Steven Williams (born January 7, 1949) is an American actor in films and television. He is known for his roles as Captain Adam Fuller on 21 Jump Street, Lt. Jefferson Burnett on The Equalizer, Det. August Brooks on L.A. Heat, X on The X-Files, Russell "Linc" Lincoln in Linc's, and Rufus Turner in Supernatural. Throughout his career, Williams has appeared in numerous films, including The Blues Brothers (1980), Twilight Zone: The Movie (1983), Jason Goes to Hell: The Final Friday (1993), 22 Jump Street (2014), It (2017), and Birds of Prey (2020). He has been nominated for a Screen Actors Guild Award and one NAACP Image Award Williams was born in Memphis, Tennessee, and was predominantly reared in Chicago. His parents were divorced, and he was raised at separate times by his father in Michigan, his mother in Chicago and by his maternal grandparents in Millington, Tennessee. In Chicago, he attended Wendell Phillips High School. After graduating, he matriculated at the General Motors Institute, an automaker's engineering school. Williams later worked as a postal carrier, salesman, and model. He was drafted into the United States Army, serving in the 2nd Armored Division, stationed in Gelnhausen, Germany and became Divisional Champion with the United States Army Boxing Team, Middleweight Division. Upon receiving an Honorable Discharge from the United States Army, Williams worked for the United States Postal Service as a mailman. After delivering the mail in subzero temperatures, he went to work in Chicago's garment district as an apparel salesman. Williams made his acting debut in the 1975 film Cooley High.  He appeared in musical comedy The Blues Brothers (1980) as Trooper Mount, and played Lt. Jefferson Burnett on the CBS drama series The Equalizer in 1985. He portrayed renegade Capt. David Nester in the 1985 film Missing in Action 2: The Beginning, He landed the role of Captain Adam Fuller, a senior police officer supervising younger cops, on Fox Network's TV series 21 Jump Street in 1987. Williams replaced Frederic Forrest, who played a similar character, early in the series. He continued playing the character until the series ended in 1991. While acting in the series, Williams played Lieutenant Gallagher in Under the Gun (1988), which featured Vanessa Williams in the cast. Following his stint on 21 Jump Street, Williams portrayed the title character in The 100 Lives of Black Jack Savage. He played the role of Det. August Brooks on the TNT series L.A. Heat in 1996. He recurred as X on the Fox hit science fiction series The X-Files.  He earned a Screen Actors Guild nomination for Outstanding Performance by an Ensemble in a Drama Series in 1997 for his work as X.