The picture was a passion project for Director Sean Penn and Jack Nicholson. Unfortunately, the screenplay was turned down by every major studio in Hollywood. Producer Elie Samaha, and his studio Franchise Pictures, who specialized in picking up screenplays in turnaround, quickly pounced on the material and signed up Penn and Nicholson for a reduced fee. The pair agreed, as long as Penn could have complete creative and casting control.
The child murders depicted in the film were loosely based on actual cases that had been worked by Detective Joe Depczynski, the film's Technical Advisor. However, the cases were not thought to be the work of a single killer, as the film depicted, nor did the real detective come to the same end that Detective Jerry Black did.
The name of the boat, from which Jerry Black (Jack Nicholson) fishes, is called "Sweet Lorraine", a name of an old evergreen song written by Mitchell Parish and Cliff Burwell. Lorraine is the name of Nicholson's sister and his daughter (with Rebecca Brousard).
There are several references to Denmark in the movie. Ginny's grandmother is called Anna-Lise Larsen (a common Danish name), at least two of H.C. Andersen's fairy tales are mentioned in the movie, and Jerry and Lori drink Carlsberg Beer.
The trivia item below may give away important plot points.
According to Tom Noonan, additional scenes were supposed to be filmed that explain that Jackson was not the killer. But the production company had just experienced the failure of Battlefield Earth (2000) and demanded that the film finish under budget. The production was rushed, and a few scenes were left unfilmed.