Robert Downey Jr.

Paul Avery

Brian Cox

Melvin Belli

John Lacy

Zodiac 4

Philip Baker Hall

Sherwood Morrill

Elias Koteas

Jack Mulanax

Charles Fleischer

Bob Vaughn

Jake Gyllenhaal

Robert Graysmith

Anthony Edwards

William Armstrong

Mark Ruffalo

David Toschi

David Fincher

Director

James Le Gros

George Bawart

Donal Logue

Ken Narlow

Zach Grenier

Mel Nicolai

John Getz

Templeton Peck

John Carroll Lynch

Arthur Leigh Allen

Bob Stephenson

Zodiac 3

Dermot Mulroney

Martin Lee

Louis Phillips

Executive Producer

Chloë Sevigny

Melanie

June Diane Raphael

Mrs. Toschi

John Terry

Charles Thieriot

Candy Clark

Carol Fisher

Richmond Arquette

Zodiac 1 / Zodiac 2

Ed Setrakian

Al Hyman

Ciara Hughes

Darlene Ferrin

Lee Norris

Young Mike Mageau