Jim Davis
— Joseph Cummins
Ian Keith
— FBI Director Sinclair
George Travell
— Rucca
Frederick Worlock
— Hugo Stregel
Stanley Andrews
— Mitchell (uncredited)
Hugh Beaumont
— FBI Chemist (uncredited)
Ralph Dunn
— Vic, Stregel's Thug (uncredited)
Byron Foulger
— Pelly, Stregel's Henchman (uncredited)
Ian Wolfe
— Gruning, Stregel's Henchman (uncredited)