Disturbing information is coming out about the influence of the occult on Oregon shooter Chris Harper-Mercer who gunned down nine people at a rural community college last week.

People Magazine is reporting on unsettling new evidence about the character and state-of-mind of Harper-Mercer in the months leading up to the October 1 massacre at Umpqua Community College.

In a bizarre manifesto allegedly found on his computer, Harper-Mercer spoke about how he hoped to be “welcomed in hell and embraced by the devil” and revealed his desire to “serve darkness”

An unnamed source familiar with the investigation told PEOPLE. “”The guy did this strictly for satanic purposes,” He did it to become a god in hell. He wants to be evil. That is his goal, to serve Satan.”

The source added: “The only thing I’ve seen that came close to this type of devotion to Satan is the ‘Night Stalker’ in Los Angeles,” referring to Richard Ramirez, a serial killer who murdered at least 13 people over the course of two years in the 1980s.

People who went to school with Harper-Mercer said he had a macabre habit of doodling skulls, bones and coffins on his notebooks.

“He had this notebook with all these pictures of skulls that he had traced, and they had like fire in their eyes and looked really weird,’ Gabriel Rivera, 25, told PEOPLE. “Chris didn’t talk to anyone. He was mad that he was at the school and didn’t like anyone. He didn’t have a lot of friends, I can’t even think of anyone who he ever was friends with.’”

Harper-Mercer also lamented his loner status in life, writing in the manifesto: “I am going to die friendless, girlfriendless, and a virgin.” After listing his favorite movies, colors, musicians and songs, he ended the document with pentagrams.

Investigators say there is some evidence that Harper-Mercer suffered from Asperger’s Syndrome, the same condition that plagued Sandy Hook Elementary School killer Adam Lanza. Authorities say the man’s mother, Laurel Mercer, wrote on a medical forum that she had “an Asperberger’s kid” and told neighbors her son had “mental issues.”

Satan’s tactic is to prey upon the vulnerable, such as those who are infirmed or otherwise weak in mind, body and/or soul. Even though not all illnesses are due to the devil, the evil one is well-known for going after those persons who are not in a state of grace and who are suffering a malady of some kind that renders them unable to defend themselves.