The ex-US Navy reservist who killed
12 people and wounded eight at a Washington DC Navy installation had received
treatment for mental health issues, US media have reported.
Aaron Alexis, 34, was treated for paranoia, trouble sleeping and hearing voices, the Associated Press reported.
Before Monday's shooting at the Washington Navy Yard he was employed as a technical contractor there.
He was shot and killed by police during the attack.
On Tuesday, the US capital remained in a state of shock
after the shootings. The flag flew at half-mast over the White House, where
hours after the shooting President Barack Obama had mourned "yet another mass
shooting".
No motive is known for the attack.
The victims ranged in age from 46 to 73, and details about their identities and lives have just begun to emerge.
The shooting began about 8:20 local time (12:20 GMT) on
Monday, when a gunman apparently shot his way into the heavily guarded Building
197, headquarters for Naval Sea Systems Command, which builds and maintains
ships and submarines for the Navy.
As an employee of an IT contractor, Alexis apparently had a card granting him access to the building - even though he had had several run-ins with the law and had been discharged from the Navy under a cloud, authorities said.
"It really is hard to believe that someone with a record as chequered as this man could conceivably get, you know, clearance to get... credentials to be able to get on the base," Washington DC Mayor Vincent Gray told CNN.
Witnesses said the suspect sprayed bullets in a hallway and fired from a balcony down on to workers in an atrium at the heavily secured installation in the US capital.
He was reportedly armed with an AR-15 semi-automatic rifle, a shotgun and a handgun that he took from a police officer at the scene.




















