According to a statement from the FBI, 19-year-old Mohammed Hamzah Khan was arrested Saturday night for allegedly attempting to journey overseas to join the Islamic State of Iraq and Syria (ISIS).

Khan was arrested at O’Hare International Airport by Chicago FBI’s Joint Terrorism Task Force. He was preparing to board a flight to Vienna, Austria, before he planned to continue on to Istanbul, Turkey.

Khan has been charged with one count of attempting to provide material support to a foreign terrorist organization.

Federal agents searched Khan’s residence and found several handwritten documents that appeared to be written by Khan, which expressed support for ISIS.

The Associated Press notes that one page in a notebook contained a drawing of what looked like an armed fighter with an ISIS flag and the phrase “Come to Jihad” written in Arabic. Another drawing, according to a complaint cited by The AP, revealed locations where Khan might attempt to cross into Syria from Turkey.

According to Reuters, agents also discovered a note in which Khan invited his family members to join him. “I extend an invitation, to my family, to join me in the Islamic State,” the note reportedly read.

If convicted, Khan faces a maximum penalty of 15 years in prison and a $250,000 fine.

According to the FBI, Khan remains in federal custody pending a detention hearing on Thursday.