SILVER SPRING, Md. » A man who railed against the Discovery Channel’s environmental programming for years burst into the company’s headquarters with at least one explosive device strapped to his body yesterday and took three people hostage at gunpoint before police shot him to death, officials said.

The hostages — two Discovery Communications employees and a security guard — were unhurt after the four-hour standoff. Montgomery County Police Chief Thomas Manger said tactical officers moved in after officers monitoring the gunman on building security cameras saw him pull out a handgun and point it at a hostage.

An explosive device on the gunman’s body detonated when police shot him, Manger said. Police were trying to determine whether two boxes and two backpacks the gunman had also contained explosives.

A law enforcement official speaking on condition of anonymity because the investigation was ongoing said authorities had identified James J. Lee as the likely suspect.

Lee listed Hawaii as his hometown on his MySpace page.

Property records show Lee was given ownership of a 12.5 percent stake in a Lahaina residence in 2003 through a family trust, and that he sold his interest in 2007 for $90,000.

It was not immediately determined what period he lived in Hawaii or when he moved to the mainland.

On his MySpace page, Lee said he is single, 43, and lives in Silver Spring, Md.

County police and firefighters last night looked at a laptop screen that showed an image of a body lying face up, surrounded by blood. Authorities also sent in a robot to disarm the explosive on the gunman’s body. Police Capt. Paul Starks said the suspect had fired a gun at least once. He also said police think the suspect was acting alone but are investigating all possibilities.

Manger said police spent several hours negotiating with the armed man after he entered the suburban Washington building about 1 p.m. None of the 1,900 people who work in the building were hurt, and most made it out before the standoff ended.

Lee was convicted of disorderly conduct for a protest he organized outside Discovery’s offices in February 2008. According to court records, he paid homeless people to carry signs and set off a scramble when he threw fistfuls of cash into the air, calling it "just trash."

Lee served two weeks in jail after his arrest, during which doctors evaluated his competency to stand trial. County State’s Attorney John McCarthy said Lee was ordered to stay 500 feet away from Discovery headquarters as part of his probation, which ended two weeks ago. A magistrate ordered a doctor’s evaluation, but the result was not immediately available yesterday.

"The Discovery Channel produces many so-called ‘Environmental Programs’ supposedly there to save the planet," Lee said in an ad he took out in a Washington newspaper to promote the protest. "But the truth is things are getting WORSE! Their programs are causing more harm than good."

In court and online, Lee faulted the Discovery Channel for shows as varied as "Future Weapons," "It Takes a Thief" and "Planet Green."

A lengthy posting that could be seen yesterday on a website registered to Lee said Discovery and its affiliates should stop "encouraging the birth of any more parasitic human infants," a possible reference to shows like "Kate Plus 8" and "19 Kids and Counting." Instead, he said, the network should air "programs encouraging human sterilization and infertility."

Discovery Communications Inc. operates U.S. cable and satellite networks including the Discovery Channel, TLC and Animal Planet.

Star-Advertiser staff contributed to this report.