Demarco Smith has been convicted of second-degree murder for the 2010 killing of Casey Downey at a house party in North Preston, N.S.
Justice Pat Duncan delivered the guilty verdict against 28-year-old Smith on Monday. Downey was 19 years old when he was stabbed at a party. He died of a single stab wound to the chest.
The conviction carries a mandatory sentence of life in prison.
The judge rejected Smith's argument that it was a case of self defence. Smith had testified that Downey lunged at him and essentially impaled himself on the knife Smith was holding.
"His overall assessment of the accused's testimony was that it was basically unreliable and wasn't a reasonable explanation of the facts that were presented before him," said Roland Levesque, the Crown attorney.
"Relying on the Crown's version of facts and especially, I believe, the autopsy results and the degree of violence that was used in the inflicting of the wound — I think he came to the only reasonable conclusion that it was an intentional act that was carried out."
'Stupid' argument over DJs speakers
The court heard the two men argued over speakers. Downey insisted Smith help the DJ carry out his equipment, the court heard.
Levesque called it "a minor, stupid argument."
"The overall facts and the circumstances that were presented to the judge and the accused's own version of events that he wasn't fearful or scared indicated clearly that he was just lying in wait for Mr. Downey," said Levesque.
Pam Downey, Casey Downey's mother, attended much of the trial. In November, she told the CBC the killing was senseless.
"It's been hell on earth, really," she said. "Every day, I cry every day, because I've lost my son."