(NEWSER– Aaron Alexis, who is now believed to have been the only shooter behind yesterday's Navy Yard massacre, suffered from serious mental issues, including paranoia and a sleep disorder, and had been hearing voices in his head, sources tell the AP. Alexis also suffered from PTSD, his father told investigators, according to theNew York Times. He had been disturbed by the 9/11 attacks, his father explained; he was an "active participant" in rescue efforts in New York.

Alexis had been getting treatment for these issues from the Veterans Administration, but the Navy hadn't declared him mentally unfit. Had it done so, he'd have lost his security clearance. Other details trickling out include:

  • Alexis was kicked out of the Navy Reserve for a "pattern of misbehavior," one Navy official tells the Washington Post. He was given a "general discharge," which is seen as a reprimand.

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