You forgot to post the part where he trots out SPLC's Potok as he connects the shooter to Ayn Rand's theme of the individual against the State, but dishonestly ignores the contradicting themes of the myriad of other popular books listed as his favorites, such as the Communist Manifesto and Mein Kampf.
“[T]here is a thread through the material... seeing the government as an enemy. The books you mentioned, there is a theme that runs through all of them, in particular the Ayn Rand book: the idea of the individual against the State. There are ideas like the idea of the only legitimate currency being backed by gold and silver. That's a core idea of the radical right in this country. […] It's not surprising than an individual like this acts out.”