Witness for the Prosecution is a 1957 American courtroom drama film with elements of Film Noir set in the Old Bailey in London. The film, based on a play by Agatha Christie, deals with the trial of a man accused of murder. The first film adaptation of this story, it stars Tyrone Power (in his final screen role), Marlene Dietrich, and Charles Laughton, and features Elsa Lanchester. The film was adapted by Larry Marcus, Harry Kurnitz and the film's director, Billy Wilder.