I dunno, to me that’s a little arbitrary. Killing someone outside of self defense is just murder. So in your view is a school shooter worse than a mall shooter? Would you say murdering a handicapped stranger in a wheelchair who cannot defend themselves is worse than killing a healthy young adult stranger?
To me it’s all just killing innocent people, their age or health is irrelevant. The law makes no difference as far as I’m aware, it’s all murder. I don’t see any point in differentiating murders based on the traits of the victims.