"It's fascinating," talking to him, Vidino said. "I've worked on issues of jihadism in the U.S. for 15 years," and even on cases in which he was an expert witness and had pored over all the court documents, Morton can astonish him. "He was with these people, planning . . . He'll tell me details that, oh my God, that completely change my perspective on the case," as with the case of Samir Khan, who wrote that he was proud to be a traitor to the United States and furthered efforts of al-Qaida's offshoot in Yemen.