There are no details as who Knepper is playing in the revivial, which will air on Showtime, but Deadline believes it will be a recurring role. Knepper is best known for playing Theodore "T-Bag" Bagwell in Fox's Prison Break. More recently, Knepper appeared in Arrow and The Flash as William Tockman/Clock King.
Not much is known about the revival's plot or even its cast. Officially, all we know is that Kyle MacLachlan will reprise his role as Dale Cooper and that Amanda Seyfried has a recurring role, though, who she is playing is a mysterious as well. However, Deadline believes David Patrick Kelly will be back as Jerry Home and rumor has it, Richard Beymer is coming back to play Jerry's brother Benjamin.
The Twin Peaks revival is currently filming and is now expected to make its debut sometime in 2017.