Policemen evacuate people near the site where a shooting incident occurred at a Metro station near the Pentagon, the United States, on March 4, 2010. Three people were shot in a shooting incident at a Metro station near the Pentagon Thursday evening. The military locked down the complex after the shooting. (Xinhua/Zhang Jun)

The person suspected of shooting two police officers near Pentagon had a history of mental illness, according to authorities, friends and court records.

"The family was working with their son on mental issues," San Benito County Sheriff Curtis Hill said at a news conference at the board of supervisors chambers Friday.

His parents reached out to local authorities weeks ago with a warning that he was unstable and might have a gun.

U.S. authorities has identified him as a man from California, who appeared to be acting alone and had no connection to terrorists. He died overnight of gunshot wounds sustained in the incident.

Pentagon Police Chief Richard Keevill identified the suspect as 36-year-old Californian John Patrick Bedell. Keevill said Bedell apparently tried to gain entry to the Defense Department complex Thursday night as he approached three Pentagon police officers who guarded a checkpoint at the exit of the Pentagon Metro station.

Bedell started shooting as he was asked by the officers for an ID pass, grazing two officers with bullets. The officers fired back and hit Bedell in the head. He was pronounced dead later in the hospital.

Bedell was wearing a business suit, carrying two semi-automatic weapons and many magazines of ammunition.