I haven't had a chance to read the entire article yet, but I'm not surprised based upon what CNN was reporting after the Parkland shooting.
They kept referring to it as the 90 something or perhaps even 100-plus something school shooting of the year. I was thinking to myself ' man, I know I can be behind the times on some things but can't believe I've missed roughly 100 school shootings in the past month-and-a-half."
So I went and looked at their reference article. It included such wonderful items as:
1. Police were called to the school football field one night with someone reporting having heard shots fired. Investigation showed no evidence of any type of shooting, the police cleared the scene.
Yep, that's a school shooting
2.. at 3 a.m. on a Saturday when no respecting schools kid was anywhere near the school, drug dealer number one pulled into the parking lot and then shot drug dealer number to in order to steal his stuff.
Yep, that's a school shooting.
3. One afternoon disgruntled spouse number one drove to the school where disgruntled spouse number two worked, and then did a murder-suicide.
Yep, that's a school shooting.
I think in the end there was maybe one or two other actual shootings where someone showed up at the school and attempted to, did, manage to shoot students. The remainder were all Bs like the above but it sure made the numbers look good.