Their reason for banning guns was the Nova Scotia shooting. A guy who only owned illegally obtained guns, had a fake police uniform and car, had family that were RCMP and knew, and soon before the shooting received a duffel bag worth of cash the same way informants and under cover cops do. RCMP handled it horribly, took long to react, and shot at a building holding civilians.

This is the reason they used to ban legal guns (while reducing charges for illegal guns used in crime because of the race of people who use them)