(AP) — 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 Associated Press didn't speak with Harper about the online postings; a knock on her door went unanswered Tuesday, and her phone's voicemail box was full. Investigators have recovered 14 firearms — six found at Umpqua Community College, where the killings occurred, and eight at the apartment. 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. 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.