Devontay Hackett will spend at least 12 years behind bars for the 2014 prom night murder of 18-year-old Brandon Volpi.

Hackett was sentenced to life in prison on Monday, with no chance of parole for 12 years.

"It doesn't really matter if he got 100 years or 10 years, it doesn't change the fact that I lost my son," says Volpi's father Danny.

"We have clossure now and we can move on with our lives."

A jury convicted Hackett of second-degree murder in February for stabbing Volpi to death outside Les Suites hotel on their prom night in June 2014.

Hackett had no reaction when the sentence was announced in court. He only looked back briefly at family and friends before leaving the courtroom. But Justice Charles Hackland had strong words for the 21-year-old.

"This was a cowardly, brutal attack on an unarmed man," Hackland said in court.

"What should've been a night of celebration, turned into a tragedy for a completely blameless young man."

Hackland had the option of allowing Hackett to be eligible for parole after 10 years, but upped it to 12 because Hackett never took responsibility for his actions.