JOPLIN, MO. ? A 13-year-old student wearing a long, dark green trenchcoat and carrying a replica of an AK-47 fired one shot in a middle school Monday morning and told two administrators, “Please don’t make me do this,” officials said.

No one was injured, and the student was taken into custody.

The student, a seventh-grader who was not identified, pointed the gun at two students as he entered Memorial Middle School and was confronted by an administrator, who tried to talk him into putting down the Mac-90 assault rifle, said Joplin police spokesman Lt. Geoff Jones.

The administrator, Assistant Superintendent Steve Doerr, told the student, “You don’t have to do this, there is another way,” Superintendent Jim Simpson said.

The boy refused to put the gun down and fired one shot into the ceiling. Doerr then went into a nearby office to call police.

The student kept trying to fire, but the rifle jammed. Joplin Police Officer Curt Farmer said the student was aiming at the ceiling when the gun jammed.

“We don’t believe he was trying to fire at administrators or students,” Farmer said. The student then left the building, followed by another administrator.

Police arrived shortly after and arrested the boy as he crouched behind a nearby building.

Farmer said officers found a note in the student’s duffel bag indicating he had placed an explosive in the school, which has about 750 students. The bag also contained military manuals, notes on how to build an improvised explosive device and detailed drawings of the school.

The student also was wearing a T-shirt over his head with holes cut out for eyes, Farmer said.

“This was quite well thought out,” Farmer said. “He had been planning this for a long time.”

Students in the school were moved to nearby Joplin Memorial Hall.

Later Monday, police searched the suspect’s home and removed rifles and handguns. The Missouri State Highway Patrol bomb squad also was called in after a suspicious looking device was found in the front yard of the home. But the package turned out to be non-threatening.

The patrol also used bomb-sniffing dogs and officers to search the school, but no bombs or weapons were found.