Christopher Alguire, 28, stopped to help when he saw the Greyhound bus pulled over near Portage la Prairie, Man. (CBC)A truck driver who scrambled to help Greyhound passengers who had witnessed a stabbing and decapitation in July aboard a bus on the Trans-Canada Highway near Portage la Prairie, Man., is criticizing the RCMP's response.

Speaking publicly for the first time, Christopher Alguire, a long-distance trucker, said in an interview with CBC News that he noticed trouble on the bus as he drove through the area west of Winnipeg on the evening of July 31, so he pulled over to see if he could help.

"You see somebody on the side of the highway, pulled over erratically in such a manner, you instantly know something is wrong, and it's just the nature of my personality, I'm always willing to stop and give a helping hand," he said from Morden, Man., Tuesday morning.

Bus passengers told him that a passenger on the bus had attacked and stabbed a man, later identified as 22-year-old Tim McLean, a Winnipeg man who had been working at a carnival in Edmonton. Both McLean and his attacker were still on the bus.

Guarded bus door

Alguire grabbed a snipe, a metre-long bar used to help secure loads on his truck, and immediately ran to the bus and assisted the bus driver, who was holding the vehicle's door closed.

"Basically I [got] everybody to a safe spot. They were pretty upset already, so I had them directed to the back of the bus, behind the cargo trailer, so they could no longer see what was happening inside," he said.

RCMP officers investigate the killing of Tim McLean, 22, onboard a Greyhound bus in Manitoba on July 30. (John Woods/Canadian Press)He told other passengers who wanted to help or were worried about their safety where they could find other tools in his truck to protect themselves, in case the suspect tried to exit the vehicle. Later, the bus driver boarded the bus, and Alguire followed.

"The bus driver had stepped onto the bus and then I had to get onto the bus and step in front of him … because I took it into my own hands to protect all the people as best I could. That was my mission," he said.

He saw McLean's head being severed, then retreated off the bus and helped again hold the door shut until RCMP arrived.

Critical of RCMP response

Alguire said he is disturbed and angry that police waited so long before arresting the suspect, allowing more time for indignities to be done to McLean's body.

"One of the things I did not like is when I did have the passengers in behind the bus … they could not see nothing. And I positioned them there for that reason," he said.

"Now after the decapitation and stuff, the one RCMP officer had the people move to the front of the second bus, so now they could stand on the highway, turn around and look into the monster windshields of this Greyhound bus to where the assailant and victim were.

"And now this ... character, he has an audience and it's like he's provoked to show them his work, and now all these innocent people have to see what this man has been doing."

McLean's mother told media last week that RCMP should have stormed the bus to save her son's body from further atrocities.

Alguire agreed.

"I told the cops a few different times to shoot him, because he has no reason in this world to live anymore," he said.

Alguire acknowledges that people hail his actions as heroic, but he shrugs off the distinction.

"I've had mentors in my life that have always shown me the way of battle, and it just came naturally to me," he said.

"We've got a very close family, we love each other very much and we'd do anything for each other to keep each other safe. It's a dangerous world out here and you know, we got to be prepared at all times to protect our loved ones."

Vince Weiguang Li, 40, is charged with second-degree murder in McLean's death. He has been ordered to undergo a psychiatric assessment to determine if he's fit to stand trial.