Exposed (1932)

A young doctor, Jim Harper, is hired by gangster Marty to attend to his thugs. When Jim's policeman friend is killed by Marty, Jim continues working for him in order to obtain evidence. Unaware of his motivations, Jim's fiance Ruth, a nurse, breaks their engagement. They are reunited, however, when they care for the deceased policeman's son, and Jim turns the gang over to the police.