Witness for the Prosecution is a 1957 American legal mystery thriller film directed by Billy Wilder and starring Tyrone Power, Marlene Dietrich, Charles Laughton and Elsa Lanchester. The film, which has elements of bleak black comedy and film noir, is a courtroom drama set in the Old Bailey in London and is based on the 1953 play of the same name by Agatha Christie. The first film adaptation of Christie's story, Witness for the Prosecution was adapted for the screen by Larry Marcus, Harry Kurnit