William Sadler is an American actor. He has been acting since the 1970s, first on television. The following decade, he started his film career with roles in Off Beat and Project X. In the 1990s, he had roles in Hard to Kill, Die Hard 2, Rush, and Freaked. He later played Heywood in The Shawshank Redemption, as well as William “Wild Bill” Overbeck in the film RocketMan. He went on to play Klaus Detterick in The Green Mile. On television, he became known for starring as Sheriff Jim Valenti in the television series Roswell. After this ended, he joined the main cast of the show Wonderfalls as Darrin Tyler. He later played Carlton Fog in the TV show Traveler. He then had recurring roles as Helmut Torben in Damages, Michael Higgins in Homeland, and Sam Milhoan in The Blacklist. As of 2017, he plays the role of Tony Teressi in the crime drama Power. This year, he played Michael Sheehan in the miniseries When They See Us.