Shooter Told Cops Enemies Harassed Him With Microwaves Also, Aaron Alexis bought a shotgun on Sunday, legally By John Johnson, Newser Staff Posted Sep 17, 2013 4:07 PM CDT 126 comments Comments This undated photo provided by Kristi Suthamtewakul shows Aaron Alexis. (AP Photo/Courtesy of Kristi Suthamtewakul) (Newser) – The evidence is stacking up that Navy Yard shooter Aaron Alexis had serious mental health problems. The latest details to emerge show that just last month, Alexis called police to his hotel room in Newport, Rhode Island, to complain that three people were following him and trying to keep him awake "by talking to him and sending vibrations to his body" with a microwave machine, according to a police report picked up by the New York Times. Alexis said he could hear their voices through the ceiling and the floor of his room, and he feared that a man with whom he had argued with at an airport had sent the trio to harass him. Police then contacted the local naval base, where Alexis had been working as an IT contractor. The Department of Veterans Affairs was aware of Alexis' problems and had treated him, reports the Washington Post, though the exact nature of the treatment wasn't clear. Alexis' mental issues and previous gun trouble didn't affect his ability to buy a weapon, however. He bought a shotgun and ammunition on Sunday from the Sharpshooters Small Arms Range in northern Virginia, reports CNN. The store's attorney says Alexis came up clean on a background check. Alexis also practiced at the store's shooting range.