Cavalcade of America - Season 5 Episode 21 The Frightened Witness
Overview: Joe Kohler happens to be in the wrong place at the wrong time. He witnesses a mob hit when a car deliberately runs over a pedestrian. When mob lieutenant Craig tells Joe that he had best keep quiet and even stops home with him to see his family, Joe gets the point. But Joe doesn't like being intimidated and goes to the police to tell his story and do the right thing.