WASHINGTON (AP) -- In some stories that moved Sept. 16 and Sept. 17 about the shootings at the Washington Navy Yard, The Associated Press erroneously reported that the gunman, Aaron Alexis, carried an AR-15. That information was based on federal law enforcement officials who were relying on initial descriptions from the scene and was included in official internal FBI reports summarizing the shooting. However, additional investigation by law enforcement concluded that Alexis carried a shotgun, took at least one handgun from an officer at the scene but did not have or use an AR-15.
A corrected version of one of the stories is below:
Gunman in Navy Yard rampage was hearing voices
Officials: Gunman in Navy Yard rampage that killed 13 had mental problems, heard voices
By ERIC TUCKER, JACK GILLUM and LOLITA C. BALDOR
WASHINGTON (AP) -- A month before he went on the shooting rampage that killed 12 people, Washington Navy Yard gunman Aaron Alexis complained to police in Rhode Island that people were talking to him through the walls and ceilings of his hotel rooms and sending microwave vibrations into his body to deprive him of sleep.
The account, contained in an Aug. 7 report from Newport, R.I., police, adds to the picture that has emerged of an agitated and erratic figure whose behavior and mental state had repeatedly come to authorities' attention but didn't seem to affect his security clearance.
Alexis, a 34-year-old information technology employee at a defense-related computer company, used a valid pass Monday to get into the Navy Yard and then killed 12 people before he was slain by police in a shootout that lasted more than a half-hour.
A day after the assault, the motive was still a mystery. U.S. law enforcement officials told The Associated Press that investigators had found no manifesto or other writings suggesting a political or religious motivation.
Alexis, a former Navy reservist, had been undergoing mental health treatment from the Department of Veterans Affairs since August but was not stripped of his security clearance, according to the law enforcement officials, who spoke on condition of anonymity because the criminal investigation was still going on.
He had been suffering from a host of serious mental problems, including paranoia and a sleep disorder, and had been hearing voices in his head, the officials said.
The assault is raising more questions about the adequacy of the background checks done on contract employees who hold security clearances -- an issue that came up recently with National Security Agency leaker Edward Snowden.
Navy Secretary Ray Mabus ordered two security reviews Tuesday of how well the Navy protects its bases and how accurately it screens its workers.
Similarly, President Barack Obama has ordered the White House budget office to examine security standards for government contractors and employees across federal agencies.
Mert Miller, associate director of Federal Investigative Services for the Office of Personnel Management, said in a statement that federal budget, personnel and intelligence officials were working to "review the oversight, nature and implementation of security and suitability standards for federal employees and contractors."
In general, he said, background security clearance investigations cover information about an individual's criminal history.
In addition, the House and Senate Veterans' Affairs Committees asked the VA for details about any treatment provided to Alexis.
At the U.S. Navy Memorial, in church and on the baseball field, the nation's capital paused to mourn the victims on Tuesday. Defense Secretary Chuck Hagel laid a wreath at the memorial's "Lone Sailor" statue as taps played.
Just a few blocks from the Navy Yard, the Washington Nationals were back to playing baseball after their Monday night game with the Atlanta Braves was postponed because of the shooting. The Nationals wore blue and gold Navy caps during warm-ups, and a moment of silence was held before the first pitch.
Those killed included: Michael Arnold, 59, a Navy veteran and avid pilot who was building a light airplane at home; Sylvia Frasier, 53, who worked in computer security; Frank Kohler, 50, a former Rotary Club president in Lexington Park, Md., who proudly reigned as "King Oyster" at the annual seafood festival; and marine engineer and naval architect Vishnu Pandit, 61, an Indian immigrant.
In the Newport, R.I., incident, Alexis told police he got into an argument with someone as he was getting on a flight from Virginia to Rhode Island, where he was working as a naval contractor, and he said the person sent three people to follow and harass him.
He said he heard voices talking to him through a wall while at one hotel, so he changed hotels twice, but the voices followed him, according to the report. He said he feared they might harm him.