HALIFAX -- A Halifax man who murdered a pizza delivery man over a longtime grudge has been sentenced to life in prison with no chance of parole for 15 years.

In his decision Wednesday, Nova Scotia Supreme Court Justice James Chipman called it "a cold-blooded murder of a completely defenceless man who was in the course of his employment."

Randy Riley was convicted of second-degree murder last April in the death of 27-year-old Chad Smith.

Smith was killed on the evening of Oct. 23, 2010, while delivering a pepperoni pizza and orange pop in Dartmouth.

He was found with what appeared to be a gunshot wound to the upper right side of his body and a red pizza delivery bag nearby.

The trial heard Riley had nursed a grudge against Smith because the victim had allegedly beaten Riley years before.

The judge called it "a truly senseless act" and said the entire extended Smith family has been devastated by the murder.

"He was tragically struck down at age 27 without a chance to see his daughters grow up," Chipman told the court.

"Two young girls have lost their father, family members have lost a loved one, a mother is without her life partner and parents have lost a son."

The conviction carries an automatic life sentence, though Riley will be eligible to apply for parole 15 years after the day of his arrest in July 2013.

However, the judge made it clear that Riley may be subject to a lifetime sentence of imprisonment.

"He may never be released on parole," Chipman said.

"If he is released, it will only be on his satisfactory compliance with whatever conditions the parole board places on him to ensure his respect for a peaceful and safe society."

Still, he said Riley "has prospects for rehabilitation" and that he has completed a number of programs and is currently enrolled in distance sociology courses through Mount St. Vincent University.