The man who allegedly killed a dozen people Monday morning at the Navy's headquarters had previously served as a member of the Navy.
The FBI named Aaron Alexis, 34, as a gunmen behind the shootings at the Navy's headquarters in Washington. He died at the scene.
Sources told The Associated Press that Alexis had been treated for serious mental illness, including "hearing voices."
Alexis's home of record is New York City.
Alexis worked as a military contractor and had legitimate access to the Navy Sea Systems Command in Navy Yard where the shooting took place, said Val Parlave, the FBI field district's assistant director.
Navy Secretary Ray Maybus said Alexis has worked as a military contractor in information technology, but he could not confirm if Alexis was currently serving in such a position.
Alexis was stationed in Fort Worth, Texas, for the majority of his naval service in the 46th Fleet Logistics support squadron. Alexis received two decorations while in the Navy — the National Defense Service Medal and the Global War on Terrorism Service Medal.
The medals are commonly given to members of the military who served while the United States was engaged in military conflicts in Iraq and Afghanistan after the 9/11 terrorist attacks.
According to a report in the Fort Worth Star-Telegram, Alexis was arrested in 2010 for shooting his weapon in his home. According to police report obtained by the newspaper, Alexis told police that his weapon discharged while he was cleaning it.
Alexis was arrested but released the next day without being formally charged.
The Seattle police department said that Alexis was arrested there in 2004 for shooting out the tires of another person’s car, in what he described as an “anger-fueled black-out.”
After being arrested he told detectives he was present during the 9/11 terrorist attacks in 2001, and said those events had “disturbed him.”
No motive has been given for the shootings at the Navy Yard.
This report was originally published on Monday at 5:33 p.m. and last updated on Tuesday at 7:58 a.m.