The Amazing Dr. Clitterhouse (1938)

Dr. Clitterhouse is fascinated with the working of the criminal mind. His interest is so deep that he finds the best way to observe criminals in action is to become one himself. Whilst robbing a safe at an exclusive party he stumbles across an organized gang trying to do the same thing. He teams up with the gang to observe them in action but one of the members, Rocks Valentine would like nothing better than to see Clitterhouse out of the way.