About the only thing good is this was a warning (which will go unheeded) which could have been much worse; only 2 died and another shot when this could have been a bloodbath, and this 17 year old jerk never got to become a cop, which would have been a future nightmare.
Self defense - some are saying now
This is why I asked in my post - what happened before he shot?
He went looking for a chance to use his rifle. He used it.
He was carrying it illegally and his mother should be charged, too.
He had a record for using his firearm while under the influence - and underage for that, of course, too.
Sounds like the makings of a career criminal. We're lucky he only killed the number he killed.
And somehow, he managed not to get shot by the police. Go figure.