Eh, you could be a decent parent and your child might still turn out fucked up for whatever reason
I find the whole conversation about his parents needing to report him for concerning behaviour sort of amusing and maybe a bit unrealistic. Let's assume he was actually a bit of a concern at home because he threatened to kill his family, who the fuck are they meant to call after that's sorted? Can't really call the police and say "my child is fucked in the head and I'm concerned he might shoot up something in the future" because what are they meant to do when he's not actually threatening to shoot anyone up?
Seen people elsewhere say that the people interacting with him online and watching his music videos should have done the same. Again, sort of the same issue, no?
Lets say they search the house and find some weird plans or stuff that suggests he may be planning to shoot something up. Great, but then there's the whole legal system part of it to deal with - how much planning do you need for it to be prosecuted? Is someone who is very right wing suddenly get more concern placed on them? I also can't really see that sort of policy/law going down very well, people would probably say it's an overreaction
It's pretty clear that whatever system was in place to stop him buying a gun after he flagged himself as a concern somehow failed