On October 25, 2003, Christopher was one of two civilian contractors working for the Central Intelligence Agency who was killed during an ambush. The region they were operating in is part of the remote mountainous region along the border of Afghanistan and Pakistan, where Osama bin Laden is thought to be hiding. It is also a stronghold for al-Qaida, Taliban and other anti-U.S. fighters. The officers, assigned to CIA's Directorate of Operations that conducts clandestine intelligence gathering and covert operations, died while tracking terrorists operating in the region. They were involved in a six-hour gunfight between Taliban rebels and U.S.-led coalition and Afghan forces.