New details have emerged about Chris Harper-Mercer, the gunman who authorities say is responsible for the Umpqua Community College shooting in Oregon on Thursday.

The 26-year-old man appeared to be a loner who spent much of his time using Web forums. He shared the 2012 BBC documentary "Surviving Sandy Hook" on a Web forum days before the Umpqua College massacre, reports Yahoo! News.

On the Web forum, Harper-Mercer used the handle "Lithium_Love." In past posts, he expressed sympathy for Vester Flanagan, the former Virginia television reporter who shot and killed two of his former co-workers on live TV in August.

"People like him have nothing left to live for, and the only thing left to do is lash out at a society that has abandoned them," Harper-Mercer reportedly wrote in a blog post on Aug. 31. "His family described him as alone, no partner/lover."

Harper-Mercer went on to say that once people like him "spill a little blood, the whole world knows who they are. A man who was known by no one is now known by everyone," and added, "Seems the more people you kill, the more you're in the limelight."

Yahoo! News claims that on Tuesday, Harper-Mercer replied to a discussion thread on the forum that asked, "How many girlfriends you have had?"

"0," he wrote. "Never had anyone."

The day before the college shooting, a site user posted to the same thread, writing, "You must be saving yourself for someone special. In due time then..."

"Involuntarily so," Harper-Mercer wrote back.

Harper-Mercer's dislike for organized religion was voiced on social media and websites he used.

He used the screen name "IronCross45" for a spiritualpassions.com dating profile where he listed interests as the "internet, killing zombies, movies, music, reading."

He also chose "Not Religious, Not Religious, but Spiritual" to describe himself on the dating site. As for traits he desired in a partner, he wrote, "Pagan, Wiccan, Not Religious, but Spiritual."

According to the dating forum, Harper-Mercer had not visited on the site in more than three months.

Oregon Live reports that he was an outdoors and horror movie enthusiast who lived with his mother, a licensed nurse, two miles from the college. He relocated to Oregon from Los Angeles, California in 2013.

A Myspace profile belonging to the gunman shows a picture of him wearing a crewcut, eyeglasses and carrying a rifle. The page shows Mercer's name and contains images of masked gunmen and references to the Irish Republican Army (IRA).

Public records do not show a criminal history for Harper-Mercer.

Roseburg, Oregon authorities have not speculated why he killed nine people at Umpqua Community College before being fatally shot in a police shootout. He wounded seven other people, three of which were in critical condition Thursday evening.

Authorities reportedly have confiscated three handguns and a rifle that were used in Thursday's massacre.

The grandson of a woman who escaped injury but witnessed victims under attack in the campus classroom described what his grandmother saw in a Thursday afternoon Twitter message.

"The shooter was lining up people and asking if they were Christian," Bodhi Looney tweeted. "If they said yes, then they were shot in the head. If they said no, or didn't answer, they were shot in the legs."

It is not known if Harper-Mercer was enrolled at the college, but students in the classroom where the shooting took place have told police they did not recognize the gunman.