Szereplők

• Jake Gyllenhaal — Robert Graysmith
• Mark Ruffalo — Dave Toschi
• Anthony Edwards — Bill Armstrong
• Robert Downey Jr. — Paul Avery
• Brian Cox — Melvin Belli
• John Carroll Lynch — Arthur Leigh Allen
• Chloë Sevigny — Melanie
• John Terry — Charles Thieriot
• Candy Clark — Carol Fisher
• Elias Koteas — Jack Mulanax
• Dermot Mulroney — Captain Martin Lee
• Donal Logue — Captain Ken Narlow
• Philip Baker Hall — Sherwood Morrill
• Jimmi Simpson — Mike Mageau
• Joel Bissonnette — Inspector Kracke
• Zach Grenier — Mel Nicolai
• Adam Goldberg — Duffy Jennings
• Karina Logue — Woman
• James Le Gros — Officer George Bawart
• Clea DuVall — Linda del Buono
• Paul Schulze — Sandy Panzarella
• Anna Katarina — Society Woman
• June Diane Raphael — Mrs. Toschi
• Ione Skye — Kathleen Johns
• Ione Skye — Kathleen Johns
• Ed Setrakian — Al Hyman
• John Getz — Templeton Peck
• Brett Rickaby — Detective Roy
• Charles Fleischer — Bob Vaughn
• Richmond Arquette — Zodiac 1 y 2
• Bob Stephenson — Zodiac 3
• John Lacy — Zodiac 4
• Lee Norris — Young Mike Mageau