## Facts

- Curtis Lee Kyles was tried in Louisiana for the 1984 murder of Delores Dye, who was shot in a supermarket parking lot and whose car was taken.
- The first trial ended in a mistrial; the second trial resulted in a first-degree murder conviction and a death sentence.
- The prosecution relied on eyewitness accounts with materially varying descriptions and on physical evidence recovered after investigative leads from an informant known as “Beanie.”
- Beanie provided evolving statements and information that led police to Kyles and to a search of Kyles’s residence, where items tied to the crime were found.
- Post-conviction proceedings revealed the State had not disclosed defense-favorable evidence, including:
  - contemporaneous eyewitness statements useful to challenge identifications;
  - police notes and reports documenting Beanie’s inconsistent accounts and other impeachment material;
  - a police computer printout listing license plates in the parking lot that did not include Kyles’s vehicle, contrary to the State’s trial theory.

## Issues

1. What standard governs “materiality” under Brady when the State suppresses evidence favorable to the defense?
2. Must courts assess materiality item-by-item or by the cumulative effect of all suppressed favorable evidence?
3. If Brady materiality is shown under Bagley, is an additional harmless-error analysis required?

## Decision

- The Supreme Court reversed and remanded, directing habeas relief unless the State granted Kyles a new trial.
- The Court held favorable evidence is material if there is a reasonable probability that disclosure would have produced a different result; the defendant need not show disclosure would more likely than not yield acquittal.
- The Court required materiality to be evaluated by the cumulative effect of suppressed evidence, not in isolation.
- The Court held that once Bagley materiality is satisfied, no separate harmless-error review is applied because Bagley is more demanding than the habeas harmless-error standard.
- Applying these standards, the suppressed evidence collectively undermined confidence in the verdict.

## Legal Principles

- Brady is violated when the State suppresses evidence favorable to the accused and the evidence is material to guilt or punishment.
- Brady materiality is satisfied by a “reasonable probability” of a different outcome had the evidence been disclosed; it is not a sufficiency-of-the-evidence test.
- Materiality is determined by the net, cumulative effect of all suppressed favorable evidence, including impeachment material.
- The State’s disclosure duty covers favorable evidence known to police and other state actors involved in the investigation, not only what the trial prosecutor personally knew.
- When Bagley materiality is found, additional harmless-error review is not required.

## Conclusion

The Court ordered a new trial because multiple undisclosed items—eyewitness statements, impeachment evidence about the informant, and evidence contradicting the State’s timeline and theory—collectively created a reasonable probability of a different result, undermining confidence in the conviction under Brady.


Kyles v. Whitley, 514 U.S. 419 (1995)