Fritz Lang's 1931 Classic Psychological Thriller VO. Longest available version, DVD

Berlin is in the grip of terror as an unknown psychopathic child molester and murderer is attacking little girls. Despite frantic searching, the police produce no clues and neighbours begin to turn against, and inform on, each other. The underworld becomes so incensed at the activity of the police and the heat being turned on them that the leaders decide to find the pervert themselves. A blind beggar identifies the murderer and marks the his back of his coat with a chalk letter "M". His next intended victim tries to wipe this off and, on seeing a reflection of the "M" (the symbol of Cain) in a shop window, the murderer hides in a disused office building. Discovered by the mob, he is tried and sentenced to death, but before this is carried out, he is rescued by the police. This is Peter Lorre at his very best. The film captures perfectly the atmosphere of a city besieged by fear and torn between the forces of order and mob violence. Although it was later denied by Lang, this psychological thriller is based on the true case of Peter Kurten, a compulsive child murderer in Düsseldorf, and Germany's worst mass killer of the period. A stickler for reality, Lang interviewed police and criminals before going into production and actually employed real criminals to play the films underworld characters. Unfortunately the ploy backfired when twenty-four of them were arrested during filming for various offences committed away from the set ! Originally entitled "Morder Unter Uns" (Murderers Among Us), the title was changed because the Nazi Party thought it could be construed as a reference to them.