Murder is the killing of another human being without justification or valid excuse, and it is especially the unlawful killing of another human being with malice aforethought. This state of mind may, depending upon the jurisdiction, distinguish murder from other forms of unlawful homicide, such as manslaughter.

Murder! is a 1930 British drama film co-written and directed by Alfred Hitchcock and starring Herbert Marshall, Norah Baring and Edward Chapman. Written by Hitchcock, his wife Alma Reville and Walter C. Mycroft, it is based on a novel and play called Enter Sir John by Clemence Dane and Helen Simpson. It was Hitchcock's third all-talkie film, after Blackmail and Juno and the Paycock.