Yeah, I looked it up too, and there were many that fit that /technical/ definition of "mass shooting", but didn't fit the /colloquial/ definition of "mass shooting".
When you say mass shooting, the image it brings to mind for most people is a lone gunman/woman, or possibly two people, getting loaded up on guns and ammo, going into a crowded area full of innocent bystanders, and opening fire on any targets that catch their eye.
What most people /don't/ think of when they hear mass shooting are mothers who kill all their children and then commit, or attempt to commit, suicide. They also don't tend to think of gangland drivebys, and they especially don't think of criminals having shootouts with cops as "mass shootings".
Hell, at least one that was counted as a mass shooting could more technically be called a killing spree, as the guy changed locations between each death.
For that matter, it doesn't occur to most people that a mass shooting can occur without anybody dying.
It's all about the framing language used. People like to claim that 330 mass shootings makes the US the worst country for that stuff, but while it is a large number of shootings, the US is far from the worst on a /per capita/ basis. In fact, the US actually ranks number 66 on the list of countries that have had mass shootings on a per capita basis.
Norway, that bastion of progressiveness and equality that lefties love to point to, actually has the highest per capita mass shooting rate, more than double that of the US. Meaning that if Norway had the same population as America, their overall number of mass shootings would be in the ballpark of 700+.
And I don't deny that focusing on per capita is using framing just as much as focusing on overall numbers, and on language used (like calling a murder-suicide a mass shooting). That's the point, things are framed to fit the desired narrative, especially these days.
