The son of the wheelchair-bound man killed in an armed standoff with Calgary police on Sunday says his father was a dedicated dad, but had been suffering from extreme loneliness leading up to his death.

David McQueen, 53, was shot and killed by police after reports he fired shots into the street — hitting several homes and a city bus — in the Huntington Hills neighbourhood.

"He was an awesome dad," said Justin McQueen, 24, who was just three when his father suffered a spinal injury after diving into Calgary's Sikome Lake.

"He didn't act as though he had the accident. He played sports, he took us fishing," said McQueen.

But his disabilities and health issues began to impact his father's well-being, said McQueen — adding that all "hell broke loose" after the death of his service dog a couple of weeks before his death.

"It was his absolute best friend. It was his only best friend."

'He was suffering'

His father became increasingly frustrated with the government and provincial health-care system, saying he was not provided with proper home care. McQueen said signs of depression and hoarding were being ignored and went untreated.

David McQueen

David McQueen posted on Facebook about his beloved dog's death in January 2016, along with numerous, lengthy complaints about the health-care system, the federal and provincial governments, police, and his neighbours. (Facebook)

"He was suffering. He was pretty much left in that house and screaming for help and nobody would help him." 

Gun ownership and hunting were not family hobbies, and how his father acquired the firearm used Sunday remains a mystery to McQueen. 

He said he shared photos from his California vacation on the last visit with his father — a memory McQueen will always cherish.

Funeral arrangements for McQueen's dad are currently underway.