PORTLAND, Oregon -- The mother of a gunman who killed nine people and himself at an Oregon community college allowed her troubled son to have guns and acknowledged in online posts that he struggled with autism, but she didn't seem to know he was potentially violent.

The online writings by Laurel Harper date from a year ago to nine years ago and offer fresh insight into the gunman, 26-year-old Christopher Harper-Mercer, and his relationship with his mother.

Harper and son shared an apartment outside Roseburg, and had moved from California several years ago.

Investigators have recovered 14 firearms - six found at Umpqua Community College, where the killings occurred, and eight at the apartment. Neighbors of the mother and son in California, where they lived before moving to Oregon in 2013, have said Harper-Mercer and his mother would go target shooting together.

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Investigators say Harper-Mercer's mother has told them the son was struggling with some mental health issues.

In her online postings, Laurel Harper talked about her love of guns and her son's emotional troubles but there are no hints of worry that he could become violent.

"I keep two full mags in my Glock case. And the ARs & AKs all have loaded mags. No one will be 'dropping' by my house uninvited without acknowledgement," reads a 3-year-old posting.

She was referring to a Glock handgun and to military-style rifles. A Glock and a military-style rifle were among the weapons seized after the Roseburg shooting rampage.

Laurel Harper wrote in another posting: "I love the long guns & I have an AK-47 en route." She complained about gun-control efforts in "lame states."

She posted several times that her son had Asperger's syndrome, a mild form of autism.

One posting reads: "He's no babbling idiot nor is his life worthless. He's very intelligent and is working on a career in filmmaking."

She wrote that she read aloud to her unborn son from Donald Trump's "The Art of The Deal."

Investigators have not yet said whether they suspect a motive in last Thursday's shooting rampage, where Harper-Mercer killed eight students and a teacher before killing himself.

Harper-Mercer's social media profiles suggested he was fascinated by the Irish Republican Army and frustrated by traditional organized religion.

Posts on an online blog that appears to belong to Mercer reference multiple shootings, including one in Virginia in August that left a television news reporter and cameraman dead. The last upload on the blog was made when a documentary about the Newtown shooting was posted.

In one post on the blog about Vester Flanagan, the man who killed the reporter and cameraman in Virginia, Mercer apparently wrote, "I have noticed that so many people like [Flanagan] are alone and unknown, yet when they spill a little blood, the whole world knows who they are. A man who was known by no one, is now known by everyone. His face splashed across every screen, his name across the lips of every person on the planet, all in the course of one day. Seems like the more people you kill, the more you're in the limelight."

While living in California, Harper-Mercer graduated from a learning center for students with learning disabilities and emotional problems. His parents divorced when he was a teenager and he lived with his mother.

He Harper-Mercer brought at least six guns and five ammunition magazines when he went to the campus the morning of the shooting.

Harper-Mercer's father, Ian Mercer, still lives in California. Over the weekend he said he had no idea his son had any guns.