In Los Angeles after the Second World War, a criminal shot and killed a policeman in the middle of the night. Without any clues, the Los Angeles Police Commissioner assigned Sergeant Chuck Jones and Sergeant Marty Brennan to investigate the murder and arrest the criminal. When Paul Reeves, an electronic equipment dealer, was selling a stolen projector, the police found the criminal and linked it to other unsolved robbery cases. They used the eyewitnesses he robbed to draw their faces, but the true identity of the clever and intelligent criminal was not disclosed. Sergeant Marty Brennan's perseverance in the investigation provided clues to where he might live.
