Knepper was born in Fremont, Ohio, and raised in Maumee, Ohio, the son of Pat Deck and Donald Knepper, a veterinarian. He was interested in acting from an early age, due to his mother's involvement as a props-handler at a community theater, and after graduating from Maumee High School in 1977, he attended Northwestern University. During this time, Knepper also obtained professional roles in plays in Chicago. Nearing the completion of his degree, Knepper quit Northwestern and went to New York City, where he continued to work in theater.
Career
Although Knepper never intended to work in film and television projects, he began his television and film career in 1986 with The Paper Chase and That's Life!. Knepper went on to have larger roles in such films as Wild Thing, Young Guns II, When the Bough Breaks and Everyone Says I Love You. He made appearances on such television series as The Twilight Zone, ', ER and Law & Order. In 2005, after a recurring role on the HBO series Carnivàle, Knepper was cast in his best-known role, as Theodore "T-Bag" Bagwell in Prison Break. The series received positive reviews upon release, and "T-Bag" is often considered to be one of the greatest television villains of all time. During his time on Prison Break, Knepper also starred in a number of films; Good Night, and Good Luck, Hitman, Transporter 3 and The Day the Earth Stood Still. After Prison Break ended in 2009, Knepper was cast as villain Samuel Sullivan in the fourth and final season of Heroes. After this, he went on to have a recurring role in Stargate Universe in 2010. He guest-starred on season six of Criminal Minds as Rhett Walden, a serial killer. The same year he played the titular character in the film adaptation of Burning Daylight. In addition, Knepper appeared as Honolulu Police Internal Affairs detective Rex Coughlin in two episodes of Hawaii Five-O. In 2011, he reprised his role of T-Bag in one episode of the A&E series Breakout Kings. The next year he played Frank Sinatra in My Way, a biopic of Claude François, a French pop singer who wrote the song "Comme d'habitude", the original version of Sinatra's song "My Way". Knepper was cast in the 2013 television series Cult as Roger Reeves, an actor playing Billy Grimm on a show called Cult. The show was canceled after only one season. The same year, he appeared in R.I.P.D., ' and guest starred on the television series The Blacklist. At the end of 2013, the TNT series Mob City premiered, in which Knepper played gangster Sid Rothman. In 2014, Knepper guest starred in episodes of Arrow and The Flash as master hacker and time-and-motion study expert William Tockman / Clock King. Since 2015, Knepper has had a recurring role on iZombie as Angus McDonough, the estranged and abusive father of Blaine DeBeers. It was announced in July 2017 that Knepper would be promoted to the show's main cast for season 4. Knepper was cast in the reboot of David Lynch's Twin Peaks as gangster Rodney Mitchum. He later voiced the audiobook adaptation for the tie-in epistolary novel of the show called The Secret History of Twin Peaks.
Personal life
Knepper has a son, Benjamin Peter, from his first marriage.
Sexual assault allegations
On November 8, 2017, costume designer Susan Bertram accused Knepper of sexual assault on the set of the film Gas Food Lodging in 1991. Knepper denied the allegations in a since-deleted Instagram post. On February 28, 2018, Bertram's lawyers announced she was filing a defamation lawsuit against Knepper in the wake of his denials, seeking damages in a jury trial. Four additional allegations taking place between 1983 and 2013 were made against Knepper on December 5. All were denied by Knepper. Late in 2017, in the wake of these accusations, The CW conducted an internal inquiry. Finding no evidence of misconduct transpiring on the set, it was announced he would be remaining on the series. On January 12, 2018, it was announced that the studio had conducted a second investigation. CW president Mark Pedowitz stated, "Again, the investigation related to the set and his behavior on the set. They found no wrongdoing on the set." Pedowitz elaborated that Knepper had signed on for a single season and that his exit from the series had already been planned.
