The Herald Examiner location in downtown Los Angeles, where the police station and biker bar scenes were shot, caught fire on the last day of shooting. The cast and crew had to be evacuated.
The film is based on the incident known as either the Laurel Canyon Murders or the Wonderland Murder Case that actually happened in the Hollywood Hills section of Los Angeles in July, 1981.
Matt Dillon was the first choice to play John Holmes but dropped out to direct his movie City of Ghosts (2002).
When the film played the Toronto Film Festival, one of the promotional items handed out was a ruler that was 13 1/2 inches long.
The actual police investigation tape of the crime scene is included as a special feature in the DVD release of the film.
During the production Val Kilmer became so immersed in the making of the film that he began a photography project which has blossomed into a behind-the-scenes pictorial book which he chose not to release.
Val Kilmer was allowed to grow out his hair during the filming of Mindhunters (2004) in order to secure his participation.
The film was only an 18 day shoot and is based on the true story of the infamous "Four on the Floor" aka "Wonderland" murders.
Christina Applegate grew up near the site of the Wonderland murders and remembers seeing the bloody mattresses on the street, which led to her agreeing to take a relatively small role in the film.
Lions Gate was not sure how to market this film due to the significant drug content, intermittent porn reference and the brutal violence depicted. The content in question remained, but the film then was only given a limited theatrical release in the domestic market for awards consideration.
In the movie, Val Kilmer (as John Holmes) wears a chain around his neck that holds a ring. The ring is was the actual wedding band that John Holmes gave his wife, Sharon, when they got married in 1965. Sharon loaned it to Val to give him good luck on the movie. When the movie was over, Sharon then gave the ring to Dawn Schiller.
In the climactic murder scene from the John Holmes perspective, there are several single-frame shots of the actual corpses from the 1981 LAPD crime scene photographs.
In the real life story, John did not call Eddie Nash after the robbery at his place. Rather, John was spotted by some of Nash's associates in Hollywood. They noticed that John was wearing some of the jewelry that was stolen in the robbery and told Nash about it. John was then accosted by two gunmen who then took him to Nash for questioning.
The movie did not portray that, while John was being beaten up at Nash's house, Liberace's lover, Scott Thorson, was present. It was his testimony that eventually led to the indictment of Eddie Nash by federal authorities.
Both Josh Lucas and Val Kilmer spent the night in the actual Wonderland house on the anniversary of the murders.