Lieutenant Harry Grant (William Lundigan
) and Sgt. Art Collins (Jeff Corey
) have been handed the unenviable assignment of tracking down "The Judge", a mysterious serial murderer responsible for seven deaths over the past few months. The police have plenty of clues and forensic evidence, but no solid leads to who this highly resourceful strangler is. Complicating Grant's work is the presence of Ann Gorman (Dorothy Patrick
), an ambitious reporter for a sensationalistic crime magazine, who keeps sticking her nose into this case and into his work. In exasperation over The Judge's latest victim, a newspaper editor named McGill (Frank Ferguson
), Grant decides to take a novel approach to catching the killer -- he prepares a life-size blank-faced dummy using all the clues the police have, as to height, weight, physique, preferred way of dressing etc., in order to give his officers a clearer picture of who and what they're looking for. The result is creepy but effective, and soon Grant is getting closer to the killer -- but The Judge is insane, and agitated by all manner of outside stimuli, and he might prove too much even for a police detective to deal with in a direct confrontation.