United States v. Bagley
Citation
473 U.S. 667 (1985)
Facts
Hughes Bagley was charged with federal drug and firearms offenses. Before trial, Bagley requested any deals, promises, or inducements made to government witnesses. The government disclosed that witnesses had signed contracts agreeing to assist law enforcement — but failed to disclose that those contracts also promised monetary compensation based on the results of the investigation. Bagley was convicted. He later discovered the undisclosed financial arrangements and argued they would have been useful for impeaching the witnesses.
Issue
Does Brady v. Maryland’s obligation to disclose material exculpatory evidence extend to impeachment evidence, and what is the proper standard of materiality for undisclosed evidence?
Holding
Yes. The Court held that Brady applies to impeachment evidence as well as directly exculpatory evidence. The Court also unified the materiality standard: suppressed evidence is material — and the conviction must be reversed — if there is a reasonable probability that disclosure would have produced a different result. A reasonable probability is one sufficient to undermine confidence in the outcome.
Rule / Doctrine
Brady materiality standard (unified): evidence is material under Brady v. Maryland if there is a reasonable probability that its disclosure would have resulted in a different outcome. This standard applies equally to exculpatory and impeachment evidence. “Reasonable probability” is less than “more likely than not” but more than a “reasonable possibility.”
Significance
Bagley unified the Brady materiality standard and explicitly extended Brady to impeachment evidence. It displaced earlier, more demanding standards and established “reasonable probability” as the operative test in all Brady claims. Together with Giglio v. United States (impeachment of prosecution witnesses) and Strickler v. Greene, Bagley defines the Brady disclosure regime that governs federal and state prosecutors.