Jencks v. United States (1957)

The petitioner, Clinton Jencks appealed, by certiorari, his conviction in a Federal District Court of violating 18 U.S.C. 1001 by filing, under 9(h) of the National Labor Relations Act, as president of a labor union, an affidavit stating falsely that he was a member of the Communist Party or affiliated with such Party. Crucial testimony against him was given by two paid undercover agents of the Federal Bureau of Investigation, who stated on cross-examination that they made regular oral or written reports to the FBI on the matters about which they had testified.

Jencks moved for production of these reports in court for inspection by the judge with a view to their possible use by the petitioner in impeaching such testimony. His motions were denied. Jencks appealed this issue by petitioning the U.S. Supreme Court for a writ of certiorari. The Court held that the denial of the motions for production of the documents was erroneous, and the conviction was reversed.