A member of the British Islamic State (ISIS) terrorist squad known as “The Beatles” pleaded guilty in a US courtroom on Thursday to helping the group torture and murder captives in Syria, including four Americans, NBC News reported.

Alexanda Kotey pleaded guilty to all charges against him in federal court in Alexandria, Virginia. US authorities said he and another British ISIS member, El Shafee Elsheikh, were involved in the kidnappings of international hostages.

Kotey and Elsheikh were each charged last year with hostage-taking resulting in death, conspiracy to commit murder against US citizens abroad, and conspiracy to provide material support to terrorists. Prosecutors have said both men could face life in prison.

Elsheikh and Kotey, along with two other British jihadists, were nicknamed “The Beatles” because of their English accents. The group's leader, Mohammed Emwazi who was known as "Jihadi John", was killed in an air strike in 2015 in Syria after an intensive manhunt.

Elsheikh and Kotey were accused them of being "leading participants in a brutal hostage-taking scheme" that resulted in the deaths of Western hostages, including American journalists James Foley and Steven Sotloff, aid workers David Haines, Allan Henning, Peter Kassig and Kayla Mueller, and Japanese hostage Kenji Goto.

A fourth member of the so-called “Beatles”, Aine Davis, is imprisoned in Turkey on terrorism charges.

Judge T.S. Ellis III on Thursday asked Kotey to approach the podium and remove his mask. When the judge asked Kotey if he pleaded guilty to counts one through eight, Kotey said, "Yes." He also said he was aware that the minimum sentence he faces is life without parole.

Family members of all four Americans were present in court to hear Kotey's plea but declined the judge’s offer to speak before the court.

Elsheikh and Kotey had been held since October 2019 in American military custody after being captured in Syria one year earlier by the US-based Syrian Democratic Forces while trying to escape Syria for Turkey.