OPINION

Frank O’Connell and Francisco Carrillo were wrongfully imprisoned for decades before eventually securing habeas relief. After release, they separately brought suit under 42 U.S.C. § 1983 in federal district court against the police investigators involved in their respective cases, arguing in part the officers failed to disclose evidence that would have cast serious doubt on the testimony of key prosecution witnesses. The defendant officers asserted qualified immunity, arguing the law at the time of the investigations did not clearly establish the duty of police officers to disclose material, exculpatory evidence under Brady v. Maryland, 373 U.S. 83 , 83 S.Ct. 1194 , 10 L.Ed.2d 215 (1963). The district court denied judgment on the pleadings in O’Connell’s case and summary judgment in Carrillo’s case, concluding the officers’ duty to disclose Brady evidence was clearly established at the time of the investigations. The officers challenge these determinations on appeal.

We conclude, first, that the law at the time of the investigations clearly established that police officers had to disclose material, exculpatory evidence under Brady , and second, that any reasonable officer would have understood that Brady required the disclosure of the specific evidence allegedly withheld. We therefore affirm the denials of qualified immunity and remand these cases to the district court for further proceedings.

BACKGROUND

1. O’Connell

In January 1984, Jay French was murdered in the parking lot of his apartment building. Los Angeles County Sheriffs Department (LASD) homicide detectives J.D. Smith and Gilbert Parra were responsible for investigating the murder. Smith and Parra discovered French was in a heated battle over the custody of his children with his ex-wife, Jeanne Lyon, and that Lyon had called French’s home on the morning of the murder. During their investigation, the officers discovered Lyon had been romantically involved with Frank O’Connell the previous summer. The eyewitness descriptions of the killer matched O’Connell, and he was ultimately charged with French’s murder. The case proceeded to a bench trial.

At trial, the prosecution introduced evidence that French had shouted, as he lay dying, that “that fucker in the yellow Pinto shot me,” and that “he was going to have to die and it had something to do with Jeanne [Lyon], it looked like somebody she hangs around with or somebody she hung around with.” Through the testimony of several witnesses, including Daniel Druecker, Alec Sanchez, Arturo Villareal and Maurice Soucy, the prosecution pinned the crime to O’Connell.

Druecker, who lived in French’s apartment building, was the only witness to the shooting itself. At trial, he described the shooter as a tall Caucasian man in his thirties with brown shoulder-length hair. He identified O’Connell as the killer at trial and testified he had selected O’Connell from a photo lineup shown to him by the officers.

Sanchez, a flagman in the area, reported and later testified he had witnessed a yellow Pinto station wagon with faded wooden sides fleeing the scene of the crime. He described the driver as a woman with blond hair and her companion as a.white male with long curly brown hair. He was unable to identify O’Connell or anyone else as the passenger in the car.

Villareal, a deliveryman, also saw the shooter leave the scene of the crime in a Pinto. He testified that, when the investigators showed him a photo lineup, he selected two photos and told the officers he “couldn’t be positive” which was the shooter. He also testified he could not identify O’Connell as the person he saw the day of the murder. Detective Smith countered this testimony, testifying Villareal had chosen only one photo from the lineup. He read from a police report that represented Villareal as remarking that O’Connell was “the strongest contender, and I’m sure that’s him.”

Finally, Soucy, a neighbor of Lyon’s, testified. Soucy recalled seeing a tall white man who drove a yellow Pinto in his apartment complex on several occasions. Soucy further testified he had seen the man who drove the Pinto kissing Lyon, and that he had seen the car parked near Lyon’s apartment on several occasions. He identified O’Connell in court as the man he had seen driving the Pinto.

O’Connell was convicted of murder following his bench trial. Over 20 years later, he filed a state habeas petition, alleging in part that the investigating officers failed to disclose material, exculpatory evidence that would have undermined the witnesses’ trial testimony and cast suspicion on an alternative suspect.

At an evidentiary hearing on O’Connell’s habeas petition, Druecker testified, offering information that would have significantly undercut his identification of O’Connell at trial. He recalled he had been working on his car on the day French was shot and was not wearing contacts or glasses, which he generally needed because he was nearsighted. He was leaning into the driver’s side of his car when he heard a loud “pop,” which he thought was a firecracker. He got out of the car to see French running and screaming that he had been shot. A man immediately behind French stopped, raised a gun and pointed it, when Druecker heard another bang. Druecker ducked behind a car. As a result, he saw the shooter only in left profile and described him as tall, with long, dark hair and carrying a long-barreled gun. Because Druecker had never seen a gun, he was focused on the weapon.

An officer on the scene asked whether Druecker had seen anything. Druecker said he thought he could identify the shooter but was not certain. Two officers (later identified as Smith and Parra) came to Druecker’s apartment to ask for a description of the shooter. Druecker told them he could not remember what the shooter looked like and asked if the officers could put him under hypnosis, which they refused to do. He testified the officers “kept calling him,” and eventually came back on their own one morning with photos of six men. Druecker took this as an indication that they must have found the shooter. He told the officers he had seen only the shooter’s profile and asked if they had profile photos. He also remarked to them that every photo depicted a. man with a mustache but that he did not remember the shooter having a mustache.

Even though Druecker told the officers he did not recognize any of the men depicted, in the photos, they told him to “really look” at the photos. Feeling he had to select one of the photos, and believing the officers already knew who the shooter was, he pointed to photo three (which depicted O’Connell) and asked, “Is this the guy?” The officers asked if this was the person he was identifying as the shooter. Thinking the officers already knew who the shooter was, Druecker responded, “I think that’s the guy.” The officers told him he had to be certain. He said he was sure, but at the evidentiary hearing on O’Connell’s habeas petition, he testified that he only did so out of intimidation. In truth, he did not recognize the photo but was simply guessing. Druecker explained he did not disclose this uncertainty either during the preliminary hearing or at trial because he was afraid and believed, based on his interactions with the officers, that he had identified the correct person.

During the habeas proceeding, O’Connell discovered a copy of the officers’ handwritten notes detailing their interview with Maurice Soucy. In the official police report, which was disclosed, the officers had written that when shown the photo lineup, Soucy “immediately pointed out photograph number three. He stated that was the person who asked him to jump start the yellow Pinto, and was also the same person he had seen hugging and kissing Jeanne Lyon.” But in the handwritten notes, which were never provided to the prosecutors or the defense, the officers had written that Soucy identified “# 3 & poss. # 1” and “picked out # 3 as poss. suspect because of face but hair was curlier.” Immediately following that statement, they noted the name “Maurice.” These notes were never turned over to the prosecution or defense.

O’Connell also discovered another set of handwritten notes revealing a possible alternative suspect to the crime. The prosecution contended French’s dying declaration, in which he shouted the killer was someone Jeanne “hung around with,” pointed solely to O’Connell, who had been romantically linked to Lyon. But other notes taken by the officers during an interview with a former attorney of French’s revealed Lyon, along with another man, had previously made an attempt on French’s life. In one note, the officers wrote that French’s “x wife attempted to run over v [victim] while trying to serve her papers for child custody. Jeannie [Lyon] was pres, in her Capri car (green). Another guy was driving.... Randy Smith driver of car.” In another note, the officers wrote that “Jeanne and a man named ‘Randy1 were waiting at the road where v would be riding. Randy was driving a green Capri registered to Jeanne Marie Hernandez. Randy attempted to run v down----Randy Smith is tall with sandy or blond hair.” Neither of these notes was turned over to the prosecutors or to the defense.

Based on Druecker’s testimony and these undisclosed notes, a California superior court granted O’Connell’s habeas petition in 2009. The court concluded O’Connell’s conviction was based “in large part on the eyewitness testimony identifying [him],” and that the officers’ notes regarding Druecker’s and Soucy’s testimony could have impeached their credibility. The court determined the conviction was further undermined by the previously undisclosed evidence that French’s dying declaration could have referred to Randy Smith rather than O’Connell. The district attorney’s office declined to re-prosecute O’Connell, and in June 2012, all charges against him were dismissed.

After his habeas petition was granted, O’Connell filed suit under 42 U.S.C. § 1983 , alleging in part that the officers violated his right to due process by withholding material, exculpatory evidence and that as a result, he was wrongfully convicted. Specifically, he alleged the officers failed to disclose evidence regarding Druecker’s uncertainty in identifying O’Connell and the officers’ insistence he select a photo from the lineup; notes revealing that Soucy initially chose multiple photos from the lineup and was uncertain of his identification; and information about a potential alternative suspect. He also alleged the police officers withheld evidence that Villareal had selected two photos from the lineup, and that the represen tation in the official police report that he had selected just one photo was false.

The officers filed a motion for judgment on the pleadings based on qualified immunity, arguing it was not clearly established in 1984 that they were bound by Brady’s disclosure requirements. The district court denied their motion, and this appeal followed.

II. Carrillo

On a January night in 1991, Donald ' Sarpy was killed in a drive-by shooting in Lynwood, California. Sarpy had been walking towards a group of six young black teenagers, one of whom was his son. The area was home to two rival gangs, including a Hispanic gang, “Young Crowd,” and an African-American gang, “N-Hood.” When interviewed by LASD deputies shortly after the shooting, two of the teenagers recalled hearing someone in the suspect vehicle shout “fuck N-Hood,” and another reported hearing someone shout “Young Crowd Locos.” Aside from recalling the people in the car were male, Hispanic teenagers, the witnesses were unable to provide any additional identification information. The deputies’ report ,of their initial conversations with the witnesses noted there were no “unique suspect identifiers” and only a “general suspect description.”

A few hours later, at 1:00 a.m., the deputies brought five of the witnesses to the sheriffs station in Lynwood for questioning. The witnesses were interviewed separately. The final witness to be interviewed was a 16-year-old boy named Scott Turner. Unlike the other witnesses, Turner was interviewed by defendant Craig Ditsch, a LASD deputy and member of Operation Safe Streets, the sheriffs gang enforcement unit. Ditsch knew Turner from previdus gang-related cases. Also unlike the other witnesses, Turner was shown photographs of several suspects. First, he was shown a “gang book,” containing 140 photographs of Latino teenagers believed to be members of the Young Crowd gang. Turner randomly selected several photos from the gang book, but each time, Ditsch told him his selection “could not be the suspect.” Finally, Turner selected Carrillo’s photo, and Ditsch responded that Turner had made the “right choice.” During Carrillo’s habeas proceeding, Turner testified as follows:

Ditsch next showed Turner a photo lineup with Carrillo’s photo in position number 1. Turner selected Carrillo’s photo. In a police report, Ditsch wrote that Turner had selected Carrillo’s photo but did not mention Turner had selected several photos of other individuals first, or that Ditsch confirmed Turner’s choice when Turner ultimately selected Carrillo’s photo. Turner then told the other eyewitnesses he had chosen the first photo in the lineup. The other eyewitnesses, who were only shown the photo lineup six months after Carrillo’s arrest, chose Carrillo as the perpetrator based on Turner’s identification.

All six eyewitnesses testified for the prosecution at Carrillo’s first trial, which ended in deadlock. Before the second trial, Turner, who was now in county jail, recanted, saying his identification had been a mistake and that he could no longer testify against Carrillo. Ditsch met with Turner in jail and threatened that Turner would face negative consequences once he was back out on the streets if he recanted.

Turner nevertheless testified for the defense at Carrillo’s second trial that his identification of Carrillo was mistaken. He did not, however, disclose that Ditsch had suggested to him that Carrillo was the shooter. Ditsch testified for the prosecution that Turner had selected Carrillo from the gang books by “put[ting] his finger on the picture [of Carrillo] and safying], ‘That’s the guy.’ ” He also denied that Turner selected anybody else before settling on Carrillo. In his capacity as a gang expert, Ditsch testified that witnesses who are incarcerated often recant because of their fear of being perceived as “snitches,” and that Turner had “do[ne] a complete turnaround in this case” after being sent to jail. Although Turner recanted, the other witnesses maintained their identifications. The jury convicted Carrillo.

Nearly 20 years later, Carrillo filed a habeas petition in California superior court, alleging the eyewitness testimony implicating him was false and that someone else had committed the shooting. During a hearing on the petition, five of the six eyewitnesses who had testified at his second trial recanted their original identification, admitting they could not see who shot Sarpy. The court granted the petition, concluding Carrillo “ha[d] established that the eyewitness evidence against him was either false, tainted, or both.” The district attorney’s office did not appeal the ruling or retry Carrillo.

Following the grant of his habeas petition in state court, Carrillo filed suit under 42 U.S.C. § 1983 , alleging in part that Ditsch violated his right to have material and exculpatory evidence disclosed under Brady , and that, as a result, he was wrongfully convicted. Specifically, he alleges Ditsch failed to disclose his “role in providing information to Scott Turner that steered him towards his identification of ... Carrillo.”

Ditsch moved for summary judgment, arguing he was entitled to qualified immunity on Carrillo’s Brady claim because it was not clearly established in 1991 that Brady applied to police officers as well as prosecutors. The district court denied his motion, and Ditsch appealed.

STANDARD OF REVIEW

A district court’s denial of summary judgment on the basis of qualified immunity is reviewed de novo. See Wilkins v. City of Oakland, 350 F.3d 949, 954 (9th Cir.2003). Similarly, the denial of a motion for judgment on the pleadings based on qualified immunity is reviewed de novo. See Somers v. Thurman, 109 F.3d 614, 616 (9th Cir.1997). “Where disputed issues of material fact exist, we assume the version of the material facts asserted by the non-moving party.” Mattos, 661 F.3d at 439. “We draw all reasonable inferences in favor of the non-moving party.” Id.

DISCUSSION

In this appeal, we consider whether the police officers in these two cases were entitled to qualified immunity for their alleged failure to disclose material and exculpatory evidence as required by Brady v. Maryland, 373 U.S. 83 , 83 S.Ct. 1194 , 10 L.Ed.2d 215 (1963).

Qualified immunity shields police officers from liability under 42 U.S.C. § 1983 unless they have violated a statutory or constitutional right clearly established at the time of the challenged conduct. See City & Cnty. of San Francisco v. Sheehan, — U.S.-, 135 S.Ct. 1765, 1774 , 191 L.Ed.2d 856 (2015). To determine whether an officer is entitled to qualified immunity, we conduct a two-part test. See Pearson v. Callahan, 555 U.S. 223, 232 , 129 S.Ct. 808 , 172 L.Ed.2d 565 (2009). First, do the facts the plaintiff alleges show a violation of a constitutional right? See id. Second, was the right “clearly established” at the time of the alleged misconduct? See id. “An officer cannot be said to have violated a clearly established right unless the right’s contours were sufficiently definite that any reasonable official in his shoes would have understood that he was violating it, meaning that existing precedent placed the statutory or constitutional question beyond debate.” Sheehan, 135 S.Ct. at 1774 (internal citations, alterations and quotation marks omitted).

The defendants do not dispute that the evidence allegedly withheld falls within Brady’s scope, and we therefore do not address the first prong of the qualified immunity analysis. See Tatum v. Moody, 768 F.3d 806 , 821 n. 10 (9th Cir.2014) (declining to address an element of qualified immunity defendants failed to ar gue). Instead, we consider only the second prong: whether the officers would have understood they were violating the Supreme Court’s 1968 decision in Brady by failing to disclose this evidence. We first address whether it was clearly established in 1984 that police officers as well as prosecutors were bound by Brady at all, and next whether the evidence allegedly withheld in these cases was clearly established to be Brady evidence.

I. The law in 1984 clearly established that police officers were bound to disclose material, exculpatory evidence.

The officers argue the law did not clearly establish that they were bound by Brady at all in 1984 and 1991. This contention lacks merit because it was clearly established well before the events in these cases that police officers were bound to disclose material and exculpatory evidence.

Brady held “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, irrespective of the good faith or bad faith of the prosecution.” 373 U.S. at 87 , 83 S.Ct. 1194 . This holding was an “extension” of Mooney v. Holohan, 294 U.S. 103 , 55 S.Ct. 340 , 79 L.Ed. 791 (1935), which held the government’s presentation of testimony it knew to be false, as well as its suppression of evidence that would have impeached that testimony, could require reversal of a conviction. See Brady, 373 U.S. at 86 , 83 S.Ct. 1194 . The Supreme Court reasoned:

Id. at 87 , 83 S.Ct. 1194 (emphasis added). Brady framed the right to material, exculpatory evidence in terms of the defendant rather than the state actor responsible for the nondisclosure. As the Court later explained, the “purpose” of Brady’s disclosure requirement is “to ensure that a miscarriage of justice does not occur.” United States v. Bagley, 473 U.S. 667, 675 , 105 S.Ct. 3375 , 87 L.Ed.2d 481 (1985).

Just one year after Brady , the Fourth Circuit held police officers as well as prosecutors were bound to disclose material, exculpatory evidence, explaining:

Barbee v. Warden, 331 F.2d 842, 846 (4th Cir.1964).

Requiring police officers as well as prosecutors to disclose material and exculpatory evidence follows logically from Brady’s rationale. “As far as the Constitution is concerned, a criminal defendant is equally deprived of his or her due process rights when the police rather than the prosecutor suppresses exculpatory evidence because, in either case, the impact on the fundamental fairness of the defendant’s trial is the same.” Moldowan v. City of Igarren, 578 F.3d 351, 379 (6th Cir.2009). Because police officers play an essential role in forming the prosecution’s case, limiting disclosure obligations to the prosecutor would “undermine Brady by allowing the investigating agency to prevent production by keeping a report out of the prosecutor’s hands.” United States v. Blanco, 392 F.3d 382, 388 (9th Cir.2004) (quoting United States v. Zuno-Arce, 44 F.3d 1420, 1427 (9th Cir.1995)).

This circuit adopted Barbee’s logic well before the investigations here. In United States v. Butler, 567 F.2d 885, 891 (9th Cir.1978), we rejected the government’s argument that no Brady violation occurred because investigative agents, and not the prosecutor, were responsible for the nondisclosure of promises made to certain prosecution witnesses, explaining:

Id. (citing Barbee, 331 F.2d at 846 ) (emphasis added). Butler thus made unmistakably clear that police officers and prosecutors alike share an obligation to disclose “pertinent material evidence favorable to the defense.” Id. at 888 (quoting United States v. Gerard, 491 F.2d 1300, 1302 (9th Cir.1974)).

The officers argue here that Butler did not clearly establish that officers are subject to Brady because it described the disclosure obligation in terms of the prosecutor rather than the police officer. But Butler undisputably put police officers on notice that their failure to disclose Brady information would constitute a violation the defendant’s constitutional rights. It “taught police officers how to conform their conduct to the law,” and “[a] police officer acting after the issuance of th[is] decision[ ] ... could not have thought that the suppression of material exculpatory evidence would pass constitutional muster.” Owens v. Baltimore City State’s Attorneys Office, 767 F.3d 379, 400 (4th Cir.2014) (explaining that, even though circuit cases including Barbee described the duty to disclose in terms of the prosecutor, they put officers on notice that withholding of Brady material would violate clearly established law).

Because “clearly established law” includes “controlling authority in [the defendants’] jurisdiction,” Butler clearly established in 1978 that police officers have a duty to disclose Brady material. See Wilson v. Layne, 526 U.S. 603, 617 , 119 S.Ct. 1692 , 143 L.Ed.2d 818 (1999); Boyd v. Benton Cnty., 374 F.3d 773 , 781 (9th Cir.2004) (explaining that sources of “clearly established law” include decisions of the Supreme Court or this circuit); see also Hope v. Pelzer, 536 U.S. 730, 741-45 , 122 S.Ct. 2508 , 153 L.Ed.2d 666 (2002) (holding defendants’ conduct violated clearly established law in light of binding circuit precedent).

The officers’ attempts to circumvent Butler are unpersuasive. First, they incorrectly characterize Butler’s explanation of police officers’ obligation under Brady as “dictum.” It is not. The passage in that case discussing police officers’ obligations under Brady was essential to the conclusion that a new trial was warranted when agents failed to disclose promises made to a key government witness, even though the prosecutors were unaware of the promises. See Butler, 567 F.2d at 891 . Furthermore, we have relied on Butler to conclude in subsequent cases that Brady was violated when a police officer failed to disclose exculpatory evidence. See, e.g., Jackson v. Brown, 513 F.3d 1057, 1074 (9th Cir.2008) (relying in part on Butler to conclude that, in 1981, “the United States Constitution, as interpreted by Brady and Giglio, compelled prosecutors to disclose evidence favorable to the accused, even when that evidence was known only to the police and not to the prosecutor”); United States v. Steel, 759 F.2d 706, 714 (9th Cir.1985) (“Because the government was required to furnish all exculpatory evidence under the doctrine of Brady , and because investigative officers are part of the prosecution, Butler, 567 F.2d at 891 , there was indeed a negligent nondisclosure.” (first internal citation omitted)).

Second, the officers argue the .law did not clearly establish they were bound by Brady until the Supreme Court itself “extended” Brady to police officers in Kyles v. Whitley, 514 U.S. 419, 438 , 115 S.Ct. 1555 , 131 L.Ed.2d 490 (1995). Kyles addressed a Brady violation in which police officers, unbeknownst to the prosecutor’s office, failed to disclose material, exculpatory evidence. See id. at 421, 115 S.Ct. 1555 . It concluded prosecutors were bound by a duty to learn of “any favorable evidence known to the others acting on the government’s behalf in the case, including the police,” id. at 437 , 115 S.Ct. 1555 , and that “any argument for excusing a prosecutor from disclosing what he does not happen to know about boils down to a plea to substitute the police for the prosecutor, and even for the courts themselves, as the final arbiters of the government’s obligation to ensure fáir trials,” id. at 438 , 115 S.Ct. 1555 . Because Kyles was decided in 1995, the defendants argue, it could not have been clearly established in 1984 or in 1991 that they were bound to disclose Brady evidence.

But Kyles did not announce a new principle of law. In fact, Kyles itself rejected the state’s argument that “it should not be held accountable under Bagley and Brady for evidence known only to police investigators and not to the prosecutor,” explaining that “[t]o accommodate the State in this matter would ... amount to a serious change of course from the Brady line of cases.” Id. (emphasis added).

In the habeas context, we rejected an argument that Kyles ’ extension of Brady to police officers announced a “new rule” of criminal procedure, concluding “the principle underlying [Kyles ’] unexceptional holding dates back, at the latest, to the Supreme Court’s decision in Giglio v. United States, 405 U.S. 150 , 92 S.Ct. 763 , 31 L.Ed.2d 104 (1972).” Jackson, 513 F.3d at 1073 (emphasis added). In Giglio , the Supreme Court held Brady error occurred when one prosecutor had promised a key witness immunity, even though other prosecutors were unaware of the agreement, because “[t]he prosecutor’s office is an entity and as such it is the spokesman for the Government,” and therefore, “[a] promise made by one attorney must be attributed ... to the Government.” Giglio, 405 U.S. at 154 , 92 S.Ct. 763 . Because “the responsibility of the prosecutor to investigate all promises made on behalf of the government extends to promises made by the police, who also make any such promises as spokespersons of the government, and for whom the prosecutor bears responsibility,” we reasoned Kyles simply applied Giglio. Jackson, 513 F.3d at 1073 .

Furthermore, the vast majority of circuits to have considered the question have adopted the view that police officers were bound by Brady well before the Court decided Kyles . The Third Circuit alone has disagreed, concluding such an obligation was not clearly established until “the Supreme Court ... settle[d] this matter” in Kyles , notwithstanding precedent in that circuit that a police officer’s failure to disclose Brady evidence could be imputed to the prosecutor. See Gibson v. Super., N.J. Dept. of Law & Pub. Safety, 411 F.3d 427 , 443-44 (3d Cir.2005), overruled on other grounds by Dique v. N.J. State Police, 603 F.3d 181, 188 (2d Cir.2010). The defendants argue that the Third Circuit’s decision created a circuit split on the issue and that, “if judges thus disagree on a constitutional question, it is unfair to subject police to money damages for picking the losing side of the controversy.” Pearson v. Callahan, 555 U.S. 223, 245 , 129 S.Ct. 808 , 172 L.Ed.2d 565 (2009) (alteration and internal quotation marks omitted).

Although disagreement among circuit courts may imply a legal principle is not “beyond debate,” and thus not clearly established, qualified immunity is not the “guaranteed product of disuniform views of the law in the other federal, or state, courts, and the fact that a single judge, or even a group of judges, disagrees about the contours of a right does not automatically render the law unclear.” Safford Unified Sch. Dist. No. 1 v. Redding, 557 U.S. 364, 378 , 129 S.Ct. 2633 , 174 L.Ed.2d 354 (2009). More importantly, however, “[i]f the right is clearly established by decisional authority of the Supreme Court or of this Circuit, our inquiry should come to an end.” Hopkins v. Bonvicino, 573 F.3d 752, 772 (9th Cir.2009) (alteration in original) (internal quotation marks omitted). Only in the absence of binding precedent do we consider other sources of decisional law such as out-of-circuit cases. See Boyd v. Benton Cnty., 374 F.3d 773 , 781 (9th Cir.2004).

Because Butler unambiguously held due process is violated where a police officer fails to disclose material, exculpatory evidence, our inquiry is over. We hold that, at the time of the relevant events in these cases, circuit precedent clearly established that police officers were bound by Brady’s disclosure requirements.

II. The specific evidence allegedly withheld in these cases was clearly established to be Brady material.

Even though it was clearly established at the time of the investigations that police officers were bound to disclose Brady evidence, we must next consider whether every reasonable police officer would have understood the specific evidence allegedly withheld was clearly subject to Brady’s disclosure requirements.

We note the officers argued in the district court only that the law did not clearly establish their duty to disclose Brady evidence at all. Similarly, the officers’ opening briefs on appeal framed the question presented as whether, in 1984 and 1991, there was “an absence of clearly established law as to whether police officers were bound by the disclosure obligations of Brady.” Elsewhere in their briefs, the officers did obliquely suggest that, even if the law established officers’ duty to disclose evidence under Brady generally, their duty to disclose the specific evidence allegedly withheld in these two cases was not clear.

“Absent exceptional circumstances, we generally will not consider arguments raised for the first time on appeal, although we have discretion to do so.” AlohaCare v. Hawaii, Dept. of Human Servs., 572 F.3d 740, 744 (9th Cir.2009) (citation omitted). Moreover, “[n]ormally we decline to address an issue that is simply mentioned but not argued.” Arredondo v. Ortiz, 365 F.3d 778, 781 (9th Cir.2004). Nevertheless, because the issue is purely one of law, and because our addressing it at this juncture will not prejudice the plaintiffs, we will do so here. See Kimes v. Stone, 84 F.3d 1121, 1126 (9th Cir.1996). .

In recent cases, the Supreme Court has cautioned us “not to define clearly established law at a high level of generality.” Ashcroft v. al-Kidd, 563 U.S. 731 , 131 S.Ct. 2074, 2084 , 179 L.Ed.2d 1149 (2011). At the same time, “[f]or a legal principle to be clearly established, it is not necessary that ‘the very action in question has previously been held unlawful/” but rather that “‘in the light of pre-existing law the unlawfulness [is] apparent.’ ” Fogel v. Collins, 531 F.3d 824, 833 (9th Cir.2008) (quoting Anderson v. Creighton, 483 U.S. 635, 640 , 107 S.Ct. 3034 , 97 L.Ed.2d 523 (1987)) (alteration in original). In other words, “the ‘contours of [the] right [must be] sufficiently clear’ that every ‘reasonable official would have understood that what he is doing violates that right.’ ” ai Kidd, 131 S.Ct. at 2083 (quoting Anderson, 483 U.S. at 640 , 107 S.Ct. 3034 ) (first alteration in original).

In the Fourth Amendment context, for example, the Court has explained the “general proposition ... that an unreasonable search or seizure violates the Fourth Amendment is of little help in determining whether the violative nature of particular conduct is clearly established.” Id. This is because “[qualified immunity is no immunity at all if ‘clearly established’ law can simply be defined as the right to be free from unreasonable searches and seizures.” Sheehan , 135 S.Ct. at' 1776.

Here, the right being violated is, by its terms, significantly more specific than the “extremely abstract” right of freedom from unreasonable searches and seizures. See Anderson, 483 U.S. at 639 , 107 S.Ct. 3034 . Brady defines the type of material the government is obligated to disclose concretely and specifically as “favorable to the accused, either because it is exculpatory, or because it is impeaching.” Strickler v. Greene, 527 U.S. 263, 281-82 , 119 S.Ct. 1936 , 144 L.Ed.2d 286 (1999). Unlike the broad touchstone of “unreasonableness,” the contours of a defendant’s right to Brady material are focused and clear.

Furthermore, although the right at issue cannot be defined at too high a level of generality, it cannot be defined “too narrowly,” either. Tennison v. City & Cnty. of San Francisco, 570 F.3d 1078, 1093 (9th Cir.2009). In Tennison , we addressed police officers’ claims of qualified immunity relating to alleged Brady violations. See id. at 1078. The plaintiff alleged the investigating officers failed to disclose the confession of an alternative suspect. See id. at 1093. The officers argued their duty to disclose “a confession that was made after a guilty verdict was rendered, that was ‘inherently unbelievable/ and that was given by someone who earlier had denied involvement in the murder” was not clearly established. See id. We rejected this argument, explaining that

Id. at 1093-94 (some internal citations, quotation marks and alterations omitted) (emphasis added).

As in Tennison , law predating the investigations in both of these cases clearly established that the type of evidence alleg edly withheld — including impeachment and alternative suspect evidence — fell within Brady’s scope. The officers’ assertions of qualified immunity, therefore, fail. We address each item of evidence in turn below.

A. O’Connell Evidence

We first address the evidence O’Connell has alleged the defendant police officers withheld, including evidence impeaching the statements of the three eyewitnesses to testify and information regarding a previous attempt on the victim’s life.

1. Druecker, Villareal and Soucy Statements

O’Connell argues the officers should have turned over evidence relating to the eyewitness identifications made by Druecker, Villareal and Soucy.

Druecker, who was the only eyewitness to the shooting, testified at trial that he was able to identify O’Connell as the killer. But the officers never disclosed that Druecker said he saw the shooter only in profile, asked to be hypnotized because he could not remember what the shooter looked like, and recalled the shooter did not have a mustache unlike every man depicted in the photo lineup.

Villareal, who saw the shooter flee in a yellow Pinto, testified at trial he was unsure whether O’Connell was the shooter. Detective Smith cast doubt on this statement by testifying Villareal had readily chosen O’Connell from a photo lineup. But the officers failed to disclose that Villareal, when shown the photo lineup, selected two photographs and said that O’Connell “looked like the person who was there, but I’m not positive.”

Soucy, a neighbor of French’s ex-wife, testified at trial that he recognized O’Connell from the lineup and that he was confident O’Connell was the same person he had seen kissing Lyon. He further testified this man drove a yellow Pinto. But again, the officers failed to disclose their handwritten notes, which said Soucy identified “# 3 & poss[ibly] # 1” and “picked out # 3 as possible] suspect because of face but hair was curlier.”

Had this evidence been disclosed, the defense could have used it to impeach the eyewitnesses’ identifications of O’Connell as the killer. The law in 1984 made clear that impeachment evidence must be disclosed under Brady . For decades prior, the Supreme Court had explained the presentation of false testimony violated due process. In its 1972 opinion in Giglio , the Court reasoned Brady encompassed evidence implicating the credibility of a government witness:

405 U.S. at 153-54 , 92 S.Ct. 763 (emphasis added) (some citations omitted). In United States v. Bagley, 473 U.S. 667, 676-77 , 105 S.Ct. 3375 , 87 L.Ed.2d 481 (1985), the Court reaffirmed this principle, citing Giglio for the proposition that “[i]mpeachment evidence ... as well as exculpatory evi dence, falls within the Brady rule.” Id. at 676, 105 S.Ct. 3375 .

Here, the disclosure of Druecker’s request for hypnosis, observation that the shooter — unlike every person depicted in the lineup — did not have a mustache, and uncertainty regarding . his identification would have cast serious doubt on his identification of O’Connell at trial. Similarly, the disclosure of Souc/s choice of two men from the photo lineup would have undermined his identification of O’Connell. The disclosure of Villareal’s hesitancy and uncertainty when shown the photo lineup would have undercut Smith’s testimony that Villareal readily chose O’Connell’s photo from the lineup and was prevaricating on the stand. Because it was clearly established by 1984 that police officers were bound by Brady , and that evidence undermining the credibility of government witnesses fell within Brady’s, ambit, it would have been clear to any reasonable officer that the nondisclosure of this evidence was unlawful.

2. Evidence of a separate attempt on victim’s life

O’Connell also alleges the police officers failed to disclose evidence of a previous attempt on the victim’s life. The officers’ notes reveal that Lyon, French’s ex-wife, had previously attempted to run him over in her car with the assistance of Randy Smith, who was described as tall, with sandy or blond hair. This information was never disclosed to the prosecution or defense, and as a result, the defense was never able to investigate it.

As a preliminary matter, the officers argue the information about Randy Smith was a “dead lead.” But as we explained in an earlier qualified immunity challenge based on nondisclosure of Brady material,

Tennison, 570 F.3d at 1094 (quoting DiSimone v. Phillips, 461 F.3d 181, 195 (2d Cir.2006)).

Any reasonable police officer in 1984 would have understood that evidence potentially inculpating another person fell within Brady’s scope. In Brady itself, the Court considered the failure to disclose an accomplice’s confession that he had committed the homicide for which he and the defendant were standing trial. The Court held suppression of this evidence violated due process. See 373 U.S. at 86 , 83 S.Ct. 1194 .

Here, the officers failed to disclose evidence that another man who resembled the eyewitness description of the killer had previously tried to kill the victim. This evidence would have cast doubt on O’Connell’s culpability and would have instilled French’s dying declaration — in which French said the killer was someone his ex-wife used to “hang[ ]around with” — with an alternative meaning. The defendants’ alleged failure to disclose this information violated O’Connell’s clearly established right to evidence that “would tend to ex- cúlpate” him. Brady, 373 U.S. at 88 , 83 S.Ct. 1194 .

B. Carrillo Evidence

Carrillo argues Ditsch failed to disclose the circumstances surrounding Turner’s identification of Carrillo. Specifically, he alleges Ditsch failed to disclose that Turner initially chose several other photos from a “gang book” — each of which Ditsch then told Turner “could not be the suspect shooter” — before ultimately selecting Carrillo’s photo, which Ditsch affirmed as the “right choice.” He also alleges Ditsch failed to disclose that he threatened Turner upon learning Turner planned to recant his identification of Carrillo before Carrillo’s second trial. Ditsch cqunters that the “potentially exculpatory nature of such evidence” would not have been clear to a reasonable police officer in 1991.

During the first trial, Turner testified for the state that he was able to positively identify Carrillo. Had the evidence of Turner’s choice of several other photos and Ditsch’s suggestive comments been disclosed, the defense could have used that information to impeach Turner’s identification at the first trial and bolster his recantation at the second trial.

Furthermore, this evidence would also have undercut Ditsch’s testimony at the second trial that Turner was “absolutely certain” of his identification of Carrillo. Ditsch’s effort to paint Turner’s selection as unequivocal implicitly recognizes that evidence of hesitancy and earlier misidentification would have been very helpful to the defense in impeaching Turner’s original identification, not to mention supporting the veracity of Turner’s recantation. Likewise, information that Ditsch had coached Turner’s identification would have contradicted Ditsch’s testimony that Turner independently selected Carrillo from the gang book and photo lineup and cast serious doubt on Ditsch’s testimony that Turner’s recantation was not genuine. Finally, evidence that Ditsch threatened Turner with negative consequences if he recanted would have further undermined Ditsch’s rebuttal of Turner’s recantation.

As previously discussed, the law in 1991 clearly established that evidence impeaching the credibility of a government witness was required to be disclosed under Brady. See Bagley, 473 U.S. at 676 , 105 S.Ct. 3375 ; Giglio, 405 U.S. at 153 , 92 S.Ct. 763 . Any reasonable officer would have understood the' withheld evidence here would have impugned the testimony of two key government witnesses, and therefore should have been disclosed.

Other circuits have recognized that police officers’ failure to disclose the use of suggestive tactics violates Brady . For instance, the Seventh Circuit concluded police officers could be held hable under § 1983 for “withh[olding] from the prose cutors information about their coaching of the witnesses and the fact that these witnesses earlier selected pictures from a book of mug shots that did not contain [plaintiffs] photo,” because under Brady it was “clearly established in 1979 and 1980 that police could not withhold from prosecutors exculpatory information about ... the conduct of a lineup.” Newsome v. McCabe, 256 F.3d 747, 749, 752 (7th Cir.2001).

Similarly, nearly three decades ago, the Fifth Circuit considered a § 1983 claim that law enforcement authorities engaged in suggestive identification techniques when showing witnesses a lineup. See Geter v. Fortenberry, 849 F.2d 1550, 1559-60 (5th Cir.1988). The plaintiff alleged the officers failed to disclose this evidence and that it would have been “favorable, and exculpatory, as it would permit [plaintiff] to demonstrate to the jury ... [t]hat [plaintiffs] identification in the instant cause is in all likelihood a mistaken identification due to his facial similarity to other persons and/or overzealous police investigatory techniques.” Id. Citing Brady , the court held “a police officer cannot avail himself of a qualified immunity defense if he procures false identification by unlawful means or deliberately conceals exculpatory evidence, for such activity violates clearly established constitutional principles.” Id. at 1559.

Any reasonable officer would have understood Turner’s choice of multiple other photos from a gang book and coached selection of Carrillo was potential impeachment evidence required to be disclosed under Brady . The same is true of Ditsch’s efforts to dissuade Turner from recanting his identification. The district court therefore properly denied Ditsch qualified immunity.

CONCLUSION

The law clearly established, well before the events in these cases, that police officers were bound by Brady and that the evidence allegedly withheld in these cases fell within Brady’s scope. We therefore affirm the denial of qualified immunity in both cases and remand to the district court for further proceedings.

AFFIRMED.

. O'Connell’s son, Nicholas O’Connell, is also party to the suit; he seeks compensation for the "wrongful denial of the society and comfort of, and companionship and familial relationship with, his father” as a result of his father's wrongful conviction and incarceration. . A district court’s denial of a claim of qualified immunity is immediately appealable under 28 U.S.C. § 1291 notwithstanding the absence of a final judgment. See Mitchell v. Forsyth, 472 U.S. 511, 530 , 105 S.Ct. 2806 , 86 L.Ed.2d 411 (1985). . At this stage, we assume the version of material facts asserted by the plaintiffs, who are the non-moving parties. See KRL v. Estate of Moore, 512 F.3d 1184, 1189 (9th Cir.2008). .The complaint does not make clear which witness testified about French's dying declaration. . O’Connell alleges these are the same two photos that Villareal chose. . The official report said Ina Soucy, not Maurice, had remarked that the hair of the man who drove the yellow Pinto was curlier. O’Connell alleges the notes make clear Maurice Soucy, not his wife, had made this statement. . The transcript of Turner’s testimony is unclear whether he immediately chose Carrillo's photograph from the six-pack or whether he selected someone else first. . Turner testified at Carrillo’s second trial that his recantation was based on an interaction with the real shooter: Q: Now, what happened that caused you to change your mind? A: Well, I came into Lynwood over my grandfather['s] house because we had a little get together.... Then I was walking from my house[,] walked down the street, went to Jack-in-the-Box, and I was in Jack-in-the-Box and I walked in. I seen this ese, this cholo. Q: You saw a cholo? That is like a Mexican gang member? A: Yes. Q: Young Crowd gang member? A: Yes. And I — and I was looking. I was like glaring at him, and he was looking at me. And kept looking at each other, but you know it wasn’t like staring. Then I stared at him and I was like don’t I know you. And he was like what? And I was like, don’t I know you, and he was like, oh, just jump; like what. Q: He became angry? A: Yeah and I — and I seen his attire and I knew he was from Young Crowds [sic].... So he was like, fool, that's why I shot your homeboy father.... Q: Before you ran up out of there, did you get a good look at the guy you had the fight with? A: Yes, I did. Q: When you got to take a look at him, what did that make you think? A: That's the fool. That’s the person who done this. Q: So did you, at that time, recognize him as being the person that was the passenger that night? A: Yes. Q: Did he look something like Frankie Carrillo? A: Looked like that guy. Q: When you saw him and you got into this argument with him, were you positive it was him? A: Positive. Surely positive. . During the pendency of Ditsch's appeal, the district court granted Carrillo’s motion to certify this appeal as frivolous under Chuman v. Wright, 960 F.2d 104, 105 (9th Cir.1992), which would have allowed the case to proceed to trial while the instant appeal was pending. See id. Ditsch filed an urgent motion to stay the district court’s order, which was granted. Carrillo then filed a motion for summary affirmance based on Tennison v. City & County of San Francisco, 570 F.3d 1078 (9th Cir.2009), which he argued "definitively answered” the question presented in this appeal. The motion for summary affirmance is dismissed as moot in light of this opinion. . Nor could they. The allegations unquestionably make out a violation of plaintiffs' right to material, exculpatory evidence. See infra Section II. . In Carrillo, the question presented is whether, in 1991, the law clearly established that police officers were bound by Brady . Because we conclude the law in this circuit clearly established that police officers were bound by Brady at least as far back as 1978, it follows this obligation was clearly established in 1991. . Although the determination of what constitutes material, exculpatory evidence may require “the exercise of legal judgment that the prosecuting attorney is better trained, not to ' mention better positioned, to make,” police must still be expected to “recognize and determine what evidence should be preserved and turned over to the prosecutor.” Moldowan, 578 F.3d at 380-81 . The Supreme Court has held government agents "could offend the Due Process Clause of the Fifth Amendment ... by deporting potential witnesses,” thereby "diminishing a defendant’s opportunity to put on an effective defense,” as well as by failing to preserve evidence "that might be expected to play a significant role in the suspect’s defense.” California v. Trombetta, 467 U.S. 479, 486, 488 , 104 S.Ct. 2528 , 81 L.Ed.2d 413 (1984). As the Sixth Circuit has explained, "[i]f the police can be expected to recognize what evidence must be preserved, certainly it is not too burdensome to demand that they simply turn that same information over to the prosecutor’s office.” Moldowan, 578 F.3d at 381 . . In recent cases, the Supreme Court has assumed for the sake of argument without explicitly holding that “controlling Court of Appeals’ authority could be a dispositive source of clearly established law.” Reichle v. Howards,-U.S.-, 132 S.Ct. 2088, 2094 , 182 L.Ed.2d 985 (2012); see also Carroll v. Carman, - U.S. -, 135 S.Ct. 348, 350 , 190 L.Ed.2d 311 (2014). None of these cases has overruled Hope or called its exclusive reliance on circuit precedent into question. . See Walker v. City of New York, 974 F.2d 293, 299 (2d Cir.1992) ("The constitutional duty to disclose exculpatory evidence has its roots in Brady.... [T]he police satisfy their obligations under Brady when they turn exculpatory evidence over to the prosecutors.”); Owens v. Baltimore City State’s Attorneys Office, 767 F.3d 379, 401 (4th Cir.2014) (concluding that circuit precedent "unmistakably provides that, by 1988, a police officer violates clearly established constitutional law when he suppresses material exculpatory evidence in bad faith”); Geter v. Fortenberry, 849 F.2d 1550 , 1559 (5th Cir.1988) (holding that a police officer who deliberately concealed exculpatory evidence could not claim qualified immunity in 1982); Moldowan v. City of Warren, 578 F.3d 351, 382 (6th Cir.2009) (holding law clearly established police officers were bound by Brady in 1990); Newsome v. McCabe, 256 F.3d 747, 752-53 (7th Cir.2001) (holding it was clearly established police officers were bound by Brady in 1979); McMillian v. Johnson, 88 F.3d 1554, 1569 (11th Cir.1996) ("[C]learly established law in 1987 and 1988 prohibited the police from concealing exculpatory or impeachment evidence.”). . The First Circuit has also held police officers were not bound to affirmatively disclose Brady evidence until Kyles. See Drumgold v. Callahan, 707 F.3d 28, 43 (1st Cir.2013). But it distinguished the affirmative duty to disclose evidence from the duty not to deliberately suppress exculpatory evidence. Where the defendant police officer was alleged to have deliberately suppressed evidence, in violation of either Brady or Mooney v. Holohan, 294 U.S. 103 , 55 S.Ct. 340 , 79 L.Ed. 791 (1935), the court concluded such conduct was clearly established as unlawful in 1989. See id. . Smith and Parra note in their opening brief the passage in Butler "was, at most, a broad general proposition insufficient to clearly establish the law on this issue,” and that the evidence withheld in that case was "significantly different than ... nondisclosure of exculpatory information regarding [the] identification [of O’Connell] as the murderer or the possibility of another suspect.” Similarly, Ditsch notes the information about Turner's selection of other photos before identifying Carrillo was different from the confession we held was clearly established Brady evidence in Tennison . . The officers also argue O’ConneH's defense counsel was aware of Randy Smith. They offer no citation for this assertion, and at this stage we must in any event'take as true the version of facts O'Connell has alleged. See Chavez v. United States, 683 F.3d 1102, 1108 (9th Cir.2012). . Carrillo also alleges Ditsch failed to disclose his membership in the Lynwood Vikings, a "white supremacist internal gang dedicated to wiping out the Young Crowd gang, including the use of fabricated evidence to obtain false convictions." Carrillo does not appeal the district court's ruling that this allegation was without merit. . Furthermore, the Supreme Court explicitly recognized the risk of police improperly influencing photo identifications, explaining: [i]t must be recognized that improper employment of photographs by police may sometimes cause witnesses to err in identifying criminals____This danger will be increased if the police ... show [the witness] the pictures of several persons among which the photograph of a single such individual recurs or is in some way emphasized. Simmons v. United States, 390 U.S. 377, 383 , 88 S.Ct. 967 , 19 L.Ed.2d 1247 (1968). Carrillo has separately alleged a Simmons violation, but that claim is beyond the scope of this appeal.