While a student at Chattanooga, he became a member of the Delta Theta chapter of the Sigma Chi fraternity.
After a brief enlistment with the United States Army Medical Corps, he entered private practice until 1983.
That year Governor Lamar Alexander appointed him to the bench, and Barker eventually served on the Tennessee Supreme Court.
Barker, along with his fellow justices, was subject to a retention election in August 2006 under the provisions of the "Tennessee Plan" and was overwhelmingly reelected to an eight-year term.
[citation needed] Barker was married and had three children, and was a member of the First Presbyterian Church of Chattanooga.