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 Wednesday 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.

In this image released by the Montgomery County Police, James J. Lee is seen is a booking mugshot from 2008 on disorderly conduct. Lee, 43, a gunman with what police described as "concerns" with the Discovery Channel networks took at least one person hostage in the company's Silver Spring, Md., headquarters Wednesday, Spet. 1, 2010. A law enforcement official speaking on condition of anonymity because the investigation is ongoing said authorities have identified Lee as the likely suspect.

Maryland State Police troopers, walk near the Discovery Channel network building in Silver Spring, Md., Wednesday, Sept. 1, 2010. Police shot and killed a man upset with the Discovery Channel network's programming who took two employees and a security officer hostage at the company's headquarters Wednesday, officials said. All three hostages escaped safely