No, it's nothing to do with the amount of guns owned but who has them. There are thousands of multiple gun owners that aren't killing anyone. The ones that are are getting their hands on them, like this one, where the gun wasn't locked away. He had a mission. To get back at those who bullied him, and that could have also been his grandparents. The legal gun his grandpa owned was available, and if it wasn't, this wouldn't have happened, unless he "found" another gun, which isn't hard to do, especially in a country where illegal guns are floating around. Mental illness not addressed will appear in one of two ways. Self destruction or against others, as this one did with both. More guns available to the public does mean more gun crimes of course, as they'll eventually fall into the wrong hands, which is why laws need to be adjusted.