Gun Moll aka Gang Smashers (1938) starring Nina Mae McKinney, Monte Hawley, Mantan Moreland, Laurence Criner, and an all black cast.

A female police detective goes undercover as a singer in a club in order to get evidence on the club owner who’s running a protection racket. Things get complicated when they recruit a notorious gangster that’s not afraid to kill.

You can watch the full movie here: Gun Moll (1938)