Libya Singles Out Islamist as a Commander in Consulate Attack, Libyans Say CAIRO — Libyan authorities have singled out Ahmed Abu Khattala, a leader of the Benghazi-based Islamist group Ansar al-Shariah, as a commander in the attack that killed the American ambassador to Libya, J. Christopher Stevens, last month, Libyans involved in the investigation said Wednesday. Witnesses at the scene of the at