A 19-year-old man from Illinois was charged with allegedly trying to join ISIS on Monday. Mohammed Hamzah Khan was trying to board a flight from O’Hare International Airport to Vienna when he was arrested, according to NBC. Investigations revealed he was trying to travel to Istanbul, then Syria and Iraq to join ISIS. Federal agents found letters at his home expressing his desire to join ISIS, according to NBC. A letter to his parents was also found, explaining his plan to them. He appeared in court Monday and remains in federal custody, according to NBC.