A British court has cleared the way for two admitted Islamic State militants to be tried in the United States, ruling Tuesday that the mother of one of the men has no further grounds to block the transfer of criminal evidence to U.S. prosecutors.

British officials promptly shared that evidence with Washington on Tuesday, ending one legal saga and commencing another as American law enforcement prepares for one of the highest-profile terrorism prosecutions in recent years.

The decision by the Queen’s Bench Division of the High Court of Justice was welcomed by the U.S. Justice Department, which is preparing to try El Shafee Elsheikh and Alexanda Kotey for crimes related to the brutal executions of American and British hostages by the Islamic State beginning in 2014.

Attorney General William P. Barr had given British officials until Oct. 15 to provide assistance or, he warned, the men would be transferred from U.S. military custody to the Iraqi government for prosecution in its justice system, which human rights activists say is tantamount to a death sentence.

Barr said the United States would take the death penalty off the table if British authorities transmitted the evidence, which U.S. prosecutors consider crucial to a successful prosecution.

The case has garnered international attention because of the horrifying and public deaths it is linked to, including the beheading on camera of American journalist James Foley, and the deaths of two other Americans and two Britons. The parents of one slain hostage, humanitarian Kayla Mueller, spoke this year at the Republican National Convention.

A masked executioner with a British accent who killed Foley and others was later identified as Mohammed Emwazi, known as “Jihadi John.” Hostages dubbed Emwazi, Elsheikh, Kotey and a fourth Islamic State militant named Aine Davis “The Beatles” for their British accents. All were either born or raised in Britain.

Emwazi was killed in a U.S. drone strike in 2015. Davis, who was captured in Turkey in 2015, was convicted in 2017 and is serving a seven-year prison sentence there.

“We are pleased with the U.K. High Court’s decision and we are grateful that the British government has passed its evidence to us and confirmed its commitment to cooperate with our efforts to investigate and prosecute the two ISIS terrorists currently being held in U.S. military custody,” a Justice Department spokesman, Marc Raimondi, said in a statement. “We remain committed to holding these defendants accountable and obtaining justice for the victims of their terrorist activity.”

Kotey and Elsheikh were captured in Syria by U.S.-backed Kurdish fighters in early 2018. Britain stripped the pair of their citizenship and determined that a trial in the United States, where prosecutors have a wider array of legal tools in terrorism cases — and where prison sentences are lengthier — would be the best approach.

In June 2018, then-Home Secretary Sajid Javid agreed to share evidence the British had gathered without seeking an assurance that Washington would forgo the death penalty. Elsheikh’s mother, Maha Elgizouli sued, seeking to halt the evidence transfer. She argued that sharing the evidence without a “death penalty assurance” would be unlawful.

The high court earlier this year suspended the transfer, saying the home secretary had failed to first analyze the transmittal under Britain’s 2018 data privacy law. Since then, the home secretary has done the proper analysis, the court ruled, saying the transfer is for “a valid law enforcement purpose.”

The court ruling said, “In our view, there is no principled basis” for Elgizouli’s appeal. On the contrary, it said, “there were good reasons to accede to the request” for assistance, which arose out of a probe “into the most shocking of criminal offences, including the murder by beheading of U.S. citizens.”

Scott Gilmore, a human rights attorney at Hausfeld LLP working with the Foley family, called Foley’s killing a “war crime and one of the most notorious atrocities of the Syrian conflict.

“We expect to see the suspects charged for torture, murder, and hostage taking — not just material support of terrorism,” he said in a statement.

Sen. Jeanne Shaheen (D-N.H.), who has worked with families of the slain U.S. hostages to press for a prosecution, said the court decision and transfer of evidence was “a critical step to ending the legal limbo that has stalled justice.”

“Today, we are several steps closer to bringing these terrorists to justice in the United States,” she said.