Reznik

Reznik means "butcher" in Czech language, which could hint at his identity as a killer. The name Trevor Reznik is derived from Trent Reznor, the founder and primary creative force behind the industrial rock band Nine Inch Nails, and the original script had NIN lyrics on the first page.[3] Other NIN tributes include the reversed N on the movie poster and early press articles describing Reznik as experiencing a "downward spiral".
However, the strongest influence is the Russian novelist Fyodor Dostoyevsky. In the DVD commentary, Scott Kosar states that he was influenced by Dostoyevsky's The Double: A Petersburg Poem. The character Reznik is shown reading Dostoyevsky's The Idiot early in the film. When Reznik is riding the "Route 666" attraction, one of the faux movie marquees reads Crime and Punishment. Reznik's physical appearance draws a distinct parallel to Hans Holbein's Christ in his Tomb; a painting that heavily influenced, and is often mentioned, in the novel. Nicholas, the epileptic boy, may also have been a reference to the novel's protagonist, Prince Myshkin, or even a reference to Dostoyevsky himself, both of whom suffered from epilepsy.
Another character, named Ivan, is a possible reference to the character Ivan Karamazov, who is wracked with guilt, goes insane and has nightmares of the devil in Dostoyevsky's The Brothers Karamazov.
Reznik's relationship with the prostitute Stevie is reminiscent of the underground man's relationship with Liza in Notes from Underground. His behavior — paranoia, extreme suppressed guilt and finally turning himself in to the police — is also reminiscent of Rodion Raskolnikov, from Crime and Punishment.