Alexanda Kotey, part of the Islamic State kidnap-and-murder cell known as the "Beatles," was sentenced to life in jail by a United States court on Friday.
Kotey, a 38-year-old former British national, pleaded guilty in September, admitting his responsibility for the deaths of four American hostages in Syria as well as the kidnapping and torture of some 20 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.
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 defendants.
"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 IS propaganda videos that shocked the world, while others were released for ransoms.