Alexanda Kotey, part of the ISIS kidnap-and-murder cell known as the "Beatles," was sentenced to life in prison Friday, with relatives of victims addressing him and another member directly in the US court.
Kotey, a 38-year-old former British national, pleaded guilty in September, admitting his role in the deaths of four American hostages in Syria as well as the kidnapping and torture of other journalists and relief workers.
He was captured along with another former "Beatle," El Shafee Elsheikh, by a Kurdish militia in Syria in January 2018 and handed over to US forces in Iraq before being flown to the United States in 2020 to face trial.
Elsheikh was found guilty of all charges earlier this month, and will be sentenced on August 19.
Both men on Friday appeared in the court in Alexandria, near Washington, where the relatives of their victims were given an opportunity to speak.
"You abducted, tortured, and even participated in the murder of good and innocent people and now you have to live with that for the rest of your lives," Bethany Haines, daughter of one of the victims, told the men.
"You both have lost," added the young British woman, whose father David Haines, a relief worker, was beheaded by the third "Beatle," Mohammed Emwazi, who was killed in a 2015 drone strike.
The nickname was given to the hostage-takers -- who grew up and were radicalized in London -- by their captives because of their British accents.
Active in Syria from 2012 to 2015, the "Beatles" are accused of abducting at least 27 other journalists and relief workers from the United States, Britain, Europe, New Zealand, Russia and Japan.
Some were executed, their deaths filmed for ISIS propaganda videos that shocked the world, while others were released for ransoms.
Among the victims was American journalist Steven Sotloff, whose mother Shirley on Friday repeatedly urged the two men to "open your eyes please and look at me."
"How do you begin to describe the unimaginable impact of the loss of a child, taken in the prime of his young adult life, and how it affects you as a parent, sibling, nephew, cousin, friend, lover?" she said.
"Steven's death was like a global worldwide horror movie that was witnessed live and continues to be replayed with the click of a button for millions to see."
The mother of aid worker Kayla Mueller, who was initially held by the "Beatles" but was later turned over to ISIS leader Abu Bakr al-Baghdadi, who reportedly raped her repeatedly, also spoke in court.
"We have learned some things, and while they are stories of rape, beatings, terror and horror, I am thankful for each shred of truth no matter how painful it is to hear," AFP quoted her as saying.
"I am not seeking revenge. I simply want the truth. I believe that is the best way forward for us and our family."
ISIS announced Mueller's death in February 2015, saying she was killed in a Jordanian airstrike, a claim disputed by US authorities.
Kotey did not speak or show any emotion as Judge TS Ellis handed down the sentence, but his lawyers said that he was remorseful and had agreed to meet the families of his victims.