In the Post-World War II, in Los Angeles, a criminal shots and kills a police officer in the middle of the night. Without any lead, the chief of the LAPD assigns Sgt. Chuck Jones and Sgt. Marty Brennan to investigate the murder and find the murderer. When the dealer of electronics devices Paul Reeves is caught selling a stolen projector, the police finds the identity of the criminal, Roy Martin, and connects him to other unsolved robberies. Using the witnesses of his heists, they draw their face, but the true identity of the smart and intelligent criminal is not disclosed. The perseverance of Sgt. Marty Brennan in his investigation gives a clue where he might live.