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Short answer. A Brady violation happens when the prosecution does not turn over evidence that is favorable to the defense and material to guilt or punishment. It violates due process, whether the prosecutor acted in good faith or bad faith. Brady v. Maryland, 373 U.S. 83, 87 (1963). After a federal conviction, the claim is usually raised in a § 2255 motion.
“Favorable” evidence is anything that helps the defense. It can point toward innocence (exculpatory evidence) or give the defense a reason to doubt a government witness (impeachment evidence). “Material” means important enough that hiding it undermines confidence in the result. This page explains the rule, the Supreme Court cases that shape it, and how a Brady claim works after conviction.
What is a Brady violation?
In Brady v. Maryland, the Supreme Court held “that 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. The point, the Court said, is not to punish the prosecutor but to avoid “an unfair trial to the accused.” Id.
Later cases filled in the details:
- Impeachment evidence counts. When “the reliability of a given witness may well be determinative of guilt or innocence,” hiding evidence that bears on that witness’s credibility falls within the rule. Giglio v. United States, 405 U.S. 150, 154 (1972). A promise of leniency to a cooperating witness is a common example.
- A defense request is not required. The same materiality test applies whether the defense made a specific request, a general request, or no request at all. United States v. Bagley, 473 U.S. 667, 682 (1985).
- The prosecutor is responsible for what the team knows. The prosecutor “has a duty to learn of any favorable evidence known to the others acting on the government’s behalf in the case, including the police.” Kyles v. Whitley, 514 U.S. 419, 437 (1995). In a federal case, that usually includes the investigating agents.
What are the three elements of a Brady violation?
The Supreme Court has said there are “three components of a true Brady violation.” Strickler v. Greene, 527 U.S. 263, 281-82 (1999). You must show all three:
- Favorable. The evidence is favorable to you, “either because it is exculpatory, or because it is impeaching.” Id. at 281-82.
- Suppressed. The government did not disclose it, “either willfully or inadvertently.” Id. at 282. An honest mistake still counts.
- Prejudice (materiality). The missing evidence mattered. Id. at 282.
When is withheld evidence “material”?
Evidence is material “only if there is a reasonable probability that, had the evidence been disclosed to the defense, the result of the proceeding would have been different.” Bagley, 473 U.S. at 682. A “reasonable probability” is one “sufficient to undermine confidence in the outcome.” Id.
That is not a “more likely than not” test. 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.” Kyles, 514 U.S. at 434. The court looks at all the withheld evidence together, “considered collectively, not item by item.” Id. at 436.
Materiality can go to punishment as well as guilt. Evidence that would likely have lowered a sentence can support a claim even if it would not have changed the verdict. Brady, 373 U.S. at 87.
Does Brady apply to guilty pleas?
Only in part. Most federal cases end in a guilty plea, so this matters. The Supreme Court has held that “the Constitution does not require the Government to disclose material impeachment evidence prior to entering a plea agreement with a criminal defendant.” United States v. Ruiz, 536 U.S. 622, 633 (2002). Ruiz addressed impeachment evidence, not evidence that points to innocence. Hidden exculpatory evidence can still matter after a plea, and the answer depends on the facts and the circuit.
If you pleaded guilty and later learned of hidden evidence, the claim may also be framed as ineffective assistance of counsel or as a plea that was not knowing and voluntary. See our page on ineffective assistance of counsel.
Is a false-testimony claim the same as a Brady claim?
No, but the two are related. A prosecutor who knowingly uses false testimony, or lets it go uncorrected, also violates due process. In Glossip v. Oklahoma, 604 U.S. 226 (2025), the Supreme Court restated that test. The defendant must show that the prosecution knowingly solicited or allowed false testimony to go uncorrected. A new trial is then warranted if the false testimony could in any reasonable likelihood have affected the jury’s judgment. The Court granted a new trial on that ground and did not reach the separate Brady claim in that case.
The “any reasonable likelihood” standard asks less of the defense than Brady’s “reasonable probability” test. A single set of facts, such as a hidden deal with a witness who then denies it on the stand, can support both claims.
What federal rules require disclosure?
- The Brady order. Since 2020, Fed. R. Crim. P. 5(f) requires the judge, on the first scheduled court date when both the prosecutor and defense counsel are present, to issue an oral and written order confirming the prosecutor’s disclosure obligation under Brady and its progeny, and the possible consequences of violating that order. The rule was added by the Due Process Protections Act, Pub. L. 116-182.
- The Justice Department’s policy. Justice Manual § 9-5.001 sets the Department’s own disclosure policy for federal prosecutors. It requires disclosure of information “beyond that which is ‘material’ to guilt.” It says exculpatory information “must be disclosed reasonably promptly after it is discovered,” and impeachment information will typically be disclosed at a reasonable time before trial. The Justice Manual is internal policy. In a § 2255 motion, the court still applies the constitutional Brady test.
How does a Brady claim work in a § 2255 motion?
A Brady violation is a due process violation, so it is a constitutional claim that fits within 28 U.S.C. § 2255(a). See our page on constitutional claims in a § 2255 motion for cases where courts heard these claims. Three rules shape the claim.
The deadline
The one-year deadline usually runs from when the conviction became final. But when the evidence was hidden, the year may instead run from “the date on which the facts supporting the claim or claims presented could have been discovered through the exercise of due diligence.” 28 U.S.C. § 2255(f)(4). You must act with reasonable diligence once you have reason to look. See newly discovered evidence and due diligence and the one-year deadline.
Procedural default
A claim that could have been raised on direct appeal but was not is usually “defaulted.” You then need to show cause and prejudice. For Brady claims, those two showings track the claim itself. “[C]ause and prejudice” in that setting “parallel two of the three components of the alleged Brady violation itself.” Banks v. Dretke, 540 U.S. 668, 691 (2004) (quoting Strickler, 527 U.S. at 282). The government’s suppression of the evidence supplies the cause, and the evidence’s materiality supplies the prejudice. Id. The Court rejected a rule of “prosecutor may hide, defendant must seek.” Id. at 696. See our page on procedural default.
A second § 2255 motion
If you already filed a § 2255 motion, a new one needs permission from the court of appeals. For new evidence, § 2255(h)(1) requires evidence that, viewed as a whole, would show by clear and convincing evidence that no reasonable factfinder would have found you guilty. See second or successive § 2255 motions.
Outcomes vary. A past result does not predict or guarantee the outcome of any other case.
Common questions
What is a Brady violation?
It is the prosecution’s failure to disclose evidence that is favorable to the defense and material to guilt or punishment. It violates due process even if the prosecutor did not mean to hide anything. Brady v. Maryland, 373 U.S. 83, 87 (1963).
How do you prove a Brady violation?
You must prove its three elements: the evidence was favorable to the defense (exculpatory or impeaching), the government suppressed it (on purpose or by mistake), and prejudice resulted because the evidence was material. Strickler v. Greene, 527 U.S. 263, 281-82 (1999).
What happens if a Brady violation is found?
If the evidence was material to guilt, the usual remedy is to vacate the conviction and order a new trial. If it was material only to punishment, the remedy may be a new sentencing. In a § 2255 case, the court “shall vacate and set the judgment aside” and order a new trial, resentencing or other appropriate relief. 28 U.S.C. § 2255(b).
Is a Brady violation a crime?
Not in itself. A Brady violation is a constitutional violation: it rests on the Due Process Clause. The remedy is relief for the defendant, such as a new trial, not a criminal charge against the prosecutor. That is why a Brady claim can be raised in a § 2255 motion, which covers sentences “imposed in violation of the Constitution.” 28 U.S.C. § 2255(a). The Rule 5(f) order also warns of the possible consequences of violating it under applicable law.
When does a Brady violation occur?
When the government fails to disclose favorable, material evidence in time for the defense to use it. A violation is usually discovered after trial or after a plea, sometimes years later, which is why the § 2255(f)(4) deadline can run from when the evidence could have been discovered with due diligence.
Can a Brady violation occur before trial?
The duty to disclose applies before trial, and Fed. R. Crim. P. 5(f) requires the court to confirm it at the start of the case. If the problem is found before trial, the defense can ask the court to order disclosure or grant other relief. Whether a late disclosure amounts to a constitutional violation depends on whether the defense could still use the evidence and whether it was material.
How do you file a Brady violation claim?
After a federal conviction, raise it as a ground in a § 2255 motion in the court that sentenced you, with the facts showing each element and when you learned of the evidence. Keep copies of everything that shows the evidence and the date you found it. If you or someone you love is dealing with this, book a consultation and tell us what happened.
Related pages
Cognizable Claims: The Conviction or Sentence Violates the Constitution
Section 2255(f)(4): Newly Discovered Evidence Restarts the One-Year Clock