Eric David Harris (April 9, 1981 – April 20, 1999) and Dylan Bennet Klebold (; September 11, 1981 – April 20, 1999) were an American mass murder duo who killed 13 people and wounded 24 others on April 20, 1999 at Columbine High School in Columbine, Colorado. This became known as the Columbine High School massacre. Harris and Klebold were seniors at the school at the time of the shooting. Both perpetrators committed suicide in the library, where they had killed 10 of their victims. The pair have become what the Napa Valley Register have called "cultural icons" for some people. Their shooting spree still remains today as one of the most infamous shootings in history. The shooting would also go on to cause a moral panic in society, leading schools to implement zero tolerance policies towards bullying and weapons on school grounds.
Harris and Klebold were both born in 1981. While Klebold stayed situated all of his life in Colorado, Harris moved around frequently due to his father being a U.S. Air Force transport pilot. Harris finally situated in Littleton, Colorado in 1993, when his father was forced to retire from active duty. The boys had met sometime while they were in the 7th grade at Ken Caryl Middle School. Over time, they became increasingly close. By the time they were juniors, they were described as inseparable. There are differing reports, some claimed Harris and Klebold were very unpopular students and frequent targets of bullying, while others claim they weren't anywhere near the bottom of the social hierarchy and each had plenty of friends. The pair were known to have opposite personalities. Harris was described as more outgoing and charismatic, while Klebold was more reserved and shy. Although, both were known to be highly intelligent and geeky, spending a lot of their time on computers and playing video games. They were both arrested in January 1998 for breaking into a van and stealing equipment. They got into a diversionary program, to help the boys stay out of any more trouble, while expunging their criminal records if they passed, which they successfully did at the beginning of 1999. Over this time, the pair had developed a hatred for the school and society in general. By May 1998, Harris and Klebold began planning the massacre, gathering an arsenal of weapons and building explosives. They left behind many journal writings and videos, foreshadowing and explaining their actions and what they hoped to achieve, like surpassing the carnage in the 1995 Oklahoma City Bombing. Ultimately, wanting the most deaths in United States history.
After the massacre, it was widely believed the boys were part of a clique in school called the "Trenchcoat Mafia", although this turned out to be untrue, as neither Harris or Klebold had any affiliation with the group, aside from being friends with a few of its members. Others attributed poor parenting, bullying and mental illness to the attack. While they left behind writings and recordings of why they attacked their school, the answer proved to not be that simple to investigators. The FBI concluded that Harris was a brooding psychopath, who showed in his journal writings a lack of empathy, narcissism and unconstrained aggression. Klebold, however, was concluded as an angry depressive. Klebold showed in his journal writings agony and sadness, feeling of no self-worth and wanting revenge against those who did not accept him. Both also seemingly had a wish to be infamous and "kickstart a revolution," as Harris stated in a home video. Dylan's mother, Sue, believes the pair had a "magnetic attraction" to one another, where one fulfilled something in one another, which made them even more sure that they could pull off their plans. The FBI's conclusion is often disputed, such as people arguing Harris was also depressed because he took the anti-depressant Luvox; and Klebold was the first to mention a killing spree in a 1997 journal entry. The motive for the attack remains inconclusive.
Harris and Klebold are often seen, depicted and referenced in popular culture through movies, television shows, video games, music, stage plays, documentaries and books. Many killers since the Columbine massacre have taken inspiration from the two, hailing them as heroes and icons. Harris and Klebold also have a fanbase who call themselves "Columbiners", who make blog posts, fan fiction and fan art on them. Others have also dressed as Harris and Klebold for Halloween and cosplay.