Zodiac is a 2007 thriller movie by David Fincher and based on Robert Graysmith's non fiction book: "Zodiac".
In 1969, an unknown individual attacks a couple, Darlene Ferrin (Ciara Hughes) and Mike Mageau (Lee Norris), at a lovers' lane in California, Vallejo. Mageau survives while Ferrin dies from her injuries. About one month later, a letter arrives at the San Francisco Chronicle, written by someone who names himself "Zodiac". Paul Avery (Robert Downey, Jr.) is a crime reporter. Robert Graysmith (Jake Gyllenhaal) is a political cartoonist in the same place.. The newspaper receives different encrypted letters that the the killer sends, mocking the police. Because of Graysmith's status as a cartoonist, Graysmith is not taken seriously by Avery or the editors and is excluded from the investigation of Zodiac, despite his interest. He is drawn to the encrypted code..