ROCKFORD, Wash. (AP) — A Washington state student accused of a deadly school shooting had been suspended for bringing threatening notes to school shortly before the attack.

Freeman School District Superintendent Randy Russell tells The Spokesman-Review that the district followed protocol by suspending the student and sending him for a mental evaluation.

The shooting occurred on the first day 15-year-old Caleb Sharpe returned from the suspension to Freeman High School in Rockford, the newspaper reported.

Court documents say he pulled an assault weapon from a bag, but it jammed.

Police say Sharpe pulled a pistol from his coat and shot and killed a 15-year-old boy, and wounded three female students.

Sharpe was arrested and has yet to make an appearance in juvenile court. He faces a charge of first-degree murder.

After the shooting, some students told The Spokesman-Review that Sharpe had passed notes to his friends warning them that he planned to do “something stupid.” One of the notes was then reportedly passed on to a school counselor.

Russell said Friday that federal law bars him from discussing details about any specific student. But when asked if a school official had contacted Sharpe’s parents about the notes, suspended Sharpe and sent him for a mental evaluation, the superintendent said, “that’s what our protocol looks like and we followed it to a T.”

Russell acknowledged that the system has some limitations.

“It’s very frustrating, because as an educator, you have to be able to work and rely on outside agencies to provide support,” he said. “Folks are doing the best they can, but they are also working with limited resources.”

He said staff would be working all weekend to prepare Freeman High School to reopen on Monday. He said parents were encouraged to accompany their kids back to the school, and to spend as much time as they would like with the students.

“Our plan is to have the students, staff and parents walk arm in arm and go through the high school. We want each student to feel safe and secure at the school,” he said.

Featured Image: In this Wednesday, Sept. 13, 2017 photo, Spokane County Sheriff’s deputies escort Caleb Sharpe from the Public Safety Building to the Juvenile Detention Center in Spokane, Wash. Authorities say Sharpe opened fire Wednesday in a hallway at Freeman High School in Rockford, south of Spokane, killing a classmate who confronted him and wounded three others before being stopped by a custodian. (Colin Mulvany/The Spokesman-Review via AP)