Acclaimed Flop: It flopped at the box office and received no Oscar nominations, but most critics gave it positive reviews and very quickly picked up steam as one of the best-regarded films of Fincher's career.
Dawson Casting: Mike Mageau is played at age 19 is played by 25-year old Lee Norris, and at age 41 is played by 31-year old Jimmi Simpson. The two actors are only 6 years apart despite playing the character separated by 22 years.
Even though Jake Gyllenhaal was Fincher's first choice for the role of Robert Graysmith, had Gyllenhaal turned the role down, Fincher's second choice was Orlando Bloom.
Originally, Gary Oldman was to play Melvin Belli but "he went to a lot of trouble, they had appliances, but just physically it wasn't going to work, he just didn't have the girth", Robert Graysmith said.