Basehart is a man named Roy Martin who is an electronics genius, however he steals others people's inventions and sells them on consignment to a dealer (Whit Bissell) who thinks they are Roy's.
One night an off duty policeman sees Roy attempting to break into an electronics shop and is killed for his interference. This brings the police in a wild chase to capture the killer.
Roy is highly intelligent and always one step ahead of the police and had an ingenious way to escape detection. he uses the Los Angeles sewer system for his travels.
This is an excellent piece of film making from Alfred Werker. Scott Brady and Roy Roberts are two cops who are determined to catch the cop killer. Look for Jack Webb in a pivotal role as a police lab worker.
The film is tense and gripping and is one of the best examples of Film Noir ever made. The final chase scene where the police close in on Roy is very reminiscent of the ending of the sci-fi film "The Indestructible Man" . The print from Mill Creek is about as good as I have seen this film.