Robert Lyle Knepper is an American actor. He is best known for his role as Theodore "T-Bag" Bagwell in the FOX drama series Prison Break from 2005 to 2009 and has also appeared in films such as Good Night, and Good Luck, Hitman, Jack Reacher: Never Go Back, and Transporter 3. Knepper joined the cast of Heroes in 2009 for its final season as Samuel Sulliva, and he played Sid Rothman in the neo-noir television series Mob City in 2013. For Disney, he played Nicholas Lang in the 1988 Touchstone Pictures film D.O.A..