A malicious robber is impersonating a police officer, usually striking when there's a red traffic light. The "Red Light Bandit" is turned in by his own father. Detective Sergeant Friday is assigned to robbery detail. A ruthless fiend roams the streets of the city masquerading as a police officer. For months helpless citizens have been robbed beaten senseless and kidnapped. The criminal is a twisted genius with cunning. It's up to Detective Sergeant Joe Friday to get him.