Upton was accused of shooting Manoloules along with his nephew Christopher Manoloules in Hyannis in 2009, according to the Cape Cod Times.
During the trial prosecutors argued Upton’s brother-in-law, Treefon Manoloules, agreed to pay him $165,000 to kill Aris Manoloules.
Upton’s defense attorney claimed he was a victim of circumstance and that Christopher and Treefon Manoloules were responsible for the shooting.
Treefon Manoloules was found not guilty of charges in connection with the killing in October 2011.
Upton's sentencing is Friday. A first degree murder conviction would mean a sentence of life in prison without parole.