Yep.
I have tremendous empathy for the parent (or other relative) of a mentally disturbed individual. Been there. Current law makes it darn near impossible to get treatment without the consent of the patient.
The question is whether she knew he was mentally unstable. If she did, she should absolutely have removed firearms (or any other weapon) from his reach.
That’s what our family did. Just common sense.
Same. In a very similar situation here. There are legal rights and then there are common sense/moral responsibilities.