Before I Hang (1940)

Before I Hang is a 1940 American science fiction horror film starring Boris Karloff, Evelyn Keyes, Bruce Bennett, and Edward Van Sloan.

Plot
A kindly doctor is sentenced to hang after a mercy killing and works on with the prison doctor on a youth serum. After secretly taking the serum he finds himself with a murderous craving.

Cast

 * Boris Karloff as Dr. John Garth
 * Evelyn Keyes as Martha Garth
 * Bruce Bennett as Dr. Paul Ames
 * Edward Van Sloan as Dr. Ralph Howard
 * Ben Taggart as Warden Thompson
 * Pedro de Cordoba as Victor Sondini
 * Wright Kramer as George Wharton
 * Bertram Marburgh as Stephen Barclay
 * Don Beddoe as Capt. McGraw
 * Robert Fiske as District Attorney