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 hotel-room walls and sending microwave vibrations to deprive him of sleep.
The account in an August 7 report from Newport police adds to an emerging picture of an agitated and erratic figure whose behaviour and mental state repeatedly came to authorities' attention without affecting his security clearance.
Alexis also apparently managed to exploit seams in the nation's patchwork of complicated gun laws. 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 defence-related computer company, used a valid pass on 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 half an hour.
A day after the assault, the motive was still a mystery. US law enforcement officials told The Associated Press that investigators had found no manifesto or other writings suggesting a political or religious motivation.
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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.
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.
Navy Secretary Ray Mabus ordered two security reviews on 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.
Alexis told Newport 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. He said the person sent three people to follow and harass him.
He said he heard voices talking to him through a wall at one hotel, so changed hotels twice but the voices followed him. 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 on Tuesday.
Alexis had run-ins with the law in 2004 and 2010 in Texas and Seattle after he was accused of firing a gun in anger. He was not prosecuted in either case.
