A 19-year-old man has pleaded not guilty to charges that he opened fire at a northern Illinois high school last month.

He entered his plea Thursday in Lee County and faces felony gun charges. He is being held in jail on $2 million bond.

He is accused of taking a semi-automatic rifle to Dixon High School on May 16 as graduation practice was taking place in the gym. Authorities allege that the student, who was a member of the graduating class, fired at a gym teacher and was running away when he was confronted by school resource officer Mark Dallas.

The student is accused of firing at Dallas. Dallas returned fire, striking him in the shoulder and the hip. Neither Dallas nor the gym teacher was injured.