You have the first post that mentions mother. Wonder how long before father is mentioned?
Likely the father isn’t in the picture at all. But it wouldn’t make much difference in that family it appears. Dysfunctional an understatement.
However at 18 and despite the lack of a decent upbringing the guy knew what was right and wrong....
Bottom line - shot his grandmother in the face-shot 19 kids to death 2 teachers and injured 17 others.
People can go on and on about mental health, unlocked schools, bad parenting, etc etc. But in our society as it is today this will continue to happen for things are just going to get worse.
He’s dead. End of story.