EXCLUSIVE: Veteran screen and stage actor Peter Weller has joined the cast of Showtime’s hit drama Dexter. He will appear in eight of the 12 episodes from the show’s upcoming fifth season, playing a troubled Miami Metro police officer who gets caught up in an internal affairs investigation. Production on season 5 is currently underway for a Sept. 26 premiere. Weller who recently guest-starred on Fringe, is probably best known for his title roles in the RoboCop movie franchise and in The Adventures of Buckaroo Banzai Across the 8th Dimension. His co-star in that 1984 sci-fi comedy? John Lithgow, who had a major role on Dexter last season that earned him a Golden Globe and an Emmy nom. Dexter received a total of 8 Emmy nominations last week, including best drama series and best lead actor in a drama series for Michael C. Hall. Weller is with APA and managers Craig Baumgarten and Bill Treusch.