* Police shoot and kill suspect; hostages safe
* Suspect had protested against Discovery Channel (Updates with suspect dead, police, company quotes)
By Maggie Fox
SILVER SPRING, Md., Sept 1 (Reuters) - U.S. police shot and killed a man who took three people hostage, waving a gun and apparently fitted out with explosives, in the headquarters of the Discovery Channel near Washington on Wednesday.
Officers who had been watching the hostage drama on a building security camera crept in while police negotiated with the emotional gunman and shot him when he pointed his pistol at one of the three men he held hostage.
"A hostage moved, he pulled his gun, and a shot was taken," Montgomery County police chief Tom Manger told reporters. He said the suspect was killed and the hostages were safe.
The man, named by a U.S. law enforcement official as James Lee, had been arrested before for protesting against Discovery Channel over environmental issues.
"He had a history ... of conflict with Discovery," Manger said.
The incident caused chaos in Silver Spring, Maryland, a shopping and office district and commuter hub on the edge of the U.S. capital.
Police sealed off the area around the building and SWAT teams deployed shortly after the suspect entered the building carrying a handgun at about 1 p.m. Manger said county and state police, FBI and Homeland Security agents joined the operation.
The building, where nearly 1,900 employees work, was evacuated and children were rushed from a day-care center.
Police said they were still trying to determine whether two boxes and two backpacks that the hostage-taker had were explosive devices. Bomb-sniffing dogs checked the area before workers were allowed to leave neighboring buildings.
PROTEST AGAINST POPULATION
A James Lee of San Diego was arrested in February 2008 after throwing money into the air in a protest outside the Discovery building, the Montgomery County Gazette reported that year.
A website registered under the name of James Lee contained demands that Discovery air programming urging people to stop having babies, which he says is leading to the overpopulation of the planet.
"Civilization must be exposed for the filth it is," reads the site, savetheplanetprotest.com. "Saving the Planet means saving what's left of the non-human Wildlife by decreasing the Human population. That means stopping the human race from breeding any more disgusting human babies!" it says.
"If you follow what he said publicly online, I don't think it's rational. We certainly were cognizant, aware of him but did not take his threats or demands seriously," said David Leavy, a Discovery Channel spokesman.
Police kept the gunman talking by telephone almost the whole time. "He went from being agitated to being calm," said Manger. The hostages, two Discovery employees and a security guard, just happened to have been in the lobby and were kept lying on the floor by the gunman, he said.
More than an hour after the gunman was shot, streets and alleyways around the sprawling glass and silver Discovery building were clogged with dozens of police vehicles, bomb disposal trucks and canine units.
Pedestrians stared silently as snipers unloaded their rifles and stripped, sweating, out of bulletproof vests.
Discovery Communications says it reaches 1.5 billion subscribers in more than 180 countries with the Discovery Channel, TLC, Animal Planet, Science Channel and Planet Green networks. (Additional reporting by Jackie Frank, Bill Trott, Diane Bartz, Xavier Briand, David Storey, Andy Sullivan and Jeremy Pelofsky; writing by Tabassum Zakaria and Alistair Bell; editing by Mohammad Zargham)