Nidal Hasan, the Army psychiatrist who killed 13 people in a 2009 Fort Hood shooting, wrote a letter expressing interest in becoming a citizen of the Islamic State, his attorney told ABC News.
Hasan, a former major, wrote a two-page letter to Abu Bakr al-Baghdadi, the leader of ISIS, which was first reported by Fox News.
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Hasan, a Muslim-American whose Palestinian-immigrant parents raised him in Virginia, has described himself as a "mujahedeen," or Muslim holy warrior in carrying out his attack.
Hasan, 43, was sentenced to death after the Texas shooting and is on the military's death row at the U.S. Disciplinary Barracks at Fort Leavenworth, Kansas.
News of Hasan's letter comes days after Minnesota native Douglas McAuthur McCain, 33, was said to have died while fighting with the brutal al Qaeda breakaway organization.
Fort Hood Gunman Wants to Join ISIS