Not wanting to trivialise a tragic incident. But there are so many of them that it is no longer shocking.
So ... this guy looks like a crazy shooter ought to.
I'd write this guy down as deranged without even bothering with a trial.
We already know that a shooting of this type will not yield changes to US gun laws, so no point trotting out the obviously correct argument that easy access to weapons causes the problems America cannot fix.
And this is why the United States won't survive. It's constitutional structure disqualifies evolutionary change.