Lon Chaney Jr.

Dan McCormick

Lionel Atwill

Dr. Paul Rigas

Anne Nagel

June Lawrence

Frank Albertson

Mark Adams

Samuel S. Hinds

Dr. John Lawrence

William B. Davidson

District Attorney Ralph B. Stanley

Ben Taggart

Detective Sergeant Regan

Constance Bergen

Nurse

Chester Gan

Chinese Boy, Wong

George Meader

Dr. Bruno

Frank O'Connor

Detective

John Dilson

Medical Examiner

Byron Foulger

Alienist #2

Jessie Arnold

Mrs. Frank Davis (uncredited)

James Blaine

Charlie, Prison Guard (uncredited)

Douglas Evans

Police Radio Announcer (uncredited)

Jack Gardner

Reporter (uncredited)

William Hall

Mike - Dynamo Operator (uncredited)

Russell Hicks

Warden Harris (uncredited)

Tom Quinn

Detective (uncredited)

Bob Reeves

Prison Guard (uncredited)

Francis Sayles

Frank Davis (uncredited)

David Sharpe

Hay Wagon Passenger (uncredited)

Victor Zimmerman

Dynamo Operator #2 (uncredited)