Elenco (na ordem dos créditos)
Sal LaBarbera
Self - Homicide Detective
Ken Mains
Self - Cold Case Expert
Kevin Knight
Self - Artificial Intelligence , USC
David Oranchak
Self - Zodiac Cipher Expert
Ryan Garlick
Self - Professor of Computer Science
Craig P. Bauer
Self - NSA Fellow
Sujith Ravi
Self - Computer Engineer, Google
Mocean Melvin
Self - Narrator
Suzanna Ryan
Self - Forensic Serologist, AISOCC
Jackie Hickey
Self - Bomb Squad Expert
Jake Herminghaus
Self - Detective, South Lake Tahoe Police Dept
Chris Christensen
Cameron Morris
Self - Park Ranger
Misty Johansen
Self - Zodiac Historian
Steve Shumway
Self - Retired Homicide Detective
Tom Bruton
Self - San Francisco PD (Retired)
Sergio G. Diaz
Self - Chief of Police, Riverside PD
Marin Pilloud
Self - Forensic Anthropologist
Jim Simons
Self - Riverside PD
John Averitt
Self - Police Psychologist
Ed Rust
Self - Retired Vallejo Police Officer
Patrick Collins
Self - Nephew of Investigative Reporter Dave Peterson
Jody Johns
Self - Daughter of Kathleen Johns
John Bennett
Self - Special Agent in Charge, FBI
Pamela Hofsass
Self - Director, Forensic Services Division, Contra Costa County
Eileen Page
Self - Handwriting Consultant
Larry Loew
Self - Friend of Donna Lass
Barbara Van Tomme
Self - College Librarian
Bob Cosley
Self - El Dorado County District Attorney
Josiah Jones
Self - Albany PD Detective
Gary Michael
Self - Former Booz Allen Hamilton Employee
Roger Pierson
Self - Lamplighter Performer 1968 - 2002
Ken Fowler
Self - Radio Expert
Taylor Berg-Kilpatrick
Self - Professor of Computer Science, Carnegie Mellon University
John Burke
Self - Ret. Albany Detective
Ed Scheidt
Self - Chairman, CIA Cryptographic Center (Retired)
Jason Wolf
Self - Executive Producer, The Hunt for the Zodiac Killer
Nico Birnbaum