He Walked by Night (1948) is a black-and-white police procedural with film noir styling, crediting Alfred L. Werker as director. In reality, most of the film was directed by western/film noir director Anthony Mann. The film, shot in semidocumentary tone, was based on the real-life actions of Erwin "Machine-Gun" Walker, a psychopathic killer whose story and capture inspired one of the film's actors (Jack Webb) to create the radio and later television program Dragnet.

The film was released by Eagle-Lion Films and is notable for the camerawork by renowed noir cinematographer John Alton.

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. Written by Claudio Carvalho, Rio de Janeiro, Brazil

When a police officer is gunned down by a man whom he had stopped to question, a city-wide dragnet fails to catch the shooter, leaving the police with only minor clues to go on. Later they discover that the same man has been selling stolen equipment through an electronics dealer, and they set a trap for him. But he shoots his way out of the trap and escapes. The police must piece together a description of the man's appearance and habits from witnesses and a few small clues, as they search untiringly for a dangerous and very resourceful criminal. Written by Snow Leopard