In the line with the post about the controversial doc below, I ran into this while digging through mons, I mean "mounds" of screen. Maybe theis is where it all went south for Charlie:

The Guinea Pig films

"The Japanese Guinea Pig films are designed to look like authentic snuff films; the video is grainy and unsteady, as if recorded by amateurs. In the late 1980s, the Guinea Pig films were one of the inspirations for Japanese serial killer Tsutomu Miyazaki's murders of preschool girls. The most infamous Guinea Pig film is Guinea Pig: Flower of Flesh and Blood, in which a woman, apparently drugged, is shown chained to a bed as a man in a samurai costume slowly kills her through torture and dismemberment. The film is so realistic that the FBI, acting on a tip from actor Charlie Sheen (who saw the video at a party), investigated the film, believing it to be a real murder. In an attempt to offset further criminal investigations and ease the public mind, the producers released The Making of Guinea Pig, a film made up of behind-the-scenes footage." (wikipedia)

If I was a Pellicano-like Sleuth, I would investigate who threw the party, what drugs were the celebrants gobbling, etc. Alas, such a life has not been permitted me. I'll let more ambitious readers take this one on. Give Charlie a few props, though. He tried to do the right thing even as his soul was being irreparably scarred.