In the years since Columbine, school shootings changed; they became ritualized. Illustration by Oliver Munday

On the evening of April 29th last year, in the southern Minnesota town of Waseca, a woman was doing the dishes when she looked out her kitchen window and saw a young man walking through her back yard. He was wearing a backpack and carrying a fast-food bag and was headed in the direction of the MiniMax Storage facility next to her house. Something about him didn’t seem right. Why was he going through her yard instead of using the sidewalk? He walked through puddles, not around them. He fiddled with the lock of Unit 129 as if he were trying to break in. She called the police. A group of three officers arrived and rolled up the unit’s door. The young man was standing in the center. He was slight of build, with short-cropped brown hair and pale skin. Scattered around his feet was an assortment of boxes and containers: motor oil, roof cement, several Styrofoam coolers, a can of ammunition, a camouflage bag, and cardboard boxes labelled “red iron oxide,” filled with a red powder. His name was John LaDue. He was seventeen years old.

One of the officers started to pat LaDue down. According to the police report, “LaDue immediately became defensive, stating that it is his storage unit and asked what I was doing and pulling away.” The officers asked him to explain what he was up to. LaDue told them to guess. Another of the officers, Tim Schroeder, said he thought LaDue was making bombs. LaDue admitted that he was, but said that he didn’t want to talk about it in the storage locker. The four went back to the Waseca police station, and LaDue and Schroeder sat down together with a tape recorder between them. “What’s going on today, John?” Schroeder asked. LaDue replied, “It’s going to be hard for me to talk about.” The interview began at 7:49 P.M. It continued for almost three hours.

He was making Molotov cocktails, LaDue said, but a deadlier variant of the traditional kind, using motor oil and tar instead of gasoline. From there, he intended to move on to bigger and more elaborate pressure-cooker bombs, of the sort used by the Tsarnaev brothers at the Boston Marathon bombing. “There are far more things out in that unit than meet the eye,” he told Schroeder, listing various kinds of explosive powder, thousands of ball bearings, pipes for pipe bombs, fifteen pounds of potassium perchlorate, nine pounds of aluminum powder, and “magnesium ribbon and rust which I use to make thermite, which burns at five thousand degrees Celsius.”

Schroeder asked him what his intentions were.

“I have a notebook under my bed that explains it,” LaDue replied.

Schroeder: “O.K. Can you talk to me about those intentions that are in the notebook?”

LaDue: “O.K. Sometime before the end of the school year, my plan was to steal a recycling bin from the school and take one of the pressure cookers I made and put it in the hallway and blow it up during passing period time. . . . I would detonate when people were fleeing, just like the Boston bombings, and blow them up too. Then my plans were to enter and throw Molotov cocktails and pipe bombs and destroy everyone and then when the SWAT comes I would destroy myself.”

In his bedroom, he had an SKS assault rifle with sixty rounds of ammunition, a Beretta 9-mm. handgun, a gun safe with an additional firearm, and three ready-made explosive devices. On the day of the attack, he would start with a .22-calibre rifle and move on to a shotgun, in order to prove that high-capacity assault-style rifles were unnecessary for an effective school attack.

Schroeder: “Do you have brothers and sisters?”

LaDue: “Yes, I have a sister. She’s one year older than me.”

Schroeder: “O.K. She goes to school too?”

LaDue: “Yes.”

Schroeder: “She’s a senior?”

LaDue: “She is.”

Schroeder: “O.K. So you would have done this stuff while she was at school as well?”

LaDue: “I forgot to mention a detail. Before that day, I was planning to dispose of my family too.”

Schroeder: “Why would you dispose of your family? What, what have they done?”

LaDue: “They did nothing wrong. I just wanted as many victims as possible.”

On February 2, 1996, in Moses Lake, Washington, a fourteen-year-old named Barry Loukaitis walked into Frontier Middle School dressed in a black duster and carrying two handguns, seventy-eight rounds of ammunition, and a hunting rifle. He killed two students and wounded a third before shooting his algebra teacher in the back. In the next two years, there were six more major incidents, in quick succession: sixteen-year-old Evan Ramsey, in Bethel, Alaska; sixteen-year-old Luke Woodham, in Pearl, Mississippi; fourteen-year-old Michael Carneal, in West Paducah, Kentucky; thirteen-year-old Mitchell Johnson and eleven-year-old Andrew Golden, in Jonesboro, Arkansas; fourteen-year-old Andrew Wurst, in Edinboro, Pennsylvania; and fifteen-year-old Kip Kinkel, in Springfield, Oregon. In April of 1999, Eric Harris and Dylan Klebold launched their infamous attack on Columbine High, in Littleton, Colorado, and from there the slaughter has continued, through the thirty-two killed and seventeen wounded by Seung-Hui Cho at Virginia Tech, in 2007; the twenty-six killed by Adam Lanza at Sandy Hook Elementary School, in 2012; and the nine killed by Christopher Harper-Mercer earlier this month at Umpqua Community College, in Oregon. Since Sandy Hook, there have been more than a hundred and forty school shootings in the United States.

School shootings are a modern phenomenon. There were scattered instances of gunmen or bombers attacking schools in the years before Barry Loukaitis, but they were lower profile. School shootings mostly involve young white men. And, not surprisingly, given the ready availability of firearms in the United States, the phenomenon is overwhelmingly American. But, beyond those facts, the great puzzle is how little school shooters fit any kind of pattern.

Evan Ramsey, who walked into his high school with a 12-gauge shotgun and killed two people, had a chaotic home life. His mother was an alcoholic who lived with a series of violent men. In one two-year stretch, he lived in ten foster homes and was both sexually and physically abused. When Evan was six, his father sent an ad to the local newspaper which it declined to publish, so he packed two guns, chained the door of the newspaper, set off smoke grenades, and held the publisher at gunpoint.

But Kip Kinkel, who shot his parents, then killed two others and wounded twenty-five at his high school, had not been traumatized. He had a loving family. He was the child of schoolteachers so beloved that seventeen hundred people came to their memorial service. Kinkel was psychotic: he thought the Chinese were preparing to attack the United States, that Disney had plans for world domination, and that the government had placed a computer chip inside his head.

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Meanwhile, the architect of the Columbine killings, Eric Harris, was a classic psychopath. He was charming and manipulative. He was a habitual lawbreaker: he stole, vandalized, bought guns illegally, set off homemade bombs, and at one point hacked into his school’s computer system. He wrote “Ich bin Gott”—German for “I am God”—in his school planner. His journals were filled with fantasies about rape and mutilation: “I want to tear a throat out with my own teeth like a pop can. I want to gut someone with my hand, to tear a head off and rip out the heart and lungs from the neck, to stab someone in the gut, shove it up to their heart.” A school shooter, it appears, could be someone who had been brutally abused by the world or someone who imagined that the world brutally abused him or someone who wanted to brutally abuse the world himself.