For most people when they think of Hunter S Thompson they think of Johnny Depp from Fear and Loathing in Las Vegas. For some they think of his wild, gonzo journalist ways. But I bet very few think of him as a crusader for justice.

And yet that’s just what he was in his final case – which is now becoming a movie. Prisoner of Denver was a Vanity Fair article written by Thompson with that magazine’s contributing editor Mark Seal, and the rights to it have been picked up by the Motion Picture Corporation of America. The article was part of Thompson’s crusade to free a woman he thought had been shafted by the law.

Says The Hollywood Reporter:

Prisoner” focused on the injustice and abuse of Colorado’s legal system that saw 21-year-old Lisl Auman charged with murder when the crime occurred while she was in the back of a patrol car, already in police custody. She was handed a life sentence with no possibility of parole.

While behind bars, she began a correspondence with Thompson. His unrelenting grass-roots activism — which included enlisting celebrity pals including Johnny Depp, Jack Nicholson, Benicio Del Toro and Woody Harrelson — and the Vanity Fair piece helped overturn Auman’s sentence in 2005.

Thompson killed himself before the sentence was overturned, so he never saw the end of the road.

The producers are going to writers right now, and they’re looking for a movie that’s a cross between Fear and Loathing and All the President’s Men. The Reporter raises an interesting question: could Depp come back for a third go-round as Thompson (see the upcoming Rum Diaries for number two) as well as playing himself? This would be a fitting project for Thompson’s good friend to take on, even if Depp’s a little young to play the gonzo journalist in his later years.