Left of Boom – April 2025
The Columbine High School massacre on April 20, 1999, was a defining moment in American history. Eric Harris and Dylan Klebold murdered 13 people and injured 24 more before taking their own lives. The attack shattered the perceived safety of schools and reshaped national policy on emergency response, school security, bullying, and mental health.
But Columbine’s legacy goes beyond policy reform. Tragically, it also created a blueprint for future attackers. Harris and Klebold achieved the infamy they desired—their images, writings, and videos were widely disseminated, fueling a dark subculture of self-described “Columbiners” who idolize them to this day.
Threat assessment professionals and academic researchers have documented the “Columbine Effect”—a phenomenon in which the 1999 massacre inspires subsequent acts of targeted violence, particularly school shootings, through the imitation and idolization of the perpetrators’ ideology, tactics, and pursuit of notoriety.
This subculture thrives on platforms like Tumblr, Telegram, and niche online forums. There, users glorify the Columbine killers as anti-heroes, share fan art, adopt their language and beliefs, and romanticize mass violence as a form of revenge against a cruel and indifferent world. For alienated youth seeking identity or significance, the Columbine shooters offer a disturbing model of validation and agency.
A Tragedy in Wisconsin and the Echoes of Columbine
On December 16, 2024, tragedy struck Abundant Life Christian School in Madison, Wisconsin. Fifteen-year-old freshman Natalie “Samantha” Rupnow opened fire in a second-floor study hall classroom. Within minutes, she killed a fellow student and a substitute teacher, wounded six others, and then died by suicide.
As investigators searched for a motive, a disturbing narrative emerged. Although born years after the Columbine massacre, Rupnow appeared deeply influenced by it. Evidence suggests she idolized Harris and Klebold, mimicking their ideology, tactics, and even elements of their online behavior. This revelation shocked many, a reminder that the shadow of Columbine stretches long and dark, reaching new generations.
Natalie Rupnow’s Obsession: A Copycat Fueled by Columbine
Rupnow was fixated on the Columbine shooters, particularly Eric Harris. On social media, she posted photos of herself wearing a T-shirt featuring the obscure German industrial rock band KMFDM—a group known for anti-establishment lyrics and dark, aggressive themes. Harris also wore a KMFDM shirt during the 1999 attack, and the group’s music has since become associated with the Columbine subculture.
Rupnow used still images from surveillance cameras from the Columbine shooting as profile pictures on social media and referenced other mass killers like Nikolas Cruz (Parkland) and Pekka-Eric Auvinen (Jokela, Finland), revealing a deep obsession with the ideology and history of mass violence.
Investigators later uncovered a document titled “War Against Humanity,” believed to be her manifesto. In it, Rupnow described humanity as a “plague” and framed her violence as retribution for years of alienation and rejection. She wrote of feeling invisible and expressed a desire to make others “feel what I felt.”
Her attack was not impulsive. It was methodically planned—a deliberate attempt to replicate Columbine’s narrative.
Red Flags and “Leakage”: The Warning Signs Were There
Rupnow’s behavior followed a familiar pattern of leakage—a term used by threat assessment professionals to describe when individuals reveal violent intentions through statements, behaviors, or online activity.
On semi-private social media accounts, she posted disturbing memes, violent imagery, and captions such as “The countdown has begun.” She also engaged with extremist communities, including a Telegram chat that celebrated a neo-Nazi attacker. On TikTok, she shared white supremacist memes and coded hate speech, suggesting her personal grievances may have merged with ideological radicalization.
While these signs were scattered across platforms, they were visible. Her obsession with Columbine, glorification of past shooters, and suicidal ideation could have raised red flags—if someone had connected the dots.
This case illustrates the need for trained, multidisciplinary threat assessment teams capable of recognizing patterns across behavioral, psychological, and digital domains.
Following the Pathway to Violence
Rupnow’s progression aligns closely with the Pathway to Violence model used by threat professionals. Her actions followed a well-documented trajectory:
- Grievance and Ideation: She internalized personal and societal grievances and began fantasizing about violent revenge.
- Planning and Research: She studied past shooters, wrote a manifesto, and developed an operational plan.
- Preparation: She practiced with firearms and chose a time and place for her attack.
- Leakage: She posted increasingly explicit warnings online.
- Triggering Event: An unconfirmed stressor—possibly bullying or the arrest of an associate—may have accelerated her plan.
- Attack and Suicide: She executed the attack and died by suicide, seeking infamy and validation.
Each stage presented a potential opportunity for intervention.
Fixation and Identification: Behavioral Red Flags
Rupnow displayed several key warning behaviors identified in the field of threat assessment:
- Fixation: A pathological preoccupation with Columbine, mass violence, and societal hatred.
- Identification: She didn’t just admire Harris and Klebold—she adopted their worldview and aspired to carry out violence in their name.
Threat assessment pioneer Dr. Reid Meloy has defined this dynamic clearly: “Fixation is what a person constantly thinks about. Identification is who the person becomes.” Rupnow exemplified this transformation. She dressed like Harris, quoted him, and saw herself as the next in line to carry out his legacy.
This evolution from fixation to identification marks a shift from passive obsession to active mobilization. For threat professionals, it’s a red flag that demands immediate action—whether through intervention, enhanced monitoring, or law enforcement engagement.
In Rupnow’s case, both behaviors were evident. Her repeated references to KMFDM—an obscure band popular long before she was born— is an example of both leakage and identification. This was a clear warning sign, if only these red flags were detected and recognized in context.
Global Scope: Statistics and Case Data
While no single global database tracks all Columbine-inspired attacks, researchers and law enforcement officials have documented a significant number of actual, planned, and disrupted incidents worldwide. Estimated Scope (as of 2024):
- 100+ documented cases globally in which Columbine was referenced or idolized.
- At least 80 U.S. incidents (per FBI and Secret Service) showing direct imitation or influence.
- 40+ disrupted plots in the U.S. involving individuals who had studied Columbine, many beginning in adolescence.
- 20+ international incidents in countries including Germany, Finland, Brazil, the UK, and Sweden, where attackers referenced Columbine in manifestos, tactics, or symbolic choices.
The Power of Diverse Threat Assessment Teams
Rupnow’s case reveals why diverse, interdisciplinary threat assessment teams are essential.
Effective teams combine:
- Professional diversity: Law enforcement, mental health experts, educators, and administrators all bring unique perspectives.
- Generational diversity: Younger members often recognize online behaviors or cultural references that older professionals might miss.
- Cultural and social diversity: Team members with varied backgrounds can better detect bias, decode hate symbols, and avoid stereotypical assumptions (e.g., assuming shooters are always male).
For example, a younger staff member might recognize a Tumblr page that glorifies Columbine or know the significance of certain memes or slogans. A culturally attuned team member might detect coded hate speech or other extremist references.
A team trained to interpret Columbine references, identify extremist codes, and assess mental health warning signs could have flagged Rupnow early. Coordinated action—engaging family, counseling, and law enforcement—might have changed the outcome.
Conclusion: A Call to Action for Security and HR Professionals
The Madison school shooting was a tragic echo of Columbine—a case study in how acts of mass violence evolve, yet follow recognizable patterns.
Key Takeaways:
- Recognize warning signs: Obsession with mass shooters, violent ideation, and digital leakage should never be dismissed as “edgy” or harmless.
- Use multidisciplinary threat teams: No single person sees the whole picture. Diverse, trained teams offer a fuller, faster understanding of threat dynamics.
- Act early and decisively: Every red flag is a chance to engage. Most attackers leave clues. The challenge is connecting those clues before violence occurs.
The Columbine Effect is an evolving and dangerous phenomenon—where one act of violence becomes a blueprint for the next. For threat assessment professionals, understanding this dynamic is essential. Recognizing warning behaviors like fixation and identification is not enough; we must act decisively to disrupt the cycle before it escalates.
As long as Columbine is mythologized in the darker corners of the internet, its legacy will continue to inspire those seeking infamy through violence. But with vigilance, training, and collaboration, we can intervene early—and prevent the next tragedy.
We honor past victims not only by remembering their names, but by taking bold, informed steps to ensure there are no more.
Prevention is not optional, it is a responsibility.
