Kyles v. Whitley
Citation: 514 U.S. 419 (1995)
Facts
Kyles was convicted of first-degree murder. The prosecution failed to disclose several pieces of evidence, including inconsistent witness statements, information about a key informant (Beanie), and conflicting descriptions of the killer’s car. Kyles was tried four times (two mistrials, then conviction, then appeal).
Issue
Was the undisclosed evidence material under Brady v. Maryland, and if so, must the government prove that non-disclosure was prejudicial?
Holding
Yes, the evidence was material. The Brady materiality test requires asking whether, considering the suppressed evidence collectively, there is a reasonable probability that the jury would have reached a different verdict. The defense need not show that disclosure would definitely have led to acquittal.
Rule
Brady materiality: Evidence is material under Brady if there is a reasonable probability — meaning a probability sufficient to undermine confidence in the outcome — that the jury would have reached a different verdict had the evidence been disclosed. Courts consider suppressed evidence cumulatively, not item by item.
Government team: The prosecution must disclose evidence known to any member of the government’s team, including police — not just evidence in the prosecutor’s personal files.
Significance
- Clarifies Brady materiality as a cumulative, not item-by-item, assessment
- Extends prosecutorial knowledge to the entire government team (police, investigators)
- Rejects the “harmless error” framing — Brady is not about harmlessness but about confidence in the verdict
- Emphasizes the prosecution’s affirmative duty to learn of and disclose favorable evidence in the government’s possession