Because it's non-fiction, it's forgiven for being unfocused

Rating: Null/10 (5 March 2007)

My favorite part of Zodiac was watching the facts about the case, accumulated by cops, reporters, and an intrepid cartoonist, slowly coalesce into a clear picture of the killer. When it's finally apparent who did it, over a decade later, it's satisfying. It's just a shame the script itself is so scattered. No where is this more apparent then in the Gyllenhaal character.
Gyllenhaal plays a cartoonist who becomes obsessed with finding the identity of the Zodiac. No clues are given as to why this straight laced Eagle Scout would shun family and job to take such a dark journey. Fincher goes to extremes to show what a loving, single father he is at first. But later, he is holed up in his apartment, surrounded by the detritus of his investigation, looking like a mad hermit. His wife comes to check up on him, but he refuses to give up the chase and resume his role as father and husband. It's not clear why this change has taken place. Ruffalo's cop pursues the killer because it's his job. It's the job of Paul Avery (Downey, Jr.) as well. But Gyllenhaal's motives are unclear.
There are whole passages of time where main characters drop out sight. Sometimes it's Gyllenhaal's movie, sometimes Ruffalo's. When the film follows Ruffalo, along side partner Anthony Edwards, the movie works best. They're continually vexed by the technological limitations of their time, yet they somehow keep plodding through. Unlike Gyllenhaal's cartoonist, they have motives for what they do. They're cops. They solve crimes.
And Paul Avery's descent into alcoholism and houseboat isolation? No reasons given. Hey, that's the way it happened in real life, so why try to give the character motives.
If this was fiction, the vague character arcs wouldn't fly, and this film would be shorter and tighter. But under the true crime rubric, the fuzzy writing and slavish adherence to the book are forgiven by many. But when the smoke clears, this is just an over-long, under-motivated paean to a certain place and time. Evocative? Yes. Good storytelling? No way.