Correction: Navy Yard Shooting story

WASHINGTON — 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

Associated Press

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.

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.

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.

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.

He also "stated that the individuals are using 'some sort of microwave machine' to send vibrations through the ceiling, penetrating his body so he cannot fall asleep."

Later that day, Newport police alerted the Rhode Island naval station and sent a copy of the police report, Newport police Lt. William Fitzgerald said Tuesday.

Alexis came to the Washington area about two weeks later and had been staying at hotels. On Saturday, two days before the attack, he went to a Virginia gun store about 15 miles from the Navy Yard.

He rented a rifle, bought bullets and took target practice at Sharpshooters Small Arms Range, the store's attorney Michael Slocum said. Alexis then bought a shotgun and 24 shells, according to Slocum.

The FBI said during Monday's attack Alexis was armed with a shotgun. Officials said he also took a handgun from a law officer.

A recording of an emergency transmission released Tuesday captures the tense moments after the shooting. A firefighter tells a dispatcher as sirens wail in the background, "We have active shooter on the fourth floor. I'll get you update on the building location, with several victims down. At this time I've requested the mass casualty bus."

In addition to those killed at the Navy Yard attack, eight people were hurt, including three who were shot and wounded, authorities said. Those three were a police officer and two female civilians. They were all expected to survive.

And his bouts of insubordination, disorderly conduct and being absent from work without authorization prompted the Navy to grant him an early — but honorable — discharge in 2011 after nearly four years as a full-time reservist, authorities said.

"He wasn't a stellar sailor," Navy spokesman Rear Adm. John Kirby told CNN. "We know that."

But he said the offenses weren't "grievously serious" and the punishments for them are fairly mild. Kirby said there was a proposal to "administratively separate him from the Navy," with less than an honorable discharge, but Alexis volunteered to leave early and received an honorable discharge.

"Looking at his offenses while he was in the Navy, that the offenses while he was in uniform, uh, none of those give you an indication that he was capable of this sort of brutal, vicious violence," Kirby said.

As for Alexis' security clearance, Kirby said he received one around the time he enlisted. "It was good for 10 years. And it was at the secret level. So the security clearance was valid when he left the Navy in 2011. And because he wasn't out of work very long before he took this next job, the security clearance went with him."

The Experts' CEO, Thomas Hoshko, said that Alexis had "no personal issues," and he confirmed that Alexis had been granted a "secret" clearance by the Defense Security Service five years ago.

Alexis' clearance — lower than "top secret" — doesn't need to be renewed for 10 years. Still, the company said it hired outside vendors twice to check Alexis' criminal history.

Said Hoshko: Alexis' background check "came back clear."