William Keighley's The Street with No Name 1948

The Street with No Name is a pretty good film noir, though Mark Stevens is a bland star and Keighley's direction is routine.  What it does have going for it is the intense villainy and homoeroticism of gangster boss Richard Widmark, who slaps around his men even more that he slaps his wife (an effectively blonde Barbara Lawrence).  It also has cinematography by the reliable Joseph MacDonald, who does a terrific job with the shadows, staircases, diners, gyms, and the general sleaziness of skid row,  where most of the film takes place (except for the house of an on-the-take police detective in the suburbs).  And everything takes place at night. The script is by the pro Harry Kleiner, who later reworked it for Samuel Fuller's House of Bamboo (1955).

The film is one of a number of 20th Century Fox films of the forties, including The House on 92nd St. (1945) and Call Northside 777 (1948), that uses a pseudo-documentary approach, with an omniscient narrator and shots of labs processing fingerprints and ballistics.  It also is one of a number of contemporaneous films about federal agents working undercover, the best of which is Anthony Mann's T-Men (1947).  One quibble I do have with The Street with No Name is that we don't know anything about FBI agent Gene Cordel (the character played by Mark Stevens) so putting him in harm's way produces little emotion or concern (not helped by Stevens's insipidness)