There was a special and poignant honour bestowed Thursday for one of the police officers who died in the mass shooting in Fredericton last summer.

The family of Const. Robb Costello has given a life-saving gift to a local mall where Costello once saved a life.

Fourteen-year-old Zach Steeves put the new automated external defibrillator, or AED, in its case at Regent Mall.

He was there when Costello, his late stepfather, used another of the mall's defibrillators to save a stranger's life.

"Seeing him go over to this person who was dying at the time, and save their life -- it was power and precision," Steeves said.

Costello died as a result of the Aug. 10, 2018 shooting on the city's north side.

But on Aug. 25, 2015, Costello activated a defibrillator and saved the life of Larry Sandford, who had a near-fatal arrhythmia.

"I don't remember any of this as it happened," Sandford said. "On the way to the jewelry store, I fell down and hit the ground."

Sandford says he credits a security guard and Costello for responding -- and for saving his life.

For Costello's family, it was only fitting that the mall be the recipient of the new AED.

The donation comes from the Atlantic 9-1-1 ride. The organization has given two other devices to families of local fallen first responders, including Const. Sara Burns, who also died in the 2018 shooting.

Sandford says he was heartbroken to hear of the shooting.

"It actually touched me right to my soul that he'd been killed in the line of duty," Sandford said. "And I recognize that a man who had saved my life, who had allowed me to carry on walking the streets of this city, had passed away."

Costello's widow isn't surprised how he acted that day.

"He responded to this incident at the mall the same way he would have had he been on patrol and gotten a call on his radio," said Jackie McLean.

With a commemorative plaque, and a new life-saving device, Costello's legacy of helping people and saving lives will continue on.

With files from CTV Atlantic's Jessica Ng.