FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

OSCAR RODRIGUEZ, AKA Lonely,

Defendant-Appellant.

No. 08-50479

D.C. No.

5:05-cr-00069-

VAP-3

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

JOSE MURILLO, AKA Yogi,

Defendant-Appellant.

No. 08-50483

D.C. No.

5:05-cr-00069-

VAP-2

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

ALEJANDRO MUJICA, AKA Slow,

Defendant-Appellant.

No. 08-50485

D.C. No.

5:05-cr-00069-

VAP-4
2 UNITED STATES V. RODRIGUEZ

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

OSCAR RODRIGUEZ, AKA Lonely,

Defendant-Appellant.

No. 12-50121

D.C. No.

5:05-cr-00069-

VAP-3

UNITED STATES OF AMERICA,

Plaintiff-Appellee,

v.

JOSE MURILLO, AKA Yogi,

Defendant-Appellant.

No. 12-50132

D.C. No.

5:05-cr-00069-

VAP-2

ORDER AND

AMENDED

OPINION

Appeal from the United States District Court

for the Central District of California

Virginia A. Phillips, District Judge, Presiding

Argued and Submitted

August 28, 2013—Pasadena, California

Filed June 19, 2014

Amended September 8, 2014
UNITED STATES V. RODRIGUEZ 3

Before: Ronald M. Gould and Johnnie B. Rawlinson,

Circuit Judges, and Ivan L.R. Lemelle, District Judge.*

Opinion by Judge Rawlinson

SUMMARY**

Criminal Law

The panel affirmed three defendants’ convictions for

conspiracy to commit murder and first degree murder

stemming from the stabbing of a prison inmate, Peter

Scopazzi.

The panel held that the district court’s exclusion of

evidence concerning medical negligence and Scopazzi’s

removal of his breathing tube does not warrant reversal of the

convictions, where the defendants failed to demonstrate that

any medical negligence related to Scopazzi’s multiple stab

wounds and his removal of his breathing tube were the sole

causes of his death or were so extraordinary and

unforeseeable as to absolve the defendants of liability for

their vicious assault. 

The panel held that the district court did not abuse its

discretion in admitting evidence of the defendants’

* The Honorable Ivan L.R. Lemelle, U.S. District Judge for the Eastern

District of Louisiana, sitting by designation.

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

been prepared by court staff for the convenience of the reader.
4 UNITED STATES V. RODRIGUEZ

connections to the Mexican Mafia to demonstrate their

motive for murdering Scopazzi. The panel also held that

expert testimony concerning the connections between the

Sureños and the Mexican Mafia within the prison gang

hierarchy and photographs of the defendants with Mexican

Mafia members did not render their trial unfair because the

district court properly minimized any prejudice stemming

from the evidence and the trial was replete with admissible

evidence regarding the defendants’ gang affiliations. 

The panel held that the defendants failed to demonstrate

under Brady, Mooney, or Napue that a new trial was

warranted based on the government’s failure to disclose

immaterial information regarding a government witness’

sentence reduction and his cooperation in a DEA

investigation.

COUNSEL

Verna Wefald (argued), Pasadena, California, for DefendantAppellant Oscar Rodriguez.

Michael J. Treman, Santa Barbara, California, for DefendantAppellant Jose Murillo.

Ethan A. Balogh (argued) and Jay A. Nelson, Coleman &

Balogh LLP, San Francisco, California, for DefendantAppellant Alejandro Mujica.

André Birotte, Jr., United States Attorney, Robert E. Dugdale,

Chief Assistant United States Attorney, Antoine F. Raphael

(argued), Assistant United States Attorney, Riverside,

California, for Plaintiff-Appellee United States.
UNITED STATES V. RODRIGUEZ 5

ORDER

The Opinion filed June 19, 2014, is amended sua sponte

to remove the language appearing on page 22, first full

paragraph of the Slip Opinion, beginning with <see also> and

continuing through the end of the paragraph.

A copy of the amended opinion is attached to the Order

and filed concurrently with the Order.

With this amendment, the panel has voted unanimously

to deny the Petition For Rehearing En Banc filed by

Alejandro Mujica on July 31, 2014. The full court has been

advised of the petition for rehearing en banc, and no judge

has requested a vote on whether to rehear the matter. See

Fed. R. App. P. 35.

The petition for rehearing en banc is DENIED. No

further petitions for panel rehearing or for rehearing en banc

will be entertained.

OPINION

RAWLINSON, Circuit Judge:

Appellants Oscar Rodriguez (Rodriguez), Jose Murillo

(Murillo), and Alejandro Mujica (Mujica) challenge their

convictions for conspiracy to commit murder and first degree

murder stemming from the stabbing of a prison inmate, Peter

Scopazzi (Scopazzi) at the United States Penitentiary at

Victorville, California. Appellants contend that the district

court abused its discretion in excluding evidence that medical
6 UNITED STATES V. RODRIGUEZ

negligence and Scopazzi’s removal of his breathing tube

during his hospitalization may have been the proximate cause

of Scopazzi’s death. Appellants also argue that the district

court abused its discretion in admitting expert testimony

concerning the relationship between two prison gangs—the

Sureños and the Mexican Mafia—because Appellants were

not members of the Mexican Mafia.

Additionally, Appellants maintain that a new trial was

warranted because the government failed to disclose, as

required by Brady v. Maryland, 373 U.S. 83 (1963) and

Giglio v. United States, 405 U.S. 150 (1972), a tacit

agreement with a key government witness that the

government would seek a sentence reduction in exchange for

the witness’s favorable testimony, and that the witness was an

informant for the Drug Enforcement Administration (DEA). 

Appellants further assert that the government violated

Mooney v. Holohan, 294 U.S. 103 (1935) and Napue v.

Illinois, 360 U.S. 264 (1959), by allowing the witness to

falsely testify that there was no promise of a sentence

reduction based on the witness’s cooperation. We affirm

Appellants’ convictions and the district court’s denial of their

motion for a new trial.

I. BACKGROUND

In a second superseding indictment, Appellants, along

with Danny Martinez (Martinez) and Walter Meneses

(Meneses), were charged with “knowingly and willfully

conspir[ing] and agree[ing] with each other to murder inmate

David Fischer . . . aka Peter Scopazzi” in violation of

18 U.S.C. § 1111. The indictment alleged that Appellants

armed themselves with prison-made knives (shanks) and

murdered Scopazzi in his cell. Appellants were charged with
UNITED STATES V. RODRIGUEZ 7

“willfully, deliberately, and with premeditation and malice

aforethought, unlawfully kill[ing] [Scopazzi].” Appellants

were also charged with assaulting two other prison inmates,

Timothy Ultsch (Ultsch) and Wayne Rondeau (Rondeau),

with the intent to commit murder, and assault with a deadly

weapon “with the intent to do bodily harm.”

Prior to trial, the government filed a motion in limine to

exclude evidence that medical negligence may have

contributed to Scopazzi’s death. The government maintained

that Appellants “proffered no witness, expert or otherwise,

nor any other evidence to the government that would indicate

that [Scopazzi’s] treatment by medical staff was somehow

negligent. . . .” The government also asserted that such

evidence was irrelevant because Appellants were liable for

murder irrespective of any medical negligence and that the

evidence might lead to juror confusion.

The government also filed a related motion in limine to

preclude or limit the testimony of the defense’s medical

expert, Dr. Marshall Morgan, concerning medical

negligence.1 The government asserted that the defense’s

notice did “not indicate that Dr. Morgan will state that

1

In a letter to the prosecution, Murillo’s attorney stated that the defense

intended to call Dr. Morgan to “testify about the nature of the stab wounds

suffered by [Scopazzi] . . . and the medical care given to [Scopazzi] by

prison and hospital personnel to treat those injuries.” “He will state that

in his opinion [Scopazzi’s] stab wounds could have been successfully

treated surgically. Furthermore, if [Scopazzi’s] condition had been

properly evaluated, the need for immediate surgery should have been

obvious.” “But because the nature of [Scopazzi’s] injuries was not

promptly or competently assessed and appropriately treated, the medical

attention he did receive fell well below well-recognized standards of care

resulting in [Scopazzi’s] death.”
8 UNITED STATES V. RODRIGUEZ

[Scopazzi’s] death was caused solely by the independent

intervening acts of the medical staff’s treatment. That

[Scopazzi’s] life may have been saved by more skillful

medical treatment, even if true, is legally irrelevant . . .

because even if this were true it would not relieve defendants

of responsibility for [Scopazzi’s] murder. . . .”

In his oppositions to the government’s motions, Murillo

responded that he did “not intend to introduce evidence of

negligence as an affirmative defense to murder. . . .” Murillo

maintained that the evidence of medical negligence and Dr.

Morgan’s testimony “would further explain that the injuries

caused by the stab wounds would have been routinely

repaired with proper medical care. The nature of [Scopazzi’s]

wounds and degree of force used to cause them may be

circumstantial evidence of whether or not there was intent to

kill. . . .”

In granting the government’s motions, the district court

held that medical negligence was not a defense to murder

charges. The district court excluded Dr. Morgan’s testimony

because Murillo failed “to proffer expert testimony that

[Scopazzi’s] death was caused solely by the independent

intervening acts of the medical staff’s treatment. . . .” The

district court held that “Dr. Morgan shall be allowed to testify

regarding the nature of [Scopazzi’s] wounds and the degree

of force used to cause them as such testimony is relevant to

the intent of the Defendants. . . .” However, Dr. Morgan was

precluded from testifying “about medical negligence in this

case as the probative value of such evidence outweighs the

danger of confusing the jury.”

2

2 The judge apparently meant to say that the probative value of the

evidence was outweighed by the danger of confusing the jury.
UNITED STATES V. RODRIGUEZ 9

In its trial memorandum, the government sought to

introduce evidence that the motive for Appellants’ murder of

Scopazzi was Scopazzi’s disrespect of Sureños gang

members. The district court held that evidence of Appellants’

Sureños membership and the Sureños’ relationship with the

Mexican Mafia was admissible as relevant to the

government’s theory that Appellants assaulted Scopazzi due

to their Mexican Mafia connections. The district court held

that the gang affiliation evidence was more probative than

prejudicial and that the government was permitted to

introduce “a limited number of photographs of [Appellants]

posing with certain members of the Mexican Mafia, as such

evidence may go to issues of planning and preparation of the

alleged offenses, and the level of retribution called for under

the tenets of the Sureños. . . .” Appellants declined the

district court’s offer to provide a limiting instruction

concerning evidence related to the Mexican Mafia.

At trial, Ryan Davis (Davis), a former Victorville inmate

imprisoned for being a felon in possession of a firearm and an

armed career criminal, testified that he had prior convictions

for burglary, providing false information to a police officer,

attempting to [elude] a police officer and reckless driving,

unlawful delivery of a controlled substance, and criminal

mischief. While in prison, Davis “used marijuana, meth and

heroin and drank,” and was involved in an attack on another

inmate.

According to Davis, he was not a gang member, but was

affiliated with the Aryan Brotherhood and Nazi Low Riders

and had several tattoos including swastikas and the phrase

“white power” on his chest. Despite his lack of gang

membership, Davis was “handed the keys for unit 4A,” a

prison housing unit. Davis was given this leadership position
10 UNITED STATES V. RODRIGUEZ

by a member of the Aryan Brotherhood. Davis related that he

became the unit’s key holder because there were no gang

members in the unit capable of the position.

According to Davis, Rodriguez belonged to the Sureños

and answered to the Mexican Mafia. Davis related that the

Sureños and the white inmates generally got along well and

“called each other comrades.” Davis got along well with

Rodriguez and the other Sureños. Davis testified that inmates

would have to receive permission to assault members of

another race “from the top person for their race on the yard.” 

Otherwise, “their race would stab them in return.”

On April 11, 2005, Davis noticed that Scopazzi, Ultsch,

and Rondeau had been drinking. Davis observed that

Scopazzi was still drinking during dinner. Davis had injected

methamphetamine on that day.

Later, Davis noticed Murillo, Rodriguez, and Mujica with

another inmate, Dan Petty (Petty), in the prison yard.3

According to Davis, Petty was escorting Murillo, Rodriguez,

and Mujica through the yard so that they would not be

stopped by the guards. Davis related that it was common

practice for an inmate to escort other inmates who had

weapons, alcohol, or drugs so as to create a diversion if

stopped by the guards.

Davis subsequently met Scopazzi on the yard. Scopazzi

“was drunk, kind of hyperactive. He was shadow boxing . . .

with [Rondeau].” Murillo, Rodriguez, and Mujica “walked

3 During his testimony, Davis refers to Murillo, Rodriguez, and Mujica

by their nicknames Yogi for Murillo, Lonely for Rodriguez, and Slow for

Mujica. This opinion refers to Appellants by their last names.
UNITED STATES V. RODRIGUEZ 11

up while [Scopazzi] was horse playing” and looked irritated.

Davis decided that he needed to “get [Scopazzi, Rondeau and

Ultsch] to go to bed, to go to sleep so that . . . hopefully

nothing would happen over in their side of the unit.”

After Davis took Scopazzi and Ultsch to their cell, Robert

Salazar (Salazar) visited the cell and inquired if there were

any problems between Scopazzi and Murillo. Scopazzi joked

that he and Murillo could “go in the TV room,” meaning that

Scopazzi and Murillo could fight. Davis told Salazar that

Scopazzi was “acting up, but everything’s all right . . .” 

Salazar responded, “all right guys” and “left the cell.” Davis

believed that Salazar “obviously was sizing stuff up.” After

Salazar left, Scopazzi told Davis that another inmate had

Scopazzi’s shank in the television room and Davis instructed

Rondeau to retrieve the shank.

Murillo, Rodriguez, and Mujica entered Scopazzi’s cell

and closed the door behind them. Murillo went to the corner

of the cell with his hands under his shirt. According to Davis,

Murillo “had his teeth locked and his jaw clenched and his

eyes were focused on [Scopazzi], and he just had a real angry

look . . .” Davis told Murillo that Scopazzi had been drinking

and pleaded with Murillo, “Don’t do this.” Murillo warned

Davis to back up or he would “get stabbed, too.” Davis

noticed a piece of white sheet in Murillo’s hand, which was

“common with shanks. Davis also observed a bandana

wrapped around Mujica’s hand as Mujica moved towards

Scopazzi. As Davis grabbed Mujica and pulled him to the

floor, Murillo stabbed Scopazzi. Rodriguez also had a shank

and stabbed Rondeau in the face. Davis noticed that

Rodriguez had gloves on his hands. When Ultsch returned to

the cell, he was stabbed by Rodriguez. According to Davis,

Scopazzi did not make any threatening moves or statements
12 UNITED STATES V. RODRIGUEZ

prior to the altercation. Davis testified that he never learned

why Murillo, Rodriguez, and Mujica attacked Scopazzi.

After the altercation, Davis assisted Scopazzi, who had

“puncture wounds in his chest.” Although Scopazzi told

Davis that he was all right, Davis was concerned about

Scopazzi’s breathing. Because Davis thought Scopazzi had

a punctured lung, he assisted Scopazzi in seeking medical

treatment. When Scopazzi continued to refuse medical

treatment, prison guards placed him on the ground and

shackled him.

Davis subsequently saw Salazar in the Special Housing

Unit’s recreation area, and Salazar told Davis to inform the

FBI that Scopazzi had a knife. Davis eventually provided a

statement to the FBI and was placed in protective custody.

Davis acknowledged that termination of his sentence was

possible based on his cooperation. Davis also conceded that

he may have received a sentence reduction and been placed

in a safer environment due to his cooperation. Davis

acknowledged that he signed a letter agreement with the

government requiring Davis to testify truthfully. According

to Davis, the letter agreement did not contain any promises

concerning a sentence reduction, and any leniency was not

contingent upon the trial’s outcome.

Regarding Davis’ testimony, the district court instructed

the jury that Davis “may have received, or may receive,

benefits from the government in connection with this case. 

For this reason, in evaluating the testimony . . . [the jury]

should consider the extent to which or whether that witness’s

testimony may have been influenced by this factor. In

addition, [the jury] should examine [Davis’] testimony with

greater caution than that of other witnesses.”
UNITED STATES V. RODRIGUEZ 13

Dr. Glenn Holt, a medical examiner for San Bernardino

County, performed the autopsy on Scopazzi. Dr. Holt

observed that there were five puncture wounds on Scopazzi’s

body. The first puncture wound was approximately three

inches deep and “went through the skin, soft tissue, and

muscle and hit the third rib and caused some hemorrhage

above and below the third rib and also in the muscle between

the third and fourth ribs. . . .” The second puncture wound

was “a little over three inches” deep and penetrated

Scopazzi’s right lung, causing the lung to collapse. The third

puncture wound was approximately five inches deep and

entered the peritoneal cavity creating a hole in the liver. The

fourth puncture wound was approximately “two and a third

inches” deep and penetrated the muscle wall into the

peritoneal cavity. The fifth puncture wound was “a third of

an inch” deep in Scopazzi’s right upper arm.

Dr. Holt opined that the cause of Scopazzi’s death was a

“sequelae of puncture wounds of torso” and “the sequelae

[were] events following an initial event, so . . . the injuries

occur and during events subsequently there were

complications that led to his death.” Dr. Holt related that

“there were some complications that flowed from the fact that

[Scopazzi] was stabbed” and that those complications led to

his death.4

Officer Robert Riley, a Bureau of Prisons correctional

officer, testified that he was working at the Special Housing

Unit in April, 2005. On April 14, 2005, Officer Riley

searched Murillo’s cell and found a small note referred to as

4 During cross-examination, the district court sustained objections to the

defense’s questions concerning the specific complications that led to

Scopazzi’s death and whether brain swelling was the major complication.
14 UNITED STATES V. RODRIGUEZ

a “kite” in “a baby powder bottle.” According to a stipulated

translation of the kite, Murillo stated that Scopazzi had

“disrespected the ‘Sur,’” that Scopazzi and the other inmates

“got what they had coming, cause [sic] I’m 100% Rider

homeboy. . . .”

Special Agent Daniel Evanilla of the California

Department of Corrections and Rehabilitation testified as an

expert on prison gangs. According to Agent Evanilla,

“Sureños are Hispanic gang members that, when they go to a

prison or a county jail, band together as a group. . . .” Agent

Evanilla related that “the Sureños are the recruitment pool for

the Mexican Mafia,” and “[t]hey are considered the foot

soldiers for the Mexican Mafia.” “The Sureños conduct

criminal activities for the Mexican Mafia prison gang. They

respond to . . . the edicts and the orders of the Mexican Mafia

prison gang in terms of their criminal activities, their rules,

their regulations and how they conduct themselves in prison.” 

Agent Evanilla testified that respect from other prisoners was

an important element of the Sureños’ credo and disrespect

was “not tolerated.” Disrespect from a member of another

race, particularly when witnessed by other Sureños, was “a

major factor” in the Sureños’ culture. According to Agent

Evanilla, the reprisal for such disrespect would be “[s]ome

violent assault.” Agent Evanilla reviewed the kite that was

discovered by prison officials in Murillo’s cell and

interpreted the kite as meaning that the white inmates had

disrespected the Sureños.

Captain Robert Hodak of the Englewood Federal

Correctional Institution also testified that the Sureños were

“the foot soldiers for the Mexican Mafia.” According to

Captain Hodak, Salazar was an influential member of the

Sureños and was considered a “[comrade] of the Mexican
UNITED STATES V. RODRIGUEZ 15

Mafia.” Captain Hodak investigated the assault on Scopazzi. 

After reviewing the video of the inmates prior to the assault,

Captain Hodak opined that, based on demeanor, positioning,

and body language, Meneses and Martinez served as

lookouts.

Salazar testified that he was serving sentences for armed

bank robbery and possession of contraband. He confirmed

that he was a Sureño, and that the Mexican Mafia controls the

Sureños “to an extent.” According to Salazar, the white

inmates and the Sureños were “friendly” and “would hang out

together.”

On April 11, 2005, Salazar and Scopazzi started to drink

wine together “right after breakfast . . . approximately 7 in the

morning.” Scopazzi became “overly drunk. He was loud. 

He was being physical with people . . . hitting on people. . . .” 

Salazar had never before observed Scopazzi in this condition.

Murillo told Salazar that Scopazzi “had disrespected

[Murillo] in a sense where he was using the restroom on the

toilet and [Scopazzi] opened the door and said something to

the effect of, I could’ve got you, something like that.” 

Although Murillo and Scopazzi were friends, Murillo was

“upset about what happened.” Salazar went to Scopazzi’s cell

to talk to him. Salazar intended to tell Scopazzi that Scopazzi

“was drunk, and that he was disrespecting people and he

needed to go to sleep.” Salazar asked Scopazzi “what’s up

with you and [Murillo]?” According to Salazar, Scopazzi

jokingly said that he and Murillo could go to the television

room and fight. Scopazzi eventually apologized. Salazar did

not observe any shanks or other weapons in Scopazzi’s cell.
16 UNITED STATES V. RODRIGUEZ

After speaking with Scopazzi, Salazar informed Murillo

that Scopazzi had apologized, and suggested that Murillo talk

to Scopazzi the next day when Scopazzi was no longer

intoxicated. However, Murillo “was upset over the

disrespect and he felt that he had that apology coming from

[Scopazzi] . . .” According to Salazar, he did not know that

Scopazzi was going to be harmed and did not realize that

Scopazzi had been stabbed until after the incident. Although

he described himself as a mediator, Salazar acknowledged

that he did not accompany Murillo to Scopazzi’s cell.

After the assault on Scopazzi, Salazar observed a shank

in Rodriguez’s cell. Rodriguez did not tell Salazar that

Scopazzi had attacked them. Salazar learned that Scopazzi

had been stabbed from “the white guys on the tier.”

Murillo testified that, while he was using the toilet in his

cell, Scopazzi entered Murillo’s cell and “put his hands on his

waist” and said, “I could have got you slipping . . .” Murillo

thought that Scopazzi “was playing around.” Later in the

day, Scopazzi entered Murillo’s cell with Ultsch and

Scopazzi “mov[ed] his body back and forth like he wanted to

punch [Murillo] . . .” Murillo did not believe that “they were

playing around anymore.”

Murillo talked to Salazar because he “didn’t want this to

escalate into a bigger problem.” Murillo told Salazar that

“[t]hese guys keep coming to my cell and disrespecting

me. . . .” Although Salazar told Murillo that Scopazzi had

apologized, Murillo went to Scopazzi’s cell for a direct

apology. Murillo denied having a shank when he went to

Scopazzi’s cell. According to Murillo, Scopazzi started

swearing at Murillo and reached for a shank. According to
UNITED STATES V. RODRIGUEZ 17

Murillo, he disarmed Scopazzi and used Scopazzi’s shank to

stab Scopazzi in self-defense.

Rodriguez testified that, when Rodriguez, Murillo, and

Mujica went to Scopazzi’s cell, they did not have any shanks. 

Scopazzi started to scream at them when they entered the cell

and Rodriguez thought that Rondeau had a shank, although he

never saw it. According to Rodriguez, he saw a shank tucked

into Scopazzi’s waistband.

James Reed Harris (Harris), an inmate at the Victorville

federal prison who was serving sentences for bank robbery

and “weapons, assault,” testified that he was Davis’ cellmate

on the day of the assault. Davis had injected

methamphetamine at least twice, had not slept for four days,

and was “getting real paranoid.” Harris described Davis as

“acting rational enough,” but Harris was concerned that Davis

“might fall over . . .” Harris explained that he was “testifying

because Ryan Davis [was] lying to get a time cut.”

The jury convicted Murillo and Rodriguez of conspiracy

to commit murder, first degree murder, and assault with a

dangerous weapon with intent to do bodily harm as to Ultsch

and Rondeau. The jury acquitted Murillo and Rodriguez of

assault with intent to commit murder as to Ultsch and

Rondeau.

The jury convicted Mujica of conspiracy to commit

murder and first degree murder, but acquitted Mujica of

assault with intent to commit murder and assault with a

dangerous weapon with intent to do bodily harm as to Ultsch

and Rondeau.
18 UNITED STATES V. RODRIGUEZ

Appellants filed a motion for new trial because the

government failed to disclose that Davis had received an

undisclosed sentence reduction and had served as a DEA

informant.5 Appellants maintained that Davis had a tacit

agreement with the government for a sentence reduction

because the government sought to reduce Davis’ sentence on

the same day as the verdicts were rendered. The motion was

denied.

Appellants filed timely notices of appeal.

II. STANDARDS OF REVIEW

“We review de novo whether an evidentiary error rises to

the level of a constitutional violation. . . .” United States v.

Pineda-Doval, 614 F.3d 1019, 1032 (9th Cir. 2010) (citation

omitted).

“We review the district court’s evidentiary rulings for

abuse of discretion and its underlying factual determinations

for clear error.” United States v. Lukashov, 694 F.3d 1107,

1114 (9th Cir. 2012) (citation omitted).

“We review de novo a district court’s denial of a new trial

motion based on a Brady violation.” United States v.

Sedaghaty, 728 F.3d 885, 899 (9th Cir. 2013) (citation

omitted). “Likewise, the question of materiality is a legal

matter that we review de novo.” Id. (citations, alteration, and

internal quotation marks omitted).

5 We granted a limited remand for the district court to consider

Appellants’ motion.
UNITED STATES V. RODRIGUEZ 19

We also review de novo the district court’s denial of a

new trial based on an asserted Mooney-Napue violation. See

United States v. Houston, 648 F.3d 806, 814 (9th Cir. 2011).

III. DISCUSSION

A. Medical Evidence Concerning Scopazzi’s Death

Appellants contend that the district court denied them a

complete defense by improperly excluding evidence that

gross medical negligence and Scopazzi’s removal of his

breathing tube contributed to Scopazzi’s death. Appellants

maintain that the excluded medical evidence was relevant to

Appellants’ defense that the stab wounds were not the

proximate cause of Scopazzi’s death and that they lacked the

requisite intent to kill Scopazzi.

The resolution of Appellants’ evidentiary challenge is

largely controlled by our decision in Pineda-Doval. In that

case, Pineda-Doval challenged his convictions for “ten counts

of transportation of illegal aliens resulting in death.” PinedaDoval, 614 F.3d at 1022. He maintained that “the jury should

have been instructed that it could find the defendant guilty

only if his conduct was the proximate cause of the ten

charged deaths. . . .” Id. Pineda-Doval argued that the

proximate cause of the aliens’ death was the negligent

deployment by Border Patrol agents of a spike strip that

caused the defendant’s vehicle to flip over. See id. at 1024. 

Prior to trial, the district court granted the government’s

motion in limine to exclude as irrelevant evidence that the

Border Patrol agents had failed to comply with the requisite

procedures for deployment of the spike strip. See id.
20 UNITED STATES V. RODRIGUEZ

Pineda-Doval argued that the district court failed to

properly instruct the jury that the “resulting in death” element

required proof that his acts were the proximate cause of the

aliens’ deaths. Id. at 1025. We observed that “[a] basic tenet

of criminal law is that, when a criminal statute requires that

the defendant’s conduct has resulted in an injury, the

government must prove that the defendant’s conduct was the

legal or proximate cause of the resulting injury. . . .” Id. at

1026 (citation and internal quotation marks omitted). We

explained that proof of proximate cause required a showing

by the government that the harm suffered by the victim was

a foreseeable outcome of the defendant’s conduct. See id. at

1028. The proximate cause showing is more easilymet when

the intervening event is “not a coincidence or unrelated to the

defendant’s prior conduct, but rather was a response to that

conduct.” Id. When the intervening event is a response to the

defendant’s conduct, “the question is whether the intervening

act was abnormal—that is, whether, looking at the matter

with hindsight, it seems extraordinary. . . .” Id. (citation

omitted). We held:

Pineda-Doval’s failed attempt to swerve

around the spike strip was the proximate

cause of the deaths of ten individuals. It was

entirely foreseeable that the Border Patrol

would deploy a [spike strip] against the

defendant’s Suburban and thatPineda-Doval’s

dangerous driving would end in an

accident. . . . No reasonable jury could have

found that a car accident was an extraordinary

result.

Id. at 1029. 
UNITED STATES V. RODRIGUEZ 21

We rejected the defendant’s argument that the Border

Patrol agents’ negligence “constituted a superseding cause of

the accident. . . .” Id. at 1029. We opined:

If we assume that [the Border Patrol agent]

made a mistake by pulling the [spike strip]

across the road several seconds too early, this

mistake was not so extraordinary as to break

the chain of causation. Pineda-Doval created

the dangerous conditions . . . and, because he

refused to pull over in response to [the Border

Patrol agent’s] lights and sirens, forced the

Border Patrol to use drastic measures to

stop him. The resulting deaths of his

ten passengers were tragic, but not

unexpected. . . .

Id. at 1029–30.

We held that any error in the district court’s exclusion of

evidence that the Border Patrol agents were negligent in

failing to follow the requisite procedures for deployment of

the spike strip was harmless. “[O]ccasional negligence that

should have been anticipated by the defendant does not defeat

proximate cause. . . .” Id. at 1029 (citation and internal

quotation marks omitted). “To show that the actions of [the

Border Patrol agent] constituted a superseding cause that

broke the chain of causation between Pineda-Doval’s

dangerous driving, that negligence would have had to be so

extraordinary that it would be unfair to hold the defendant

responsible for the resulting accident and deaths.” Id. at 1034

(citation and internal quotation marks omitted). “Even

assuming that the defendant persuaded the jury that timing

was essential to the correct and safe deployment of [the spike
22 UNITED STATES V. RODRIGUEZ

strip] and that [the Border Patrol agent] made the mistake of

pulling the spike strip across the road several seconds too

early, no reasonable jury could have found that [the Border

Patrol agent’s] actions were extraordinary and could not have

been foreseen by [the defendant].” Id. (citations and footnote

reference omitted). Therefore,“[t]he district court’s error in

excluding evidence of [the Border Patrol] policies on spike

strips was harmless beyond a reasonable doubt.” Id.

Similarly, in this case we conclude that any error in the

district court’s exclusion of evidence concerning medical

negligence or Scopazzi’s removal of his breathing tube was

harmless beyond a reasonable doubt. Because medical

treatment was a foreseeable response to Appellants’ conduct

of stabbing Scopazzi, proximate cause was established by the

government. See id. at 1028. Appellants failed to proffer

evidence establishing medical negligence as a superseding

cause of Scopazzi’s death. To make the required showing, 

Appellants would have to demonstrate that medical

negligence and Scopazzi’s removal of his breathing tube were

“so extraordinary that it would be unfair to hold [Appellants]

responsible for the resulting . . . death[ ].” Pineda-Doval,

614 F.3d at 1034 (citation and internal quotation marks

omitted); see also Mitchell v. Prunty, 107 F.3d 1337, 1341

n.8 (9th Cir. 1997), as amended, overruled on other grounds

by Santamaria v. Horsley, 133 F.3d 1242, 1248 (9th Cir.

1998) (observing that “if gross maltreatment of the wound

was the sole cause of death, the person inflicting the wound

will not be liable, because the wound was not the proximate

cause of death. In this case, gross maltreatment would have

been required to render [the victim’s] gunshot wounds fatal.”)

(citation and internal quotation marks omitted).
UNITED STATES V. RODRIGUEZ 23

As it was foreseeable in Pineda-Doval that Border Patrol

agents would deploy a spike strip to stop a fleeing suspect, it

was similarly foreseeable in this case that a victim of multiple

deep stab wounds would receive medical care. See PinedaDoval, 614 F.3d at 1034. And, as we held in Pineda-Doval,

any negligence in the foreseeable response to the stab wounds

does not break the causation chain. See id. The same is true

regarding Scopazzi’s removal of his breathing tube. See

Sedation and Delirium in the Intensive Care Unit, 14 New

England J. of Med. 444 (Jan. 30, 2014) (discussing the

accidental removal of endotracheal tube due to delirium and

agitation).

Dr. Morgan’s proffered testimonydid not address whether

medical negligence was the sole cause of Scopazzi’s death or

even an intervening cause. Although Dr. Morgan purportedly

opined that “the medical attention [Scopazzi] did receive fell

well below well-recognized standards of care resulting in

[Scopazzi’s] death,” Dr. Morgan did not state that

extraordinary medical negligence or Scopazzi’s removal of

his breathing tube caused Scopazzi’s death independent of the

stab wounds themselves. Although the district court ruled

that Dr. Morgan could testify “regarding the nature of

[Scopazzi’s] wounds and the degree of force used to cause

them,” Dr. Morgan never actually testified. Appellants also

informed the district court that they did not intend to rely on

medical negligence as an affirmative defense. Thus, the

district court’s exclusion of Appellants’ proffered evidence

had no bearing on the fairness of Appellants’ trial because

that evidence did not establish medical negligence or removal

of the breathing tube as a superseding cause of Scopazzi’s

death.
24 UNITED STATES V. RODRIGUEZ

Our conclusion that Appellants failed to proffer

admissible evidence that extraordinarymedical negligence or

Scopazzi’s removal of his breathing tube constituted a

supervening cause of Scopazzi’s death is bolstered by the

Seventh Circuit’s rationale in Brackett v. Peters, 11 F.3d 78

(7th Cir. 1993). In Brackett, the habeas petitioner was

convicted of felony murder based on his rape and assault of

an 85-year-old woman. See id. at 79. The victim “was

admitted to the hospital with a broken arm, a broken rib, and

extensive bruises. During her stay in the hospital, which

lasted several weeks, she—described as feisty before the rape

and beating—became depressed, resisted efforts to feed her,

and became progressively weaker.” Id. (internal quotation

marks omitted). After her transfer to a nursing home, she

continued to regress, even though her physical injuries were

healing. Because of her lack of appetite, her doctor ordered

placement of a nasal gastric feeding tube. However, the tube

could not be inserted, in part because the victim’s facial

injuries made insertion of the tube too painful. See id.

Approximately ten days after her admission, the victim died

when a large quantity of food became lodged in her trachea,

asphyxiating her. See id. The habeas petitioner contended

that the negligence of the nurse who was feeding the victim

caused her death. See id. at 80.

In rejecting the habeas petitioner’s argument and holding

that the petitioner’s assault was the proximate cause of the

victim’s death, the Seventh Circuit observed that “an act is a

cause of an event if two conditions are satisfied: the event

would not have occurred without the act; the act made the

event more likely.” Id. at 79. The Seventh Circuit opined

that the nurse’s purported negligence was nothing more than

another cause of the victim’s death. See id. at 80. The

Seventh Circuit concluded that “a murderer does not avoid
UNITED STATES V. RODRIGUEZ 25

conviction by pointing out that his act was only one of many

causes that concurred to bring about his victim’s death.” Id.

“It is enough if his act was one of the causes-enough

therefore if [the petitioner’s] assault made [the victim’s]

death more likely and if, but for the assault, she would not

have died as soon as she did. . . .” Id. (citations omitted). 

“Death was the last link in a continuous series of events that

began with the assault. [The victim] died a month later, never

having returned home. . . .” Id. The court emphasized that

had the victim never been assaulted, it is unlikely that she

would have been admitted to the hospital to die one month

later. See id.

The petitioner also argued that the assault caused the

victim to become clinically depressed and suicide-prone. 

According to the petitioner, the victim committed suicide by

refusing to eat, and that suicide was a superseding cause of

the victim’s death. See id. at 80–81. The Seventh Circuit

rejected this argument, reasoning that “[t]he fact that a

psychiatric condition, whether or not by precipitating suicide,

is one of the causes of a victim’s death does not excuse his

murderer. Otherwise, it would be open season on sufferers

from mental illness.” Id. at 81 (citations omitted). The court

contrasted a chance occurrence, such as a fire at a nursing

home, that would be a superseding cause if death resulted. 

See id. at 80.

Other circuits have also held that defendants are liable for

murder notwithstanding additional occurrences. For example,

in United States v. Swallow, 109 F.3d 656 (10th Cir. 1997),

the Tenth Circuit affirmed the defendant’s murder

convictions despite the defendant’s argument that the district

court erred in failing to provide a “proposed instruction

characteriz[ing] an independent intervening cause as the
26 UNITED STATES V. RODRIGUEZ

unforeseeable gross negligence of a third party that relieves

the defendant of responsibility for the death of the

victim. . . .” Id. at 659 (citations omitted). In rejecting the

defendant’s argument that negligence on the part of rescuers

contributed to the victims’ deaths, the Tenth Circuit held that

“in cases involving death from injuries inflicted in an assault,

courts have uniformly held that the person who inflicted the

injury will be liable for the death despite the failure of third

persons to save the victim.” Id. at 660 (citations and

alteration omitted).

Similarly, in United States v. Guillette, 547 F.2d 743 (2d

Cir. 1976), the Second Circuit held that the defendant was

liable for the death of a victim who may have accidently

triggered a bomb. See id. at 747–48. “The trial judge

instructed the jury that even if [the victim] died accidentally

through his own actions, the defendants would nonetheless be

guilty of conspiracy with death resulting if [the victim’s]

death was induced or brought about by some act of a

conspiracy in furtherance of the purposes of a conspiracy.” 

Id. at 748. The Second Circuit ruled that “[a] fundamental

principle of criminal law is that a person is held responsible

for all consequences proximately caused by his criminal

conduct. The concept of proximate cause incorporates the

notion that an accused may be charged with a criminal

offense even though his acts were not the immediate cause of

the victim’s death or injury.” Id. at 749 (citation omitted). 

“In many situations giving rise to criminal liability, the death

or injury is not directly caused by the acts of the defendant

but rather results from intervening forces or events, such as

negligent medical treatment, escape attempts, or the negligent

or intentional acts of a third party.” Id. “Where such

intervening events are foreseeable and naturally result from

a perpetrator’s criminal conduct, the law considers the chain
UNITED STATES V. RODRIGUEZ 27

of legal causation unbroken and holds the perpetrator

criminally responsible for the resulting harm.” Id. (citations

omitted); see also United States v. Rodriguez, 279 F.3d 947,

950–51 (11th Cir. 2002) (holding in the sentencing

enhancement context that “one may be held criminally liable

for a victim’s death even where medical negligence or

mistreatment also contributed to the victim’s death”) (citation

omitted).

State courts have also consistently held that the defendant

must demonstrate extraordinary medical negligence as the

sole cause of death to break the causation chain. See, e.g.,

People v. Mars, 985 N.E.2d 570, 575 (Ill. App. Ct. 2012), as

modified (“The presumption [of causation] must be rebutted

by the defendant’s presentation of contrary evidence that the

sole cause of death was the intervening gross negligence of

physicians. Unskilled or improper medical treatment that

aggravates a victim’s preexisting condition or contributes to

the victim’s death is considered reasonably foreseeable and

does not constitute an intervening act unless the treatment is

so bad that it can be classified as gross negligence or

intentional malpractice. . . .”) (citations omitted) (emphasis in

the original); State v. Shabazz, 719 A.2d 440, 445 (Conn.

1998) (“The rule . . . that such gross negligence may permit

the defendant to escape liability when it was the sole cause of

the death, strikes an appropriate balance between the notions

of criminal responsibility for one’s conduct, on one hand, and

intervening cause, on the other.”) (citation omitted); State v.

Kirby, 39 P.3d 1, 12 (Kan. 2002) (“It is clear that the

physicians’ actions were not so unusual, abnormal, or

extraordinary that they could not have been foreseen. The

physicians’ negligence, if any, did not supersede the effect of

the wounds inflicted by [the defendant] so as to become the

sole legal cause of [the victim’s] death.”); People v. Roberts,
28 UNITED STATES V. RODRIGUEZ

826 P.2d 274, 295 (Cal. 1992) (in bank), as modified (“If a

person inflicts a dangerous wound on another, it is ordinarily

no defense that inadequate medical treatment contributed to

the victim’s death. To be sure, when medical treatment is

grossly improper, it may discharge liability for homicide if

the maltreatment is the sole cause of death and hence an

unforeseeable intervening cause. . . .”) (citations omitted).

Given the weight of such consistent federal and state

precedent, we conclude that Appellants failed to proffer any

probative evidence that extraordinary medical negligence or

Scopazzi’s removal of his breathing tube was the sole cause

of Scopazzi’s death. Indeed, Scopazzi would not have

needed medical care or a breathing tube absent Appellants’

infliction of five stab wounds, including a wound that

punctured Scopazzi’s lung. The alleged medical negligence

or removal of Scopazzi’s breathing tube may have been

“another cause of [Scopazzi’s] death,” but neither was a

supervening event exonerating Appellants from the death

resulting from their assault. Brackett, 11 F.3d at 80 (citations

omitted). It was not sufficient for Appellants to simply

proffer some evidence of medical negligence or Scopazzi’s

removal of his breathing tube without otherwise satisfying the

standard for proximate cause. See Pineda-Doval, 614 F.3d at

1034; see also Guillette, 547 F.2d at 749 (“Where such

intervening events are foreseeable and naturally result from

a perpetrator’s criminal conduct, the law considers the chain

of legal causation unbroken and holds the perpetrator

criminally responsible for the resulting harm. This principle
UNITED STATES V. RODRIGUEZ 29

applies even where the direct cause of death is a force set in

motion by the victim himself. . . .”) (citations omitted).6

United States v. Main, 113 F.3d 1046 (9th Cir. 1997) does

not compel a contrary result. In Main, we delineated the

applicable standard for proximate cause involving an

involuntary manslaughter conviction resulting from the

defendant’s reckless driving while intoxicated. See id. at

1047. In reversing the conviction, we held that the district

court failed to properly instruct the jury that it must find that

the defendant’s acts were the proximate cause of the victim’s

death. See id. at 1049–50. We observed that “[a]ll of the

authorities agree that to be guilty of involuntarymanslaughter

the harmful result must be within the risk foreseeably created

by the accused’s conduct; if the physical causation is too

remote, the law will not take cognizance of it. . . .” Id. at

1049. We considered the foreseeability determination more

difficult when the manslaughter charges stem from excessive

speed or drunk driving because many individuals speed

and/or drive while impaired without killing anyone. See id.

Therefore, the foreseeability determination would require

6 Consistent with its prior rulings on the government’s motions in limine,

the district court did not abuse its discretion when it denied Appellants’

request to cross-examine Dr. Holt, the medical examiner, regarding his

description of “the sequelae of puncture wounds” ultimately leading to

Scopazzi’s death. Appellants specifically sought to question Dr. Holt

concerning Scopazzi’s removal of his breathing tube, a sudden loss of

blood, cardiac arrest, and brain swelling. Dr. Holt’s testimony did not

open the door to this additional medical evidence because Dr. Holt

acknowledged that the complications “flowed from the fact that

[Scopazzi] was stabbed.” In any event, Appellants’ proffer did not satisfy

the proximate cause standard of complications “so extraordinary that it

would be unfair to hold [Appellants] responsible for the resulting . . .

death[ ].” Pineda-Doval, 614 F.3d at 1034 (citation and internal quotation

marks omitted); see also Brackett, 11 F.3d at 80.
30 UNITED STATES V. RODRIGUEZ

careful examination of the individual “conduct engaged in.” 

Id. We held that reversal of the conviction was warranted

because “[w]hen the jury is not told that it must find that the

victim’s death was within the risk created by the defendant’s

conduct an element of the crime has been erroneously

withdrawn from the jury.” Id. at 1050 (citations omitted).7

In stark contrast to Main, Appellants’ convictions were

not premised on the more ambiguous acts of “excessive speed

or drunk driving.” Main, 113 F.3d at 1049. Rather,

Appellants’ use of deadly weapons to directly inflict serious

stab wounds carried the completely foreseeable risk that

Scopazzi’s injuries would result in death. Moreover, the

district court included the concept of proximate cause in the

instruction on voluntary manslaughter, and the concept of

foreseeability in other instructions.8

7 We offered the following example of a sufficient intervening cause:

“Suppose [the victim] had been pinned in the wreck and then eaten by a

bear. His death would have been the result of the wreck; but for [the

defendant’s] driving, he would not have been killed, yet a jury could find

as a fact that the death was not within the risk that [the defendant] had

created. In the language of the American Law Institute death from a bear

was not within the risk foreseeably created by the reckless driving[.]”

Main, 113 F.3d at 1049 (citation omitted).

8 Appellants’ reliance on United States v. Chouteau, 102 U.S. 603

(1880) is also misplaced. In Chouteau, the Supreme Court considered

whether a distiller was liable for breach of certain bond conditions. See

id. at 608. Within that context, the Supreme Court merely observed that

“[i]f, for example, a party should charge another with inflicting upon his

person a wound by which he lost an arm, it would be a good defence to

show that the loss resulted fromunskilful medical treatment or neglect and

not from the wound inflicted. So here, it is enough for the sureties to

show that the loss to the government was produced by other means than

the particular breach of duty by their principal, of which the government

complains. . . .” Id. at 609. Needless to say, the law has evolved in the
UNITED STATES V. RODRIGUEZ 31

Because Appellants failed to demonstrate that any

medical negligence or removal of a breathing tube was “so

extraordinary that it would be unfair to hold [Appellants]

responsible for the resulting . . . death[ ],” Pineda-Doval,

614 F.3d at 1034 (citation and internal quotation marks

omitted), and because the jury instructions included the

concepts of foreseeability and proximate cause, the district

court acted within its discretion when it cabined the medical

evidence.

B. Evidence of Gang Affiliation

Appellants next contend that the district court erred in

admitting irrelevant and prejudicial evidence concerning

Appellants’ alleged connection to the Mexican Mafia. 

Appellants also maintain that the district court erred in

holding that the evidence’s probative value outweighed any

prejudice under Federal Rule of Evidence 403.

In United States v. Santiago, 46 F.3d 885 (9th Cir. 1995),

we rejected an analogous evidentiary challenge. In that case,

to establish the motive for the defendant’s first degree murder

of another inmate, the government introduced a cellmate’s

testimony that the defendant sought to become a member of

the Mexican Mafia. See id. at 887–88. In affirming the

district court’s admission of evidence concerning the

defendant’s ties to the Mexican Mafia, we observed that the

testimony did not violate Rule 404(b) because it “did not

relate to other crimes,” and it fell within the exception for

evidence regarding motive. Id. at 888–89. “[T]he testimony

relating to the Mexican Mafia was necessary to explain the

century-plus since Chouteau was decided. See Pineda-Doval, 614 F.3d

at 1034.
32 UNITED STATES V. RODRIGUEZ

reason that Santiago would kill a stranger – to be accepted

into the gang – and to show how and why other inmates

assisted him in obtaining the weapon.” Id. at 889. We

rejected the argument that the government’s use of the

testimony was a pretense intended to denigrate the defendant

for his affiliation with a prison gang. See id. at 889–90. 

Because the evidence reflected that the defendant had

expressed interest in the gang and had associated with gang

members, including on the night before the murder, a

sufficient foundation was laid to admit the testimony. See id.

at 890.

We similarly conclude that testimony relating to the

Mexican Mafia was relevant to Appellants’ murder of

Scopazzi, and that its probative value was not substantially

outweighed by any prejudice. Although Appellants attempt

to distinguish Santiago on the basis that the government did

not present any evidence that Appellants stabbed Scopazzi

based on their ties to the Mexican Mafia, the record supports

a contrary conclusion. As in Santiago, the Mexican Mafia

testimony was critical to the government’s theory that

Appellants did not act in self-defense and that their attack on

Scopazzi for seemingly insignificant acts of disrespect was

motivated by their ties to the Mexican Mafia. See Santiago,

46 F.3d at 889–90. The government also introduced the kite

from Murillo’s cell that implied the attack on Scopazzi was

motivated by Scopazzi’s disrespect of the Sureños.

Appellants’ trial was also permeated with references to

their gang affiliations, and Agent Evanilla’s expert testimony

addressed the connection between the Sureños and the

Mexican Mafia within the prison gang hierarchy. Given

Appellants’ admitted gang connections, the expert testimony

concerningthe Mexican Mafia and photographs of Appellants
UNITED STATES V. RODRIGUEZ 33

with members of the Mexican Mafia was not unduly

prejudicial as “the Mexican Mafia was not the entire theme of

the trial, so as to infect the trial with the threat of guilt by

association. . . .” Santiago, 46 F.3d at 889 (citation,

alteration, and internal quotation marks omitted). This is

particularly true in this case where the trial focused primarily

on the events that transpired in Scopazzi’s cell and the jury

was presented with numerous photographs and videos of the

events without reference to Appellants’ connections to the

Mexican Mafia.

Notably, the district court also took several steps to

minimize any undue prejudice. In particular, the district court

permitted only “a limited number of photographs of

[Appellants] posing with certain members of the Mexican

Mafia” and “brief testimony by qualified witnesses regarding

the hierarchy, customs, practices and tenets of the Mexican

Mafia and its relationship and connection to the Sureños.” 

The district court also committed to “include in its voir dire

of prospective jurors examination on this subject and its

effect, if any, on any juror’s ability to judge the case fairly

and objectively.” Appellants rejected the district court’s offer

to provide a limiting instruction concerning why the Mexican

Mafia testimony was being admitted into evidence. See

United States v. Decoud, 456 F.3d 996, 1012 (9th Cir. 2006)

(rejecting evidentiary challenge in part because the defendant

“did not take up the district court on its offer to provide the

jury with a limiting instruction that could have mitigated, if

not negated, [the defendant’s] concerns”).

We conclude that the district court did not abuse its

discretion in admitting evidence pertaining to the connection

between the Sureños and the Mexican Mafia as relevant to

Appellants’ motive in attacking Scopazzi. See Santiago,
34 UNITED STATES V. RODRIGUEZ

46 F.3d at 889–90; see also United States v. Major, 676 F.3d

803, 810 (9th Cir. 2012) (holding that the district court did

not abuse its discretion in admitting gang affiliation evidence

as relevant to motive).

Appellants’ reliance on Kennedy v. Lockyer, 379 F.3d

1041 (9th Cir. 2004), as amended, Spivey v. Rocha, 194 F.3d

971 (9th Cir. 1999), and Dawson v. Delaware, 503 U.S. 159

(1992) is misplaced as those cases are entirely

distinguishable. In Kennedy, we did not address an

evidentiary challenge to gang affiliation evidence. Instead,

we held that a habeas petitioner was prejudiced because the

attorney for his retrial was not provided a complete trial

transcript that included the trial court’s prior ruling excluding

such evidence. See Kennedy, 379 F.3d at 1042–43. Because

the prosecution elicited the precluded testimony in the second

trial in violation of the trial court’s prior order, we held that

the petitioner was prejudiced in part because “where, as here,

gang evidence is proffered to prove a substantive element of

the crime (and not for impeachment purposes), it would likely

be unduly prejudicial. . . .” Id. at 1056 (citation and internal

quotation marks omitted).

In Spivey, we considered whether the trial court erred in

excluding evidence of the witnesses’ gang affiliation

proffered by the defendant. See Spivey, 194 F.3d at 977. The

trial court excluded the evidence because it did not support

the defendant’s assertion that the victim “was killed by a

phantom killer” and there was already sufficient evidence of

the witness’s potential bias. Id. We held that, because the

evidence was purely speculative, exclusion of the evidence

did not render the defendant’s trial fundamentally unfair. See

id. at 979. Contrary to Appellants’ assertion, Spivey did not

hold that the prosecution was required to establish that gang
UNITED STATES V. RODRIGUEZ 35

affiliation was the actual motive for the murder. Instead, we

articulated that, under California law, “[i]n order for evidence

of another suspect to be admissible . . . there must be direct or

circumstantial evidence linking the third person to the actual

perpetration of the crime. Motive or opportunity is not

enough. . . .” Spivey, 194 F.3d at 978 (citations and internal

quotation marks omitted).

In Dawson, the Supreme Court held that evidence

concerning the Aryan Brotherhood was inadmissible because

it contravened the defendant’s associational rights. See

Dawson, 503 U.S. at 164–65. The Supreme Court opined that

“the Aryan Brotherhood evidence was not tied in any way to

the murder of [the defendant’s] victim” and that “the

inference which the jury was invited to draw . . . tended to

prove nothing more than the abstract beliefs of [a particular

Aryan Brotherhood] chapter. . . .” Id. at 166. Unlike in

Dawson, the Mexican Mafia evidence in this case was “tied

to the murder” of Scopazzi as evidence of motive.

C. Brady and Mooney-Napue Claims

1. Non-Disclosure of A Tacit Agreement That

Davis Would Receive A Sentence Reduction

Appellants posit that a new trial is warranted because the

government’s failure to disclose a tacit agreement to reduce

Davis’ sentence contravened Brady. “Under Brady, the

suppression by the prosecution of evidence favorable to an

accused upon request violates due process where the evidence

is material either to guilt or to punishment.” United States v.

Stinson, 647 F.3d 1196, 1208 (9th Cir. 2011), as amended

(citation and internal quotation marks omitted). “There are

three components of a Brady violation: the evidence at issue
36 UNITED STATES V. RODRIGUEZ

must be favorable to the accused, either because it is

exculpatory, or because it is impeaching; that evidence must

have been suppressed by the State, either willfully or

inadvertently; and prejudice must have ensued.” Id. (citation,

alteration, and internal quotation marks omitted). “To

determine whether prejudice exists, we look to the materiality

of the suppressed evidence. When looking to materiality, the

question is whether admission of the suppressed evidence

would have created a reasonable probability of a different

result, so the defendant must show only that the government’s

evidentiary suppression undermines confidence in the

outcome of the trial.” Id. (citation and internal quotation

marks omitted).

The record reflects that there was no Brady violation

premised on Davis’ cooperation. Although the government

initiated the process under Federal Rule of Criminal

Procedure 35 to reduce Davis’ sentence on the same day the

jury found Appellants guilty, we are unable to conclude that

this temporal proximity alone establishes a Brady violation. 

At trial, Davis testified that early termination of his sentence

was possible based on his cooperation. Davis related that the

letter agreement required that he testify truthfully and that the

agreement did not provide any promises of leniency or a

sentence reduction contingent upon the trial’s outcome. As

reflected byDavis’ testimony, the government fully disclosed

the letter agreement and the FBI interviews.9 Appellants

failed to demonstrate that any of the government’s post9 Appellants maintain that Davis falsely denied that he expected any

leniency based on his testimony. However, Appellants have not presented

any evidence of a tacit agreement for leniency or that Davis was aware of

any such agreement.
UNITED STATES V. RODRIGUEZ 37

verdict actions were inconsistent with the letter agreement or

were premised on an undisclosed tacit agreement.10

We conclude that no Brady violation occurred because

there was no tacit agreement to disclose. See United States v.

Price, 566 F.3d 900, 910 n.11 (9th Cir. 2009) (“If the record

is conclusive that all relevant agents of the government did

not know about the Brady material, then, of course, no Brady

violation has occurred as the government has no obligation to

produce information which it does not possess or of which it

is unaware. . . .”) (citation and internal quotation marks

omitted) (emphasis in the original). The district court also

cautioned the jury that Davis “may have received, or may

receive, benefits from the government in connection with this

case” and that the jury should examine Davis’ testimony

“with greater caution than that of other witnesses.”11 Davis’

10 Appellants’ reliance on Sivak v. Hardison, 658 F.3d 898 (9th Cir.

2011) is unavailing. In that case, the witness testified that certain charges

were dismissed but “he did not know whether the prosecutor’s office was

involved in the dismissals.” Sivak, 658 F.3d at 904. The witness also

testified that he cooperated based on fears for his family’s safety and that

he was not “seeking any particular favoritism from State authorities in

exchange for his testimony . . .” Id. at 903 (internal quotation marks

omitted). We held that there was a Brady violation based on undisclosed

letters reflecting a tacit agreement for leniency. See id. at 909–10. Davis,

unlike the witness in Spivak, acknowledged that he hoped that his

cooperation would result in a sentence reduction and no tacit agreement

for leniency was unearthed.

11 Appellants maintain that the district court’sinstruction was ineffective

because it required the jury to speculate. However, it is unclear how the

district court’s instruction was ineffective as it specifically cautioned the

jury about the potential impact of any benefits Davis received for his

cooperation.
38 UNITED STATES V. RODRIGUEZ

credibility, therefore, was significantly undermined

irrespective of any tacit agreement for a sentence reduction.

2. Non-Disclosure of Davis As A DEA Informant

Appellants also argue that a new trial is required because

the government failed to disclose that Davis served as a DEA

informant.

Although it is arguable that the government was required

to disclose this information as impeachment evidence, see

United States v. Si, 343 F.3d 1116, 1123 (9th Cir. 2003)

(observing that “these [informant] reports can be considered

favorable to [the defendant] because, as information about

[the witness’s] ongoing informant activities, they would

constitute impeachment evidence tending to show [the

witness’s] motives in testifying for the government”), its

disclosure would not “have led to a different result. . . .” 

United States v. Olsen, 704 F.3d 1172, 1184 (9th Cir. 2013)

(citation omitted). As discussed, Davis’ credibility was

sufficiently undermined by the defense, given his admitted

cooperation with the prosecution, his extensive criminal

history, and his illicit prison activities. Although the DEA

report may have further demonstrated Davis’ willingness to

cooperate with the government, Appellants do not point to

any benefits that Davis received from his cooperation,

particularly as Appellants do not rebut the government’s

representation that Davis was never classified as a DEA

informant. “The cross-examination of [Davis] raised

reasonable doubts as to his motivation for testifying and there

was sufficient impeachment evidence for the jury to question

seriously the veracity of [Davis’] original statement. Thus,

regardless of the failure to disclose the informant status of

[Davis], [Appellants] received a trial resulting in a verdict
UNITED STATES V. RODRIGUEZ 39

worthy of confidence.” Gentry v. Sinclair, 705 F.3d 884, 905

(9th Cir. 2013), as amended (citation and internal quotation

marks omitted); see also Si, 343 F.3d at 1123 (holding that

information of witness’s role as an informant in unrelated

cases was not material).

3. Mooney-Napue Violation

Appellants contend that the government knowingly failed

to correct Davis’ false testimony that he was not promised a

sentence reduction in violation of Mooney and Napue.

“A conviction obtained using knowingly perjured

testimony violates due process, even if the witness’s perjured

testimony goes only to his credibility as a witness and not to

the defendant’s guilt.” United States v. Houston, 648 F.3d

806, 814 (9th Cir. 2011) (citations omitted). “The

government’s failure to correct testimony that it later learns

is perjured is also a Mooney–Napue violation.” Id. (citation

omitted). “To prevail on a Mooney–Napue claim, the

defendant must show that (1) the testimony was actually

false, (2) the prosecution knew or should have known that the

testimony was actually false, and (3) that the false testimony

was material.” Id. (citation, alteration, and internal quotation

marks omitted). “In assessing materiality under Napue, we

determine whether there is any reasonable likelihood that the

false testimony could have affected the judgment of the jury;

if so, then the conviction must be set aside. Under this

materiality standard, the question is not whether the

defendant would more likely than not have received a

different verdict with the evidence, but whether in its absence

he received a fair trial, understood as a trial resulting in a

verdict worthy of confidence.” Id. (citation omitted). 

“However, if it is established that the government knowingly
40 UNITED STATES V. RODRIGUEZ

permitted the introduction of false testimony reversal is

virtually automatic.” Id. (citation omitted).

Appellants’ Mooney-Napue claim is premised on their

contention that there was a tacit agreement that the

government would assist Davis in receiving a sentence

reduction based on his favorable testimony. However,

Appellants failed to proffer any evidence of a tacit agreement,

particularly as the government’s post-verdict actions were

consistent with the fully disclosed letter agreement and with

Davis’ testimony that the letter agreement was not contingent

upon the trial’s outcome. Appellants are unable to

demonstrate that Davis’ testimony“was actuallyfalse” or that

“the prosecution knew or should have known that the

testimony was actually false . . .” Id. (citation omitted). Thus,

a new trial was not warranted.12

IV. CONCLUSION

The district court’s exclusion of evidence concerning

medical negligence and Scopazzi’s removal of his breathing

tube does not warrant reversal of Appellants’ convictions. 

Appellants failed to demonstrate that any medical negligence

related to Scopazzi’s multiple stab wounds and his removal

of his breathing tube were the sole causes of Scopazzi’s death

or were so extraordinary and unforeseeable as to absolve

Appellants of liability for their vicious assault. The district

12 Although Appellants maintain that cumulative error warrants a new

trial, there were no errors, cumulative or otherwise, requiring reversal of

Appellants’ convictions. See Pineda-Doval, 614 F.3d at 1036 (holding

that even if the defendant had been permitted to introduce evidence

concerning proximate cause, “[t]here was no prejudice, cumulative or

otherwise”).
UNITED STATES V. RODRIGUEZ 41

court did not abuse its discretion in admitting evidence of

Appellants’ connections to the Mexican Mafia to demonstrate

Appellants’ motive for murdering Scopazzi. Expert

testimony concerning the connections between the Sureños

and the Mexican Mafia within the prison gang hierarchy and

photographs of Appellants with Mexican Mafia members did

not render their trial unfair because the district court properly

minimized any prejudice stemming from the evidence and

Appellants’ trial was replete with admissible evidence

regarding Appellants’ gang affiliations. Appellants also

failed to demonstrate that a new trial was warranted based on

the government’s failure to disclose immaterial information

regarding Davis’ sentence reduction and his cooperation in a

DEA investigation.

AFFIRMED.