Cornel Wilde as Leonard Diamond

Jean Wallace as Susan Lowell

Brian Donlevy as Joe McClure

Richard Conte as Mr. Brown

Lee Van Cleef as Fante

Earl Holliman as Mingo

Robert Middleton as Police Capt. Peterson

Helen Walker as Alicia Brown

Jay Adler as Detective Sam Hill

John Hoyt as Nils Dreyer

Ted de Corsia as Ralph Bettini

Helene Stanton as Rita

Roy Gordon as Audubon

Baynes Barron as Young detective

James McCallion as Frank - Lab technician

Tony Michaels as Photo technician

Rita Gould as Nurse

Bruce Sharpe as Detective

Michael Mark as Fred (hotel clerk)

Donna Drew as Miss Hartleby

Brian O'Hara as Attorney Malloy

Steve Mitchell as Bennie Smith, Boxer