A US federal jury in Virginia has convicted an ex-British jihadist over his involvement with a notorious Islamic State terror cell.
El Shafee Elsheikh, 33, was linked to the abduction, torture and beheading of several IS hostages in Syria, including journalists and aid workers.
On Thursday, after an 11-day trial, he was found guilty of lethal hostage taking and conspiracy to commit murder.
Elsheikh was the highest profile IS fighter to stand trial in the US.
Hostages nicknamed the Sudanese-born Londoner and two other men the Beatles - after the rock band - because of their UK accents.
The group's actions are said to have resulted in the deaths of four American hostages: journalists James Foley and Steven Sotloff, and aid workers Kayla Mueller and Peter Kassig.
They are also blamed in the deaths of British aid workers David Haines and Alan Henning, and Japanese journalists Haruna Yukawa and Kenji Goto.
Some of the victims were beheaded, with their deaths filmed and broadcast on social media. The killings triggered outrage around the world.
Elsheikh was the only one of the three militants to go on trial in the US, after Alexanda Kotey pleaded guilty to his own charges last September and Mohammed Emwazi was killed in a 2015 drone strike in Syria. Aine Davis, an alleged fourth member, is currently imprisoned in Turkey.
Four rows in the courtroom were permanently reserved for former hostages and their family members.
Over the course of the trial, several of them took the stand for the government, depicting the Beatles as a cohesive unit that revelled in brutality.
Witnesses recounted receiving random beatings, being given dog names and being forced to sing a parody of the Eagles' pop song Hotel California retitled "Hotel Osama".
Families also detailed their painstaking negotiations with the group, with Marsha Mueller telling the court how she and her husband had "begged" for their daughter Kayla's life in emails.
Lawyers for Elsheikh, meanwhile, claimed that he "a simple Isis fighter" who went to Syria alone on behalf of "suffering Muslims".
Outside the courtroom, Diane Foley - whose son James was executed on camera, with the video widely distributed by IS - told the BBC she was feeling "relief and a tremendous sense of gratitude that mercy and justice has prevailed".
"This is a big day for accountability," she said. "We will never stop hostage taking without accountability."
Mike Haines, whose brother David also died in the group's captivity, said Thursday's result marked the end of "an eight-year chapter of pain" for his family.
"This unanimous judgement is a triumph for society over ills like terrorism and helps differentiate us from the hateful, divisive ideologies that fuel these individuals," he said.
"It must also act as a warning to anyone else seduced by the false glamour of extremism."
Elsheikh's extradition to Virginia was part of a complex negotiation between the US and UK.
As part of the agreement, he will not face the death penalty - but his conviction on all eight charges means he faces a maximum sentence of life in prison.
He will be sentenced in August but must also appear in court on 29 April for victim impact statements read during Kotey's sentencing.
- BBC