In the undated letter, Hasan — who fatally shot 13 people and injured more than 30 at Fort Hood in 2009 in what the Defense Department called “workplace violence”– tells ISIS leader Abu Bakr al-Baghdadi that he wants to join the caliphate.

“I formally and humbly request to be made a citizen of the Islamic State,”Hasan says in the handwritten document addressed to “Ameer, Mujahid Dr. Abu Bakr al-Baghdadi.”

“It would be an honor for any believer to be an obedient citizen soldier to a people and its leader who don’t compromise the religion of All-Mighty Allah to get along with the disbelievers.”