RICHMOND, Va. (CN) - The wife of deceased ISIL member Abu Sayyaf has been charged in the 2014 murder of American humanitarian aid worker Kayla Jean Mueller.
On August 3, 2013, Mueller, 26, of Prescott, Ariz., was abducted by members of the terrorist group while leaving a Doctors Without Borders hospital in Aleppo, Syria, where she had been volunteering with a friend.
Court documents do not indicate how or when Mueller died, but according to testimony from FBI Special Agent William Heaney, ISIL sent an email notifying the young woman's family of her death on Feb. 7, 2015, approximately a year and a half after her abduction.
ISIL, an acronym for the Syrian-based terrorist organization Islamic State of Iraq and the Levant, became was designated a terrorist organization by the U.S. in 2014, the same year the organization's leader Abu Bakr al-Baghdadi declared the group a caliphate.
"The objective of the terrorist organization is the forcible acquisition of land for the stated goal of creating an Islamic State without recognizing any national boundaries ... The criminal acts committed by members of the organization include murder, kidnapping, hostage taking, enslavement of women, sex trafficking, and more," according to FBI reports.
Mueller was held for several weeks at an ISIL-operated prison along with three unidentified abductees; a fellow volunteer and two Yazidi Kurdish women from northern Iraq, Heaney claims.
The captors were released from prison in September 2013, and shuffled between multiple residences owned by Sayyaf and his wife Nisreen Assad Ibrahim Bahar, court documents say.
Under custody of Sayyaf and Bahar, the women were bound, forced to watch violent footage of ISIL propaganda and enslaved by male ISIL members who bought or traded them-Mueller was declared property of al-Baghdadi who frequently raped her, Heaney stated.
"Ms. Mueller and the other young women had no freedom and were compelled to serve at the behest of the ISIL men who acquired them," said Heaney in a statement on Tuesday.
Sayyaf, a gas and oil minister for ISIL who reported directly to al-Baghdadi, often traveled for business, leaving his wife in charge of the prisoners, FBI reports say. Bahar allegedly threatened to kill the women if they did not follow orders.
"The defendant chastised the captives by calling them 'kafir' or 'infidels,'" according to Heaney's statement. "The 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 statement continues.
U.S. forces executed a May 15, 2015 reconnaissance mission which recovered one Yazidi prisoner and an arsenal of firearms stashed in the Sayyafs' home, Heaney said.
Bahar was apprehended in the raid and extradited to the U.S., where she was charged Tuesday in federal court with conspiring to provide material support to a designated terrorist organization resulting in death.
According to FBI testimony, Bahar claimed she though Mueller was being held for ransom.
If convicted, Bahar faces a maximum sentence of life in prison.
Sayyaf was allegedly killed in the scuffle, while al-Baghdadi remains at large.