"Zodiac" starts out with the potential to be an exciting movie. After the first 15 minutes, you are left with nothing but the minutia of a curious newspaper cartoonist with the hobby of figuring out who may be the serial killer. Unfortunately, the film WALLLOWS in this minutia because it drags on for another 2 1/2 hours after anything that resembles excitement/suspense happens. Mark Ruffalo and Jake Gyllenhaal are respectable in their extremely tedious and boring roles but Robert Downey Jr. makes both of them seem amateurish by comparison. If the film were edited down by an hour and a half, it would be worth renting. Otherwise, it seems like a dull "America's Most Wanted" re-enactment.