| Person | Type | Job | Role(s) |
|---|---|---|---|
 Al Martin | Crew | Writing | Screenplay, Story |
Fred Preble | Crew | Art | Set Designer |
Glen Glenn | Crew | Sound | Sound Recordist |
Harvey Gould | Crew | Crew | Cinematography |
Heinz Roemheld | Crew | Sound | Music |
 Helen Martin | Crew | Writing | Screenplay, Story |
 Joseph H. Lewis | Crew | Directing | Director |
Lew Porter | Crew | Sound | Music |
Marcel Le Picard | Crew | Crew | Cinematography |
Pete Mayer | Crew | Production | Associate Producer |
Robert Golden | Crew | Editing | Editor |
Sam Katzman | Crew | Production | Producer |
Charles Dunworth | Crew | Sound | Music |
 Bela Lugosi | Cast | Actor | Dr. Charles Kessler |
 Betty Compson | Cast | Actress | Mrs. Kessler |
 Clarence Muse | Cast | Actor | Evans the Butler |
 Dorothy Vernon | Cast | Actress | Kessler's Cook (uncredited) |
 Ernie Adams | Cast | Actor | Jules Mason, caretaker |
 Fred Aldrich | Cast | Actor | Guard at Ralph's Execution (uncredited) |
 Fred Kelsey | Cast | Actor | Detective Ryan |
 George Pembroke | Cast | Actor | Lt. Williams |
 Jack Mulhall | Cast | Actor | Jim, a detective |
 John McGuire | Cast | Actor | Ralph Dickson / Paul Dickson |
 Lloyd Ingraham | Cast | Actor | Psychiatrist (uncredited) |
 Ottola Nesmith | Cast | Actress | Mrs. Mason |
 Polly Ann Young | Cast | Actress | Virginia Kessler |
Robert F. Hill | Cast | Actor | Trial Judge (uncredited) |
 Robert Strange | Cast | Actor | Kirby--Coroner (uncredited) |
 Terry Walker | Cast | Cecile Mannix, maid | |
| Person | Type | Job | Role(s) |
