Ash has seen this movie.
Over the course of a decade, editors of the San Francisco Chronicle entice themselves in the murders of the Zodiac Killer. However, as time runs its course, interest in the case dwindles in the eyes of the professionals. The Killer stops interacting with the public. However, believing he has the answers, an amateur cartoonist from the initial sightings races against time to prevent what he believes is another murder.
| Robert Graysmith | Jake Gyllenhaal |
| David Toschi | Mark Ruffalo |
| William Armstrong | Anthony Edwards |
| Paul Avery | Robert Downey Jr. |
| Melanie | Chloë Sevigny |
| Jack Mulanax | Elias Koteas |
| Arthur Leigh Allen | John Carroll Lynch |
| Melvin Belli | Brian Cox |
| Martin Lee | Dermot Mulroney |
| Bob Vaughn | Charles Fleischer |
| Mel Nicolai | Zach Grenier |
| Sherwood Morrill | Philip Baker Hall |
| George Bawart | James Le Gros |
| Ken Narlow | Donal Logue |
| Zodiac 1 / Zodiac 2 | Richmond Arquette |
| Zodiac 3 | Bob Stephenson |
| Zodiac 4 | John Lacy |
| Al Hyman | Ed Setrakian |
| Templeton Peck | John Getz |
| Charles Thieriot | John Terry |
| Carol Fisher | Candy Clark |
| Mrs. Toschi | June Diane Raphael |
| Darlene Ferrin | Ciara Hughes |
| Young Mike Mageau | Lee Norris |
| Bryan Hartnell | Patrick Scott Lewis |
| Cecilia Shepard | Pell James |
| Father | David Lee Smith |
| Lab Tech Dagitz | Jason Wiles |
| Cabbie / Paul Stine | Charles Schneider |
| Shorty | James Carraway |
| Jim Dunbar | Tom Verica |
| Mike Mageau | Jimmi Simpson |
| Belli's Housekeeper | Doan Ly |
| Woman | Karina Logue |
| Inspector Kracke | Joel Bissonnette |
| Riverside Captain | John Mahon |
| John Allen | Matt Winston |
| Catherine Allen | Jules Bruff |
| Terry Pascoe | John Ennis |
| Police Commissioner | J. Patrick McCormack |
| Duffy Jennings | Adam Goldberg |
| Linda del Buono | Clea DuVall |
| Sandy Panzarella | Paul Schulze |
| Detective #1 | Adam Trese |
| Mulanax's Secretary | Penny Wallace |
| Donald Cheney | John Hemphill |
| Man on Marquee | Michel Francoeur |
| Copy Editor #1 | Thomas Kopache |
| Copy Editor #3 | Barry Livingston |
| Copy Editor #4 | Christopher John Fields |
| Young David Graysmith | Jack Samson |
| David Graysmith | Micah Sauers |
| Aaron Graysmith | Zachary Sauers |
| Margot Graysmith | Jessica Baltutis |
| Patrolman Fouke | Peter Quartaroli |
| Patrolman Zelms | Geoff Callan |
| Truck Driver | Michael Hungerford |
| Society Woman | Anna Katarina |
| Informant (Hall of Justice A) | E.P. McKnight |
| Informant | Betty Murphy |
| Informant | Jeff Daniel Phillips |
| Informant | Shane Woodson |
| Informant #8 | Cookie Crawford |
| Uniform Cop | Cassius M. Willis |
| Florence Douglas | Judith Drake |
| Prison Guard | Phoebe Holston |
| Pinole Foreman | Marty Lodge |
| Internal Affairs Agent #1 | Cooper Thornton |
| Internal Affairs Agent #2 | Cazimir Milostan |
| Kathleen Johns' Baby | Charlotte Ferguson |
| Kathleen Johns' Baby | Phoebe Ferguson |
| Kathleen Johns' Baby | Kacey Malmsten |
| Kathleen Johns' Baby | Karly Malmsten |
| Director | JD Cullum |
| Staff Editor | Stanley B. Herman |
| Distraught African American Male | Roy Lee Jones |
| Navy Project Leader | Michael Rose |
| DOD Project Leader | James Joseph O'Neil |
| FBI Codebreaker | Rod Damer |
| Donald Harden | John Sarno |
| Bettye Harden | Gloria Grant |
| Detective Roy | Brett Rickaby |
| Detective #2 | M.F. Bernier |
| Newscaster #2 | Carter Evans |
| TV News Anchor | Bill Seward |
| Newscaster #4 | Dave Nemeth |
| Anchorman #1 | Ted Garcia |
| Interviewer #1 | Greg Wolf |
| Reporter | Barry LeBrock |
| Kathleen Johns (uncredited) | Ione Skye |
| Vallejo Desk Ofiicer (uncredited) | David Winston Barge |
| Hardware Store Customer (uncredited) | Hayati Akbas |
| Camera Man (uncredited) | Brad Carr |
| Reporter (uncredited) | Mitchell Fink |
| Traveler (uncredited) | Erica Ford |
| Informant (uncredited) | Tish Hicks |
| Prisoner (uncredited) | Danielle McKee |
| Office Worker (uncredited) | Derris Nile |
| Janie (uncredited) | Carmen Plumb |
| Child Witness (uncredited) | Callie Thompson |
| Patrolman (uncredited) | Bud Davis |
