The movie is a follow-up to The House on 92nd Street (1945), which uses the same semi-documentary style to tell the story of an FBI investigation. Lloyd Nolan plays FBI Inspector George A. Briggs in both films.
"Lux Radio Theater" broadcast a 60-minute radio adaptation of the movie on January 31, 1949 with Richard Widmark, Lloyd Nolan and Mark Stevens reprising their film roles. An additional broadcast of the same radio adaptation was done on December 12, 1949, with Mark Stevens reprising his film role.
Just after Mark Stevens steps off the bus in Center City, he walks past a movie theater with a poster out front, advertising his co-star, Lloyd Nolan, in Manila Calling (1942). (Nolan himself appears in the previous scene, only 30 seconds before his name is seen on the movie poster.)
Lloyd Nolan and Mark Stevens would both play the lead character in the private eye TV series, Martin Kane (1949), in different seasons of the show. Nolan played Kane in Season 3, while Stevens played Kane in Season 5. Walter Greaza who plays a police lieutenant in this movie, also played a police captain in Season 3 of "Martin Kane," opposite Nolan.