National polls taken shortly after the attack would identify all sorts of culprits contributing to the tragedy: violent movies, video games, Goth culture, lax gun laws, bullies, and Satan. Eric did not make the list. Dylan didn’t either. They were just kids. Something or someone must have led them astray.

The frightening part of this book is that it offers no scapegoat, no easy answer. The closest thing it offers is in the psychological profiles of the two perpetrators, Eric Harris and Dylan Klebold: that Eric was a psychopathic and Dylan was majorly depressed. And “an angry, erratic depressive and a sadistic psychopath make a combustible pair.”

Insanity was marked by mental confusion. Eric Harris expressed cold, rational calculation. Fuselier ticked off Eric’s personality traits: charming callous, cunning, manipulative, comically grandiose, and egocentric, with an appalling failure of empathy. It was like reciting the Psychopathy Checklist.

The closest thing I came to any sort of conclusion while reading this was when I was watching a documentary of the JFK assassination and some perceptive videographer captured this image from the movie poster of the film Lee Harvey Oswald was watching at the Texas Theatre when he was captured, War is Hell:

As chilling as that sentiment is, this book is a well-crafted snapshot of the late 90s. David Cullen approaches this delicate subject with nuance and respect. Along with 9/11, I consider this travesty to be one of the defining mass events of my adolescence. Harrowing, but necessary, reading.

But in the great media blunders during the initial coverage of this story, where nearly everyone got the central factors wrong, I was among the guilty parties. I hope this book contributes to setting the story right.

In the year since the book’s release one of the most common questions I heard was “Why no pictures?” While I knew from the beginning that I did not want to include them, it took lengthy discussion with readers to articulate exactly why. It comes down to the fact that photos capture one instant in a person’s life. I hoped to bring these people alive as complex individuals: hopeful, gloomy, anxious, playful, devious, etc. Photos, within these covers, undermine that, in my opinion. So we left them out.

A terrifying affliction had infested America’s small towns and suburbs: the school shooter. We knew it because we had seen it on TV. We had read about it in the newspapers. It had materialized inexplicably two years before. In February 1997, a sixteen-year-old in remote Bethel, Alaska, brought a shotgun to high school and opened fire. He killed the principal and a student and injured two others. In October, another boy shot up his school, this time in Pearl, Mississippi. Two dead students, seven wounded. Two more sprees erupted in December, in remote locales: West Paducah, Kentucky, and Stamps, Arkansas. Seven were dead by the end of the year, sixteen wounded.

The following year was worse: ten dead, thirty-five wounded, in five separate incidents. The violence intensified in the springtime, as the school year came to a close. Shooting season, they began to call it. The perpetrator was always a white boy, always a teenager, in a placid town few had ever heard of. Most of the shooters acted alone. Each attack erupted unexpectedly and ended quickly, so TV never caught the turmoil.

And then…nothing. During the entire 1998-1999 school year, not a single shooter emerged. The threat faded and a distant struggle took hold of the news. The slow disintegration of Yugoslavia erupted again. In March 1999, as Eric and Dylan finalized their plans, NATO drew the line on Serbian aggression in a place called Kosovo. The United States began its largest air campaign since Vietnam. Swarms of F-15 squadrons pounded Belgrade. Central Europe was in chaos; America was at war. The suburban menace of the school shooter had receded.

Eric had no plans, with seemed odd for a kid with so much potential. He was a gifted student taking a pass on college. No career plans, no discernible goals. It was driving his parents crazy.

Rejection was Eric’s weak spot, especially by females.

Columbine High School was built in 1973 on a dirt road off a larger dirt road way out in horse country. It was named after the flower that blankets sections of the Rockies. Scraggy meadows surrounded the new building, fragrant with pine trees and horse manure. Hardly anybody lived there, but Jeffco was bracing for an influx. Court-ordered busing had spurred an avalanche of white flight out of Denver, and subdivisions were popping up all along the foothills.

By April 1999, the plain was nearly filled, all the way to the foothills. But the fiercely independent residents refused to incorporate. A new town would only impose new rules and new taxes. The 100,000 new arrivals filled one continuous suburb with no town center: no main street, no town hall, town library, or town name. No one was sure what to call it. Littleton is a quiet suburb south of Denver where the massacre did not actually occur. Although the name would grow synonymous with the tragedy, Columbine lies several miles west, across the South Platte River, in a different county with separate schools and law enforcement.

You can’t really teach a kid anything: you can only show him the way and motivate him to learn it himself.

The fire alarm had not been silenced. The men used hand signals. Every cupboard or broom closet had to be treated as a hot zone. Many doors were locked, so they blasted them open with rifle fire. Kids trapped in classrooms heard gunfire steadily approaching. Death appeared imminent. Parents, reporters, and even cops outside heard the shots and came to similar conclusions. One room at a time, the team worked methodically toward the killers. It would take three hours to reach their bodies.

Much of the country was watching the standoff unfold. None of the earlier school shootings had been televised; few American tragedies had. The Columbine situation played out slowly, with the cameras rolling. Or at least it appeared that way: the cameras offered the illusion we were witnessing the event. But the cameras had arrived too late. Eric and Dylan had retreated inside after five minutes. The cameras missed the outside murders and could not follow Eric and Dylan outside. The fundamental experience fore most of America was almost witnessing mass murder. It was the panic and frustration of not knowing, the mounting terror of horror withheld, just out of view.

It took a certain voice to talk down a gunman.Agent Fuselier was always gentle and reassuring. No matter how erratic the subject’s behavior, Fuselier always responded calmly. He exuded tranquility, offered a way out. He trained negotiators to read a subject quickly, to size up his primary motivations. Was the gunmen driven by anger, fear, or resentment? Was he on a power trip? Was the assault meant to feed his ego, or was he caught up in events beyond his control? Getting the gun down was primarily a matter of listening. The first thing Fuselier taught negotiators was to classify the situation as hostage or nonhostage. To laymen, humans at gunpoint equaled hostages. Not so.

An FBI field manual citing Fuselier’s research spelled out the crucial distinction: hostages are a means to fulfill demands. “The primary goal is not to harm the hostage,” the manual said. “In fact, hostage takers realize that only through keeping the hostages alive can they hope to achieve their goals.” They act rationally. Nonhostage gunmen do not. The humans mean nothing to them. “These individuals act in an emotional, senseless, and often self-destructive way.” They typically issue no demands. “What they want is what they already have, the victim. The potential for homicide followed by suicide in many of these cases is very high.”

To the FBI, the nonhostage distinction is critical. The Bureau recommends radically different strategies in those cases–essentially, the opposite approach. With hostages, negotiators remain highly visible, make the gunmen work for everything, and firmly establish that the police are in control. In nonhostage situations, they keep a low profile, “give a little without getting in return” (for example, offering cigarettes to build rapport.), and avoid even a slight implication that anyone but the gunman is in control. The goal with hostages is to gradually lower expectations; in nonhostage crises, it’s to lower emotions.

Mass murderers tended to work alone, but when they did pair up, they rarely chose their mirror image. Fuselier knew he was much more likely to find a pair of opposites holed up in that building. It was entirely possible that there was no single why–and much more likely that he would unravel one motive for Eric, another for Dylan.

The Columbine crisis was never a hostage standoff. Eric and Dylan had no intention of making demands. SWAT teams searched the building for over three hours, but the killers were lying dead the entire time. They had committed suicide in the library at 12:08, forty-nine minutes after beginning the attack. The killing and the terror had been real. The standoff had not.

It was a common response. Survivors focused on mundane tasks–tiny victories they could still accomplish. Many were horrified by their thoughts.

He made it to the podium and began with an apology: “I am so sorry for what happened and for what you are feeling.” He reassured them and promised to stand by them–“I will be there for you, whenever you need it”–but refused to sugarcoat what they were in for. “I’d like to take a wand and wipe away what you are feeling, but I can’t do that. I’d like to tell you those scars will heal, but they will not,” he said.

His students were grateful for the candor. So many kids in Clement Park that morning would describe how tired they already were of hearing so many people tell them everything would be all right. They knew the truth; they just wanted to hear it.

Kids were having trouble with their parents, especially their moms. “It’s kind of hard for me to sit at home,” a boy said. “Like when my mom come home, I try to stay out of the house.” Lots of other boys nodded; more and more told the same story. Their mothers were so scared, and the fear hadn’t abated when they’d found their kids; now they just wanted to hug them. Hug him/her forever–that was the refrain Tuesday. Wednesday, it was My mom doesn’t understand. Emotionally, their mothers were wildly out of sync. At first, the kids needed the hugs badly; now they needed them to stop.

National polls taken shortly after the attack would identify all sorts of culprits contributing to the tragedy: violent movies, video games, Goth culture, lax gun laws, bullies, and Satan. Eric did not make the list. Dylan didn’t either. They were just kids. Something or someone must have led them astray.

Detectives had stripped down Eric and Dylan’s bedrooms, left the furniture, and hauled out much of the rest. The Klebold house yielded little–some yearbooks and a small stack of writings–but Dylan had wiped his hard drive clean. Eric’s house provided a mother lode: journals, more computer rants, an audiotape, videotapes, budgets and diagrams and timelines…Eric had documented everything. He’d wanted us to know.

There were plenty of witnesses, but a few were tempted to inflate their accounts, and the more dramatic versions of their stories tended to travel.

Reverend Don Marxhausen disagreed with all the riffs on Satan. He saw two boys with hate in their hearts and assault weapons in their hands. He saw a society that needed to figure out how and why–fast. Blaming Satan was just letting them off easy, he felt, and copping out on our responsibility to investigate. The “end of days” fantasy was even more infuriating.

The kids kept pouring into the churches. What began Tuesday night as a means to escape from their parents and find each other quickly became a habit. Night after night they returned to the churches in vast numbers–kids who had not seen an altar in years. For some it was a conscious choice to look to God in desperation, but most said it was just a place to go.

Had the propane bombs detonated, they would have incinerated most or all of the inhabitants of the commons. They would have killed five hundred people in the first few seconds. Four time the toll in Oklahoma City. More than the ten worst domestic terrorist attacks in U.S. history combined.

For investigators, the big bombs changed everything: the scale, the method, and the motive of attack. Above all, it had been indiscriminate. Everyone was supposed to die. Columbine was fundamentally different from the other school shootings. It had not really been intended as a shooting at all. Primarily, it had been a bombing that failed.

Detectives assembled portraits of the killers that felt maddeningly similar and vanilla: youngest sons of comfortable, two-parent, two-child, quiet small-town families. The Klebolds had more money; the Harrises were more mobile. Each boy grew up in the shadow of a single older sibling: a bigger, taller, stronger brother. Eric and Dyan would eventually share the same hobbies, classes, jobs, friends, clothing choices, and clubs. But they had remarkably different interior lives. Dylan always saw himself as inferior. The anger and the loathing traveled inward. “He was taking it out on himself,” Judy Brown said.

“The impression I always got from them was they kind of wanted to be outcasts,” another classmate said. “It wasn’t that they were labeled that way. It’s what they chose to be.”

“Outcast” was a matter of perception. Kids who slapped that label on Eric and Dylan meant the boys rejected the preppy model, but so did hundreds of other kids at the school. Eric and Dylan had very active social calendars, and far more friends than the average adolescent.

Dr. Frank Ochberg, a professor in psychiatry at Michigan State University and a leading expert on PTSD, would be brought in by the FBI a few months later and would spend years advising mental health workers on the case. He and a group of psychiatrists had first developed the term in the 1970s. They had observed a phenomenon that was stress-induced but was qualitatively more severe, and brought on by a really traumatic experience. This was something that produced truly profound effects and lasted for years or, if untreated, even a lifetime.

After the murders, controversies raged about the role of violent films, music, and video games. Some columnists and talk-radio hosts saw an easy cause and effect. That seems simplistic for Eric–who was a gifted critical thinker with a voracious appetite for the classics–and absurd for his partner. Dylan identified with depressives on the brink of suicide. He focused on fictional characters mired in the hopelessness he already felt.

Investigators identified nearly a dozen common misperceptions among library survivors. Distortion of time was rampant, particularly chronology. Witnesses recalled less once the killers approached them, not more. Terror stops the brain from forming new memories. Survivors also clung to reassuring concepts: that they were actually hiding by crouching under tables in plain sight.

When the conspiracy evaporated, it left a dangerous vacuum. Dr. Fuselier saw the danger early on. “Once we understood there was no third shooter, I realized that for everyone, it was going to be difficult to get closure,” he said. The final act of the killers was among their cruelest: they deprived the survivors of a living perpetrator. They deprived the families of a focus for their anger, and their blame. There would be no cathartic trail for the victims. There was no killer to rebuke in a courtroom, no judge to implore to impose the maximum penalty. South Jeffco was seething with anger, and it would be deprived of a reasonable target. Displaced anger would riddle the community for years.

Insanity was marked by mental confusion. Eric Harris expressed cold, rational calculation. Fuselier ticked off Eric’s personality traits: charming callous, cunning, manipulative, comically grandiose, and egocentric, with an appalling failure of empathy. It was like reciting the Psychopathy Checklist.

A second, less common approach to the banality of murder seems to be the dyad: murderous pairs who feed off each other. Criminologists have been aware of the dyad phenomenon for decades: Leopold and Loeb, Bonnie and Clyde, the Beltway snipers of 2002. Because dyads account for only a fraction of mass murderers, little research has been conducted on them. We know that the partnerships tend to be asymmetrical. An angry, erratic depressive and a sadistic psychopath make a combustible pair. The psychopath is in control, of course, but the hotheaded sidekick can sustain his excitement leading up to the big kill. “It takes heat and cold to make a tornado,” Dr. Fuselier is fond of saying. Eric craved heat, but he couldn’t sustain it. Dylan was a volcano. You could never tell when he might erupt.

It’s revealing that Eric took on a provocative issue and gauged exactly how far he could run with it. Fuselier saw no moral confusion, clearly no mental illness–Eric demonstrated his sanity by his ability to navigate such tricky terrain. He got the satisfaction of warning us in yet another way without giving himself away.

Eric was counting on a slow recovery. He was less concerned about killing hundreds of people on April 20 than about tormenting millions for years. His audience was his target.

For years after his death, Eric would be seen as a bundle of contradictions. But the threads come together in “I aint going out without a fight.” Eric dreamed big but settled for reality. Unfortunately, that passage remained hidden from the public for years. Scattered quotes from his writing would leak out, and viewed as fragments, they could seem contradictory. Was Eric planning a gun battle or a plane crash or a terrorist attack bigger than Oklahoma City’s? If he was so intent on mass murder, why did he kill only thirteen? Trying to understand Eric from the information available was like reading every fifth page of a novel and concluding that none of it made sense.

Dr. Fuselier had the advantage of reading Eric’s journal from start to finish. Without the holes, the thrust was obvious: humans meant nothing; Eric was superior and determined to prove it. Watching us suffer would be enjoyable.

No significant national gun-control legislation was enacted in response to Columbine.

That is a standard recruitment technique for aspiring mass murderers, Fuselier explained. They toss out the idea, and if it’s shunned it’s a “joke”; if the person lights up, the recruiter proceeds to the next step.

Six months after the tragedy, Mr. D had run into a Japanese film crew up there, enraptured by the charming rodents. The crew had come to shoot a documentary about the massacre; they had expected teen angst and American social Darwinism. They were seduced by the tranquility–less than a hundred yards from the school. They shot hours of footage of the twelve-inch prairie dogs.

The Japanese film crew saw this place somewhat differently than Americans did. Their depiction was by turns tumultuous, brutal, explosive, and serene.

In the ten years after Columbine, more than eighty school shootings took place in the United States.