Well, I =think= the original idea was that Raúl's character was an ordinary guy suddenly possessed by the evil spirit of the dead serial killer. That was the impression I got from the original character study breakdown.
But that was back in February and scripts and stories can change dramatically as the move forward and especially after they get to filming. So who knows what he'll be now. Serial killer version 3.2.8, maybe....
The IMDb site says 2009 for a release date, and they tend to put out a lot of horror in January and February, so maybe as soon as that. That'll give them a good six months to do post, assuming they wrap filming on schedule.
NYTIMES, FRI July 11: By JULIE BOSMAN; Compiled by JACQUES STEINBERG Published: July 11, 2008 Raúl Esparza, the Tony-nominated star of “The Homecoming,” will join the cast of “Speed-the-Plow,” the acerbic David Mamet play returning to Broadway in October. Mr. Esparza has signed on to play the role of Charlie Fox, a Hollywood producer, opposite Jeremy Piven, who will play the production executive Bobby Gould. The role of Karen, the ditsy secretary played by Madonna in the original 1988 production, has yet to be cast.