Southside 1-1000 is a 1950 semidocumentary-style film noir directed by Boris Ingster featuring Don DeFore, Andrea King, George Tobias and Gerald Mohr as the off-screen narrator. Based on a true story, it is about a Secret Service agent (DeFore) who goes undercover and moves into a hotel run by a beautiful female manager (King), so that he can investigate a counterfeiting ring. The agent is up against hardened felons such as the gang member played by Tobias, an unusual example of casting against type for the typically comic actor. It is one of Ingster's two films noir, the other being Stranger on the Third Floor (1940), an early picture in the genre.