ISIS-Linked Militants: We Killed an American Egyptian group posts photos of William Henderson's passport, ID cards By Newser Editors and Wire Services Posted Dec 1, 2014 2:30 AM CST 11 comments Comments An Egyptian soldier takes position on a military armored vehicle in Cairo after a series of Ansar Beit al-Maqdis attacks. (AP Photo/Amr Nabil, File) (Newser) – An Egyptian militant organization that pledged allegiance to ISIS has claimed responsibility for the killing of an American oil worker. Ansar Beit al-Maqdis—which now refers to itself as the Sinai Province—said on its official Twitter account last night that it killed William Henderson. The group published pictures of his passport and two identification cards, but it did not say when or how it killed him. The passport said he was a 58-year-old from Texas, and his identification cards said he worked for Texas-based energy company Apache Corp. The company said in August that one of its supervisors had been killed in an apparent carjacking in Egypt's Western Desert.