While the City Sleeps

The plot is sparked by the misbehavior of heroine Myrtle who enjoys rubbing shoulders with gangsters like Skeeter. When she learns too much about Skeeter's set-up, Myrtle is put on the spot by the mob. Veteran police officer Dan takes it upon himself to put Myrtle in "protective custody" in his own apartment. Dan falls in love with the girl, but at fadeout time he willingly gives up to likable reformed gangster Marty. (answers.com)