El Shafee Elsheikh, 33, a former member of a four-person ISIS cell nicknamed “the Beatles,” appeared in U.S. federal court on Wednesday for the beginning of his criminal trial. Elsheikh and “the Beatles”—named for their British accents—were responsible for releasing videos of the notorious beheadings and murders of American journalists James Foley and Steven Sotloff and aid workers Kayla Mueller and Peter Kassig, among many others. Spanish journalist Javier Espinosa and a former captor of the cell has stated that of the four cell members, Elsheikh “was the most brutal” because he decided “who was going to be beaten.” Elsheikh’s lawyer, Edward MacMahon, plans to argue that his client shouldn’t bear any legal responsibility for the killings. “It was horrific and senseless. None of that is in dispute,” MacMahon said. “What is in dispute—and what you must decide—is whether Mr. Elsheikh bears any legal responsibility.” Prosecutor John Gibbs stated in opening remarks that he does not “intend to display the most graphic evidence publicly,” but the trial will feature testimony from released hostages. He said Elsheikh “played a role in a brutal hostage-taking scheme.” One other member of the cell was flown from Iraq to the U.S. for trial by the U.S. military, while another died in a drone strike, and the fourth was convicted and jailed for terrorism in Turkey.