M (1951)

In post-war Germany, a city is terrorized by a serial killer who preys on children. As the police struggle to catch the killer, a widespread manhunt ensues, leading to mass hysteria and an atmosphere of fear. The main suspect is a mentally ill man named Hans Beckert, whose crimes have left the city in anguish. The police and the criminal underworld both launch their own investigations, and a race against time begins to capture the elusive murderer.