Brady v. Maryland is the 1963 U.S. Supreme Court decision holding that a prosecutor violates the Due Process Clause by suppressing evidence favorable to the accused when that evidence is material to guilt or punishment. The ruling grew out of a Maryland murder case in which prosecutors kept a co-defendant’s confession from the defense, and it has since become the foundation for the constitutional rules governing what the government must share with the people it puts on trial.1Justia U.S. Supreme Court Center. Brady v. Maryland, 373 U.S. 83 (1963)
The Case Behind the Rule
John Brady and Charles Boblit were convicted of first-degree murder committed during a robbery. Brady admitted his role in the robbery but insisted Boblit was the one who actually killed the victim. Before trial, Brady’s lawyer asked to see Boblit’s statements to police. Prosecutors handed over several of them but withheld one: a written confession in which Boblit admitted doing the killing himself.1Justia U.S. Supreme Court Center. Brady v. Maryland, 373 U.S. 83 (1963)
Brady was sentenced to death. After his lawyers discovered the hidden confession, the Maryland Court of Appeals ordered a new trial limited to punishment, reasoning that the suppressed statement affected sentencing rather than guilt. The Supreme Court agreed and used the case to announce a broader rule: suppression by the prosecution of evidence favorable to an accused violates due process when the evidence is material either to guilt or to punishment.1Justia U.S. Supreme Court Center. Brady v. Maryland, 373 U.S. 83 (1963)
Why the Rule Exists
The Brady rule sits on the Due Process Clause of the Fourteenth Amendment. The Court’s reasoning was direct: a criminal trial is not a scoreboard for the government, and it cannot be fair if the prosecution is sitting on evidence that would help the defendant. Society wins, the Court said, whenever justice is done in the courts, not whenever the state wins a verdict.1Justia U.S. Supreme Court Center. Brady v. Maryland, 373 U.S. 83 (1963)
The prosecutor’s state of mind is irrelevant. Whether favorable evidence was buried on purpose or lost through carelessness, the constitutional violation is the same. The focus is the harm to the defendant, not the fault of the lawyer across the aisle.1Justia U.S. Supreme Court Center. Brady v. Maryland, 373 U.S. 83 (1963)
What Prosecutors Must Turn Over
Favorable evidence falls into two categories, and both must be disclosed.
Exculpatory Evidence
This is anything tending to show the defendant is innocent or that reduces the severity of the offense. Boblit’s hidden confession is the textbook example. Physical evidence, forensic results, witness statements, and documents can all qualify. If it helps the defense on guilt or sentencing, it goes to the defense.
Impeachment Evidence
In Giglio v. United States (1972), the Supreme Court extended Brady to cover evidence that could undermine a prosecution witness’s credibility. That includes prior inconsistent statements, criminal history, bias, and any deals, payments, or promises of leniency the government made to secure the witness’s cooperation.2Justia U.S. Supreme Court Center. Giglio v. United States, 405 U.S. 150 (1972)
A cooperation agreement gives a witness a strong motive to tailor testimony. The jury needs to know about it, and the defense cannot cross-examine on something it never learns exists.
The Three Elements of a Brady Claim
In Strickler v. Greene (1999), the Supreme Court pulled the case law together into a three-part test. A defendant must prove all three:3Justia U.S. Supreme Court Center. Strickler v. Greene, 527 U.S. 263 (1999)
- The evidence was favorable to the defense, either as exculpation or impeachment.
- The government suppressed it, whether intentionally or inadvertently.
- The suppression caused prejudice, meaning a reasonable probability that the outcome would have been different had the evidence been disclosed.
Most Brady claims fail on the third element. Showing the evidence would have helped is not enough. The defense has to show the missing evidence genuinely undermines confidence in the verdict.
The Materiality Standard
Not every hidden document produces a constitutional violation. In United States v. Bagley (1985), the Court defined materiality: evidence is material only if there is a reasonable probability that its disclosure would have changed the result, and a reasonable probability means enough to undermine confidence in the outcome.4Justia U.S. Supreme Court Center. United States v. Bagley, 473 U.S. 667 (1985)
Bagley also erased a distinction some courts had drawn between evidence the defense specifically requested and evidence it never asked about. The same materiality standard applies whether the defense made a specific request, a general one, or none at all.4Justia U.S. Supreme Court Center. United States v. Bagley, 473 U.S. 667 (1985)
Courts look at suppressed evidence collectively rather than item by item. A single document might seem minor in isolation, but combined with other undisclosed material, the cumulative effect can be enough to require a new trial.5Justia U.S. Supreme Court Center. Kyles v. Whitley, 514 U.S. 419 (1995)
When Disclosure Must Happen
The Supreme Court has never set a fixed calendar deadline. The constitutional floor is that favorable evidence must be disclosed in time for the defense to make effective use of it at trial. Department of Justice policy calls for exculpatory information to be disclosed reasonably promptly after it is found, with impeachment material typically produced a reasonable time before trial and sentencing-related evidence disclosed no later than the initial presentencing investigation.6U.S. Department of Justice. Justice Manual 9-5.000 – Issues Related to Discovery, Trials, and Other Proceedings
The absence of a hard deadline creates real friction. Late disclosures can arrive too close to trial for the defense to investigate or use them effectively. The Brady obligation runs through the criminal proceeding but does not extend to post-conviction proceedings; in District Attorney’s Office v. Osborne (2009), the Court held that once there has been a fair trial and conviction, the Brady framework no longer applies in the same way.7Cornell Law Institute. District Attorneys Office for Third Judicial District v. Osborne
The Prosecution Team’s Collective Knowledge
A prosecutor cannot dodge Brady by claiming not to know what the police know. In Kyles v. Whitley (1995), the Court held that the disclosure duty reaches evidence held by anyone on the government’s team, including police departments, crime labs, and other investigative agencies. Prosecutors have an affirmative obligation to look for favorable material in those files.5Justia U.S. Supreme Court Center. Kyles v. Whitley, 514 U.S. 419 (1995)
The rule exists because the defendant has no independent way to see the government’s files. If an investigator finds a helpful witness statement and never passes it up the chain, the violation still belongs to the prosecution.
Brady and Guilty Pleas
Most criminal cases end in plea agreements, so how Brady applies to plea bargaining matters enormously. In United States v. Ruiz (2002), the Supreme Court held that the Constitution does not require the government to disclose material impeachment evidence before a defendant enters a guilty plea. The Court reasoned that impeachment goes to trial fairness, and a defendant who pleads is voluntarily giving up the trial.8Justia U.S. Supreme Court Center. United States v. Ruiz, 536 U.S. 622 (2002)
Ruiz did not address whether exculpatory evidence of actual innocence must be disclosed before a plea, and the federal circuits are split. Some read Ruiz narrowly and still require pre-plea disclosure of evidence suggesting the defendant is innocent. Others read it broadly and impose no pre-plea disclosure duty at all. A defendant’s rights during plea negotiations depend on where the case is charged.
What Happens When a Violation Is Found
The usual remedy is vacating the conviction and ordering a new trial where the previously suppressed evidence can be considered. The charges are not dismissed; the prosecution can retry the case, but this time the defense has the full picture. If the violation surfaces mid-trial, the judge may declare a mistrial.
After conviction, defendants raise Brady claims on direct appeal or through habeas corpus petitions. Outcomes on retrial often look very different from the first result: a death sentence may become a prison term, or the prosecution may decide it cannot win without the hidden evidence and drop the case.
Why Accountability for Violations Is Limited
The doctrine’s remedies focus on the defendant’s conviction, not on the prosecutor who broke the rule. Under Imbler v. Pachtman (1976), prosecutors have absolute immunity from civil suits for actions taken while initiating and presenting a case. A prosecutor who deliberately hides exculpatory evidence cannot be sued for money damages, even if the defendant spends years wrongfully imprisoned.9Justia U.S. Supreme Court Center. Imbler v. Pachtman, 424 U.S. 409 (1976)
The Court’s rationale is that personal liability would make prosecutors timid and cautious in ways that would hurt the system. State bar discipline is theoretically available, but studies find it is rarely imposed for Brady violations.
Suing the office itself is nearly as difficult. In Connick v. Thompson (2011), the Court held that a district attorney’s office cannot be held liable under 42 U.S.C. § 1983 for failing to train prosecutors based on a single Brady violation. A plaintiff must show a pattern of similar violations reflecting deliberate indifference. The Court’s view was that prosecutors, as trained lawyers, are expected to know constitutional rules without the kind of tailored in-house training courts might expect for police officers.10Justia U.S. Supreme Court Center. Connick v. Thompson, 563 U.S. 51 (2011)
Brady Lists and Police Witnesses
One practical outgrowth of the rule is the “Brady list,” an internal roster some prosecutors’ offices keep of law enforcement officers with documented histories of dishonesty, misconduct, or bias that could affect their credibility. When a listed officer is a witness, the prosecutor is supposed to disclose the credibility problem to the defense.
In practice, these lists are uneven. Only one state requires prosecutors to maintain them, and many offices have no coherent policy for collecting or disclosing police misconduct. Whether an officer’s disciplinary history reaches the defense often depends on the individual prosecutor and the culture of the office. Underlying personnel files are confidential in many jurisdictions, so defense lawyers frequently have no independent way to find out whether the officer in their case has a history of lying. The system depends heavily on prosecutors policing themselves.