20 Things You Didn't Know About American Psycho
18. Willem Dafoe Was Asked To Act Each Scene Three Different Ways
Willem Dafoe appears in a supporting capacity as private detective Donald Kimball, who becomes suspicious of Bateman's murderous activities over the course of the film but isn't ever able to prove them correct.
Director Harron asked Dafoe to play his scenes three different ways in alternate takes: firstly, he'd play Kimball as though he knew that Bateman killed Paul Allen (Jared Leto), secondly as totally unaware, and thirdly as unsure either way.
Harron then alternated between these takes while editing Dafoe's scenes, creating an intentionally inconsistent portrayal of the character throughout the film in order to keep the audience unsure of what Kimball really made of Bateman.
Given the already dynamic energy Dafoe brings to just about any movie role, it was a smart choice that paid off splendidly.