The Alberta Serious Incident Response Team has found the shooting of a Calgary man in January 2016 was lawful and justified.

Police were called to a home in the 1000 block of 78 Avenue N.W. at 4:40 p.m. on January 24, 2016, for reports of shots being fired into the street, originating from somewhere inside.

The bullets ended up hitting the side of a Calgary Transit bus and narrowly missed the driver.

The home was blocked off and police engaged in a standoff with the man inside.

The situation ended when the man came out of a rear door and engaged officers with a handgun.

The 53-year-old man was killed with a single gunshot wound to the head.

Susan D. Hughson, ASIRT executive director, says that without the actions of the CPS, the potential for civilians or police officers being seriously injured or killed was extremely high.

“”Every shot that man fired increased the risk of serious injury.”

The tactical decision to stop the man from firing was made when police were left with no other alternative but to fire on him.

Hughson says this is, in her opinion, the closest time Calgary has ever had an active shooter situation.

"There were lots of people in the community at the time. The shot that was fired into the bus, whether he intended to fire into the bus or not, came dangerously close to hitting that bus driver.  He was very lucky that day. There were officers throughout that neighbourhood that he was firing his revolver and they could hear shots whizzing by their heads and seeing them strike the houses beside them."

She said the officers used great restraint but it was clear that it was not going to go the way they wanted.

"There is just so much that the police cannot control that it is just a highly dangerous situation," Hughson said. "He crossed the line he couldn't cross."

Hughson said that the police officers did not commence firing on the suspectuntil he had emerged from this home and began shooting at them.

"The plan that had been developed very clearly in indicated that if he retreated back into the house, they would let him go and they would not pursue."

The suspect was identified as David McQueen, described by area residents as a very kind man who’d go out of his way to help people.

Patricia Norris, a home care worker who helped McQueen, said that he struggled with mental illness. “Unfortunately, he was very depressed and very delusional.”

McQueen was injured in 1994, when he was left paralyzed after he dove into Sikome Lake. The incident left him confined to a wheelchair.

He tried to sue the city and the province and lost but continued to complain on Facebook about a lack of medical support for his condition.

Hughson said she has spoken with the family members of McQueen and expressed her condolences towards them.

"I did speak to one of his sons yesterday to inform him of the outcome of the investigation. It's heartbreaking."

She said the conversation went very well and she provided him with as many answers to the questions they had as she could.