Before I Hang (1940)
A physician on death row for a mercy killing is allowed to experiment on a serum using a criminals' blood, but secretly tests it on himself. He gets a pardon, but finds out he's become a Jekyll-&-Hyde.
Directed by: Nick Grindé
Starring: Boris Karloff, Evelyn Keyes, Bruce Bennett, Don Beddoe, Edward Van Sloan, Ben Taggart
Links: Columbia Pictures, IMDb, Movie posters, Movie stills