"Suspect": I'm the Zodiac.
Inspector William Armstrong: And how did you kill your victims?
"Suspect": With a gun. No... with a hammer.
Dave Toschi: Hey, how do we know that this lead is real?
Inspector William Armstrong: It's very real. How do I know? Because I saw it on TV.
Paul Avery: Do you know more people die in the East Bay commute every three months than that idiot ever killed? He offed a few citizens, wrote a few letters, then faded into footnote... Not that I haven't been sitting here idly, waiting for you to drop by and reinvigorate my sense of purpose.
Robert Graysmith: Just because you can't prove it doesn't mean it isn't true.
Dave Toschi: Easy, Dirty Harry.
Robert Graysmith: I... I Need to know who he is. I... I need to stand there, I need to look him in the eye and I need to know that it's him.
Arthur Leigh Allen: Oh. "The Most Dangerous Game."
Inspector William Armstrong: What?
Arthur Leigh Allen: "The Most Dangerous Game." That's why you're here isn't it? It was my favorite book in high school. It's about this man who waits for these people to get shipwrecked on this island. Because he was tired of hunting animals, he hunted the people for the challenge.
Dave Toschi: And man is the most dangerous animal of all?
Arthur Leigh Allen: That's the whole point of the story.