Which 1957 legal thriller based on an Agatha Christie play features a dramatic courtroom twist?

The 1957 legal thriller based on an Agatha Christie play with a dramatic courtroom twist is Witness for the Prosecution.

Directed by Billy Wilder, the film is adapted from Christie’s 1953 play of the same name. It follows London barrister Sir Wilfrid Robarts, played by Charles Laughton, as he defends Leonard Vole, a man accused of murdering a wealthy widow. Marlene Dietrich plays Vole’s wife, Christine, while Tyrone Power portrays Vole in his final completed film role.

The story unfolds largely around London’s Old Bailey and is built on testimony, credibility, and reversals that challenge what the audience thinks it knows. Its final twist is so central that the film’s promotional campaign famously asked viewers not to reveal it. The Caine Mutiny, Anatomy of a Murder, and 12 Angry Men are courtroom-related films, but they are not Christie adaptations and have different plots.