JOPLIN, Missouri (AP) -- Fascinated by the Columbine bloodbath, a 13-year-old boy in a dark green trench coat and mask carried an assault rifle into his school Monday, pointed it at students and fired a shot into a ceiling before the weapon jammed, authorities said. No one was hurt.
"Please don't make me do this," he was quoted as telling administrators before police arrested him and thwarted what they called a "well thought-out plan" to terrorize his school.
Police said a note in the student's backpack indicated he had planted an explosive in the school, but no bombs were found.
Lt. Geoff Jones said the boy's motives were unclear. School officials said the student had no major disciplinary problems.
The seventh-grader, whose name was not immediately released, pointed the gun at two students inside Joplin Memorial Middle School but was confronted by an administrator who tried to talk him into putting the gun down, Jones said.
The boy refused and fired a shot into the ceiling of an entryway, police said. He tried to continue firing but the rifle jammed, according to Jones. The student then left the building.
"We don't believe he was trying to fire at administrators or students," Officer Curt Farmer said.
Officers arrested the teen behind a nearby building. Police described his weapon as a Mac-90, a replica of an AK-47 assault rifle.
Superintendent Jim Simpson said police told him the boy had a fascination with the Columbine High shooting that left 15 people dead near Littleton, Colorado in 1999.
The student was wearing a trench coat -- like the student gunmen at Columbine -- and had a T-shirt over his head with eye holes cut out, Farmer said.
Farmer said that along with note indicating an explosive was placed in the school, the boy's backpack held military manuals, instructions on assembling an improvised explosive device and detailed drawings of the school.
"This was quite well thought-out," Farmer said. "He had been planning this for a long time."
Jones said the gun belonged to the boy's parents, who kept the weapon in a safe at home. The parents told police their son apparently knew the combination to the gun safe. Farmer said it is not uncommon for people in the area to own assault weapons.
The shooting happened about 10 minutes before school started.
"A lot of the kids were scared," said eighth-grader Deron Moore. "After they said on the intercom that there was someone with a gun, I kind of went into shock."
Joplin, which has about 41,000 residents, is on the Kansas state line about 140 miles south of Kansas City, Missouri.
Schools across the country have been on alert since three deadly school shootings in three states in a week. In Pennsylvania, church bells tolled Monday morning in remembrance of the five young Amish girls killed at their one-room schoolhouse one week earlier.