One of three men charged in the Sept. 9, 2010, murder of 21-year-old Chance LeCroy in Hixson pleaded guilty on Monday and was given a 20-year prison sentence to serve at 100 percent.
Billy Bob Partin pleaded guilty to second-degree murder in the appearance before Criminal Court Judge Barry Steelman.
Ronald Lee Pittman earlier gave testimony against Partin and Patrick Carmody. The trial for Carmody was moved to August.
Prosecutor Neal Pinkston earlier said the testimony of Pittman was key, saying the state has not found any physical evidence against any of the defendants.
Pittman testified that he held a gun on Lecroy's roommate in the living room, while in a back bedroom Carmody first fired a shot at Lecroy and then struggled with him and then Partin finished him off with a second gunshot.
He said he later regretted taking part in the robbery and decided to tell the full story.