I watched the movie couple of times but
i forgot who was the zodiac killer.
can you write it down with a spoiler quote? thanks
In reality, there was no single 'Zodiac Killer'. It is a myth, an urban legend, not unlike the case of Jack the Ripper. There was, of course, a string of murders in San Fran during the late-60s and early-70s, but not a lot tying them all together to one single 'Zodiac Killer'.
But in the film (as well as in real life), the main suspect is Arthur Leigh Allen.