When people search for who was the Colorado school shooter, they usually aren’t looking for one single name. That’s because Colorado has an incredibly heavy, complicated history with school violence. It’s a state that has been forced to become the epicenter of a conversation nobody wanted to have. You’re likely thinking of Columbine, or maybe the Aurora theater (which wasn't a school, but feels linked), or the STEM School Highlands Ranch.
The reality? There isn't just one person. There’s a timeline of individuals whose actions changed American education forever.
People often get hung up on the "why" or the "who." Honestly, the "who" is a gallery of troubled backgrounds, missed red flags, and a terrifyingly easy access to weaponry. If we’re being real, looking at these individuals isn't about giving them fame. It's about figuring out the patterns so it stops happening.
The Names That Changed Everything: Eric Harris and Dylan Klebold
You can't talk about Colorado without talking about April 20, 1999. Eric Harris and Dylan Klebold weren't just "the Colorado school shooters"—they became a dark blueprint. For years, the media painted them as bullied outcasts in trench coats who targeted athletes.
That was mostly a lie.
Harris was a clinical psychopath. Klebold was a depressive follower. According to Dave Cullen, an investigative journalist who spent ten years researching the case for his book Columbine, Harris wasn't just some kid who got picked on. He was a bright, manipulative teenager who wanted to leave a "lasting impression" on the world. He kept journals. Detailed ones. He talked about "natural selection" and his hatred for the human race. Klebold, on the other hand, was deeply suicidal and largely went along with Harris’s grandiose plans for a massive terrorist attack that was actually supposed to involve bombs, not just guns.
The bombs failed. That’s a detail many people forget. They wanted to level the school.
Because their journals were eventually released, we saw a glimpse into a terrifying level of planning. They weren't just "snapping." This was calculated. The impact of their names is so deep that even today, law enforcement tracks "Columbiners"—people who obsess over these two. It's a grim reality of the digital age.
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The STEM School Shooting: A Different Set of Circumstances
Fast forward to May 2019. This happened in Highlands Ranch, just a short drive from Columbine. The world asked again: who was the Colorado school shooter this time?
It was Devon Erickson and Alec McKinney.
This case was different. It felt modern in a way that Columbine didn't. There were layers of social media influence, complex gender identity issues involving McKinney, and a deep-seated resentment toward the school environment. McKinney was younger, only 16 at the time, and Erickson was 18. They didn't use long guns; they used handguns hidden in guitar cases.
One thing that sticks out about this specific event is Kendrick Castillo. He was the student who lunged at the shooter. He died a hero. When we look at the "who" in these stories, people like Kendrick deserve more space in the narrative than the perpetrators. Erickson was eventually sentenced to life without parole, and McKinney, because he was a juvenile, received a sentence that allows for a chance at parole after 40 years.
The 2023 East High School Incident
Denver’s East High School has had a rough go of it lately. In March 2023, the question surfaced again. Who was it this time? Austin Lyle, a 17-year-old student.
This case highlighted a massive failure in "safety plans." Lyle was already under a plan where he had to be patted down every day because of previous behavioral issues and weapons charges. He brought a gun to school, shot two administrators during his daily search, and later took his own life.
It sparked a massive walkout. Students were fed up. They marched to the Colorado State Capitol. They weren't just asking who the shooter was; they were asking why the system allowed someone with a known violent history to be in a position where administrators were basically playing Russian roulette every morning during a pat-down.
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Arapahoe High School and the "Revenge" Narrative
In December 2013, Karl Pierson entered Arapahoe High School. He was looking for one specific person: his debate coach. Pierson was a "smart" kid. He was an Eagle Scout. He was on the speech and debate team.
But he had a grudge.
After being demoted from the debate team, he decided to take action. He didn't just target the coach; he ended up shooting a 17-year-old girl named Claire Davis, who was just sitting in the hallway. She had nothing to do with his grievance.
This is a recurring theme in Colorado. The shooters often feel "wronged" by a system—whether it’s a coach, a social clique, or a teacher—and they choose the most public, violent way to settle the score. Pierson took his own life in the school library.
What People Get Wrong About These Shooters
We love to put these people in boxes. We want to say they were all "bullied" or they all "played video games."
The data doesn't back that up.
The Secret Service’s National Threat Assessment Center has studied these cases for decades. They found that there is no "profile." Some are popular. Some are loners. Some are honor students. Some are failing.
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However, there are "leakages." Almost every single one of these Colorado school shooters told someone, posted something, or wrote something down before they acted. Harris and Klebold had a website. Lyle had a history of weapons violations. The common thread isn't a personality type; it's a series of behavioral warnings that usually get ignored or dismissed as "kids being kids."
The Impact on Colorado’s Laws
Because of who these shooters were and how they got their weapons, Colorado has some of the strictest "Red Guard" laws in the country now.
- The Straw Purchase: In the Columbine case, a friend bought the guns for them. Now, that’s a massive felony with serious federal weight.
- ERPO Laws: The "Extreme Risk Protection Order" allows family or police to ask a judge to temporarily remove firearms from someone who is a danger to themselves or others.
- Waiting Periods: Colorado now requires a three-day waiting period for firearm purchases.
These laws exist because names like Harris, Klebold, and Erickson became household words.
Actionable Steps for Safety and Awareness
Understanding who was the Colorado school shooter in various contexts helps us identify what to look for in our own communities. We can't just look at the past; we have to apply it.
- Take "Leakage" Seriously: If a student mentions "doing something" or expresses an obsession with past shooters, it isn't a joke. Report it to Safe2Tell, which is an anonymous reporting tool started in Colorado that has since become a national model.
- Focus on Threat Assessment: Schools should have multidisciplinary teams (psychologists, SROs, administrators) to evaluate students who show concerning behavior, rather than just relying on suspension.
- Secure Firearm Storage: Many of these shooters used guns they found at home or through friends. Using biometric safes or cable locks is a simple, non-political way to reduce risk.
- Advocate for Mental Health Resources: The ratio of students to counselors in Colorado is still higher than recommended national standards. Pushing for more "boots on the ground" in schools can catch a crisis before it turns into a headline.
The history of school shootings in Colorado is a dark one, filled with names we wish we didn't know. But by looking at the facts—the real, unvarnished details of who these people were—we can move away from the "monster" myths and toward actual prevention. It's about seeing the person before they become the "shooter."
The best way to honor the victims of these tragedies is to be the person who speaks up when something doesn't feel right. Prevention isn't a single law or a single metal detector; it's a community that pays attention.
References and Further Reading:
- Columbine by Dave Cullen
- Reports from the National Threat Assessment Center (NTAC)
- Colorado Bureau of Investigation Case Archives
- Safe2Tell Colorado Annual Reports