I would like to know if he was on any medications. It's no excuse but it's also something we as a nation don't seem to want to look into. He sounded kind of down in those two posts.
His parents haven't stepped forward yet, (poor people) so we don't know what's up with them either.
From the moment he was summoned to their house, he just went Crazy knowing what they were going to tell him. That's why he took the guns. He couldn't have been thinking clearly about the consequences of blowing them away. He wasn't thinking at all.
He killed the parents, instead of himself.
sw