Washington: The gunman who killed 12 people before being shot dead by police in a military complex in the heart of Washington is being described as a young man with an interest in Buddhism and flashes of rage. Officials on Tuesday said he had serious mental health issues but was not stripped of his security clearance.
Aaron Alexis' motive in Monday's rampage remained a mystery. But US law enforcement officials told The Associated Press that he had paranoia and a sleep disorder and was hearing voices in his head.
The officials also said there has been no connection to international or domestic terrorism, and investigators have found no manifesto or other writings suggesting a political or religious motivation.
Monday's attack was unlikely to lead to tighter gun controls. Measures proposed during national outrage over a school shooting in December that killed 20 children failed this year in Congress. "Yet another mass shooting," US President Barack Obama said on Monday. It was at least the seventh mass shooting of his presidency.
Family members told investigators that Alexis, 34, was being treated for his mental health issues. He had been treated since August by the federal Veterans Administration, the officials said. They spoke on condition of anonymity because the criminal investigation was continuing.
The Navy had not declared its defense contract employee mentally unfit, which would have rescinded a security clearance that Alexis had from his earlier time in the Navy Reserves.
Alexis used a valid pass to get into the Washington Navy Yard. In the past, he had complained about the Navy about being a victim of discrimination and had several incidents with law enforcement, including two shootings
Alexis carried three weapons in the attack: an AR-15 assault rifle, a shotgun, and a handgun that he took from a police officer at the scene, according to two federal law enforcement officials who spoke on condition of anonymity because they were not authorized to discuss the investigation. The AR-15 is the same type of rifle used in last year's mass shooting at a Connecticut school that killed 20 students and six adults. The weapon was also used in the shooting at a Colorado movie theater that killed 12 and wounded 70.
By late Monday, authorities said they were convinced Alexis had acted alone.
Eight people were hurt, including three who were shot and wounded, Mayor Vincent Gray said. They were all expected to survive.
At the time of the shooting, Alexis was an employee with The Experts, a company that was a Defense Department subcontractor on a Navy-Marine Corps computer project, authorities said.
Valerie Parlave, head of the FBI's field office in Washington, said Alexis had access to the Navy Yard as a defense contractor and used a valid pass to enter the complex where more than 18,000 people work.
Alexis had been a full-time Navy reservist from 2007 to early 2011, the Navy said. It did not say why he left.
A convert to Buddhism who grew up in New York City, Alexis had had shooting incidents in 2004 and 2010 in Fort Worth and Seattle and was portrayed in police reports as seething with anger.
Witnesses on Monday described a gunman opening fire from a fourth-floor overlook, aiming down on people on the main floor, which includes a glass-walled cafeteria. Others said a gunman fired at them in a third-floor hallway.
"It was three gunshots straight in a row - pop, pop, pop. Three seconds later, it was pop, pop, pop, pop, pop, so it was like about a total of seven gunshots, and we just started running," said Patricia Ward, who was in the cafeteria.
Todd Brundidge said he and co-workers encountered a gunman in a long hallway on the third floor. The gunman was wearing all blue, he said.
"He just turned and started firing," Brundidge said.