From Wikipedia, the free encyclopedia. He Walked by Night (1948) is a black-and-white police procedural film noir, crediting Alfred L. Werker as director. The film, shot in semidocumentary tone, was loosely based on newspaper accounts of the real-life actions of Erwin "Machine-Gun" Walker, a former Glendale police department employee and World War II veteran who unleashed a crime spree of burglaries, robberies, and shootouts in the Los Angeles area during 1945 and 1946. During production, one of the actors, Jack Webb, struck up a friendship with the police technical advisor, Detective Sergeant Marty Wynn, and was inspired by a conversation with Wynn to create the radio and later television program Dragnet. Today the film is in public domain. Description above from the Wikipedia article He Walked by Night, licensed under CC-BY-SA, full list of contributors on Wikipedia.