Eric David Harris (April 9, 1981 – April 20, 1999) and Dylan Bennet Klebold ( KLEE-bohld; September 11, 1981 – April 20, 1999) were an American mass murder duo who perpetrated the Columbine High School massacre, where they killed 13 students and one teacher, and wounded 23 others. After killing most of their victims in the school library, the two died from suicide by gunshot. At the time, the attack was the deadliest high school shooting in United States history. The ensuing media frenzy and moral panic turned "Columbine" into a byword for school shootings, and the event into one of the most infamous mass shootings.
Harris and Klebold met while attending middle school and gradually became close. By their junior year of high school, they were described as best friends who were dependent on one another. Early reports characterized them as unpopular and frequent targets of bullying; however, many peers later stated that the two were not near the bottom of the school's social hierarchy, as both had numerous friends and active social lives. Columbine High School was alleged to have an intense "jock culture", in which popular students—primarily athletes—received preferential treatment from faculty and peers. Harris and Klebold often wore black trench coats in their everyday attire; as a result, it was initially believed that they were members of a school clique known as the "Trenchcoat Mafia", a group of students who were said to rebel against the school's norms. This was later found to be unsubstantiated, as Harris and Klebold had little to no affiliation with the group.
According to their writings, Harris and Klebold appear to have begun planning the attack by May 1998, nearly a year beforehand, although each had previously made references to a shooting. Over the following eleven months, they secretly built explosives and amassed an arsenal of weapons, planning to attack in April 1999, just weeks before their graduation. Both left behind journals and video recordings, created individually and together, that foreshadowed the massacre and provided insight into their rationale for the shooting. They intended for this material to be widely viewed and to inspire followers, although much of it has never been released by authorities. The FBI concluded in May 2000 that Harris exhibited psychopathic traits, including narcissism, unconstrained aggression, and a lack of empathy, while Klebold was described as an angry depressive with a vengeful attitude toward individuals he believed had mistreated him. However, since neither Harris nor Klebold had been formally diagnosed with any personality disorders during their lifetimes, these conclusions have been criticized and remain debated. In the years after the massacre, news outlets and commentators have attributed the attack to various motivating factors, including bullying, mental illness, racism, psychiatric medication, and exposure to violence in media. The exact motive for the attack remains inconclusive.
Harris and Klebold have become figures in popular culture, portrayed, alluded to, and depicted in various media. Some perpetrators of subsequent attacks have cited the duo as an influence, a phenomenon commonly referred to as the "Columbine effect".
Eric David Harris was born on April 9, 1981, in Wichita, Kansas, to Katherine Ann (née Poole) and Wayne Harris. His father served in the United States Air Force as a transport pilot, while his mother was a part-time caterer. Both of his parents were born and raised in Colorado. Their first son, Kevin, was born in 1978.
When Harris was two years old, the family moved to Dayton, Ohio. In 1989, they moved to Oscoda, Michigan. While living in Oscoda, pastor William Stone recalled the family as "great neighbors" and said he often saw Wayne highly engaged with his sons. The Harris family then moved to Plattsburgh, New York, in 1991. At Stafford Middle School, Harris played Little League Baseball, regularly attended birthday parties, and was described as "part of the crowd". Kyle Ross, a former classmate in Plattsburgh, remembered him as "just a typical kid." The Harris family then settled in Littleton, Colorado in 1993 following Wayne's retirement from the military. They lived in rented accommodations during their first three years in the area, until purchasing a home south of Columbine High School. Harris's father took a job with Flight Safety Services Corporation, and his mother became a part-time caterer. In a 1997 English class assignment, Harris recalled the difficulty of moving from New York to Colorado: "It was the hardest moving from Plattsburgh. I have the most memories from there. When I left [my friends] I felt alone, lost and even agitated that I had spent so much time with them and now I have to go because of something I can't stop." In one of the so-called "Basement Tapes", he blamed his father for moving the family frequently, stating that it forced him to "start out at the bottom of the ladder."
Shortly after moving to Littleton, Harris began attending Ken Caryl Middle School. Around the same time, he underwent two surgical operations to correct pectus excavatum, a congenital condition in which the breastbone sinks into the chest. The deformity remained mildly observable at the time of his autopsy.
Dylan Bennet Klebold was born on September 11, 1981, in Lakewood, Colorado, to Sue (née Yassenoff) and Thomas Klebold. Both of his parents were born and raised in Ohio, where they met while studying at Ohio State University. After graduating, they married in 1971, and their first son, Byron, was born in 1978.
In a 2016 interview with Colorado Public Radio, Sue recalled experiencing a fleeting sense of foreboding at Dylan's birth, describing it as "a passing feeling that went over very quickly, like a shadow", which she interpreted as a warning that her child might bring her great sorrow. As an infant, Klebold was treated for pyloric stenosis, a condition in which the opening between the stomach and small intestine thickens, causing severe vomiting during the first few months of life.
After living in Littleton, the Klebold family sought a change of scenery and, in 1989, moved to a large home south of the city in the Deer Creek Mesa foothills. Thomas had previously worked in geophysical consulting but was operating a rental management business from home at the time of the massacre. Sue worked for the Colorado Community College System, where she administered job training grants for people with disabilities. In line with Thomas's religious background, the family attended a Lutheran church for a period about five years before the shooting, where Klebold and his brother attended confirmation classes. The family also observed Passover, reflecting Sue's distant Jewish heritage. Both parents were described as generally non-religious and pacifists who opposed weapons.
Klebold attended Normandy Elementary School for first and second grade before transferring to Governor's Ranch Elementary School, where he was part of the Challenging High Intellectual Potential Students (CHIPS) program for gifted children. Classroom accounts reported that he was academically bright as a young child but appeared somewhat sheltered, which reportedly made his transition to middle school difficult. His parents were described as mostly unconcerned about his adjustment difficulties, believing such challenges to be typical for young adolescents.
During his earlier school years, Klebold was a member of the Cub Scouts alongside Brooks Brown, who had been his friend since first grade. He also played baseball and was described as an avid fan of the sport, participating in a fantasy league and frequently wearing a Boston Red Sox cap.
Harris and Klebold became friends while attending Ken Caryl Middle School. They entered Columbine High School in 1995 as freshmen, shortly after the school had undergone a major renovation and expansion. At Columbine High School, they formed a close-knit friend group, with social activities including bowling, shooting pool, carpooling, watching films, and playing video games together. After their sophomore year of high school, Harris and Klebold were described as nearly inseparable. Detailed information about their private conversations remains limited: aside from the "Basement Tapes", for which only transcripts have been released, along with a brief audio clip recorded surreptitiously by a victim's father, few direct records are available.