I Cheated the Law (1949)

A lawyer, John Campbell (Tom Conway) defends gangster Frank Bricolle (Steve Brodie), on a murder charge and gets him acquitted. Campbell later finds out that Bricolle was really guilty, but since he cannot be tried again on the same charge, Campbell devises a way of pinning another charge on Bricolle. Once he gets him in court, he tricks the gangster into revealing his crooked ways.