A Virginia inmate who pleaded guilty to killing his cellmate and vowed to kill again unless he was sentenced to death has rescinded his plea and will go to trial next year.

Robert Gleason Jr. pleaded not guilty Tuesday and asked for a jury trial for the May 2009 death of Harvey Watson Jr.

Gleason was serving life in prison for killing a man in 2007 when Watson was killed. He fired his attorneys and pleaded guilty in May, saying he would kill again if not given the death penalty.

Prosecutors say Gleason killed another inmate, 26-year-old Aaron Cooper, last month.

In letters to The Associated Press, Gleason admitted strangling both inmates. He has not been charged in Cooper's death.

Gleason's trial will begin Feb. 21.