HARRISBURG, Pa. (WHTM) – A Harrisburg man accused of helping ISIS has pleaded guilty to terrorism charges.

Jalil Ibn Ameer Aziz, 20, pleaded guilty Monday before US District Court Chief Judge Christopher C. Conner to conspiracy to provide material support and resources to a designated foreign terrorist organization and transmitting a communication containing a threat to injure.

Aziz could spend up to 20 years in prison. He’s accused of using Twitter to spread ISIS propaganda, actively recruit new members and share the names and addresses of about 100 American service members with statements such as “kill them in their own lands” and “behead them in their own homes.”

Authorities also suspect Aziz may have been plotting an attack before his arrest in December 2015. They said a backpack in his closet had five high-capacity magazines loaded with ammunition, a modified kitchen knife, a thumb drive, medication and a balaclava.

No sentencing date has been scheduled.Get breaking news, weather and traffic on the go. Download our News App and our Weather App for your phone and tablet.