“Early warning signs began to surface in 1996, when Eric Harris first created a private website on America Online. Harris had initially created the site to host gaming levels of the video game Doom which he and his friend, Dylan Klebold, had created, primarily for friends. Upon this site, Harris began a blog, which included jokes and small journal entries concerning his thoughts on parents, school, and friends. By the end of the year, the site contained instructions on how to cause mischief, as well as instructions on how to make explosives and logs in which he described the trouble he and Klebold were causing. Beginning in early 1997, the blog postings began to show the first signs of Harris’s ever-growing anger against society.^[4]

Harris’s site attracted few visitors, and caused no concern until late 1997, when Klebold gave the web address to Brooks Brown, a former friend of Harris. Brown’s mother had filed numerous complaints with the Jefferson County Sheriff’s office concerning Harris, believing him to be dangerous. The website contained numerous death threats directed against Brown: Klebold apparently knew that if Brooks accessed the address, he would discover the content and inform his parents, with the parents’ subsequent actions resulting in the authorities being notified. Brown’s parents did subsequently view the content and contacted the Jefferson County Sheriff’s Office, and an investigator named Michael Guerra was subsequently notified of the site’s existence.^[4] Upon accessing Harris’s website site, Guerra discovered numerous violent threats directed against the students and teachers of Columbine High School. Other material included blurbs Harris had written concerning his general hatred of society, and his desire to kill those who annoyed him. Harris had begun noting the completion of construction of pipe bombs upon his site. In addition, he had noted a gun count and compiled a hit list of individuals he wished to target (although no overall plan detailing how he intended to attack targets he had specified was ever posted upon the site).^[5] As Harris had stated upon his website that he was in possession of explosives, Guerra wrote a draft affidavit, requesting a search warrant of the Harris household, but the document was never filed.^[4][6]

On January 30, 1998, Eric Harris and Dylan Klebold committed an act of theft in which the pair stole tools and other equipment from a van parked near the city of Littleton, Colorado.^[7] Both youths were arrested and subsequently attended a joint court hearing, where they pleaded guilty to the felony theft. The judge sentenced the pair to attend a juvenile diversion program.

Within the juvenile diversion program, both boys attended mandated classes and conversed with diversion officers. One of the classes the pair attended focused upon anger management. Harris also began attending therapy classes with a psychologist. However, despite Klebold having a history of drinking and his failing a dilute urine test, neither he nor Harris attended any substance abuse classes.^[8]

Harris and Klebold were eventually released from diversion several weeks early due to their good behavior upon the program,^[4] although both youths remained on probation.^[9] Harris wrote an ingratiating letter to the owner of the equipment they stole, offering apologies and empathy for his and Klebold’s actions.^[10] Harris would continue to attend scheduled appointments with his psychologist until a few months before he and Klebold were to commit the Columbine High School massacre.

Shortly after his and Klebold’s court hearing, Harris’s online blog disappeared, and his website was reverted to its original purpose of posting user-created levels of the online video game Doom. Harris began to write a paper journal, where he documented his thoughts and plans. He also boasted in these journal entries that he had faked his previously written letter of regret to the owner of the van from which he and Klebold had stolen items and applauded himself as to his deception skills.^[11]

Despite having reverted his website to the its initially created purpose of hosting video game trivia, Harris continued to dedicate a section of his website to posting information regarding his and Klebold’s progress regarding their collection of guns and building of the bombs they subsequently used in the attack upon their school. (After the existence of this website was made public, AOL permanently deleted the website from its servers.)^[12]

In one of his scheduled meetings with his psychiatrist, Eric Harris complained of depression, anger and to possessing suicidal thoughts. As a result of this, he was prescribed the anti-depressant Zoloft. He subsequently complained to feeling restless and to experiencing a lack of concentration to his doctor, and in April, he was switched to a similar anti-depressant drug— Luvox.^[13] At the time of his death, Harris had therapeutic Luvox levels in his system. Some analysts, such as psychiatrist Peter Breggin, have argued that one or both of these medications may have contributed to Harris’s actions. Breggin claimed that side-effects of these drugs include increased aggression, loss of remorse, depersonalization, and mania.^[14] A subsequent study conducted by the Institute for Safe Medication Practices identified Luvox as being 8.4 times more likely than other medications to be associated with violence.^[15]

Harris and Klebold both began keeping journals of their progress soon after their arrests. The pair documented their arsenal with video tapes that were kept secret.^[4][16]

Journal entries reveal that the pair had formulated an elaborate plan for a major bombing rivaling theOklahoma City bombing. The entries contained blurbs about ways to escape to Mexico, hijacking an aircraft at Denver International Airport and crashing into a building in New York City, as well as details about the attacks. The pair hoped that after setting off bombs in the cafeteria at the busiest time of day, killing many hundreds of students, they would use their guns to shoot survivors as they fled from the school. Then, as police cars, ambulances, fire trucks, and reporters came to the school, bombs set in the boys’ cars would go off, killing the emergency personnel, media, and law officers; this original plan failed when their main explosives did not detonate.^[4][17] The pair kept videos that documented the explosives, ammunition, and weapons they had acquired illegally. In these videos, the shooters revealed all the elaborate and creative ways the two had thought up to hide their arsenals in their own homes, as well as the ways they would deceive their parents about their activities. Some videos contained footage of the pair doing target practice in nearby foothills, as well as shots of the areas of the high school they planned to attack.^[4] On April 20, approximately thirty minutes before the attack,^[18] a final video had the pair saying goodbye and apologizing to their friends and families.

In the months prior to the attacks, Harris and Klebold acquired two 9 mm firearms and two 12-gaugeshotguns. A rifle and the two shotguns were bought by a friend named Robyn Anderson at the Tanner Gun Show in December 1998.^[19] Harris and Klebold later bought a handgun from another friend named Mark Manes for a sum of $500. Manes was subsequently jailed following the massacre for selling a handgun to a minor^[20] as was Philip Duran, who had introduced the duo to Manes.^[21]

With instructions from the Internet, they built 99 improvised explosive devices of various designs and sizes. They sawed the barrels and butts off their shotguns to make them easier to conceal.^[4] The perpetrators committed numerous felony violations of state and federal law, including the National Firearms Act and theGun Control Act of 1968, even before the massacre began.

The link between bullying and school violence has attracted increasing attention since the 1999 attack at Colorado’s Columbine High School. Both of the shooters were classified as gifted children and had allegedly been victims of bullying for years. A year later, an analysis by officials at the US Secret Service of 37 premeditated school shootings found that bullying, which some of the shooters described “in terms that approached torment,” played the major role in more than two-thirds of the attacks.^[37] A similar theory was expounded by Brooks Brown in his book on the massacre; he noted that teachers commonly looked the other way when confronted with bullying.^[22]

Early stories following the shootings charged that school administrators and teachers at Columbine had long condoned a climate of bullying by the so-called jocks or athletes, allowing an atmosphere of outright intimidation and resentment to fester which, they claimed, could have helped trigger the perpetrators’ extreme violence.^[38] Reportedly, homophobic remarks were directed at Klebold and Harris.^[39]

However, Dave Cullen (in Columbine), while acknowledging the pervasiveness of bullying in high schools including Columbine, strongly disputes the theory of “revenge for bullying” as a motivation for the actions of Harris and Klebold, on the grounds that the two were not actually victims of bullying. Indeed, Harris in particular was more a perpetrator of bullying than a victim. ^[40]

In July 1999 the FBI organized a major summit on school shooters in Leesburg, Virginia. Attending were psychologists, psychiatrists, and representatives from recent school shootings, including a large Columbine contingent. Attorney General Janet Reno was in attendance. The FBI eventually published a major report on school shooters, though it steered clear of pinpointing the causes of any individual case.^[41]

On the fifth anniversary of Columbine, the FBI’s lead Columbine investigator and several psychiatrists went public with their conclusions in a news article.^[42] There they argued Harris was a clinical psychopath and Klebold was depressive. They believed the plan was masterminded by Harris, who they thought had a messianic-level superiority complex and hoped to illustrate his massive superiority to the world.

The attack on Columbine High School was the culmination of more than a year of planning, firearms acquisition, and bomb building. Harris’s journals, in particular, show methodical preparation over a long period of time, including several experimental bomb detonations. ^[43] The massacre was anything but a failure of impulse control.

Jerald Block, a US psychiatrist, has differed with the FBI opinion of psychopathology and depression, arguing that the killers’ actions are not well explained by such diagnoses. Rather, he states that Klebold and Harris were immersed in games like Doom, and that their lives were most gratifying while playing in a virtual world.

Both Harris and Klebold were fans of video games such as Doom and Wolfenstein 3D. Harris often created levels for Doom that were widely distributed; these can still be found on the Internet as the Harris levels. Rumors that the layout of these levels resembled that of Columbine High School circulated, but appear to be untrue.^[44] Harris spent a great deal of time creating another large mod, named Tier, calling it his “life’s work.”^[45] The mod was uploaded to the Columbine school computer and to AOL shortly before the attack, but appears to have been lost. One researcher argued that it is nearly certain the Tier mod included a mock-up of Columbine High School.^[8]

As they got into trouble, the two teenagers started to get their computer access restricted. Jerald Block believes that anger that was being projected into the games was now unleashed into the real world. In addition, the computer restrictions opened up substantial amounts of idle time that would have otherwise gone towards their online activities. They increasingly used that time to express their anger, and their antisocial tendencies likewise increased. This, in turn, generated more restrictions. Finally, after being arrested and banned from their computers for about a month, the two teens became homicidal and began documenting plans to attack the school. Block writes that the plan to attack the school first appears in Klebold’s writings, and that Klebold may have considered using a different partner-in-crime than Harris. That person’s name was redacted by the police from Klebold’s journal.^[8]

Some analysts argued that part of the killers’ problem may have been desensitization due to their constant exposure to violent imagery in such video games, as well as music and movies, theorizing that their obsession with these forms of media may have led them to depersonalization.^{[citation needed]} American news media compared the massacre to a fantasy sequence from the 1995 film The Basketball Diaries, in which protagonist Leonardo DiCaprio wears a black trench coat and shoots six classmates in his school’s hallways.^{[citation needed]} Several unsuccessful lawsuits against video game manufacturers were filed as a result by parents of some of the victims.^[46][47] Harris and Klebold were fans of the movie Natural Born Killers, and used the film’s acronym, NBK, as a code in their home videos and journals.^[8]

Blame for the shootings was directed on a number of metal or ‘dark music’ bands such as KMFDM andRammstein.^[50] The majority of that blame was directed at Marilyn Manson and his eponymous band.^[51][52]After being linked by news outlets and pundits with sensationalist headlines such as “Killers Worshipped Rock Freak Manson” and “Devil-Worshipping Maniac Told Kids To Kill,”^[53][54] many came to believe that Manson’s music and imagery were, indeed, Harris and Klebold’s sole motivation,^[55] despite later reports that the two were not fans.^[56][57]

In the immediate aftermath, the band canceled the remaining North American dates of their Rock is Dead Tour out of respect for the victims, while steadfastly maintaining that music, movies, books or video games were not to blame. Manson stated:^{[58][59][60][61]}

On May 1, 1999, the embattled musician expanded his rebuttal to the accusations leveled at him and his band in his Rolling Stone magazine op-ed piece, “Columbine: Whose Fault Is It?” He castigated the ensuing hysteria and moral panic and what he saw as the irresponsibly handled news media coverage; he chastised America’s habit of hanging blame on scapegoats to escape responsibility.^[62][63][64] Columbine and America’s fixation on a culture of guns, blame, and ‘celebrity by death’ was further explored in the group’s 2000 album Holy Wood.

In 2002 Manson appeared in Michael Moore‘s documentary, Bowling for Columbine; his appearance was filmed during the band’s first show in Denver since the shooting. When Moore asked what he would have said to the students at Columbine, he replied, “I wouldn’t say a single word. I would listen to what they have to say, and that’s what no one did.”^[65]

Sascha Konietzko of KMFDM released a statement stating their music denounced “war, oppression, fascism and violence against others.”^[50]

A US Secret Service study concluded that schools were placing false hope in physical security, when they should be paying more attention to the pre-attack behaviors of students. Zero-tolerance policies and metal detectors “are unlikely to be helpful,” the Secret Service researchers found. The researchers focused on questions concerning the reliance on SWAT teams when most attacks are over before police arrive, profiling of students who show warning signs in the absence of a definitive profile, expulsion of students for minor infractions when expulsion is the spark that push some to return to school with a gun, buying software not based on school shooting studies to evaluate threats although killers rarely make direct threats, and reliance on metal detectors and police officers in schools when the shooters often make no effort to conceal their weapons.^[66]

In May 2002 the Secret Service published a report that examined 37 US school shootings. They had the following findings:

Following the Columbine shooting, schools across the United States instituted new security measures such as see-through backpacks, metal detectors, and security guards. Some schools implemented school door numbering to improve public safety response. Several schools throughout the country resorted to requiring students to wear computer-generated IDs.^[68] At the same time, police departments reassessed their tactics and now train for Columbine-like situations after criticism over the slow response and progress of the SWAT teams during the shooting.^[69]

In response to concerns over the causes of Columbine and other school massacres, some schools instituted new anti-bullying policies as well as zero tolerance approaches to weapons and threatening behavior.^[70]Despite the nature of the Columbine incident, some social science experts feel the zero tolerance in schools has gone overboard.^[71]

One significant change to police tactics following Columbine is the introduction of the Immediate Action Rapid Deployment tactic, used in situations with an active shooter. Police followed the traditional tactic at Columbine: surround the building, set up a perimeter, contain the damage. That approach has been replaced by a tactic which takes into account the presence of an active shooter whose interest is to kill, not to take hostages. This tactic calls for a four-person team to advance into the site of any ongoing shooting, optimally a diamond-shaped wedge, but even with just a single officer if more are not available. Police officers using this tactic are trained to move toward the sound of gunfire and neutralize the shooter as quickly as possible.^[72] Their goal is to stop the shooter at all costs; they are to walk past wounded victims, as the aim is to prevent the shooter from killing or wounding more. David Cullen, author of the 2009 bookColumbine, said that, “The active protocol has proved successful at numerous shootings during the past decade. At Virginia Tech alone, it probably saved dozens of lives.”^[73]

The shooting resulted in calls for more gun control measures. In 2000 federal and state legislation was introduced that would require safety locks on firearms as well as ban the importation of high-capacity ammunition magazines. Though laws were passed that made it a crime to buy guns for criminals and minors, there was considerable controversy over legislation pertaining to background checks at gun shows. There was concern amongst the gun lobby over further restrictions on Second Amendment rights in the US.^[74][75] In 2001, K-Mart, which sold ammunition to the shooters, announced it would no longer sell handgun ammunition, action encouraged by and documented in Michael Moore‘s film Bowling for Columbine.

In 2000 youth advocate Melissa Helmbrecht organized a remembrance event in Denver featuring two surviving students, called the “Day of Hope.”^[76][77]

A permanent memorial “to honor and remember the victims of the April 20, 1999 shootings at Columbine High School” was dedicated on September 21, 2007, in Clement Park, a meadow adjacent to the school where impromptu memorials were held in the days following the shooting. The memorial fund raised $1.5 million in donations over eight years of planning.^[78]

Since the shooting, “Columbine” or “the Columbine incident” has become a euphemism for a school shooting. Charles Andrew Williams, theSantana High School shooter, reportedly told his friends that he was going to “pull a Columbine,” though none of them took him seriously. Many foiled school shooting plots mentioned Columbine and the desire to “outdo Harris and Klebold.”^[79] Convicted students Brian Draper and Torey Adamcik of Pocatello High School in Idaho, who murdered their classmate Cassie Jo Stoddart, mentioned Harris and Klebold in their homemade videos, and were reportedly planning a “Columbine-like” shooting.^[80]

Seung-Hui Cho, the shooter in the Virginia Tech massacre, mentioned “martyrs like Eric and Dylan,” apparently referring to Columbine High School gunmen Eric Harris and Dylan Klebold.^[81]