David Fincher, the director of Fight Club and Seven, grew up in San Francisco when the city lived in fear of Zodiac, who haunted the Bay Area during the late Sixties and Seventies. Much like Jack the Ripper, Zodiac is an elusive figure, a sexually unbalanced psycho-path who murdered at least five people – although he claimed to have dispatched up to 37 – but was never caught. His attacks were made all the more potent by the dialogue he maintained with the police in letters that he had published in the press.

Nowadays, the killer exists in a murky world, his story shifting with each retelling. Hollywood was quick to exploit Zodiac’s deeds, with Don Siegel’s Dirty Harry (1971), which changed the murderer’s moniker to Scorpio, coming just two years after his first strike.

Now Fincher, 44, has picked up the case. “He was like Son of Sam to us,” he says. “It’s startling when you’ re 7 and it suddenly occurs to you that there are people who on the surface appear part of this civilised society yet secretly they have the desire to hunt other people.”

Many critics believe Zodiac to be Fincher’s most mature movie to date, and he talks passionately about his work. “I love the notion that with the Zodiac case there’s only opinion, no real truth. We’ve sat in rooms with so many people who in police reports have said certain things, and when you show the report to those people they deny it, say it never happened. So we decided to make a movie about the unknowability of the truth and the unsatisfactory nature of justice.”

BACKGROUND

• Zodiac

• Zodiac - Sunday Times review

• The world of a serial killer

• The killers who conquered cinema

• The murderer I grew up with

A deadly obsession

Who was Zodiac? Robert Graysmith believes he knows, he tells Martyn Palmer

Related Internet Links

• 2007 London Film Festival coverage

• Times Online Film Trailers

In its attempt to follow these themes, Fincher’s film focuses not on the killer but on those trying to track him down. The story is drawn from two books, Zodiac and Zodiac Unmasked, written by Robert Graysmith (played in Fincher’s film by Jake Gyllenhaal), a cartoonist on the San Francisco Chronicle who immersed himself in the case. Graysmith, like the journalist Paul Avery (Robert Downey Jr) and a cop, Dave Toschi (Mark Ruffalo), sees his obsession with the chase destroy much of his personal life.

“I guess obsession is a theme that runs through a lot of my work,” Fincher says. “Maybe the interest stems from my dad. He was very much like Graysmith – he was a journalist and he had these obsessions. I remember that he was once shown a card trick and he was in his bathrobe for four weeks trying to figure out how the trick worked.”

Driven by their compulsion, Graysmith et al – and indeed San Francisco itself – find everyday life thrown into disorder by the emergence of a dark, uncontrollable force, a theme that lurks in much of Fincher’s work from Alien 3 to Seven, and even The Game and Fight Club. The difference is that while those films are all expertly shot, each one parading its director’s stylistic flourishes, in Zodiac the story takes precedence.

“Zodiac is not my most visually complex film,” he says, “because it is difficult to find a visual grammar that supports the idea that these are real people and that this really happened. If I did magic crane shots and I had cameras going through floors, or in through windows, then people are going to think it’s a movie. If I can keep it simple then my chances are better to get an audience to respect that we didn’t hyperbolise.”

Even so, he still creates a taut, muted and paranoiac world. Whether it is the dimly lit, musty bar where the journalists congregate, or the scene of the second murder, carried out in glaring sunshine in front of an idyllic rural vista, each sequence is drenched in atmosphere. It is a feat made all the more impressive by the fact that Fincher shot Zodiac on digital cameras, which traditionally do not render images as luxuriously as film.

“I don’t think that an audience is going to be able to tell the difference between a film shot digitally or on film,” says Fincher. “Technology moves on, and it’s going to be vital for my next film.”

That film is The Curious Case of Benjamin Button, an adaptation of the F. Scott Fitzgerald short story about a man who is born as a 70-year-old and ages in reverse, getting younger with each passing year. Film-mak-ers have long yearned to render the tale on screen, but technology has lagged behind their ambition. Until now.

“Once you may have had different actors playing him at different stages of his life, but here I can use Brad Pitt throughout, just putting his head on different people’s bodies. I really think that it will work. At least I hope it does; if not, it’s going to look bloody awful!”

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