In May, a U.S. Special Forces operation in Syria killed senior ISIS leader Abu Sayyaf, one of the top money men for the terror state. His wife Umm Sayyaf was taken prisoner and placed in detention in Iraq. Umm Sayyaf has now been charged in U.S. federal court with conspiracy in the death of Kayla Mueller, the American aid worker who was kidnapped, enslaved, brutalized, and ultimately killed by the Islamic State.