Hollow Triumph (1948)

John Muller, medical school dropout and brilliant crook, plans a holdup which goes a little bit wrong, and finds vindictive gambler Rocky Stansyck after him. At the end of his tether, he stumbles onto a lucky chance to assume an impenetrable new identity as psychiatrist Victor Bartok. But irony piles on as Muller finds it's out of the frying pan, into the fire.