From Headquarters

SEE...The Miracles of Science the "lab" blood test x-ray and ultra-violet ray track down a murderer!

When a Broadway playboy is found dead, it's up to detective Jim Stevens to pick the murderer out of several likely candidates.

George Brent

Lt. Jim Stevens

Margaret Lindsay

Lou Winton

Eugene Pallette

Sgt. Boggs

Edward Ellis

Dr. Van de Water

Robert Barrat

Anderzian

Theodore Newton

Jack Winton

Murray Kinnell

Horton

Hobart Cavanaugh

Muggs Manton

Hugh Herbert

Manny Wales

Henry O'Neill

Inspector Donnelly

Dorothy Burgess

Dolly White

Frank Darien

Manley

Kenneth Thomson

Gordon Bates

Frank McHugh

Man picked up by police wagon

Ken Murray

Mac

Spencer Charters

Teletype Man (uncredited)

Al St. John

Detainee Touching Cigarette Pack (uncredited)

Matt McHugh

Man picked up by police wagon (uncredited)