Burrows’s review published on Letterboxd:
ZODIAC stands out from the pack of cinematic investigative procedurals because its central character is not one that is fleshed out by one of the several fantastic leads. Fincher's narrative hangs on the character development of the actual Zodiac investigation itself. The myth of the Zodiac killer is born in the opening scene with the first crime, matures as the story arc goes through its various rises and falls--regardless of which cop or journalist grabs the baton and takes the lead on the clue-chasing.
At first, it seems to be both a police and newspaper reporter effort. But then Robert Downey Jr.'s smug journalist and Mark Ruffalo's good-guy cop pass the torch back and forth a bit as the guys driving the investigation onward. Meanwhile, as the months go by with no major thrust in the Zodiac case, the high-public profile of the crimes and threats to public safety cause mini-frenzies
It's interesting to watch the film get heavier the further it goes. The sheer weight and the gnawing details of the case, which add up to everything except proper legal or investigative closure, wear down and defeat Ruffalo and Downey Jr. before Gyllenhaal, another obsessed writer takes on the case and rejuvenates the investigation, and the creepy legend that accompanies it.
The case is gripping. Fincher wisely follows the case more carefully than he follows the men on the case. The crimes were horrific and very intensely staged. The local chaos and media circus on the periphery is also fascinating depth to the story. And the cast is amazing--realistically worn down and frustrated professionally.
What is it with obsession? The dogged, OCD behaviour that disconnects people from rational decision-making capacities? ZODIAC fascinatingly looks at how three high-functioning, smart career men melt and wither (to different degrees) because they can't quite bring a puzzle to a close.
This may be Fincher's best film. Brilliant narrative and subtext, and super haunting. Not to mention its chilling 1970s earth-toned cinematography. This film, more than most horrors is one that makes you feel queasy and want to double-check under your bed before light-out.