Earlier on Monday, a 19-year-old American was put on trial for attempting to join the Islamic State.

Mohammed Hamzah Khan, a U.S. citizen, was arrested on Saturday at O’Hare International Airport. Khan is from suburban southwest Bolingbrook, Illinois and was charged with attempting to provide material support to a foreign terrorist organization.

The FBI apprehended Khan before he boarded a flight on Australia Airlines to Vienna, where he would take another flight to Istanbul and then travel by bus to Syria to join the extremist group. According to an affidavit, federal agents searched his home and found a notebook outlining his itinerary as well as notes expressing his support of ISIL.

The affidavit also describes a note the teenager left behind for his parents in order to explain his departure. “First and foremost, please make sure to not tell the authorities for if this were to happen it will jeopardize not only the safety of us but our family as well,” it reads.

The note describes that Khan “was upset that, as an adult, he was obligated to pay taxes that would be used to kill his Muslim brothers and sisters.”

“Western societies are getting more immoral day by day. I do not want my kids being exposed to filth like this … I extend an invitation, to my family, to join me in the Islamic State,” Khan wrote.

According to an article by The Guardian, Khan told officials that an individual approached him on the Internet in regards to participating in the Islamic State. On September 26 that same individual bought Khan a $4000 round-trip plane ticket and gave him a number to call once he reached Istanbul.

The Chicago resident also told authorities that “he expected to be involved in some type of public service, a police force, humanitarian work, or a combat role.”

There will be a sentencing hearing on Thursday for Mohammed Hamzah Khan; a maximum sentence entails 15 years in prison along with a $250,000 fine. He is currently in custody.