20 Things You Didn't Know About Zodiac

20. Three Actors Played The Zodiac Killer Throughout The Film

Given that the Zodiac Killer hasn't been caught, it was important for the film to keep his identity ambiguous, and so Fincher ultimately decided to cast three different actors to play him during his various appearances, with each actor having their faces obscured at all times.

This was a simple but effective trick to ensure the audience remained as mystified by Zodiac as the real investigators were at the time, unable to assign a concrete identity to the killer.

Had Fincher instead cast an even vaguely familiar character actor as Zodiac, much of that chilly slipperiness would've been lost. Instead, without a discernible face for audiences to fix their eyes on, he remains an eerily shadowy figure.