Gill was armed with a Beretta Cx4 Storm carbine, a Glock 9mm handgun, and a 14-inch Norinco HP9-1 shotgun. He fired sixty shots, ten of which were fired outside the school. With the exception of five shots from his pistol, including the one to kill himself, all the shots came from the carbine....
All of the weapons Gill had in his possession can be legally purchased and owned by a civilian in Canada. As manufactured by Beretta, the Cx4 Storm is a semi-automatic, pistol-calibre centre-fire carbine with a 422mm barrel length. As such, it is categorized as "restricted" in Canada. Any person with a Possession and Acquisition Licence (PAL) with restricted-class privileges may purchase this weapon, subject to the approval of the Chief Firearms Officer of the respective province. Kimveer Gill did in fact have a restricted-class PAL and his weapons were registered with the Canadian gun registry. Therefore, he owned the weapons legally under Canadian law though he broke the law by not obtaining an Authorization To Transport (ATT) to bring the firearm to the school and by discharging it outside of an approved range.
The above should not be possible. What would you suggest as a way to prevent it? Or do you just think it can't be prevented?
What did he have to do to buy the weapons legally?
In a situation like that I don't think there is anything you can do short of banning private ownership of firearms (which doesn't stop them from being brought in illegally) or perhaps catching some kind of red flag mental health issue this guy may have had.
The man in your example did everything that was legally required to purchase a firearm. Some of the firearms he used were restricted meaning it was illegal for him to use it anywhere other than an approved shooting range- obviously that didn't stop him.