UK & World News
Washington Navy Gunman's 30-Minute Rampage
Former Navy reservist Aaron Alexis went on a 30-minute rampage "determined to kill as many people as possible" inside a Washington navy yard, police have said.
The 34-year-old, who has a history of mental illness and gun violence, acted alone after "legitimately gaining access" to the sprawling military complex armed with a shotgun.
In a police and FBI news conference, law enforcement officials confirmed that Alexis engaged in running gun battles with officers armed with AR-15 rifles during which he managed to obtain a handgun.
Alexis, who was working at the yard as an IT contractor, wounded one officer, who remains in hospital where he is being treated for leg injuries, before he was killed.
In the most detailed account of events yet, Washington Police Chief Cathy Lanier described how the massacre unfolded in building 197 at US Navy Sea Systems Command headquarters.
She said: "Within seven minutes (of receiving the emergency call) we had officers at the building, entering the building to engage in active shooting.
"We had officers who heroically went into the building witnessing multiple casualties and continued to pursue and engage a gunman who was determined to kills as many people as possible and law enforcement officers were not discriminated against as far as the shooter was concerned.
"So the officers ... did an incredible job and there is no doubt in my mind that they saved numerous lives in acting the way they did."
FBI Washington's Valerie Parlave said that Alexis had acted alone and had been able to get on to the naval base because he had a valid pass.
Despite being discharged from the Navy after a string of misconduct incidents and having a police record for a gun-related crimes, Alexis had access to the highly secure Washington Navy Yard as a defence contractor.
He was working for The Experts, a team subcontracted by IT giant Hewlett-Packard to work on IT for the Navy.
A Pentagon official has said that Defence Secretary Chuck Hagel plans to order a review of security at US military bases worldwide as a result of the shooting.
The disclosure followed a day of increasingly tough questions over how defence contractors are vetted for security clearances.
According to his employers Alexis had started at the yard only last week but the FBI said that he has been in Washington since August 25 and had been staying at a number of local hotels.
Washington Mayor Vincent Gray said he was baffled how Alexis had the job and the access to the yard and questioned whether spending cuts had led to lax security.
"It's hard to believe that someone with a record as chequered as this man could get clearance, credentials, to get on the base," he told CNN.
"We know this is one of the most secure facilities in the nation. So how this could happen is beyond belief."
The yard, a sprawling labyrinth of buildings and streets, is protected by armed guards and metal detectors, and employees have to show their IDs at doors and gates.
The US Navy's top civilian, Ray Mabus, earlier said he had ordered a review of security at all naval and Marine Corps bases.
According to law enforcement officials, Alexis had been hearing voices in his head and was suffering from paranoia and a sleep disorder.
He had been treated since August by the Veterans Administration for his mental problems, the officials said.
Some of those who knew him said that he regularly played violent video games.
A Seattle Police report said Alexis was "seething with anger" after an incident in 2004 in which he shot out the tyres of a car belonging to builders he believed were mocking him.
It also described how Alexis, a convert to Buddhism who was brought up in Brooklyn, had been suffering post-traumatic stress disorder following 9/11 as a result of helping with rescue efforts.
In 2010 he was arrested after discharging a firearm in his apartment. He told police he had been cleaning the gun when it accidentally went off. In 2008 he was given a ticket for disorderly conduct by police after being thrown out of an Atlanta nightclub.
US officials said that Alexis received an honourable discharge from the Navy despite a string of misconduct problems during his three years in the military, when he based in Forth Worth Texas from 2008 to 2011.
They said incidents of insubordination and disorderly conduct were enough to make it clear Alexis would not be a good sailor but not enough to warrant a general or less-than-honourable discharge.
He received two medals during his service - both are issued to large numbers of service members who served since the 9/11 attacks.
Police have named the 12 victims as Michael Arnold, Martin Bodrog, 54, Arthur Daniels, 51, Sylvia Frasier, 53, Kathy Gaarde, 62, John Roger Johnson, 73, Frank Kohler, 50, Mary Francis Knight, 51, Kenneth Bernard Proctor, 46, Vishnu Pandit, 61, Gerald L Read, 58 and Richard Michael Ridgell, 52.
Another 14 people - including three who were shot - were injured.