I wonder if this was the trigger,did he want Independence or did he think his mom was trying to push him out into the world.
http://www.nypost.com/p/news/local/mother_devoted_her_life_to_him_then_PADqWsNSMfrx3KnO6JnlrI
she had spent months going over his options for engineering schools, Hanoman said.
They had recently gone to many different colleges looking for the right program for Adam, and the right living situation, he said.
He wanted to study engineering. Nancy was going to move wherever he was going to go. Not to live with him but to live near him.
They were looking at schools in Seattle and one of the Carolinas. It was his goal to be independent.
I don't see independence as a trigger for the planned violence that followed his mother's murder. It still makes no sense that he violently travelled to an unfamiliar school, blasted his way into it, confronted and murdered the adults and then executed the little ones. I'm still having a rather difficult time believing Adam acted alone.
JMO