Since everything is so politicized (it only took about 10 seconds for the liberals to start banging the drum for more gun control), anything connected to the teaching profession has to be downplayed.
I don’t think that the mother has to be connected to the school. But it’s likely that the shooter is connected somehow. If his mother didn’t work or volunteer there, maybe it’s where he went to school as a kid. Or maybe it’s just the closest school to where he lives now, or one that he drives past frequently. Who knows what motivates a crazy person?
What is odd is that so many hours later .. we still don’t know.