20 Things You Didn't Know About Zodiac
16. The Filmmakers Spent 18 Months Tirelessly Researching The Case
While it's no secret David Fincher is one of cinema's all-time great perfectionists, he went the extra mile even for his own high standards when prepping Zodiac.
Alongside screenwriter James Vanderbilt and producer Bradley J. Fischer, Fincher spent 18 months researching the murders, interviewing witnesses, family members, investigators, suspects, and even hiring a P.I. to track down Mike Mageau, one of the two survivors of a confirmed Zodiac attack.
Beyond that, Fincher was insistent that the characters' clothes - especially those of the victims - were identical to what was actually worn in reality, even using forensic evidence as a reference.
While filming the grisly Lake Berryessa murder on location, Fincher even had extra trees flown there due to the landscape changing significantly since 1969.
Finally, Fincher also had Nancy Slover, the 911 operator who actually took the original Zodiac call, to help decide upon the voice used for Zodiac's calls throughout the film.