Details are still emerging about the recent shooting at Umpqua College in Roseburg, Oregon, including writings left behind by the gunman, Christopher Harper-Mercer.

Law enforcement revealed that the 26-year-old shooter reportedly wrote about not having a girlfriend while also feeling like he was the only sane person among everyone around him. Officials revealed that he wrote something to the effect of, “Other people think I’m crazy, but I’m not. I’m the sane one.”

A source that read the manifesto revealed to People magazine that it read, “Many will ask how can they have prevented this? You can’t. You could never give me what I wanted. Nothing could have stopped it.”

Survivor Anastasia Boylan, 18, told Good Morning America that “He sounded really deranged because he said he’d been waiting to do that [kill people] for a really long time,” and added that “He laughed after he shot the teacher.”

Boylan also revealed that Harper-Mercer singled out Matthew Downing, 18, and telling him that he was the “lucky one” whose life was spared to give the shooter’s manifesto to authorities. The survivor added that students from her class were asked to state their religion before being shot.

“He had us get up one by one and asked us what our religions were. The shooter said that [one of the first victims] would only feel the pain for a couple of seconds and that he would be with God soon, and then he shot him.”

President Obama has restated his call for stricter gun laws in light of the shooting, as it was revealed that he would visit Roseburg on Friday.