(Update August 2014: I actually changed my review of Dr. Keppel's book in which this film was adapted from a 4 to a 5 a while back. It might be the best serial book ever.)
From what I remember, it was Ted Bundy who coined the name "Riverman" for the killer of prostitutes in the Seattle area during the 70s and 80s. I guess the name derived from the fact that the then unknown post-Bundy killer liked to dump his victims in the Green River.
Not a bad name given by not such a good guy, but Cary Elwes is fantastic here as the supposedly nastiest serial killer in US history: Ted Bundy. Sure, there have been those that have killed more people, such as Gary Ridgeway -- the actual Riverman himself -- but few that have killed in such a violent fashion such as Bundy. But while Bundy was indeed bad, Mr. Elwes is not, never devolving into caricature as he seems to invade the true psyche of Bundy in this film. I gave the film "Silence of the Lambs" five stars, but I believe that Mr. Elwes was given more realistic dialog here than Anthony Hopkins in that award-winning film, and this lesser known actor took advantage of it.
I read the book "The Riverman: Ted Bundy and I Hunt for the Green River Killer" quite awhile ago, and I gave it four stars. In reality, I probably should have gone five (I already did as I wrote above) since it is easily the best true crime book that I've read to date, surely better than "Stranger Beside Me" by Ann Rule. Dr. Robert Keppel did an excellent job describing the things that I'm looking for in the genre: what was going on from an historical perspective at the time, what were the motivations of the killer, and how did the detectives catch the perpetrator. Not only that, but Dr. Keppel seems to be not only objective -- after all, he gave even an evil guy such as Bundy some kudos for helping catching Ridgeway -- but Dr. Keppel also seems to not be the "gatekeeper" type; he is willing to share his knowledge with others. Note how Dr. Keppel spent so much of his life in a professor role, as evidence.
A very good movie that was adapted from an excellent book. A pretty big recommendation by me.