A Toronto police officer fired nine shots in 13 seconds at 18-year-old Sammy Yatim, who was holding a knife in an empty streetcar early Saturday morning.
The unidentified police officer yelled several times at Yatim, "Drop your knife!" and then fires the shots.
A Taser was later used on Yatim, notes the Daily Mail.
It's not clear what suddenly prompted the officer to repeatedly shoot Yatim.
Ontario's Special Investigations Unit (SIU), which is reviewing the shooting, confirmed that Yatim died from multiple gunshot wounds.
"I recognize there is a need for answers," said Toronto Police Chief Bill Blair, who is also conducting an investigation.
"If you look at it on its face value at this point, it's not hard to come to the conclusion that excessive force was used," said Mark Mendelson, a former Toronto police detective.
Hundreds of Canadians marched tonight to protest for justice for Yatim and an end to police violence.
According to the Toronto Police Association president Mike McCormack, who leads the police union, the police officer who shot and killed Yatim is "devastated."