The materials were found after Everson attended a counseling session and allegedly made threats against other people.
Officials believe they averted a possible tragedy.
"I will simply say I am absolutely confident that something could have happened with what he had at his disposal," said CSUN Police Chief Anne Glavin.
Everson is being held in a mental health facility at the Twin Towers Correctional Facility. He's scheduled to return to court Jan. 28.