The 14-year-old, whose name is not being released because he is a juvenile, is facing 16 felony charges.
He is accused of bringing several weapons, including guns and knives, to the school and firing one of the guns into a ceiling.
Prosecutors also contend the boy briefly prevented people from the leaving the room before he was tackled and detained by a teacher.
At a previous court hearing, a fitness exam was ordered for the boy, who is in custody at the McLean County Juvenile Detention Center.
Assistant State's Attorney Bill Workman said Tuesday the exam is over and showed the boy is fit to stand trial.
A hearing is set for November 6.
Workman said the state expects to make a decision by then on whether it will seek a request to transfer the case to adult court.
No one was hurt in the shooting.