [] 

information’ at the time of his state court proceedings, but 

did not present it until federal habeas proceedings, ‘failed to 

develop the factual basis for his claim diligently.’” Rhoades 

v. Henry, 598 F.3d 511, 517 (9th Cir. 2010) (quoting 

Cooper-Smith v. Palmateer, 397 F.3d 1236, 1241 (9th Cir. 

2005)).

Cook claims he was diligent simply because he requested 

an evidentiary hearing in his 2005 habeas petition to the 

California Supreme Court but was denied. However, 

Sergeant Eatmon allegedly threatened Cook during his 

interrogation in 1992, which was nearly two years prior to 

his trial. Thus, Cook was aware of the facts underlying this 

claim both prior to trial and long before he first raised it in 

his habeas petition. Cook does not explain whether he 

informed his counsel about this incident, or why this factual 

allegation was not raised at trial or on appeal, except in the 

context of his claim that his trial counsel was ineffective. 

Cook’s counsel did not cross-examine Sergeant Eatmon on 
34 COOK V. KERNAN

this alleged threat, nor do they mention the incident in either 

the motion to suppress the confession at trial, or in their 2005 

state habeas affidavits—all of which suggests that Cook’s 

counsel were unaware of Sergeant Eatmon’s alleged threat 

during the interview because Cook never informed them. 

Cook does not assert otherwise, nor does he proffer any 

reason for why he should be absolved of his personal 

responsibility for the diligent pursuit of his claims. Under 

§ 2254(e)(2), we may not grant Cook an evidentiary 

hearing—almost three decades after trial in federal habeas 

court—to develop the factual basis of a claim that Cook 

knew of before trial and failed to develop during his state 

proceedings.

For similar reasons, we also reject Cook’s claim that the 

state habeas court’s denial of an evidentiary hearing into his 

Sergeant Eatmon allegation was, in itself, an “unreasonable 

determination of the facts” under § 2254(d)(2). We view 

Cook’s argument here as essentially an “intrinsic” challenge 

to the state court’s determination of fact under § 2254(d)(2), 

which “may be based on a claim . . . ‘that no finding was 

made by the state court at all,’ when it was required to make 

a finding.” Murray v. Schriro, 745 F.3d 984, 999 (9th Cir. 

2014) (quoting Taylor v. Maddox, 366 F.3d 992, 999 (9th 

Cir. 2004)). When performing an intrinsic review, we “may 

only hold that a state court’s factfinding process is materially 

defective if we are ‘satisfied that any appellate court to 

whom the defect is pointed out would be unreasonable in 

holding that the state court’s fact-finding process was 

adequate.’” Id. (quoting Taylor, 366 F.3d at 1000). Cook 

fails to overcome this standard because he does not show 

how the state court was required to afford him an evidentiary 

hearing to develop a factual allegation of which he was 

aware, but did not raise, at trial. In short, Cook is not entitled 
COOK V. KERNAN 35

to an evidentiary hearing under AEDPA, and the district 

court did abuse its discretion in denying his request.

IV.

We affirm the district court’s denial of relief on Cook’s 

claim that his confession was obtained in violation of his 

constitutional rights. Based on the record, the state habeas 

court had a reasonable basis for finding that Cook’s waiver 

was knowing and intelligent, and that his confession was not 

coerced and involuntary. In addition, Cook is not entitled to 

an evidentiary hearing on the issue of the voluntariness of 

his confession because he failed to timely develop in state 

court the factual basis for his claim that Sergeant Eatmon 

threatened him at gunpoint. The district court’s denial of 

Cook’s habeas petition is AFFIRMED.

CALLAHAN, Circuit Judge, concurring:

Because the state court could have reasonably denied 

Cook’s claim on the ground that his Miranda waiver was 

valid and his statements to police were voluntarily given, we 

are compelled to deny relief under AEDPA and need not 

reach the question of whether Cook was prejudiced by the 

admission of his statements. But if we did, I would agree 

with the district court that the California Supreme Court 

could have reasonably denied Cook’s claim on the ground 

that any error was harmless.

“For reasons of finality, comity, and federalism, habeas 

petitioners ‘are not entitled to habeas relief based on trial 

error unless they can establish that it resulted in actual 

prejudice.’” Davis v. Ayala, 135 S. Ct. 2187, 2197, 192 L. 

Ed. 2d 323 (2015) (quoting Brecht v. Abrahamson, 507 U.S. 
36 COOK V. KERNAN

619, 637 (1993)). In testing for prejudice under AEDPA’s 

deferential standard of review, “relief is proper only if” we 

have “grave doubt about whether a trial error of federal law 

had ‘substantial and injurious effect or influence in 

determining the jury’s verdict.’” Id. at 2197–98 (quoting 

O'Neal v. McAninch, 513 U.S. 432, 436 (1995)). This 

standard “reflects the view that a ‘State is not to be put to 

th[e] arduous task [of retrying a defendant] based on mere 

speculation that the defendant was prejudiced by trial error; 

the court must find that the defendant was actually 

prejudiced by the error.’” Id. at 2198 (quoting Calderon v. 

Coleman, 525 U.S. 141, 146 (1998) (per curiam)). Thus, to 

warrant relief under AEDPA, Cook must show that he was 

actually prejudiced by the admission of his statements at 

trial—“a standard that he necessarily cannot satisfy if a 

fairminded jurist could agree with the California Supreme 

Court’s decision that [the error was harmless].” Id. at 2199.

Given the totality of the record evidence, Cook is unable 

to establish that his statements regarding the murders of 

Bettencourt and Morris, if erroneously admitted, had 

“substantial and injurious effect” on the jury’s findings of 

guilt as to those murders. Brecht, 507 U.S. at 637. As the 

dissent points out, a “defendant’s own confession is 

probably the most probative and damaging evidence that can 

be admitted against him.” Arizona v. Fulminante, 499 U.S. 

279, 296 (1991) (citing Bruton v. United States, 391 U.S. 

123, 139–40 (1968) (White, J., dissenting)). In Cook’s case 

however, the equivocal statements he made in confessing to 

the Bettencourt and Morris murders are not particularly 

damning admissions of guilt. Even after seven hours of 

questioning, Cook provided little detail as to why or how he 

committed the murders, offering only vague accounts that he 

was at each of the crime scenes with a weapon in hand and 

“blanked out.” If anything, Cook’s admissions in his taped 
COOK V. KERNAN 37

interview provided evidence that mitigated his mental 

culpability for the crimes, which his defense team 

reasonably viewed as helpful to his case.

Moreover, both the Bettencourt and Morris murders 

were supported by several different sources of evidence—

including the corroborating testimonies of multiple 

witnesses and forensic evidence—all of which consistently 

demonstrated that Cook’s shootings of these victims 

amounted to similar instances of unprovoked, cold-blooded 

murder. The Bettencourt murder was witnessed by a large 

group of individuals at the scene, and seven witnesses gave 

statements to police that identified Cook as the shooter. 

Likewise, the Morris murder was witnessed by the two other 

inhabitants in Cook’s car, as well as the women in the car 

behind them.

The dissent claims that most of this evidence was “either 

seriously compromised or inconclusive” based on witness 

recantations at trial, bias and motives to fabricate, and some 

inconsistencies in the evidence.1 However, even without the 

1 The dissent also argues that the admission of Cook’s confession 

was prejudicial because it led to the trial court’s improper joinder of his 

three murder charges, even though Cook himself does not raise this 

argument in his habeas petition. In reviewing a state court’s summary 

denial of a habeas claim under AEDPA, our task is to determine “what 

arguments or theories . . . could have supported[] the state court’s 

decision,” Harrington v. Richter, 562 U.S. 86, 102 (2011), not to search 

for any arguments or theories that could have supported an opposite 

conclusion and grant of relief. Even if we were to consider the question 

of prejudice through the lens of an improper joinder claim, the California 

Supreme Court reasonably found on direct appeal that the trial court’s 

joinder of the charges was proper, and did so by relying on evidence that 

was independent of Cook’s confession—i.e., the “substantial crossadmissibility” of the ballistics evidence between the Bettencourt and 
38 COOK V. KERNAN

eyewitness accounts that were allegedly “compromised” by 

bias or recantation, the record contains evidence from 

unbiased sources sufficient to support the jury’s verdicts for 

the two murders. For instance, in regard to the Morris 

murder, Sharoon Reed—a neutral bystander eyewitness with 

no apparent bias or motive to fabricate—provided an 

account that corroborated the testimony of Senegal and 

Branner. Similarly, Nathan Gardner, a bystander who 

happened to be on Alberni Street when he saw Cook shoot 

Bettencourt, gave Cook a ride from the murder scene and 

testified that Cook explained that he shot Bettencourt 

because Bettencourt had tried to “gaffle” him. Perhaps more 

importantly, Cook’s various challenges to the witnesses’ 

credibility and other evidence were fully presented to and 

weighed by the jury at trial. Ultimately, they do not 

undermine the highly probative facts that multiple 

witnesses—from different vantage points at each of the 

crime scenes and with different relationships to Cook—

provided generally consistent accounts, which, along with 

the ballistics evidence, clearly implicated Cook.

In light of the weight of the evidence in the record, the 

state habeas court could have reasonably denied Cook’s 

claim on the basis that the admission of his confession did 

not prejudice him at trial. Because Cook is unable to show 

actual prejudice or that no fairminded jurist could agree with 

the California Supreme Court’s rejection of his claim on the 

basis of harmlessness, he is not entitled to relief under 

AEDPA.

Morris murders, and the common eyewitness between the Morris and 

Sadler murders. See People v. Cook, 139 P.3d 492, 505 (Cal. 2006).
COOK V. KERNAN 39

MURGUIA, Circuit Judge, dissenting:

I respectfully disagree with the majority’s conclusion 

that the California Supreme Court could have reasonably 

denied habeas relief on the basis that Cook (1) knowingly 

and intelligently waived his Miranda rights; and (2) suffered 

no prejudice from the improper admission of his unlawfully 

obtained confession to the Bettencourt murder and other 

incriminating statements. Accordingly, I would reverse the 

district court’s denial of habeas relief.

1. Standard of Review.

Under the Antiterrorism and Effective Death Penalty Act 

(“AEDPA”), a writ of habeas corpus may not be granted 

unless the state court’s decision (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, 28 U.S.C. § 2254(d)(1); 

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, id.

§ 2254(d)(2).

“The state court unreasonably applies clearly established 

federal law if it ‘either 1) correctly identifies the governing 

rule but then applies it to a new set of facts in a way that is 

objectively unreasonable, or 2) extends or fails to extend a 

clearly established legal principle to a new context in a way 

that is objectively unreasonable.’” DeWeaver v. Runnels, 

556 F.3d 995, 997 (9th Cir. 2009) (quoting Hernandez v. 

Small, 282 F.3d 1132, 1142 (9th Cir. 2002), and then citing 

Williams v. Taylor, 529 U.S. 362, 408–09 (2000)); see also 

Mann v. Ryan, 828 F.3d 1143, 1151 (9th Cir. 2016) (en 

banc). “As a condition for obtaining habeas corpus from a 

federal court, a state prisoner must show that the state court’s 
40 COOK V. KERNAN

ruling on the claim being presented in federal court was so 

lacking in justification that there was an error well 

understood and comprehended in existing law beyond any 

possibility of fairminded disagreement.” Harrington v. 

Richter, 562 U.S. 86, 103 (2011); see also Metrish v. 

Lancaster, 569 U.S. 351, 358 (2013).

“Factual determinations by state courts are presumed 

correct absent clear and convincing evidence to the contrary, 

§ 2254(e)(1), and a decision adjudicated on the merits in a 

state court and based on a factual determination will not be 

overturned on factual grounds unless objectively 

unreasonable in light of the evidence presented in the statecourt proceeding, § 2254(d)(2).” Miller-El v. Cockrell, 

537 U.S. 322, 340 (2003); Davis v. Ayala, 135 S. Ct. 2187, 

2199–2200 (2015) (“State-court factual findings, . . . are 

presumed correct; the petitioner has the burden of rebutting 

the presumption by clear and convincing evidence.” (quoting 

Rice v. Collins, 546 U.S. 333, 338–39 (2006))). “Even in the 

context of federal habeas, ...[d]eference does not by 

definition preclude relief. A federal court can disagree with 

a state court’s credibility determination and, when guided by 

the AEDPA, conclude the decision was unreasonable or that 

the factual premise was incorrect by clear and convincing 

evidence.” Miller-El v. Cockrell, 537 U.S. at 340.

Here, the California Supreme Court “denied on the 

merits” all of Cook’s habeas claims—including that he did 

not knowingly and intelligently waive his Miranda rights—

in a summary order, unaccompanied by an opinion 

explaining the reasons relief was denied. “Section 2254(d) 

applies even where there has been a summary denial.” 

Cullen v. Pinholster, 563 U.S. 170, 187 (2011) (citing 

Richter, 562 U.S. at 98). “Where a state court’s decision is 

unaccompanied by an explanation, the habeas petitioner’s 
COOK V. KERNAN 41

burden still must be met by showing there was no reasonable 

basis for the state court to deny relief.” Richter, 562 U.S. 

at 98. Therefore, when the state court summarily denies a 

petitioner habeas relief, “[u]nder § 2254(d), a habeas court 

must determine what arguments or theories . . . could have

supported the state court’s decision; and then it must ask 

whether it is possible fairminded jurists could disagree that 

those arguments or theories are inconsistent with the holding 

in a prior decision of [the Supreme] Court.” Id. at 102 

(emphasis added); see also Wilson v. Sellers, 138 S. Ct. 

1188, 1191–92 (2018) (“Deciding whether a state court’s 

decision ‘involved’ an unreasonable application of federal 

law or ‘was based on’ an unreasonable determination of fact 

requires the federal habeas court to ‘train its attention on the 

particular reasons—both legal and factual—why state courts 

rejected a state prisoner’s federal claims,’ and to give 

appropriate deference to that decision” (quoting Hittson v. 

Chatman, 135 S.Ct. 2126, 2126 (2015) (Ginsburg, J., 

concurring in denial of certiorari) and then citing Richter,

562 U.S. at 101–102)); Johnson v. Williams, 568 U.S. 289, 

293 (2013) (holding that where a state habeas court issues an 

opinion that addresses some issues but does not expressly 

address the federal habeas claim in question, that claim 

“must be presumed to have been adjudicated on the merits 

by the [state habeas court] . . . [and] the restrictive standard 

of review set out in § 2254(d)(2) applies”).

If we conclude that the state habeas court committed a 

constitutional error during a criminal trial, we “must [then] 

assess the prejudicial impact of the error under the 

‘substantial and injurious effect’ standard set forth in Brecht 

v. Abrahamson.” Fry v. Pliler, 551 U.S. 112, 114 (2007) 

(quoting 507 U.S. 619 (1993)); see also Jones v. Harrington, 

829 F.3d 1128, 1141 (9th Cir. 2016) (“In AEDPA 

proceedings, [the court] appl[ies] the actual-prejudice 
42 COOK V. KERNAN

standard set forth [Brecht].”). “There must be more than a 

‘reasonable possibility’ that the error was harmful.” Ayala,

135 S. Ct. at 2198 (quoting Brecht, 507 U.S. at 637). “[A] 

‘State is not to be put to th[e] arduous task [of retrying a 

defendant] based on mere speculation that the defendant was 

prejudiced by trial error; the court must find that the 

defendant was actually prejudiced by the error.’” Id. 

(quoting Calderon v. Coleman, 525 U.S. 141, 146 (1998) 

(per curiam)).

2. The state habeas court’s summary conclusion 

that Cook knowingly and intelligently waived his 

Miranda rights was an unreasonable application 

of Thompkins and its progeny and relied on an 

unreasonable determination of the facts.

The state habeas court’s summary order finding that 

Cook knowingly and intelligently waived his Miranda rights 

is an unreasonable application of Berghuis v. Thompkins, 

560 U.S. 370, 384 (2010), which is clearly established 

federal law, and relies on an unreasonable determination of 

the facts. Therefore, the admission of Cook’s confession to 

the Bettencourt murder and other incriminating statements 

about the Morris murder constitutes an unconstitutional trial 

error under AEDPA.

I would affirm the district court’s well-supported finding 

that Cook’s Miranda waiver was not knowing and intelligent 

under Thompkins, “[g]iven substantial evidence of his 

inability to comprehend his rights, including his youth, low 

IQ, psychological deficiencies, inability to follow verbal 

instructions, dissociation, and his statements to interrogators 

that he did not understand he had the right to have a lawyer 

present at his interrogation[.]”
COOK V. KERNAN 43

The Supreme Court has clearly established that a 

Miranda waiver must be done knowingly and intelligently. 

Thompkins, 560 U.S. at 383 (quoting Miranda v. Arizona, 

384 U.S. 436, 475 (1966)). There is a well-established 

presumption against waiver, North Carolina v. Butler, 

441 U.S. 369, 373 (1979) (quoting Miranda, 384 U.S. 436, 

475 (1966)), and the government bears the burden of 

overcoming that presumption by introducing sufficient 

evidence that, under the totality of the circumstances, Cook 

was aware of “the nature of the right being abandoned and 

the consequences of the decision to abandon it.” Moran v. 

Burbine, 475 U.S. 412, 421 (1986); see also Thompkins, 

560 U.S. at 384 (clarifying “that this ‘heavy burden’ is . . .

the burden to establish waiver by a preponderance of the 

evidence” (citing Colorado v. Connelly, 479 U.S. 157, 168 

(1986))). The government’s burden to make such a showing 

“is great,” and we “must indulge every reasonable 

presumption against waiver of fundamental constitutional 

rights.” United States v. Heldt, 745 F.2d 1275, 1277 (9th 

Cir.1984) (citing Johnson v. Zerbst, 304 U.S. 458, 464 

(1938)).

There is no objectively reasonable basis for the 

California Supreme Court’s holding that Cook, an 

intellectually disabled man with severe mental illnesses, was 

competent to fully understand and waive his Miranda rights. 

Although the Supreme Court has never directly addressed 

whether intellectually disabled and mentally ill defendants 

can knowingly and intelligently waive their Fifth 

Amendment rights, it would be unreasonable not to apply the 

principles of Thompkins and its progeny to award habeas 

relief in this case. See Williams, 529 U.S. at 407 (holding 

that a state-court decision can be overturned by the federal 

courts if the state “unreasonably refuses to extend [a] 

principle to a new context where it should apply”); cf. 
44 COOK V. KERNAN

Bradley v. Duncan, 315 F.3d 1091, 1100–01 (9th Cir. 2002) 

(holding that state court’s refusal to allow petitioner to put 

on entrapment defense constituted unreasonable application 

of federal law as it violated his “right to present a complete 

and meaningful defense to the jury under the principles set 

out in [Supreme Court cases]”).

The majority advances what are the only four possible 

reasons that could have supported the California Supreme 

Court’s decision to summarily deny Cook’s claim that he did 

not knowingly and intelligently waive his Miranda rights. 

First, my colleagues state that Cook fully understood he was 

waiving his Miranda rights because, at the outset of the 

June 26, 1992 interrogation, he “readily affirmed that he 

understood his rights and wanted to speak anyway.” Op. 

at 25. Second, they reason that “throughout much of the 

[June 26 interrogation], Cook was able to respond 

coherently to the investigator’s questions.” Op. at 26. Third, 

they submit that he “changed his mind the next day, 

proffering the self-serving excuse that he had not earlier 

understood his right to counsel.” Op. at 26–27. Finally, the 

majority relies significantly on the fact that Cook had been 

arrested and presumably read his Miranda rights in the past. 

Op. at 26. None of these reasons “could have led a 

fairminded jurist to conclude that” Cook knowingly and 

intelligently waived his constitutional rights pursuant to 

Thompkins and its progeny. Sexton v. Beaudreaux, 138 

S. Ct. 2555, 2559 (2018) (citing Richter, 562 U.S. at 102). 

In turn, I will address each of the majority’s misguided 

reasons for denying habeas relief.

First, I disagree with the majority’s unsupported holding 

that one-word verbal affirmations are sufficient, considering 

the totality of other circumstances involved here, to establish 

that a man with Cook’s acute intellectual disability and 
COOK V. KERNAN 45

mental illnesses had a “full awareness of both the nature of 

the right being abandoned and the consequences of the 

decision to abandon it.” Thompkins, 560 U.S. at 382–83 

(quoting Burbine, 475 U.S. at 421).

It is undisputed that Cook verbally responded “yeah” and 

“uh-hum” when asked if he understood his Miranda rights 

at the outset of the June 26 seven-hour interrogation, during 

which he confessed to the Bettencourt murder and made 

other incriminating statements about the Morris murder. At 

best, this “establishes that a Miranda warning was given and 

the accused made an uncoerced statement,” which “standing 

alone, is insufficient to demonstrate ‘a valid waiver’ of 

Miranda rights.” Thompkins, 560 U.S. at 384 (quoting 

Miranda, 384 U.S. at 475). “The prosecution must make the 

additional showing that the accused understood these 

rights.” Id. (citations omitted). Here, there is overwhelming 

evidence that Cook did not understand his rights due to his 

serious intellectual disability and mental illnesses. In fact, 

at the direction of the California Supreme Court, the trial 

court found that Cook was intellectually disabled within the 

meaning of Atkins v. Virginia, 536 U.S. 304 (2002), vacating 

his death penalty and imposing a sentence of life without the 

possibility of parole.1 Although not determinative, the state 

trial court’s finding that Cook was intellectually disabled 

under Atkins creates a strong presumption that Cook was 

unable to understand his Miranda rights, and thus unable to 

knowingly and intelligently waive them. See United States 

1 The Supreme Court explicitly reasoned in Atkins that intellectually 

disabled defendants are ineligible for the death penalty, in large part, 

because they are very susceptible to offering false confessions. See 

536 U.S. at 320 (citing Everington & Fulero, Competence to Confess: 

Measuring Understanding and Suggestibility of Defendants with Mental 

Retardation, 37 Mental Retardation 212, 212–213, 535 (1999)).
46 COOK V. KERNAN

v. Garibay, 143 F.3d 534, 538 (9th Cir. 1998) (holding that 

defendant could not have knowingly and intelligently 

waived his Miranda rights because his “IQ is borderline 

retarded” and he was unable “to understand oral 

instructions”).

In order to reach the opposite outcome, the state habeas 

court and the majority completely—and erroneously—

overlook the uncontroverted expert testimony of Dr. Woods 

and Dr. Wilkinson that Cook is “dependent upon cues and 

guidance from others to maintain a useful and functional 

organization of information”, “readily incorporates cues, 

prompting and direction from others,” and is vulnerable to 

“suggestibility and confabulation.” This uncontradicted 

expert testimony conclusively establishes that Cook was 

unable to understand his constitutional rights, even if he 

made statements to the contrary.

The state trial court’s determination that Cook is 

intellectually disabled was also supported by an 

overwhelming wealth of expert testimony that expanded on 

the depth and severity of Cook’s intellectual disability. 

Before trial, Doctor William Lynch, a neuropsychologist, 

testified that Cook’s “verbal and performance abilities fall[] 

at the extreme low-end of the Average range,” that he suffers 

from a developmental learning disability involving reading 

and writing, and that he had a “narrow, precarious attention 

span that can be interrupted easily.” As a result, Cook “often 

fails to apprehend complete messages (words, phrases or 

numbers)” and “is apt to have difficulty with understanding 

complex spoken and written speech.” Doctor Myla Young, 

a clinical psychologist, also testified that Cook’s mental 

function was “Borderline to Low Average” and that, even 

though his general IQ was a very low 83, his performance on 

the part of the test that measures his ability to process new 
COOK V. KERNAN 47

information resulted in a below-average IQ of 78. 

Accordingly, Dr. Young concluded that Cook had a 

cognitive “level of performance . . . similar to that 

demonstrated by most children with an age equivalence of 

9.9 years old.” Similarly, Dr. George Wilkinson, who 

evaluated Cook, concluded that Cook “had life-long 

attentional and learning disabilities that reduced his 

performance even below his measured intelligence level of 

borderline to below average.” In other words, all these 

experts agreed that Cook is intellectually disabled to such a 

degree that it was impossible for him to understand his 

constitutional rights, let alone waive them.

Mental health experts who evaluated Cook also testified 

that, in addition to his low IQ, Cook suffers from grave 

mental illnesses that prevented him from understanding the 

rights he was giving up. Doctor George Woods, a 

psychiatrist, diagnosed Cook with an organic brain disorder 

that causes him to dissociate and to fail to recall information 

and details. He also diagnosed Cook with post-traumatic 

stress disorder (“PTSD”) and depression. According to 

Dr. Woods, Cook “readily incorporates cues, prompting and 

direction from others” and is vulnerable to “suggestibility 

and confabulation.” Therefore, Dr. Woods concluded that 

Cook satisfies the diagnostic criteria for “mental retardation” 

if you couple these mental illnesses with his borderline 

intellectual functioning. Given Cook’s cognitive and mental 

disabilities, Doctor Zakee Matthews, a clinical psychiatrist 

who reviewed the video recording of Cook’s interrogation, 

also opined that “it was extremely unlikely Mr. Cook could 

have meaningfully understood the admonition regarding his 

legal rights as expressed in the language and manner used by 

the interrogating officers.”
48 COOK V. KERNAN

The government never offered expert testimony to 

contradict the opinions of the mental health experts who 

unanimously testified that Cook’s intellectual disabilities 

and severe mental illnesses prevented him from 

understanding the rights he was giving up. See Garibay, 

143 F.3d at 538 (finding no valid Miranda waiver because 

“[t]he government presented no evidence to contradict the 

fact that [the defendant] . . . is borderline retarded with 

extremely low verbal-English comprehension skills”). 

Therefore, there is no expert evidence in the record to 

support the state habeas court’s summary denial or the 

majority’s holding, which rely on the disproven assumption 

that Cook was intellectually competent to knowingly and 

intelligently waive his rights. See United States v. Glover, 

596 F.2d 857, 865 (9th Cir. 1979) (upholding Miranda

waiver because the court properly relied on the prosecution’s 

expert’s testimony “that [the defendant] was competent to 

waive his rights if they were explained to him in simple 

language”).

In light of Cook’s significant intellectual disabilities and 

mental illnesses, the majority’s contention that Cook’s oneword affirmations at the outset of the June 26 interrogation 

were enough for the California Supreme Court to deny 

habeas relief defies common sense and federal law clearly 

established by the Supreme Court in Thompkins and its 

progeny. Rather, any fairminded jurist faithfully applying 

those controlling precedents in this case would conclude that 

Cook was so intellectually disabled and mentally ill that he 

was unable to knowingly and intelligently waive his 

constitutional rights.

Second, the majority’s contention that Cook provided 

coherent answers to the investigators’ questions during the 

June 26, 1992 interrogation is an unreasonable 
COOK V. KERNAN 49

determination of the facts. To the contrary, the transcript and 

videotape of the interrogation show that Cook is obviously 

confused and distressed, and his responses are unfocused 

and hard to follow. At the outset of the interrogation, for 

example, Cook stated that his birthday was September 25, 

1971 (which would have made him twenty years old) and 

that he was nineteen years old. When Inspector Sabin 

explained the contradiction between his answers, Cook 

responded with “. . . that’s what, what my mother told me, 

so.” But, Cook stated, he “knew for a fact” he was going to 

be “twenty this year.” He was wrong about his birthday and 

his age. Cook also did not know addresses of where he had 

lived for the past five or six months; gave multiple 

contradictory statements about dates and durations; did not 

know the day of the week or what month it was; and failed 

to remember how he got to Oklahoma. All this occurred 

within the first couple of minutes of the June 26 

interrogation. The district court therefore correctly 

interpreted this colloquy—the first set of questions after 

Cook was Mirandized—as one of the first “signs that Cook 

was either seriously confused, or otherwise mentally 

incompetent.”

Later in the interrogation, at round 9:34 p.m., in response 

to lengthy and suggestive questions by Inspector Sabin about 

what Morris said or did to trigger the shooting, Cook began 

to cry, stating, “No, I never do nothing to nobody, I try to be 

everybody friend. I can’t work ‘cause I live on another part 

[of town].” As Inspector Sabin persisted with questions 

about the Morris shooting, Cook continued to cry 

uncontrollably and to reiterate incessantly that he was afraid 

to endanger his family.2

 It is in this highly rambling and 

2 Cook made increasingly paranoid statements about his family 

being in danger: “I’m in for it regardless if I say something or not, if I, 
50 COOK V. KERNAN

distressed mental state that Cook made the incriminating 

admissions that he was in the car with Branner and Senegal 

the night of the Morris murder, had a gun with him, and 

“blanked out” after Morris approached the vehicle. No 

reasonable jurist could read this transcript or view this 

videotape and conclude that Cook was responding 

“coherently.”

Cook’s distress and confusion got worse. At around 

11:13 p.m., Cook was sobbing loudly when he disclosed that 

his father used to beat his mother in response to Inspector 

Sabin’s question about why he went to see a therapist when 

he was younger. From this point, Cook became increasingly 

emotional and incoherent. Sabin and Eatmon offered him a 

drink, which he declined, and unsuccessfully tried to loop 

back to questioning about Morris. While still crying 

uncontrollably, Cook continued to talk about his abusive 

childhood while making distressed and nonsensical 

statements, such as: “I don’t care, they can kill me, do 

whatever they want, I don’t care no more,”; “I hope they kill 

me or whatever, I don’t want to worry about waking up every 

night, just thinking about got to help my mother, and I can’t 

do nothing to stop it . . . let them kill me, I don’t care, I have 

nothing to live for, nobody even care about me anyway so, I 

mean, it’s better if I’m gone”; and “I don’t care what happens 

to me, kill me, I’d be more of a big heavy burden.” At 

if I tell you something, then put my family life in danger, I’d rather 

something just happen to me;” “It shouldn’t really matter, whatever I say 

now, you said I’m guilty, you got, you got all this stuff that I’m in it, so 

. . . regardless of what I say, you know what I’m saying, it’s not going to 

happen, you know what I’m saying, if you all plan on killing me or 

whatever . . . well, I’m doing electric chair or 25 to life . . . it’s, it just 

don’t matter now;” “And then, after I tell you all the truth, whatever it is, 

who, you know what I’m saying, I got to face the consequences of what 

happened to, what if somebody kill my father and them.”
COOK V. KERNAN 51

around 11:38 p.m., the investigators decided to take a break 

for Cook to calm down and escorted Cook back to his cell. 

When the taped interview resumed at around 12:10 a.m., 

Inspector Sabin reminded Cook of his Miranda rights and 

then began questioning him about the Bettencourt murder. 

But the break did not work, because Cook quickly became 

very distressed, confused, and incoherent. This is when 

Cook abruptly confessed to the Bettencourt murder. Cook’s 

distress and confusion during the lengthy interrogation 

escalated to the point that by the end he was violently 

coughing and vomiting.

The mental health experts who evaluated Cook 

confirmed that Cook was confused, distressed, and 

incoherent during the June 26 interrogation. Coupled with 

Cook’s intellectual disability and mental illnesses, these 

experts unanimously concluded that it was impossible for 

him to understand his Miranda rights, let alone to knowingly 

and intelligently waive them. “[B]ased on signs of 

Mr. Cook’s impaired cognition, distractibility[,] and 

dissociative tendencies during clinical assessments, and 

similar signs appearing in the videotape,” Dr. Matthews 

testified that “it is evident that [Cook’s] limited abilities to 

attend to or comprehend minimally complex language were 

overwhelmed during the commencement of the interview.” 

Dr. Wilkinson agreed that “the circumstances of the 

interrogation, including Mr. Cook’s neuropsychological and 

intellectual impairments and the effects of his trauma-based 

symptoms, prevented him from knowingly and intelligently 

understanding and waiving his right to remain silent.”

Therefore, the majority’s contention that Cook was 

“coherent” throughout most of the June 26 interrogation is 

simply unfounded. Such an unreasonable determination of 

the facts in the record could not justify the California 
52 COOK V. KERNAN

Supreme Court’s denial of relief here. Rather, a fairminded 

jurist reviewing the transcript and videotape of the 

interrogation—and the expert evaluation of those 

materials—would find that Cook was distressed, confused, 

and incoherent throughout most of the interview, especially 

when he confessed to the Bettencourt murder and made other 

incriminating statements about the Morris murder.

Third, the majority argues that the California Supreme 

Court could have reasonably found that Cook conveniently 

pretended that he did not understand his rights the day after 

the June 26 interrogation as “a self-serving excuse” to 

backtrack his prior waiver. Op. at 26–27. This conclusion 

is also an unreasonable determination of the facts under 

AEDPA.

The day after his June 26 interrogation—during which 

he confessed and made other incriminating statements—

Cook explicitly stated that he did not understand his 

Miranda rights, including the right to have an attorney 

present during questioning. When the investigators again 

read his rights before the second interview, Cook asked, 

“when you all talk to me, I’m supposed to have an attorney 

here or something?” The officers clarified that he had the 

right to have an attorney present. This led to the following 

exchange:

Cook: Is that the only time you could have an 

attorney to be able, when you go to court?

Inspector Sabin: You can have an attorney 

present any time during these [] proceedings.

Cook: I didn’t know that.
COOK V. KERNAN 53

Inspector Sabin: Okay, well, do you 

remember me reading that off to you 

yesterday?

Cook: Not really, but I remember you was 

reading something about my rights.

At this juncture, Cook asked to speak with his mother and 

refused to continue talking until he had done so. Inspector 

Sabin then asked him a series of questions trying to surmise 

what Cook had understood to be his Miranda rights when he 

appeared to waive them the day before. Cook reiterated that 

he “didn’t know that . . . when you guys talked to me that I 

could have a lawyer here.” Cook then proceeded to meet 

privately with his mother, after which he refused to continue 

speaking to the investigators until he had a chance to talk to 

a lawyer.

The only objectively reasonable interpretation of this 

exchange—given his intellectual disability and mental 

illnesses—is that Cook did not understand his Miranda 

rights until he had a chance to talk to his mother, well after 

he confessed to the Bettencourt murder and made other 

incriminating statements the night before. The majority’s 

skepticism of Cook’s motives in asking these questions is 

unreasonable, especially considering the undisputed 

evidence that he was intellectually disabled and suffered 

from grave mental illnesses. If anything, no fairminded 

jurist would disagree that these questions are further 

evidence that Cook did not truly understand his 

constitutional rights the night before.

Finally, the majority proclaims that Cook understood his 

Miranda rights because he “[he] has been arrested and 

provided Miranda waivers on several occasions in the past.” 
54 COOK V. KERNAN

Op. at 26. But the record clearly supports a finding that 

Cook did not understand his Miranda rights at the time of 

his previous arrests, either. As an initial matter, those arrests 

occurred when he was a minor. More importantly, when 

Inspector Sabin asked him if he had read and understood his 

Miranda rights when he was arrested in the past, Cook 

explained that “[he] didn’t know . . . when [] people come to 

question you, you can have a lawyer present with you.” 

Therefore, these past experiences “do not indicate that 

[Cook] was familiar with his Miranda rights and his option 

to waive those rights” based on his prior experiences with 

law enforcement. Garibay, 143 F.3d at 539 (citing Cooper 

v. Griffin, 455 F.3d 1142. 1144–45 (5th Cir. 1972)). The 

majority’s contention otherwise is an unreasonable 

determination of the facts and thus cannot justify the 

California Supreme Court’s denial of habeas relief.

In sum, under AEDPA, it was both “an unreasonable 

application of clearly established federal law, as determined 

by the Supreme Court of the United States” in Thompkins

and its progeny, and “an unreasonable determination of the 

facts,” for the state habeas court to summarily conclude that 

Cook’s Miranda waiver was knowing and intelligent despite 

the overwhelming evidence to the contrary. 28 U.S.C. 

§§ 2254(d)(1), (d)(2). Indeed, “there was no reasonable 

basis for the state court to deny relief,” or for the majority to 

conclude—contrary to uncontroverted expert testimony—

that a defendant who is intellectually disabled and suffers 

from serious mental illnesses, is interrogated for seven 

hours, and shows visible physical signs of extreme distress 

and confusion, knowingly and intelligently waived his 
COOK V. KERNAN 55

Miranda rights. Richter, 562 U.S. at 98. No reasonable 

fairminded jurist would conclude otherwise.3 Id. at 103.

3. The admission of Cook’s unlawfully obtained 

confession and other incriminating statements 

was harmful.

The conclusion that no reasonable jurist would have 

found Cook’s Miranda waiver valid does not end our 

inquiry. Cook is “not entitled to habeas relief based on trial 

error unless [he] can establish that it resulted in actual 

prejudice.” Ayala, 135 S. Ct. at 2197 (2015) (quoting 

Brecht, 507 U.S. at 637). The California Supreme Court’s 

summary order denying habeas relief also failed to explicitly 

address whether Cook was prejudiced by the improper 

admission of his unlawfully obtained confession to the 

Bettencourt murder and other incriminating statements 

about the Morris murder. Nonetheless, “relief is proper only 

if the federal court has ‘grave doubt about whether a trial 

error of federal law had substantial and injurious effect or 

influence in determining the jury’s verdict.’” Id. at 2197–98 

(quoting O’Neal v. McAninch, 513 U.S. 432, 436 (1995)).

A “defendant’s own confession is probably the most 

probative and damaging evidence that can be admitted 

against him.” Fulminante, 499 U.S. 279, 296 (1991) (citing 

Bruton v. United States, 391 U.S. 123, 139–40 (1968) 

(White, J., dissenting)). “Certainly, confessions have 

profound impact on the jury, so much so that we may 

justifiably doubt its ability to put them out of mind even if 

told to do so.” Id. Therefore, in order to deny Cook’s claim 

3 Because Cook’s Miranda waiver was not done knowingly and 

intelligently, we do not need to reach the issue of whether his confession 

was involuntary or coerced.
56 COOK V. KERNAN

on the basis that there was no prejudice, the California 

Supreme Court “must be able to declare” that the admission 

of Cook’s confession and other incriminating statements 

“was harmless beyond a reasonable doubt.” Id. at 295 (citing 

Chapman v. California, 386 U.S. 18, 24 (1967)). In other 

words, “[t]he prejudice from [a defendant’s] confession 

cannot be soft pedaled.” Anderson v. Terhune, 16 F.3d 781, 

792 (9th Cir. 2008) (en banc).

Here, the unconstitutional admission of Cook’s 

confession to the Bettencourt murder and other 

incriminating statements at trial was harmful in two distinct 

ways: (1) the trial court relied on these admissions to 

impermissibly hold a single joint trial for the unrelated 

murders of Sadler, Bettencourt, and Morris, in violation of 

Cook’s due process rights; and (2) the confession was central 

to his conviction because the other evidence against him was 

inconsistent and highly compromised. Therefore, I “think 

that the [admission of Cook’s unlawfully obtained 

confession to the Bettencourt murder and other 

incriminating statements about the Morris murder] 

substantially influenced the jury’s decision” and I have no 

doubt that it had an injurious effect on the jury’s verdict. 

O’Neal, 513 U.S. at 436; see also Poyson v. Ryan, 879 F.3d 

875, 891–92 (9th Cir.) (as amended), cert. denied, 138 S. Ct. 

2652 (2018).

a. The admission of Cook’s confession and other 

incriminating statements resulted in the 

harmful consolidation of the three unrelated 

murders into a single trial.

The unconstitutional admission of Cook’s unlawfully 

obtained confession to the Bettencourt murder and other 

incriminating statements led the trial court to impermissibly 

consolidate the three unrelated murders of Bettencourt, 
COOK V. KERNAN 57

Morris, and Sadler into a single trial, which “resulted in 

prejudice so great as to deny [Cook] of his Fifth Amendment 

right to a fair trial.” United States v. Lane, 474 U.S. 438, n. 

8 (1986); see also Bean v. Calderon, 163 F.3d 1073, 1084 

(9th Cir. 1998) (“The simultaneous trial of more than one 

offense must actually render petitioner’s state trial 

fundamentally unfair and hence, violative of due process 

before relief pursuant to 28 U.S.C. § 2254 would be 

appropriate” (quoting Featherstone v. Estelle, 948 F.2d 

1497, 1503 (9th Cir. 1991)); Davis v. Woodford, 384 F.3d 

628, 638 (9th Cir. 2004) (modifications in original) (holding 

that there is a prejudicial constitutional violation where the 

“simultaneous trial of more than one offense . . . actually 

render[ed] petitioner’s state trial fundamentally unfair and 

hence, violative of due process.” (quoting Sandoval v. 

Calderon, 241 F.3d 765, 771–72 (9th Cir. 2001)).

Cook’s joint trial for the three unrelated murders of 

Bettencourt, Morris, and Sadler was highly prejudicial 

because it allowed evidence admissible as to only one of the 

murder charges to impermissibly “spillover” to the other 

murder charges. “We have recognized that the risk of undue 

prejudice is particularly great whenever joinder of counts 

allows evidence of other crimes to be introduced in a trial 

where the evidence would otherwise be inadmissible.” See 

Sandoval, 241 F.3d at 772 (citing United States v. Lewis, 

787 F.2d 1318, 1322 (9th Cir.1986)); Davis, 384 F.3d 

at 638–39 (finding no prejudice to the defendant when 

evidence was cross-admissible); Fields v. Woodford, 

309 F.3d 1095, 1109–10 (9th Cir. 2002) (same); United 

States v. Johnson, 820 F.2d 1065, 1070–71 (9th Cir. 1987) 

(same). For example, of the fifteen witnesses who testified 

at trial, only two—Shawnte Early and Shannon Senegal—

allegedly witnessed more than one of the murders, and none 

of them allegedly witnessed all three murders. People v. 
58 COOK V. KERNAN

Cook, 139 P.3d 492, 502 (Cal. 2006). Similarly, the 

ballistics evidence for the Bettencourt and Morris murders 

was introduced together, even though the San Mateo 

Sheriff’s Department was unable to confirm that the casings 

and bullets recovered from both crime scenes originated 

from the same weapon. Id. at 502. Most importantly, 

Cook’s highly prejudicial and unlawfully obtained 

confession, and other incriminating statements, were 

introduced at the joint trial for all three murders, even though 

they only pertained to the Bettencourt and Morris murders, 

respectively. None of these statements had anything to do 

with the Sadler murder.

On direct appeal, the California Supreme Court 

nonetheless affirmed the trial court’s finding that 

“substantial cross-admissibility” of evidence existed 

between the Bettencourt and Morris murders because “those 

victims were killed by multiple shots fired from the same

gun, which [D]efendant admitted was his.” Id. at 505 

(emphases added). But, as discussed above, a San Mateo 

County Sheriff’s criminalist testified that it was impossible 

to link the casings recovered from the Morris and 

Bettencourt murders to the same gun, especially because no 

gun was ever recovered. Op. at 8. Cook, 139 P.3d at 502. 

Therefore, in order to link the gun to both murders, the 

prosecution had to rely on Cook’s incriminating statements 

that “he had used his [nine]-millimeter handgun to shoot 

Bettencourt and that on the day after the Morris shooting he 

had thrown the gun off the Dumbarton Bridge.” Id. These 

incriminating statements should not have been admitted into 

evidence, however, because they were unlawfully obtained 

after Cook’s invalid Miranda waiver. Therefore, the state 

trial court had no legitimate justification or good cause to try 

these otherwise unrelated murders together. Lane, 474 U.S. 

at 446 n. 8 (“[M]isjoinder would rise to the level of a 
COOK V. KERNAN 59

constitutional violation only if it results in prejudice so great 

as to deny a defendant his Fifth Amendment right to a fair 

trial.”); Bean, 163 F.3d at 1084 (holding that defendant was 

highly prejudiced by the improper joint trial of otherwise 

unrelated crimes).

Moreover, “there was no cross-admissibility between 

[the Sadler] murder and the [Bettencourt and Morris 

murders]” because Sadler was beaten rather than shot.4 

Cook, 139 P.3d at 505. Therefore, in order to affirm the trial 

court’s denial of Cook’s motion to sever the trial for the 

Sadler murder, the California Supreme Court, on direct 

appeal, had to summarily conclude that the joinder of the 

Sadler murder did not prejudice Cook because the 

Bettencourt and Morris murders had already been properly 

joined into a single trial. Id. But the Morris and Bettencourt 

murders were improperly joined using Cook’s unlawfully 

obtained confession and other incriminating statements, so 

the additional joinder of the Sadler murder—for which there 

was no cross-admissibility of evidence—was also improper 

and highly prejudicial.

The reason the consolidation of the three unrelated 

murders into a single trial was harmful is that “the jury could 

not ‘reasonably [have been] expected to compartmentalize 

the evidence so that evidence of one crime [did] not taint the 

jury’s consideration of another crime.’” Bean 163 F.3d 

at 1084 (quoting Johnson, 820 F.2d at 1071); United States 

v. Douglass, 780 F.2d 1472, 1479 (9th Cir. 1986) (same). 

We have long observed that “[i]t is much more difficult for 

jurors to compartmentalize damaging information about one 

4 Shawnte Early identified Cook as the man who repeatedly shot 

Bettancourt and who beat Sadler with a stick. Cook, 139 P.3d at 505–

06. However, she repudiated her pretrial statements on the stand. Id.
60 COOK V. KERNAN

defendant derived from joined counts, than it is to 

compartmentalize evidence against separate defendants 

joined for trial.” Lewis, 787 F.2d at 1322. Indeed, studies 

show that “joinder of counts tends to prejudice jurors’ 

perceptions of the defendant and of the strength of the 

evidence on both sides of the case.” Id. Cook was entitled, 

under the Fifth Amendment, to three separate trials precisely 

to ensure that the jury in each of those trials was able to fairly 

evaluate the evidence of each unrelated murder, and not be 

prejudiced by their inability to compartmentalize the 

cumulative evidence of the other two murders. See Bean, 

163 F.3d at 1084 (“As the joinder of the [] charges did in fact 

prejudice [the defendant’s] trial on the latter counts, we 

conclude that [the defendant’s] due process rights were 

violated.”).

Indeed, the jurors in Cook’s case admit, in no uncertain 

terms, that they were unable to compartmentalize the 

evidence because their perception of it was tainted by 

Cook’s unlawfully obtained confession to the Bettencourt 

murder and his incriminating statements about the Morris 

murder. One juror stated: “[Cook] admitted to one of the 

killings, so it seemed likely that he had done the other two.” 

Another confirmed that “[a]fter hearing from all of these 

witnesses in the guilt phase, we heard Walter’s confessions 

about his involvement in the crimes,” notably failing to 

distinguish between the Bettencourt murder and the other 

two murders. In order to find that the admission of Cook’s 

confession and other incriminating statements was harmless, 

the state habeas court would have had to unreasonably 

ignore these deeply troubling statements from the jury.

Accordingly, because the jury unfairly considered the 

cumulative evidence against Cook—rather than 

compartmentalizing the evidence for each unrelated 
COOK V. KERNAN 61

murder—no fairminded jurist would disagree that the trial 

court’s use of Cook’s confession to consolidate the three 

unrelated murders into a single trial had a “substantial and 

injurious effect or influence in determining the jury’s 

verdict.” Bean, 163 F.3d at 1086 (quoting Brecht, 507 U.S 

at 637). This impermissible joinder, on its own, is sufficient 

to establish prejudice for purposes of granting Cook habeas 

relief.

b. The admission of Cook’s confession and other 

incriminating statements was harmful 

because the other evidence against Cook was 

inconclusive or highly compromised.

Even assuming the improper misjoinder of the three 

unrelated murders into a single trial did not prejudice Cook, 

the admission of his unlawfully obtained confession and 

other incriminating statements was not “harmless error” 

because the other evidence against Cook was most likely 

insufficient for the jury to convict him. Fulminante, 

499 U.S. at 297 (reversing conviction and ordering a new 

trial because “[o]ur review of the record leads us to conclude 

that the State has failed to meet its burden of establishing, 

beyond a reasonable doubt, that the admission of 

[defendant’s] confession [] was harmless error”); Martinez 

v. Cate, 903 F.3d 982, 999 (9th Cir. 2018) (“[Defendant’s] 

improperly-admitted statements were clear and damning; 

they were the backbone of the State’s argument against selfdefense. Thus, we have grave doubts that their admission 

did not affect the verdict.”); Anderson, 516 F.3d at 792 (9th 

Cir. 2008) (holding that “the error was not harmless[,]” 

because “[t]he confession was central to the conviction” 

(citing Brecht, 507 U.S. at 623, and then citing Fulminante, 

499 U.S. at 296)).
62 COOK V. KERNAN

I will explain in turn how the other evidence of Cook’s 

guilt for each of the three murders was inconclusive and 

highly compromised. 

i. The Sadler murder

For the Sadler murder, most of the evidence was 

inconclusive or highly compromised. For example, the three 

bystanders who testified against Cook—Ernest Woodard, 

Shawnte Early, and Velisha Sorooshian—admitted that they 

were coerced and threatened by the police in exchange for 

their testimony incriminating Cook. Their testimony was 

also inconclusive. Woodard never testified that he saw Cook 

beat Sadler to death with a stick. Cook, 139 P.3d at 500–01. 

Early recanted at trial, testifying that she did not remember 

making the statement accusing Cook, that the statement was 

untrue, and that the police coerced her to make it. Similarly, 

Sorooshian admitted at trial that she could not remember the 

details of her interview with detectives because she “ha[d] 

been on crack so long.”

The only other testimony against Cook was that of 

Shannon Senegal, who claims that Cook told him he beat up 

Sadler the day after the murder. But Senegal’s testimony is 

highly unreliable given that he was a suspect to the Morris 

killing, which means he had a strong incentive to see Cook 

take the blame for both crimes. Cook, 139 P.23d at 501. In 

fact, Senegal’s charge as an accessory to the Morris murder 

was dropped for a misdemeanor count of giving false 

information to a peace officer in exchange for his statement 

incriminating Cook in the Sadler murder.

There was also substantial forensic and testimonial 

evidence that Thomas Young and his cousin Kenny Young, 

not Cook, killed Sadler. Frankly, given this evidence, it is 

baffling that the detectives investigating the Sadler murder 
COOK V. KERNAN 63

failed to interview Thomas Young until May 2, 1994—over 

two years after Sadler’s death, and sixteen days into Cook’s 

trial. Detectives never interviewed Kenny Young. This 

means that the jury was never presented with the available 

evidence against all the credible suspects to the murder; they 

were only presented with highly compromised evidence of 

Cook’s alleged involvement.

Considering these serious evidentiary pitfalls, 

fairminded jurists would have to agree that the jury had to 

rely on Cook’s improperly admitted confession and other 

incriminating statements to convict Cook of the Sadler 

murder.

ii. The Bettencourt murder.

Virtually every piece of evidence of the Bettencourt 

murder is either inconclusive or highly compromised. For 

example, Tamika Asburry, Shawnte Early, Teresa Beasley, 

and Darnell Earby, who gave statements to the police 

identifying Cook as Bettencourt’s shooter, later recanted at 

trial, stating that their statements had been coerced and 

reflected what the police wanted them to say. Nathan 

Gardner and Keith Johnson also testified that they saw Cook 

shoot Bettencourt. However, their testimony was 

inconclusive because both witnesses initially admitted they 

could not definitely identify Cook as Bettencourt’s shooter, 

even though they both later testified that they did see Cook 

shoot Bettencourt. Importantly, Gardner and Johnson 

received lenient plea deals in unrelated charges for violent 

drug crimes as a result of their testimony against Cook.

The other witness who accused Cook of shooting 

Bettencourt was Sims, who was the only other suspect to the 

murder. Sims admitted that he was also on the scene selling 

crack, and he was kneeling inside the victim’s car (where he 
64 COOK V. KERNAN

allegedly dropped a crack rock) moments before the 

shooting began. In fact, there is compelling ballistics 

evidence suggesting that the first shot could only have come 

from Sims’s location, and that because every shot came from 

the same gun, there is at least some probability that Sims, not 

Cook, shot Bettencourt.

Moreover, although Sims testified on the stand that he 

hoped to receive a lighter sentence for his multiple parole 

and drug charges in exchange for his testimony against 

Cook, he neglected to share with defense counsel and the 

jury that he had already received a very generous deal. In 

fact, Inspector Sabin wrote to the Board of Prisons to ensure 

that Sims was released on his own recognizance from a 

prison sentence for parole violations on two occasions—July 

1992 and May 1993. After Sims violated the terms of his 

supervised release a third time, his probation officer, 

Timothy Gatto, had to write to the San Mateo Superior Court 

seeking a bench warrant, describing Sims as “clearly out of 

control” and noting that “his veracity is questionable in all 

matters.” Ultimately Sims secured a two-year get-out-ofjail-free pass for his multiple parole violations and drug 

offenses in exchange for his testimony incriminating Cook. 

It is thus extremely problematic that the prosecution only 

turned over Sabin’s letters to the Board of Prisons after

Sims’ trial testimony, and never turned over Gatto’s letter. 

Had the prosecution turned over this key evidence showing 

that Sims received special treatment in exchange for his 

testimony against Cook, there is a reasonable probability that 

the jury would have concluded that Sims seriously lacked 

credibility. But the opposite happened. One of the jurors 

explained that “there was one guy in particular we really 

liked, a young man named Jap [Sims’s nickname],” who 

“wanted to help the police with the case because he was 

trying to turn his life around.”
COOK V. KERNAN 65

Therefore, the district court correctly found that the 

witness statements identifying Cook as the Bettencourt 

shooter were “compromised,” either due to alleged police 

misconduct in feeding details or threatening the witnesses, 

or because the witness was also a suspect and thus had a 

motive to fabricate. Without the confession to the 

Bettencourt murder, it is highly likely that the jury would 

have viewed this evidence in a substantially less prejudicial 

way.

iii. The Morris murder.

The evidence for the Morris murder is even more 

problematic. Two of the witnesses who testified that they 

saw Cook shoot Morris—Lavert Branner and Shannon 

Senegal—were themselves suspects and granted leniency by 

the prosecution for testifying against Cook.5 Furthermore, 

there was strong forensic and testimonial evidence that 

Branner or Senegal killed Morris, including testimony from 

Monique Barrett, Lakishain Smith, and Tasha Bradford.

In sum, the evidence against Cook for the Sadler, 

Bettencourt, and Morris murders was so lacking that there is 

“more than a ‘reasonable possibility’ that” the admission of 

Cook’s confession to the Bettencourt murder and other 

incriminating statements about the Morris murder was 

“harmful” under Brecht. Ayala, 135 S. Ct. at 2198 (quoting 

507 U.S. at 637). The prosecution’s case for all three 

murders was otherwise flimsy and weak. In fact, without 

Cook’s unlawfully obtained confession and other 

5 It is highly problematic that the police waited over a year to 

interview Branner and Senegal about the Morris killing given that they 

were both natural suspects. The police spoke with Branner for the first 

time in November 1993, and with Senegal in March 1994.
66 COOK V. KERNAN

incriminating statements, the remaining evidence consists of 

recanted, coerced, or otherwise compromised testimony, and 

inconclusive ballistics evidence. Therefore, “absent the 

confessions, it is unlikely that [Cook] would have been 

prosecuted at all, because the physical evidence from the 

scene and other circumstantial evidence would have been 

insufficient to convict.” Fulminante, 499 U.S. at 297.

Furthermore, because the trial court admitted the 

unlawfully obtained confession and other incriminating 

statements, Cook’s defense counsel was forced to 

acknowledge that Cook shot Bettencourt, focusing their 

efforts instead on establishing that Bettencourt’s killing was 

at most second-degree murder because Cook had been 

drinking heavily. Cook, 139 P.3d at 502. In other words, 

had the confession and statements not been admissible, the 

defense would not have had to acknowledge that Cook shot 

Bettencourt. It is thus highly likely that Cook’s defense 

counsel would have attempted to convince the jury that Cook 

did not shoot Bettencourt, especially because the 

prosecution’s case was otherwise unconvincing.

Cook’s wrongfully admitted confession and other 

incriminating statements were highly prejudicial.6 In 

Fulminante, the Supreme Court warned us, in no uncertain 

terms, that we must “exercise extreme caution before 

determining that the admission of a confession at trial was 

harmless,” because confessions “may tempt the jury to rely 

upon that evidence alone in reaching its decision.” 499 U.S. 

at 296. Here, the inconclusive and highly compromised 

6 Judge Callahan filed a concurrence, in which Judge Smith did not 

join, arguing that “the state habeas court could have reasonably denied 

Cook’s claim on the basis that the admission of his confession did not 

prejudice him at trial.”
COOK V. KERNAN 67

evidence in the record, coupled with the deeply troubling 

post-trial statements of the jurors, give me—and should give 

this Court—“grave doubt about whether [the impermissible 

admission of Cook’s unlawfully obtained confession and 

other admissions] had a substantial and injurious effect or 

influence in determining the jury’s verdict.” Ayala, 135 

S. Ct. at 2197–98 (quoting O’Neal, 513 U.S. at 436).

4. Conclusion 

Cook is entitled to habeas relief because the California 

Supreme Court’s summary ruling that he intelligently and 

knowingly waived his Miranda rights involved an 

unreasonable determination of the facts and an unreasonable 

application of clearly established federal law, given that he 

was not—indeed he could not be—“full[y] aware[] of both 

the nature of the right being abandoned and the 

consequences of the decision to abandon it.” Thompkins, 

560 U.S. at 384 (quoting Burbine, 475 U.S. at 421).

Furthermore, the record clearly shows that the admission 

of Cook’s unlawfully obtained confession to the Bettencourt 

murder and incriminating statements about the Morris 

murder were harmful. First, the admission of these 

unlawfully obtained incriminating statements resulted in a 

fundamentally unfair joint trial of the three unrelated 

murders of Sadler, Bettencourt, and Morris, during which 

the jury failed to compartmentalize the evidence for each 

crime, violating Cook’s due process rights. Second, the 

record highlights that the prosecution’s other evidence of 

Cook’s guilt was inconclusive or highly compromised, 

which led the jury to rely heavily on Cook’s unlawfully 

obtained incriminating statements to convict him.

Accordingly, I respectfully dissent.