New and undiscovered impeachment evidence may constitute exculpatory evidence within the meaning of Brady v. Maryland (1963) 373 U.S. 83. A state prisoner convicted of sexual assault moved to set aside the verdict based on a newly disclosed document that would have impeached the women who had testified against him at his trial. The state courts denied relief, but the United States Supreme Court granted a petition for certiorari, vacated the judgment, and remanded for consideration of the Brady claims. The Court noted that the Brady claim was not defeated by the fact that the document’s existence was only known to a law enforcement officer rather than to the prosecutor, or by the fact that the document may have constituted impeachment evidence rather than exculpatory evidence.