Scribe William Monahan ("The Departed," "Kingdom of Heaven") will pen a fact-based thriller for Paramount Pictures says Variety.

Based on a Playboy article by Hillel Levin, the story follows Jim Keene, the son of a police chief who was arrested for dealing drugs.

As an alternative to a 10 years-to-life sentence, he was allowed to go undercover at a maximum security hospital for the criminally insane.

The he cozied up to a man authorities believed murdered 25 young women and tried to get him to divulge the whereabouts of his victims.

Only the prison psychiatrist knew Keene was undercover, plus a visiting "girlfriend" who was actually an FBI agent.

Monahan also wrote the upcoming thrillers "Body of Lies", "Nothing in the World" and recently signed to adapt a remake of hit Korean film "The Chaser".