'IS Beatles member' trial on 'beheading Americans in Syria' to begin in US
Elsheikh - dubbed 'Jihadi George' - was charged with the capture, detention, and beheading of four American, two British, and one Japanese hostages.
Elsheikh and three other alleged British IS members were accused of appearing in execution videos and propaganda for the group, dubbed by their captives - and later international press - as 'The Beatles' due to their British accents.
Despite efforts to prevent her testimony, a former Yazidi slave will be at the trial to present evidence against the accused terrorist.
Elsheikh was captured by the Syrian Democratic Forces (SDF) in 2018 as the murderous group's self-proclaimed caliphate collapsed.
Alexanda Kotey, who admitted to being an IS member, was also captured.
The pair were handed over to US authorities who took them into custody.
Both Elsheikh and Kotey were charged with taking hostage US citizens James Foley, 40, Steven Sotloff, 31, Peter Kassig, 26, and Kayla Mueller, 26, who all died either at the hands of their captors or in alleged airstrikes.
They will also face charges of conspiracy of providing material support to terrorists, leading to the deaths of British aid workers David Haines, 44, and Alan Henning, 47, and a Japanese national.
The executions of some of the hostages were carried out by the group's leader, Mohammed Emwazi, who was killed in a US drone strike in Syria, in 2015.
In the run-up to his trial, Elsheikh tried and failed to prevent US prosecutors from calling a former Yazidi slave as a witness at the trial.
Prosecutors reportedly intend to use the former slaves' testimony to describe the treatment that was endured by Mueller, who was kept as a sex-slave by IS' former leader, Abu Bakr Al-Baghdadi.
In his ruling, Judge Thomas Ellis said that the jury would hear testimony from the former slave, and would be shown IS documents that showed "justifications and guidelines for slavery under Islamic law".
Ellis said that the testimony was "plainly relevant" because the woman knew Mueller, and would be able to testify to "an ongoing conspiracy to capture and hold hostages and provide material support to IS as alleged in the indictment".
IS claimed that Mueller was killed in a 2015 Jordanian airstrike on Raqqa, the capital of the group's self-proclaimed caliphate.
Elsheikh and Kotey, travelled from the UK to join the IS but were later stripped of their citizenship by the British Home Office.
Alexanda Kotey pleaded guilty at trial last September and will be sentenced on 29 April, when Elsheikh’s trial is expected to conclude.