Zodiac - 2007
On July 4, 1969, an unknown male attacks Darlene Ferrin (Ciara Hughes) and Mike Mageau (Lee Norris) with a handgun, at a lovers' lane in Vallejo, California. Mageau survives; Ferrin dies. One month later, the San Francisco Chronicle receives encrypted letters written by the killer calling himself the "Zodiac" and taunting the police.
Political cartoonist Robert Graysmith (Jake Gyllenhaal) is not taken seriously by crime reporter Paul Avery (Robert Downey, Jr.) or the editors and is excluded from the initial details about the killings despite his interest in the case. When the newspaper publishes the letters, a married couple is able to decipher one. At a local bar, Avery initially makes fun of Graysmith before they discuss the coded letters.
Graysmith does some interpretation of the letter, which Avery finds helpful and Avery begins sharing information. The Zodiac killer attacks again on September 27, 1969. Law student Bryan Hartnell (Patrick Scott Lewis) and Cecelia Shepard (Pell James) are attacked at Lake Berryessa in Napa County. Shepard dies two days later while Hartnell survives. Two weeks later, San Francisco taxicab driver Paul Stine is shot and killed in the city's Presidio Heights district immediately after dropping the killer off.
The Zodiac killer mails pieces of Stine's blood stained shirt to the Chronicle, along with a taunting letter. San Francisco police detectives Dave Toschi (Mark Ruffalo) and his partner Bill Armstrong (Anthony Edwards) are assigned to the Stine case, and work closely with Vallejo's Jack Mulanax (Elias Koteas) and Detective Ken Narlow (Donal Logue) in Napa.
The killer, or someone posing as him, continues to toy with authorities by sending more letters, and speaking on the phone with lawyer Melvin Belli (Brian Cox) when he makes an appearance on a television talk show. Avery and Graysmith form an alliance, delving deeper into the case as time permits. In 1971, Detectives Toschi, Armstrong, and Mulanax question Arthur Leigh Allen (John Carroll Lynch), a suspect in the Vallejo case. Allen behaves suspiciously during the interview.
However, a handwriting expert (Philip Baker Hall) insists that Allen did not write the Zodiac letters, even though Allen is said to be ambidextrous. Avery receives a letter threatening his life; becoming increasingly paranoid, he turns to drugs and alcohol. At one point, he shares information with the Riverside Police Department, angering both Toschi and Armstrong.
The case's notoriety weighs on Toschi, who is bothered when Graysmith shows up at the theater where Toschi is watching a Hollywood film, Dirty Harry, loosely based on the Zodiac case, with his wife. In 1978, Avery leaves the Chronicle, and moves to the Sacramento Bee. Graysmith persistently contacts Toschi about the Zodiac murders, and eventually impresses the veteran detective with his knowledge of the case.
While Toschi cannot directly give Graysmith access to the evidence, he provides contact names of other police departments in other counties where Zodiac murders occurred. Armstrong transfers from the San Francisco Police homicide division, and Toschi is demoted for supposedly forging a Zodiac letter. Graysmith continues his own investigation, which is profiled in the Chronicle, and he allows himself to be interviewed on television about his book-in-progress concerning the case.
He begins receiving anonymous phone calls with heavy breathing. Because of his immersion in the case, Graysmith loses his job and his wife Melanie (Chloï¿½ Sevigny) leaves him, taking their children with her. Graysmith acquires more information that points to Allen as the Zodiac, and although circumstantial evidence seems to indicate his guilt, the physical evidence, such as fingerprints and handwriting samples, indicates a different suspect.
In December 1983, Graysmith tracks Allen down to a Vallejo Ace Hardware store, where he is employed as a sales clerk. The men have a brief encounter before Graysmith leaves. Eight years later, victim Mike Mageau (Jimmi Simpson) meets with authorities and identifies Allen from a police mugshot. As the authorities walk by an airport book store, copies of Graysmith's book Zodiac are shown.
Final title cards inform the audience that Allen died in 1992 before he could be questioned further. A DNA test performed in 2002 on an archived autopsy sample did not match a partial DNA sample gathered from the postage stamp on one of the Zodiac letters, but this does not rule him out as a suspect.