ITV News Security Editor Rohit Kachroo explains the latest
The US will not seek the death penalty against two Islamic State fighters who were part of the all-British execution cell known as "The Beatles". In a letter to Home Secretary Priti Patel, seen by ITV News, America's attorney general confirmed if Britain grants their extradition request, the pair will not be executed.
William Barr's letter to Ms Patel could allow Britain to begin sharing evidence with US prosecutors for any case against El Shafee Elsheikh and Alexanda Kotey.
Elsheikh and Kotey were captured two years ago by a Kurdish-led, US-backed militia.
"I know that the United Kingdom shares our determination that there should be a full investigation and a criminal prosecution of Kotey and Elsheikh," Mr Barr wrote to the UK home secretary.In their last TV interview before both were taken into custody by the US, Alexanda Kotey and El Shafee Elsheikh dodged the opportunity to directly apologise for the death of British aid worker David Haines.
ITV News Security Editor Rohit Kachroo carried out the last interviews on camera with the remaining 'Beatles' - Kotey and Elsheikh
He added he has "no problem apologising" for moving Mr Haines from location to location during his time in captivity.
Kotey, however, remained evasive when pressed by ITV News Security Editor Rohit Kachroo: "I won't forget what I've said before."
Before adding: "I find your line of questioning irritating."
ITV News Security Editor Rohit Kachroo's analysis on the latest developments
What began with an informal email sent a few weeks ago - from the family of one of the "Beatles" alleged kidnap victims straight to the personal account of the US attorney general - ends tonight with this signification intervention.
Bill Barr wrote to Priti Patel about the two men known as "The Beatles", members of this alleged all-British execution cell, to say this contentious issue of the threat of the death penalty has been taken off the table by US authorities.
In part, that is what has prevented UK authorities from sharing the intelligence it has about the two men with the Americans, preventing a trial from taking place in the US.
The letter is from one ally to another, but it reads like a warning, saying that now the threat of the death penalty has been removed, Britain should hand over the evidence and allow a trial in the United States.
"Time is of the essence. Further delay is no longer possible," Attorney General Barr writes.
He gave Britain a deadline of mid-October and said that if it was not met, the men could be tried in Iraq.
What I understand changed all this was an email sent a month ago from the family of the American aid worker, Kayla Mueller, requesting the change, in order to make a trial more likely.
Attorney General Barr then spoke to the American families to tell them he would write to the home secretary.
There’s a complication though.
The case is still being considered by the Supreme Court which can’t meet again until October.
Bethany Haines, the daughter of David Haines, the British aid worker murdered by ISIS said, "I'm glad something is finally happening.
"We've waited over two years and have been let down by the UK legal system."