Jencks Act

In the United States, the Jencks Act (18 U.S.C. § 3500) requires the prosecutor to produce a verbatim statement or report made by a government witness or prospective government witness (other than the defendant), but only after the witness has testified.

Jencks material is evidence that is used in the course of a federal criminal prosecution in the United States. It usually consists of documents relied upon by government witnesses who testify at trial. The material is described as inculpatory, favoring the United States government's prosecution of a criminal defendant.

The Jencks Act also covers other documents related to the testimony, or relied upon by government witnesses at trial. Typically, the material may consist of police notes, memoranda, reports, summaries, letters, related to an indictment or verbatim transcripts used by government agents or employees to testify at trial. This also includes a witness's grand jury testimony, if the witness testified at trial.

After the government's witness testifies, the court must, upon motion of the defendant, order the government to produce any statement of the witness in the government's possession relating to the subject matter as to which the witness testified. The court's denial of such a motion by a defendant is reversible error, although the court need not order the disclosure sua sponte. The usual remedy for failure of the government to produce the documents is a mistrial and dismissal of criminal charges against the defendant.