You can tell by Chief Blair's original reaction to the video he thinks that there was no reason for this kid to be shot and killed by this officer.
Police by and large in North America are out of control. They are not peace officers or guardians of both the law and society, but bullies hiding behind a badge and a gun. Poorly trained and supervised, more interested in writing tickets or catching you on your cell phone than protecting society and serving the public good. They have more in common with the crooks they chase than you and I.
You can see from the video that no other officer had their gun drawn until he started shooting, there was a female officer there who was closer to the front steps and both of her hands were on her gun belt.
Toronto is not a war zone, police do not put their lives on the line everyday they put on their uniforms. They are in less danger than the guy from the CAA who tows disabled cars off the highway. He does take his life in his hands every time he hooks up a car.
When COPS used to walk a beat and go into bars to toss drunks into the Paddy Wagon, they knew how to handle themselves and some punk with a knife or a broken bottle. Not now, different mind set and both physically and mentally unable to handle a situation without drawing a gun. And as we see in this case over reacting.
In this age of cell phone cameras, we the public get to see just how heroic some of our police, ambulance and fire fighters are, and how pathetic. They're human and make mistakes, but their mistakes cost lives.
The police need better and repeated training in close quarter combat using both lethal and non lethal methods in bringing a situation under control. Issue better body armour to provide protection against edged weapons as most of us don't have guns. Batons, shotguns with bean bags, flash bang grenades, hell even old fashioned stink bombs.
As for the street cars, I believe there are switches on the outside to open and close the doors keeping a perp inside. Also in the future it should be policy to kill power to the overhead wires so the car can move.
Finally every officer should be equipped with full audio and video equipment so we can see what happened from the perspective of all of the officers there. Possibly something like google glasses to make sure that there can be no cover ups.