James Whitmore

Sgt. Ben Peterson

James Arness

FBI Agent Robert Graham

Joan Weldon

Dr. Pat Medford

Edmund Gwenn

Dr. Harold Medford

Onslow Stevens

Brig. Gen. Robert O'Brien

Sean McClory

Maj. Kibbee

Sandy Descher

The Ellinson Girl

Chris Drake

Trooper Ed Blackburn

Don Shelton

Trooper Capt. Fred Edwards

Fess Parker

Alan Crotty

Mary Alan Hokanson

Mrs. Lodge

Olin Howland

Jensen

William Schallert

Ambulance Attendant

Ann Doran

Child Psychiatrist

Dub Taylor

Railroad Yard Watchman

Leonard Nimoy

Army Sergeant

Richard Deacon

Bald Reporter at L.A. News Conference

Forbes Murray

Government Official

Kenner G. Kemp

Trooper #2

Charles Perry

Soldier

Dorothy Green

Matron

Willis Bouchey

Official at D.C. Meeting

Mary Lou Holloway

Blonde at Police Station

Dick York

Teenager in Police Station

Bronislau Kaper

Original Music Composer

Gordon Douglas

Director

David Weisbart

Producer

Ted Sherdeman

Screenplay

Thomas Reilly

Editor

Sidney Hickox

Director of Photography

Stanley Fleischer

Art Direction

G.W. Berntsen

Set Decoration

George Worthing Yates

Story

Russell S. Hughes

Adaptation

Francis J. Scheid

Sound

Gordon Bau

Makeup Artist

Moss Mabry

Wardrobe Designer

Henry Vilardo

Makeup Artist

Robert Turner

Props