Zodiac / ***½ (R)

Robert Graysmith: Jake Gyllenhaal
Inspector David Toschi: Mark Ruffalo
Paul Avery: Robert Downey, Jr.
Inspector William Armstrong: Anthony Edwards
Melanie: Chloe Sevigny
Arthur Leigh Allen: John Carroll Lynch

Paramount Pictures and Warner Bros. present a film directed by David Fincher. Written by James Vanderbilt, based on the book by Robert Graysmith. Running time: 158 min. Rated R (for some strong killings, language, drug material and brief sexual images).

“Zodiac” is a fascinating movie. An epic police procedural, it details the search for the real life Zodiac killer, who terrorized the San Francisco Bay area for nearly a decade before disappearing, in the process becoming one of the most famous serial murder cases ever to remain unsolved. Based on the book by Robert Graysmith, a cartoonist employed at the San Francisco Chronicle during the Zodiac slayings, this film contains a cast of characters as long as the years that passed between the first reported Zodiac murders and the San Francisco Police Department’s decommissioning of the case in the early nineties.

I went into “Zodiac” knowing very little about the actual case beyond the fact that the killer was never caught and Graysmith had written a book about it. Other than that, my knowledge consisted mainly of the countless crime films with plots loosely based on the evidence made public during the Zodiac investigation. David Fincher’s new film on the subject had me mesmerized.

Unlike most of Fincher’s previous films, which often focused on the spectacle of crime and violence, “Zodiac” takes a more methodical and meditative look at what goes into solving such a crime (or in this case, not solving it) and examines the large toll the obsessive dedication to finding the truth can take on the men who are compelled to do so. The film concentrates on three men pursuing the killer: Paul Avery, the crime beat reporter for the San Francisco Chronicle; Robert Graysmith, the Chronicle’s cartoonist with a knack for solving cipher codes sent in by the killer; and David Toschi, the homicide detective assigned to the case.

These men prove the film’s tagline, “There is more than one way to lose your life to a killer.” And each actor brings their own personal strengths to these roles. Robert Downey, Jr. (“Kiss Kiss Bang Bang”) plays Avery as a man who can’t help but push the envelope by peppering his stories with personal attacks against the killer; he self destructs when he finds himself trapped in the very envelope he sealed and stamped. Mark Ruffalo (“Just Like Heaven”) brings a quiet intensity to the cop driven instinctually to the most likely suspect; but with only circumstantial evidence, he finds time erodes his personal support structure. Jake Gyllenhaal’s (“The Day After Tomorrow”) Graysmith is a hero who, after being left out of the loop during the initial investigation, proves to be the most driven of the three, at the cost of his family and personal safety, in his obsession to find a man that baffled every expert of the day.

While the film’s focus is the investigation into the Zodiac by these men and the price they paid for it, the details of the case are laid out here with absorbing effect. Although the Zodiac’s actions were impossible to predict and trace at the time, it would probably be impossible today for such a criminal to evade the police for so long, thanks to modern police procedure and investigation technology. This movie is as much a period crime investigation as “L.A. Confidential” or last year’s “The Illusionist”. It is Zodiac’s constantly changing M.O. that makes the case so frustrating for the characters and audience alike.

Covering a period of time from 1968 through 1991, Fincher does a wonderful job capturing the look and feel of this span, especially the late sixties and early seventies, which account for the majority of the film’s action. Period production design is as flashy as Fincher gets this time around, however. Whereas past films like “Se7en” and “Fight Club” were filled with thrills and twists, Fincher keeps the tone here on an even simmer. James Vanderbilt’s (“The Rundown”) superb script shows the inevitable psychological toll non-progress takes on the investigators.

The massive time span also allows for an epic cast of characters. Employing just about every B-list actor whose name you don’t know but whose face you’ll recognize, Fincher luxuriates in allowing these wonderful performers to flesh out their character’s entire make up with minimal lines and screen time. Some of the cast’s standouts include Anthony Edwards (NBC’s “ER”) as Toschi’s partner, Dermot Mulroney (“About Schmidt”) as their captain, Philip Baker Hall (“Magnolia”) as a hand writing expert, Brian Cox (“The Bourne Supremacy”) as famed celebrity attorney Melvin Belli, John Carroll Lynch (“Fargo”) as prime suspect Arthur Leigh Allen, Chloe Sevigny (“Boys Don’t Cry”) as Graysmith’s estranged wife, and Donal Logue (“Ghost Rider”) and Elias Koteas (“The Thin Red Line”) as two of the surrounding San Francisco Bay area communities’ chief investigators.

“Zodiac” is not without its flaws. It loses a good deal of momentum going into its final act as the investigation itself stalls out for so many years while Graysmith puts the pieces together to write his book. But Fincher does a good job jump-starting the action with some suspense from a false lead late in the film, and he never loses touch with that sense of fascination that drives Graysmith to see the investigation through to the end.

“Zodiac” is an admirable film, not only for the way it diligently dissects the investigation of this unsolved mystery, but also for its devotion to its purpose as a character study of the investigators themselves. The film is never sidetracked for too long into the actual murders, which would rely heavily upon speculation. “Zodiac” doesn’t stray from its true inspiration, the people whose lives were consumed, and in some cases destroyed, by not discovering the killer’s identity.