Dominic Purcell has signed on to play Wesley Snipes' vampire nemesis in New Line Cinema's upcoming "Blade: Trinity." Purcell is the latest addition to a cast that includes Kris Kristofferson, Jessica Biel and Ryan Reynolds. The third installment of the Marvel Comics-based franchise is being written and directed by David Goyer. "Trinity" is being produced by Goyer, Snipes, Lynn Harris and Peter Frankfurt. Emmerich and New Line production exec Cale Boyter are overseeing the project, with production scheduled to start this month in Vancouver. Purcell has appeared in such films as "Mission: Impossible II" and "Equilibrium" as well on the small screen in the Fox television series "John Doe." Purcell is repped by Endeavor and Untitled Entertainment.