As investigators sift through the lives of Tamerlan and Dzhokhar Tsarnaev trying to understand their radicalization and descent into violence, one clue almost seemed expected. Two U.S. officials tell The Daily Beast that, during his hospital room interrogation, Dzhokhar told FBI agents that he and his brother were influenced by the Internet sermons of Anwar al-Awlaki, the American-born preacher who was killed in a U.S. drone strike in Yemen in September 2011. The charismatic cleric was seen by the Obama administration as a uniquely dangerous terrorist because of his sermons (delivered in fluent, American-inflected English), his intuitive grasp of U.S. culture, and a burning desire to strike his birth nation…

We know Awlaki influenced the Tsarnaevs at least indirectly, through one of AQAP’s main propaganda organs. According to law enforcement sources, Dzhokhar has admitted to the FBI that he and his brother learned how to the build pressure cooker bombs they allegedly used in Boston from the terror group’s English-language Internet magazine, Inspire. For much of its existence, Inspire was run by Samir Khan, an American propagandist for AQAP who was close to Awlaki and was ultimately killed in the same U.S. drone strike that killed the Yemeni-American cleric.