A *very* long but extremely engrossing film.

Rating: 9/10 (18 May 2018)

The real-life Zodiac murders that plagued the Bay Area in the late 1960s make for great drama in this, one of David Finchers' finest achievements as a director. The "Zodiac", as he dubs himself, delights in taunting the cops and mailing letters to them, while obviously enjoying being one step ahead of them most of the time.
However, the film doesn't really focus on him. Some of the murders are re-enacted, but this story focuses on the people who hunted the killer down, in particular Dave Toschi (Mark Ruffalo), who inspired the Steve McQueen performance in "Bullitt", and Bill Armstrong (Anthony Edwards). It's only in the last hour or so of "Zodiac" that it fully becomes the story of Robert Graysmith (Jake Gyllenhaal), a cartoonist for the San Francisco Chronicle who becomes obsessed with playing amateur detective, and keeping the case alive when everybody else has seemingly given up.
Although this would seem to be unwieldy at two hours and 37 minutes (two hours and 43 minutes if you're watching the directors' cut), it remains utterly absorbing throughout, making the most of the police-procedural aspect of the storytelling. The material IS rather fascinating, remaining one of the most fascinating unsolved cases of all time.
Towards the end, the narrative does become awfully familiar, as Graysmith alienates his wife (Chloe Sevigny, who is unfortunately not given anything really interesting to do) and ropes his kids into helping him work the clues. It's no surprise when she takes the kids and hauls ass out of there.
Yet, as portrayed by Gyllenhaal, a very fine actor indeed, the mans' earnestness does make him a reasonably likeable character. And "Zodiac" also offers impressive showcases for a rich variety of supporting actors: Robert Downey, Jr., Brian Cox, Elias Koteas, John Carroll Lynch (who plays the late Arthur Leigh Allen, the person who remained the prime suspect for a long time), John Getz, John Terry, Candy Clark, Dermot Mulroney, Donal Logue, Philip Baker Hall, Zach Grenier, John Mahon, Adam Goldberg, James Le Gros, Charles Fleischer, and Clea DuVall. The scene in Fleischers' basement late in the film is brilliantly creepy.
Fincher and company took themselves very seriously in making this film, and it shows. They were supposedly real sticklers for detail, using Graysmiths' books and actual case files as their source material. They also refrain from making this all about Zodiac, not bothering to re-enact those murders which had no witnesses or survivors. The documentary-style approach ultimately works wonders; there's very little room for melodrama, or overstatement. Set largely in the 1970s, emulation of that era is well done, including a score by veteran composer David Shire and a vintage opening Paramount logo sequence.
While this viewer would hesitate to come right out and call this "perfect", he will say that it does come pretty close, entertaining and informing its audience and never making the film seem as long as it is.
Nine out of 10.