How the CIA identified and killed Al-Qaeda leader Zawahiri
Al Qaeda leader Ayman al-Zawahiri was killed in a U.S. strike in Afghanistan over the weekend, the biggest blow to the militant group since its founder Osama bin Laden was killed in 2011.
"We were able to build a pattern of life through multiple independent sources of information to inform the operation," the official said.
Once Zawahiri arrived at the Kabul safe house, officials were not aware of him leaving it and they identified him on its balcony - where he was ultimately struck - on multiple occasions, the official said.
The strike was ultimately carried out at 9:48 p.m. ET (0148 GMT) on July 30 by a drone firing so-called "hellfire" missiles.