What Is a Brady Violation?
In 1963, the Supreme Court decided Brady v. Maryland and established a rule that prosecutors must disclose to the defense any evidence that is favorable to the defendant and material to guilt or punishment. This evidence — called Brady material — includes anything that could help prove innocence, reduce a sentence, or impeach a prosecution witness. When prosecutors fail to disclose this evidence, it is called a Brady violation, and it is a violation of the defendant's constitutional right to due process.
Brady violations are not rare mistakes. Studies of wrongful convictions consistently find prosecutorial misconduct — including evidence suppression — as one of the leading causes. The National Registry of Exonerations found official misconduct, including Brady violations, in more than half of all documented exoneration cases. If you believe a prosecutor hid evidence in your case, you have a constitutional claim that courts take seriously.
What Counts as Brady Material
Brady material is broader than most people realize. It is not just evidence that directly proves innocence — it includes anything that could reasonably have helped the defense. This covers evidence that contradicts prosecution witnesses, evidence of alternative suspects, evidence about a witness's deal with the prosecution in exchange for testimony, evidence of a witness's prior false statements or criminal history, forensic test results that were never disclosed, police reports that were not turned over, and witness statements that conflict with testimony given at trial.
The key legal standard is materiality — the suppressed evidence must be material to the outcome, meaning there is a reasonable probability that disclosing it would have produced a different result. Courts have found Brady violations in cases where a single undisclosed witness statement, if known to the defense, would likely have changed the verdict.
How Brady Violations Are Discovered
Brady violations are often discovered years after conviction, when information becomes available through other channels — a co-defendant's later case, a Freedom of Information Act request for police files, a journalism investigation, or a witness who comes forward to admit they were pressured or that their testimony was false. Post-conviction investigations by innocence organizations and defense attorneys frequently uncover evidence that was never disclosed to the original defense team.
If you suspect a Brady violation in your case, the starting point is identifying what evidence you believe existed and was not disclosed. Requesting the prosecution's complete file, police investigation reports, and any informant agreements through public records requests or post-conviction discovery can surface materials that were withheld. This investigation often requires legal help, but it can be done in parallel with other post-conviction efforts.
What You Can Do If You Believe There Was a Brady Violation
A Brady violation is grounds for post-conviction relief — a new trial or, in some cases, dismissal of charges. To succeed on a Brady claim, you need to show that the evidence was favorable to you, that it was suppressed by the prosecution, and that it was material — that there is a reasonable probability that the outcome would have been different if the evidence had been disclosed.
Brady claims can be raised in state post-conviction petitions and in federal habeas corpus proceedings. They are among the strongest post-conviction claims available because they are based directly on constitutional violations by the government. Courts have vacated convictions in Brady cases decades after the original trial when the suppressed evidence was significant enough to undermine confidence in the verdict.
Giglioand Napue: Related Protections
Brady has companion doctrines that extend the same principles. Under Giglio v. United States, the prosecution must disclose any deals, promises, or benefits given to witnesses in exchange for their testimony — information that is directly relevant to the witness's credibility. Under Napue v. Illinois, prosecutors cannot knowingly allow false testimony to stand uncorrected at trial. If a witness lied on the stand and the prosecutor knew it, that is a constitutional violation that can support post-conviction relief even if no physical evidence was suppressed.
Many wrongful conviction cases involve combinations of Brady, Giglio, and Napue violations — withheld deals with informants, false testimony about prior criminal history, and suppressed investigative reports that pointed to other suspects. Each violation, alone or in combination, can provide grounds for relief.