Missing Witnesses (1937)

The daring of the racketeers all working for one organization in an East Coast city, leads the Governor to create a new undercover law agency formed to combat the gangsters, and to find witnesses against them. Heading the agency is the Special Prosecutor's aide, Inspector Lane, and his assistants, Emmet White and Bull Regan. Mary Norton, who Bull has fallen in love with, is the secretary for one of the legitimate enterprises ran by Ward Sturgis, the head of the crime ring. Mary had accidentally learned of this, and had just managed to escape with her life from his yacht. Sturgis is found dead floating in the bay with several bullet holes in his body. Mary is the lead suspect and Bull is assigned the job of finding and arresting her, but she gives him the slip. When he does catch up with her again, he rescues her from the very-much-alive Ward Sturgis, who faked his death by having a lookalike killed.