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, Rhode Island, 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 also apparently managed to exploit seams in the nation's patchwork of complicated gun laws designed to keep weapons out of the hands of dangerous people. He was able to buy a shotgun in Virginia with out-of-state identification, even though that would have prevented him from buying a handgun.
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 the Newport, Rhode Island 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.
A spokeswoman for the naval station had no comment 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 (24 kilometers) 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. Slocum said Alexis passed a federal background check.
It is illegal for gun dealers to sell handguns to such out-of-state buyers, but the Firearms Owners' Protection Act, passed by Congress in 1986, opened up interstate sales for shotguns and rifles. Virginia gun laws require only that an out-of-state buyer show valid identification, pass a background check and otherwise abide by state laws in order to buy a shotgun in the state. Alexis was never prosecuted for two misdemeanor charges involving guns.
Federal gun laws bar the mentally ill from legally buying guns from licensed dealers. But the law requires that someone be involuntarily committed to a mental health facility or declared mentally ill by a judge, and that information must be reported to the FBI in order to appear on background checks. In the wake of the mass shooting at Virginia Tech in 2007, state authorities changed state