Those two officers, and a third who came to assist, all fired at the man, who was shot in the head and died early Friday. The two wounded officers had superficial injuries and have been released from the hospital.

Pentagon Police Chief Richard S. Keevill said surveillance video shows the gunman acted alone. There is no known connection to domestic or international terrorism, he said.

The gunman "was very well dressed in a suit" and showed "no distress in his appearance" as he approached a screening area to enter Pentagon grounds about 6:40 p.m. Thursday, Keevill said. "He walked very directly to the officers and engaged. He was very well armed. I will tell you that he had two 9 mm semiautomatic weapons and many magazines."

The man wore no body armor, Keevill said.

The shooter, identified by a law enforcement source as John Patrick Bedell, appears to have railed against the government repeatedly on the Internet.

Through podcasts and a Wikipedia page, a man identified online as JPatrickBedell cast the government as a criminal force destroying personal liberties.

"This seizure of the United States government by an international criminal conspiracy is a long-established reality," the man said in a podcast in November 2006, which also was published as text online.

Such an organization, the man said, "would use its powers to convert military, intelligence, and law enforcement bureacracies (sic) into instruments for political control and the domination and subjection of society, while discrediting, destroying, and murdering honest individuals within those services that work to root out corruption and faithfully serve their fellow citizens."

A Pentagon spokesman, Terry Sutherland, described the shooter as a 36-year-old who lived in California. Court records from California show that investigators arrested a John Patrick Bedell in June 2006 on charges of cultivating marijuana and resisting arrest; that man would be 36 now, according to the birth date on his arrest warrant.

In an Internet posting, JPatrickBedell referred to being arrested in 2006 on marijuana charges.

"Given my belief that cannabis prohibition is the least defensible and most unjust aspect of the prohibitionist regime existing throughout the world today, I decided in March 2006 to cultivate cannabis in full view of the world," the person said in a 2006 podcast.

In a video posted on YouTube in October 2006, a man identified as jpbedell talked about his idea for "information currency," which he said would "create a financial market for information." The man's voice sounds similar to the voice in the podcasts. A person using the screen name JPatrickBedell also wrote about the same idea on a Wikipedia page that was taken down early Friday.

At a news conference Friday morning, Keevill, the Pentagon police chief, said Pentagon and Metro cameras of the area show the gunman in the time leading up to the shooting.

He showed "no real emotion in his face" as he approached the officers Thursday evening, Keevill said. When asked for identification to enter the Pentagon, authorities said, he pulled a gun out of his pocket and fired.

Officers Jeffrey Amos and Marvin Carraway returned fire with semiautomatic weapons, Pentagon spokesman Sutherland said.

The officers suffered nonthreatening injuries -- one in the thigh and the other in the shoulder, Keevill said. They were placed on administrative leave, which is routine in officer-involved shootings.

Investigators closed the Pentagon subway station Friday, affecting the commutes of thousands of Washington-area residents. Subway trains were instructed to bypass the Pentagon, transit officials said.

"It's a complicated crime scene. There were a lot of bullets fired," Keevill said.

He applauded the officers for ensuring that the gunman did not set foot in the nation's defense headquarters, where about 23,000 military and civilian employees work.

The officers took less than a minute to neutralize him, the chief said, adding that their action saved lives. Keevill said it was not immediately clear which officers shot hit the gunman.

"The Fort Hood incident put us on notice that this can happen anywhere," he said, referring to a Texas shooting in November that left 13 people dead.

The FBI, which is helping investigate, is checking "everywhere" the man has ever visited, Keevill said.

Authorities do not know what the man's motive may have been, he said.