At 9:40 p.m., September 11, members of Ansar al-Sharia attacked the American diplomatic compound in Benghazi resulting in the deaths of U.S. Ambassador to Libya J. Christopher Stevens and U.S. Foreign Service Information Management Officer Sean Smith. Stevens was the first U.S. ambassador killed in the line of duty since 1979. At around 4:00 a.m. on September 12, the group launched a mortar attack against a CIA annex approximately one-mile (1.6 km) away, killing CIA contractors Tyrone S. Woods and Glen Doherty and wounding ten others. Initial analysis by the CIA, repeated by top government officials, indicated that the attack spontaneously arose from a protest. Subsequent investigations showed that the attack was premeditated – although rioters and looters not originally part of the group may have joined in after the attacks began.
There is no definitive evidence that al-Qaeda or any other international terrorist organization participated in the Benghazi attack. The United States immediately increased security worldwide at diplomatic and military facilities and began investigating the Benghazi attack. Many Libyans condemned the attacks. They staged public demonstrations condemning Ansar al-Sharia, which had been formed during the 2011 Libyan civil war in opposition to leader Colonel Muammar Gaddafi.
Despite persistent accusations against President Obama, Hillary Clinton, and Susan Rice, ten investigations — six by Republican-controlled congressional committees — did not find that they or any other high-ranking Obama administration officials had acted improperly. Four career State Department officials were criticized for denying requests for additional security at the facility prior to the attack. Eric J. Boswell, the Assistant Secretary of State for Diplomatic Security, resigned under pressure, while three others were suspended. In her role as Secretary of State, Hillary Clinton subsequently took responsibility for the security lapses.
On August 6, 2013, it was reported that the U.S. had filed criminal charges against several individuals alleged to have been involved in the attacks, including militia leader Ahmed Abu Khattala. Khattala has been described by Libyan and U.S. officials as the Benghazi leader of Ansar al-Sharia. The U.S. Department of State designated Ansar al-Sharia as a terrorist organization in January 2014. Khattala was captured in Libya by U.S. Army Special Operations Forces, who were acting in coordination with the FBI, in June 2014. Another suspect, Mustafa al-Imam, was captured in October 2017.