Depending where you are, in Southern Ontario, it's very likely to see weapons in the highschool, whether they're being sold or there to cause harm is a very different story.
I went to high school with 4 buses of kids off the local native reserves in the area, and I know city kids, black, white, or otherwise were pretty much ganged up on in a mob mentality, to the point that in my first month there was a situation where a black kid got in a fight with a native, and all the natives circled him while he fought with the other, shoving him back in, one with a pitbull harassing him.
Everyone else had to step up and put a stop to it, so we had a bit of a race riot and a lock down to classrooms. Though outside media labeled it simply gang violence, it was a very contrasted skintone on one side.
We had to keep friends from the reserve so that nobody messed with us, and of these people, it might not have been handguns, but they could bring anything they wanted in off the buses.
Hunting Knives $10, Machete, $15, Ammunition $10 for shotguns and rifles, I never saw anyone bring in an actual gun, however it still was retardedly dangerous that these were being sold from lockers in the high school literally throwing distance from my front door in a rather calm residential neighbourhood.
Last year, my best friend's 15 year old brother had his face rearranged by 2 kids with brass knuckles for no reason except walking home from school and being white, there isn't much "Black vs. White" Violence here, but Lebanese & Native Reserves seem to harbor hate on anybody otherwise walking alone.