Jake Gyllenhaal wears a Timex Model 84

In a fluorescent-lit San Francisco Chronicle newsroom, with a file box marked NIXON sitting on the desk between them, Robert Graysmith leans against a colleague's workstation holding a paper coffee cup while crime reporter Paul Avery talks. Jake Gyllenhaal plays Graysmith in David Fincher's Zodiac (2007), and the real Graysmith was exactly what the film shows: a political cartoonist at the Chronicle who grew obsessed with the unsolved Zodiac killings and eventually wrote the books the movie draws from. On his left wrist sits a modest gold-toned dress watch on a metal expanding bracelet, time-only, the kind of unshowy piece a salaried newspaper artist would actually own. The watch has been identified as a Timex Electric Model 84. The Model 84 is not a mechanical watch at all; it is one of Timex's electric watches, where a battery drives a balance wheel through a moving coil, a design Timex introduced in 1965. Its documented form matches what we see on Graysmith: a gold-finished cushion case with a steel back, a light gold dial with plain line markers enlarged into squares at twelve, three, six, and nine, all on a steel expanding band with a wide dark center. It is the watch of a man whose budget and ego both run small. Timex turns out to run all through the real case. Graysmith's own account notes that two of the Zodiac's victims, David Faraday and Paul Stine, wore Timex watches, and that the killer of Cheri Jo Bates left a broken Timex behind. There is even a second, very different timepiece in the film, worn by the prime suspect: Arthur Leigh Allen, played by John Carroll Lynch, wears a vintage Zodiac Sea Wolf dive watch, so a movie called Zodiac quite literally puts a Zodiac on the man the investigators most want to be guilty. The dial of Graysmith's Timex is too small to read on screen, so the exact model rests on the watch's shape and the published identification rather than on legible text, but the watch is plainly there on the correct wrist in the right scene, and it looks the part.