It could have been prevented.

The two-gun Californian shot to death trying to attack the Pentagon had a history of mental illness and marijuana abuse, along with a grab bag of anti-government conspiracy theories, law enforcement officials said Friday.

The parents of John Patrick Bedell, 36, of Hollister, Calif., warned California authorities last month that their son was missing and might have a gun.
"We are devastated as a family," Kaye and John Bedell said in a statement. "We may never know why he made this terrible decision. One thing is certain though - his actions were caused by an illness and not a defective character."

Bedell drove cross-country in his green 1998 Toyota Avalon and confronted members of the Pentagon Force Protection Agency at the main entrance to the building Thursday after emerging from the nearby Metro subway entrance.
Bedell pulled out one of his two semi-automatic handguns and opened fire. Three guards returned fire, and two of them suffered slight "grazing" wounds.

The FBI said the initial investigation showed no links to international or domestic terrorism.
In numerous Internet postings, Bedell railed against his 2006 arrest for growing marijuana in his apartment and outlined schemes to use marijuana as money.
Bedell also sent the Pentagon a 28-page proposal on his plans to help the military with smart weapons, despite his belief that a government-run criminal enterprise was behind the 9/11 attacks.
In a blog posting, Bedell said the government viewed "an event such as the Sept. 11 attacks as a small cost in order to perpetuate its barbaric control." (SOURCE)