CHICAGO–An Aurora, Illinois man was sentenced Friday to 15 years in prison, and a lifetime of supervised release, for attempting to travel overseas to Syria to join Jabhat al-Nusrah, a designated foreign terrorist organization.

Abdella Ahmad Tounisi, 23, was arrested at O’Hare International Airport in Chicago in April 2013 as he attempted to board a flight to Istanbul, Turkey. Tounisi had spent four months conducting online research related to overseas travel and violent jihad, focusing specifically on Syria and the violent Jabhat al-Nusrah terrorist organization

He pleaded guilty in 2015 to one count of attempting to provide material support to a foreign terrorist organization. According to his plea agreement, Tounisi in early 2013 made online contact with an individual he believed to be a recruiter for Jabhat al-Nusrah. He and the purported recruiter exchanged a series of emails, during which Tounisi shared his plan to go to Syria by way of Turkey, as well as his willingness to fight for the jihadist cause, the plea agreement states. Unbeknownst to Tounisi, the purported recruiter was actually an FBI employee.

Tounisi, a U.S. citizen, requested an expedited passport and purchased an airline ticket for the flight from Chicago to Istanbul. He arrived at O’Hare on the evening of April 19, 2013, and was arrested after passing through security in the international terminal.

The defendant was a close friend of Adel Daoud, of Hillside, Illinois, who was arrested on Sept. 14, 2012, for allegedly attempting to detonate a bomb outside a bar in downtown Chicago. Tounisi recommended certain attack techniques to Daoud but ultimately decided against participating in the attack. Daoud was charged separately and is awaiting trial in federal court in Chicago.