M is German director Fritz Lang’s masterpiece and is often recognized as the best German movie of all time. It illustrates the portrait of a child murderer that has caused an entire city to begin rioting. The film is based on actual events. A psychotic child murderer stalks a city, and despite an exhaustive investigation fueled by public hysteria and outcry, the police have been unable to find him. But the police crackdown does have one side-affect, it makes it nearly impossible for the organized criminal underground to operate. So they decide that the only way to get the police off their backs is to catch the murderer themselves. Besides, he is giving them a bad name.