Umm Sayyaf, also known as Nasrin As'ad Ibrahim, was captured by U.S. forces in a raid in Deir Ezzor, Syria, in May. She was married to Abu Sayyaf, a senior ISIS operative
, who was killed in the same raid in eastern Syria in 2015.
Sayyaf, 25, was charged in federal court on Monday with "conspiring to provide material support to a designated foreign terrorist organization resulting in death," the Justice Department announced.
Umm and Abu Sayyaf forcibly held Mueller and other female captives in several of their residences after the American was captured in northern Syria in 2013
, according to the indictment. While held in the Sayyaf's home, Mueller and other female captives were at "various times handcuffed, held in locked rooms, and given orders on a daily basis with respect to their activities, movements, and liberty," the criminal complaint said.
Sayyaf was aware of how Mueller was sexually abused by ISIS leader Abu Bakr al-Baghdadi while she was in captivity inside the Sayyafs' home, the Justice Department documents say. U.S. government officials and Mueller's family had been previously aware of Baghdadi's treatment of Mueller while in captivity
. According to the documents released Monday, Sayaff admitted Baghdadi "owned" Mueller during her captivity at the Sayyaf residence.
Mueller was killed in February 2015. At the time, ISIS said she was killed by a coalition strike. The United States confirmed her death but denied it was by a coalition strike.
"We will continue to work alongside the FBI to investigate this case and remain steadfast in our pursuit of justice for the Mueller family," Dana J. Boente, U.S. Attorney for the Eastern District of Virginia, said.
Sayyaf is being held in Iraq. She was transferred in August 2015
by the United States to Kurdish authorities to stand trial.
"We fully support the Iraqi prosecution of Sayyaf and will continue to work with the authorities there to pursue our shared goal of holding Sayyaf accountable for her crimes. At the same time, these charges reflect that the U.S. justice system remains a powerful tool to bring to bear against those who harm our citizens abroad," said Assistant Attorney General John Carlin in a statement Monday.
Sayyaf faces a maximum penalty of life in prison if convicted.