On the 2nd of March 2007 when David Fincher's Zodiac was released to an indifferent audience at the US box office, many of its creators might not have been surprised. A film about obsession, with an inconclusive ending was always unlikely to have a sustained presence in cinemas, despite major critical acclaim. Much like the real-life events that inspired it, this was a story to linger in the mind, to be taken in by the details and the contradictions of evidence. It also represented its director, David Fincher, a man obsessed with the details of film-making and notorious for punishing his actors with multiple takes and his crews by knowing their jobs inside-out. It's interesting that the Zodiac killer had an obsession with a particular film (referenced in the notorious 408 Cipher), 1932's The Most Dangerous Game a story that detailed a man hunting and killing on an island. Art sometimes echoes the truth.

The film opens in July 1969, with a sequence where we witness an attack from the perspective of a couple about to be attacked by the Zodiac killer, one of only a few times in the film that this happens. It's a shocking, visceral moment that shows the impact and the random nature of the Zodiac killer's attacks and what was happening to the victims. This becomes more important later on, as the emphasis changes from the actual killings, to the men investigating it. Three of them in particular, Robert Graysmith (Jake Gyllenhaal), Dave Toschi (Mark Ruffalo) and Paul Avery (Robert  Downey Jr).

Graysmith was a cartoonist for the San Francisco Chronicle, a “boy scout” as one character humourously describes him. The film is based on the two books that he ended up writing about the subject, titled 'Zodiac: The Full Story of the Infamous Unsolved Zodiac Murders in California' published in 1986 and 'Zodiac Unmasked: The Identity of America's Most Elusive Serial Killer', published in 2002. Indeed, Fincher had read Graysmith's book in high school and remembered being obsessed with it.

Paul Avery was a journalist with the San Francisco Chronicle and had a high chemical dependency and a taste for theatrical reporting, often with himself as the primary concern. Downey Jr, just at the beginning of his spectacular career revival, is perfect casting with his own brushes with alcohol and substance abuse adding another layer of subtext.

Dave Toschi was a detective with the San Francisco Police Department, within the Homicide department. Toschi had served as Steve McQueen’s primary influence for his character in Bullitt (1968) and later would serve as the inspiration for Clint Eastwood's Dirty Harry (1971), along with the whole Zodiac investigation -famously the film features the 'Scorpio' killer – who targeted school children, just like the real Zodiac's most infamous threat – a clear case of fiction being taken from fact.

All three of these characters would end up losing themselves to some degree within the investigation, with Fincher not afraid to show us the personal losses that occur along the way. Jobs, girlfriends, partners, and professional respect all fall to the wayside in pursuit of the truth. One of his primary inspirations would be a classic of the era that he was trying to present: the classic adaptation of Carl Bernstein and Bob Woodward's All The Presidents Men (1975) -itself a tale of two crusading journalists detailing the Watergate scandal for The Washington Post, which infamously ended the presidency of Richard Nixon.

Zodiac represented Fincher's first foray into feature length digital cinematography and it proves to be an inspired choice. Though a period piece, with a soundtrack dominated by some great choices from the era -most notably the chilling use of Donovan's “Hurdy Gurdy Man”, Fincher uses it to present the 60's and predominantly the 70's as contemporary, shooting in a style that makes the past seem modern. The whole cinematography, by Harris Savides, has a look of distilled lighting and a very grey scale, almost a look of mundanity. The influence of photography is clear, with shots presented almost as evidence of its own. A few segments were shot on 35mm, primarily the murder sequences as to get a higher shutter speed. Savides had previously worked with Fincher on Se7en (1995) but this was to be a very different feeling project. The visual effects are seamlessly integrated too, one particular moment calling for a recreation of the corner of Washington and Cherry which Fincher shot as a series of green screen composites. To this day, many may be unaware of just how many visual effects shots are actually in Zodiac.

The cinematography and colour palette of Zodiac further ties into the obsession around the crimes and the clues, through a subtly disruptive use of the colour blue. Look for examples of this in the choice of ink in Zodiac's letters to the press, clothing of the characters and so much more. This is very purposeful in that it ties to Gareth Penn's “water theory” of Zodiac’s crimes (surrounding Michael O'Hare as a suspect), something that is explored in the film by Graysmith and Avery.

One example of the use of shades of blue in the characters' wardrobe.

The screenplay was written by James Vanderbilt and pursued a high level of historical accuracy, with Fincher wanting to be as accurate as possible with the facts and to determine the truth behind such a high profile case. At two hours and forty two minutes in length, there would be room for presenting all of this and in a rare move for modern Hollywood, two studios would share the burden financially, Warner Bros and Paramount.

Zodiac Killer wanted poster, October 18, 1969.

What's particularly impressive about Zodiac is the sheer amount of information that's presented to an audience and how the tension and suspense builds through it, despite the ebb and flow of the actual case. By keeping our focus on the three main characters and especially on Graysmith's obsession, we are drawn into the characters and suspects surrounding the case, all performed by an impressive ensemble of character actors including Brian Cox, Philip Baker Hall, and perhaps most memorably John Carroll Lynch as Arthur Leigh Allen, the primary suspect in the Zodiac case. In one un-nerving sequence at Allen's workplace, Lynch gives a sustained performance of confidence in what the character is saying, no matter how weird it appears to Toschi and the other detectives questioning him. A similar moment is achieved when Graysmith speaks with Bob Vaughn (portrayed by Charles Fleischer, the memorable voice of Roger Rabbit in 1988's Who Framed Roger Rabbit) a former employee of a potential Zodiac suspect. When Graysmith realises that Vaughn himself may have had more to do with the killings than he initially considered, thanks to an excellent dialogue reveal, he tries to get out as quickly as possible, only to be met with a locked door that he nervously cannot open. It's a bravura sequence.

The film concludes in 1991, with over a decade having passed and Graysmith's book having been published. The finger is pointed once again at Arthur Leigh Allen, after years of dead ends and the case being reduced in importance by the San Francisco Police Department. Again though, the investigation is thwarted by Allen's death, leaving the film as an open book. But the narrative doesn't want you to think of the film that way. It's presented as a true life story and real life is full of narrative dead ends and lost obsession. It's trying to transcend the crime genre itself and present a story of details and the men who lost their lives – some literally – in pursuit of the truth. Fincher is always searching for perfection within a truth whilst making his films and it's absolutely logical that he would want to direct this story. Zodiac remains an excellent film 10 years on because of that obsession and will continue to lose audiences to its labyrinth of information for many years to come.