Jim Davis

Joseph Cummins

Ian Keith

FBI Director Sinclair

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)