Const. Lee Chipperfield, the officer who fired nine shots at Paul Boyd, including the final shot to the head, didn't face criminal charges and wasn't disciplined.
But investigators didn't have the advantage of a bystander's video. That only came to light recently.
The new information prompted the B.C. government to ask the Alberta Serious Incident Response Team to re-open the investigation.
"I can't see how this will result in another conclusion, although I'd very much like to see Const. Chipperfield removed from the police force. I feel his conduct was not worthy of a police officer," David Boyd, Paul's father, said in an interview.
The B.C. Civil Liberties Association said the video proves Boyd wasn't a threat as the already-injured man crawled on his hands and knees across the street towards police.
Police had been called to the busy intersection in August 2007 after a 911 call and were confronted by Boyd, who witnesses said was swinging a bike chain.
Boyd had bipolar disorder and had not taken his medication that day.
The dark and shaky video shows 49 seconds of a confrontation where an officer reaches down and picks up the chain, and a groaning Boyd crawls towards officers who are in a shooting stance.
The camera jerks upward just before the final shot is fired.
Chipperfield testified at a coroner's inquest that he believed Boyd was still armed when he fired the fatal shot to the man's head.
The inquest heard that eight of the nine shots he fired hit Boyd over an 80-second period.
The Crown ruled against laying charges against the officer and the B.C. Police Complaint commissioner ruled Chipperfield was suffering from what is called "inattentional blindness," a condition where his intense emotional reaction combined with his restricted focus impaired his abilities to see the whole scenario.
Boyd wasn't surprised by what he saw on the video, after piecing the event together from witnesses at the coroners' inquest.
"The fact that it fit together with what I had in my mind was really remarkable. I imagined Paul crawling, I didn't imagine he would have so much vitality left, he seemed to be crawling very rapidly.
"But the fact that he was crawling was disturbing, that they would still be feeling that a man crawling towards them was a threat."
Danny Antonucci, a colleague and friend of Paul Boyd, said he hopes the video will finally lead to some answers and some accountability.
"I still, after five years, do not understand this. And I don't understand why there hasn't been some sort of justice brought upon this," said Antonucci, an animator who worked alongside Boyd until the day he was killed.
"That video is absolutely heartbreaking. It's heartbreaking. To see Paul crawling on his hands and knees and to have some ignorant person shoot a gun into his head, I mean, it's just insane.
"And I'm in the business where I'm supposed to be making people laugh all day long."
Three police officers told the inquest they still felt threatened by Boyd after he was shot and crawling towards the cops.
But the video shows a police officer next to Boyd bending down and picking up the chain before the final, deadly, shot was fired.
Antonucci said in the years since his friend died, he's lost all faith in the justice system and said Boyd's case — and the emergence of a key bystander video — reminds him of the death of Robert Dziekanski at Vancouver's airport.
In that case, RCMP maintained they shot an armed, delirious man before a witness video showed Dziekanski wielded only a stapler before he was zapped by a police Taser within seconds of officers arriving on the scene.
"With all the situations that have happened, the fellow at the airport, of police deaths of people dying within the police realms," said Antonucci. "It's just a really scary scenario."
The Crown ruled out charges against the officer in Boyd's case and the B.C. Police Complaint Commission found too many conflicting versions to proceed with disciplinary action against Chipperfield.
But the new video prompted Attorney General Shirley Bond to have the case sent to the Alberta Serious Incident Response Team, an independent agency that handles cases of serious injury or death involving Alberta officers.
Clifton Purvis, the director of the Alberta team, said his entire Calgary team of nine members is working on the investigation.
He agreed the video had the potential to shore up witness accounts and discount others.
He said the investigation will likely take months.
Antonucci said he has never believed his friend's death was properly probed and said he is glad there is another effort to get answers.
He noted he and his co-workers knew of Boyd's condition and knew how to handle him if he hadn't taken his medication.
"Why couldn't the police?"