Walter Sergei Skinner is an Assistant Director in the Federal Bureau of Investigation after having served as a Marine in the United States Marine Corps when he was aged eighteen. One of the FBI sections under his jurisdiction was the X-Files Unit. (TXF: "Tooms", et al.) He was assigned to the FBI between at least the mid-1980s until 2008. (TXF: "Tooms", The X-Files: I Want to Believe) For many years, he had a wife named Sharon. (TXF: "Avatar")