By Pat Pheifer, Minneapolis Star Tribune

WASECA — A Waseca teenager who idolized the Columbine High School shooters plotted to murder his parents and sister, then go on a rampage through Waseca’s junior high and high school, setting off pressure cooker bombs, throwing Molotov cocktails and gunning down fleeing students, according to criminal charges filed Thursday.

John David LaDue, 17, allegedly detailed his plans in a 180-page notebook, police say. He’d been amassing a stockpile of handguns, automatic weapons and bomb-making equipment in his bedroom and in a storage unit, the charges claim.

He intended to carry out his attack on April 20, the 15-year anniversary of the Columbine shootings in Littleton, Colo., that killed 13 people. But he scrapped that plan when he realized April 20 was Easter Sunday, police said, and authorities believe he was instead planning the attack for the next few weeks.

“I think he had put enough preparation and forethought into this … that he was well on his way to carrying it out,” said Capt. Kris Markeson of the Waseca Police Department.

After his arrest, LaDue told police he intended to kill “as many students as he could,” the criminal complaint said.

LaDue was caught when a witness saw him enter the storage unit at Mini Max storage in Waseca on Tuesday evening and close the door behind him. Thinking it suspicious, the bystander called police, who found LaDue inside with his stockpile of equipment, which included “numerous materials commonly used for making explosive devices,” the complaint said.

They discovered evidence including ammo boxes, a scale, a pressure cooker box and packing material for red iron oxide, the complaint said. It appears that LaDue obtained many of his bomb-making materials and instructions over the Internet, Markeson said.

LaDue apparently didn’t expect to survive his attack, figuring that he’d be shot by a SWAT team during his attack, the complaint said.

Police say LaDue admitted to setting off small bombs at the playground at Hartley Elementary School in March, as well as at other locations around town, to practice for his plot.

Neighbors said LaDue, a junior at the high school, is quiet. Many remarked that he was often seen in his family’s yard, throwing knives and axes at a tree.

“This little boy was shy,” said Bailey Root, 19, a neighbor who said she grew up with LaDue. “He never talked. He always followed the leader. He was never one to step up and do anything.”

LaDue never got into trouble at school and was on the B honor roll, said Waseca Schools Superintendent Tom Lee.

LaDue appeared in court Thursday morning and was sent to a juvenile detention center in Red Wing. He’d been detained at such a center in Rochester after his arrest, but that facility refused to take him back after he made “homicidal threats” against staff members, said Assistant Waseca County Attorney Brenda Miller.

He is charged with four counts of attempted premeditated first-degree murder, two counts of first-degree damage to property and six counts of possession of a bomb by someone under 18. His next court hearing is set for May 12.

Read more: Waseca murder plot suspect described as good student