M (1931)
Fritz Lang's 1931 German film. Peter Lorre as a child murderer hunted by both police and the criminal underworld.
Gustaf Gründgens played the criminal leader who organises the manhunt in M, and his career in Germany under the Nazi regime, in which he ran the state theatre, became the basis for the novel and film Mephisto. He was a major figure of German theatre both before and after the war.