The gunman who opened fire at the Pentagon Thursday night, injuring two police officers, died of a gunshot wound to the head after police returned fire, authorities said Friday morning.
Investigators are looking into online rants against the government as a potential motive.
John Patrick Bedell, 36, of Hollister, Calif., died at the hospital Thursday night after Pentagon police returned fire. Police told ABC News that the two police officers wounded in the shooting have been released from the hospital after suffering minor injuries. They are now on administrative leave pending the investigation of the incident, police said.
The two officers were identified as Jeffrey Amos and Marvin Carraway. One was hit in the shoulder, the other in the thigh.
"Those injuries were grazing injuries," said Pentagon Police Chief Richard S. Keevill. "The police officers were able to return fire."
The officers and the suspect were taken to George Washington Hospital in Washington, a hospital spokeswoman said. Bedell was reported dead several hours after the shootout.
The attack may be another suicide mission aimed at the government. While police have said they are not certain of a motive, they are investigating Internet postings in which Bedell may have written and recorded audio expressing his anger at toward the government. Court records show he was charged with cultivating marijuana and resisting a police officer in Orange County, Calif., in 2006.
"The moral values of individuals and communities are increasingly attacked by a political system where deceit is routine and accepted and the only standard is power," said an online video.
One Internet posting with the name JPatrickBedell on it talks about suspicions that the attacks of Sept. 11, 2001 were staged, calling them "the September 11 demolitions."
The posting says, "I am determined to see that justice is served in the death of Colonel James Sabow." The Associated Press reports that Sabow was found dead in the back yard of his California home in 1991. The death was ruled a suicide but the case has long been the source of theories of a cover-up.
Sabow's family has maintained that he was murdered because he was about to expose covert military operations in Central America involving drug smuggling.
Keevill said Friday that authorities had not made "a final determination" that the shooter was the same Bedell.
Shooter in Business Clothing, Said Nothing
Bedell was well-dressed, in slacks, a white collared shirt and blazer when he came to the checkpoint, police said. They said he had two semiautomatic weapons concealed in his clothing and a large amount of ammunition.
"The officers were emphatic about saying he was very calm, that there was no distress," said Keevill. "He had his arms down at his pocket. We see folks come up to the Pentagon every day that have their passes in different places. He reached into his pocket. They assumed he was going to get his pass out. He came out with a gun and just started shooting."
Bedell drove to Washington from California over the past few weeks, Keevill said, adding that police have been able to trace his movements from credit card records. He parked his vehicle in a local garage; it has since been impounded.
The shooting occurred at a Pentagon pre-screening area near the entrance to the Pentagon Metro Station.
The officers belonged to the Pentagon Force Protection Agency.
Code Red Lockdown at the Pentagon
When the shots rang out at around 6:40 p.m. on Thursday night, hundreds of employees at the Pentagon were ordered to go into "Code Red" -- the entire building locked down, with no one allowed to enter or leave.
At least three ambulances were seen at the location, and all parking lots at the massive Defense Department headquarters were closed off.
After about 45 minutes, people were allowed to leave the Pentagon building through entrances other than the one closest to the Metro station, though Metro trains bypassed the Pentagon station.
Service to the station resumed around 8 p.m., according to a statement by Metro officials, though parts of the facility remained closed as police continued to investigate the shooting.
26,000 People Work at Pentagon
The Pentagon Metro station stop is a couple of hundred feet from the famous five-sided building. People leaving the station who wish to enter the Pentagon must show ID to Pentagon police in order to get close to the building.
The Pentagon, just across the Potomac River from downtown Washington, is, by area, the world's largest office building. About 26,000 people work there, according to the Defense Department.
The story has been updated since its original posrting. ABC News' Jason Ryan, Steven Portnoy, Martha Raddatz and Jennifer Wlach contributed to this story. Additional information from The Associated Press.