Babe Paley
Truman Capote
Kitty Dean
Nelle Harper Lee
Marella Agnelli
Bennett Cerf
El Morocco Band
Alvin Dewey
Perry Smith
Diana Vreeland
Gore Vidal
Slim Keith
William Shawn (as Frank Curcio)
D.A.'s Secretary (as Terri Bennett)
Jack Dunphy
Reporter 1
Reporter 2
Waitress (as Sheila Bailey-Lucas)
Man on Street
Desk Clerk (as Norman Jamison Bennett)
Clifford Hope
Marie Dewey
Delores Hope
Paul Dewey
Ellen Bechner
Nancy Hickey
Andy Erhart (as Richard Jones)
Everett Ogburn
Dick Hickock
Charles McAtee
Prisoner 1 (as Paul Mitchell Wright)
Prisoner 2
Lee Andrews
Piano Player
Bill Paley
Tex Smith
Flo Smith
Young Perry
Young Truman
Herb Clutter (as Brent Mccoy)
Bonnie Clutter
Kenyon Clutter
Nancy Clutter
Judge Tate
Foreman
Prison Guard 1
Prison Guard 2
Chaplain
Doctor (as Michael Conway)
New Yorker (uncredited)
Morocco Club Patron (uncredited)
Restaurant Patron (uncredited)
Restaurant patron (uncredited)
Jailer (uncredited)
Deputy Bishop (uncredited)
El Morocco Band (uncredited)
El Morroco Playboy (uncredited)