“Or having the parents being forced and responsible for locking up guns?”
Whoever provided the shooter with the guns she used has to bear some of the responsibility.
Car salesmen, look out. Or the glassmakers who provided the glass that contained the whiskey that the drunk driver consumed before running over grannie.
The responsibility falls on the perp only. Unless someone else instigated or was part of the planning of the perps actions.
Other sources are saying it was a 38 year old woman.