Roman 'Puggo' Thomas, of Central Village, St Catherine, was found guilty of triple murder and could face the death penalty.
A Home Circuit Court jury retired for more than three hours yesterday and found him guilty.
Supreme Court Judge Paulette Williams has put off sentencing until March 6.
The Crown, represented by Crown Counsel Karen Seymour-Johnson, led evidence that on February 22, 2004, Thomas went to Watson Grove, Portmore, St Catherine and shot dead two men and a woman.
The sole witness who was in the Witness Protection Programme only knew the deceased by their aliases. Photographs were shown to him in court and he identified the deceased as the persons who he saw Thomas firing shots at on February 22, 2004.
One of the deceased was a Rastafarian whose correct name was Paul Henry but he was known as 'Matlock'. The others were Anthony 'Teo' Hunter and his girlfriend Cleta Atkinson.