How the attackers knew about what was supposed to be a secret CIA facility is important. If the attackers had known for weeks about the facility and had staked out a position to fire the mortar rounds, it suggests the Benghazi attack was planned in advance and not the “flash mob with guns” that Obama administration officials described to reporters in the weeks following the attack.

If the attackers learned the location of the facility that evening, it would suggest the Benghazi assault was more of a target of opportunity and was therefore not planned well in advance of the 11th anniversary of the Sept. 11, 2001, terrorist attacks on New York and Washington.

One U.S. official familiar with the briefing told The Daily Beast that one working theory about the attack on the annex is that the militants that fired the mortars learned of the CIA annex location earlier that evening, when Woods and others rescued U.S. personnel from the diplomatic mission, and then drove a convoy through Benghazi to get to the annex. The convoy carrying the Americans was chased and fired on by attackers along the route back to the annex.

However, one U.S. intelligence official with detailed knowledge of the events in Benghazi disputed that view. This official said the Special Operations team that arrived by aircraft that evening from Tripoli was tailed by the attackers on the drive from the Benghazi airport to the CIA annex.