This article examines five school shooters and five perpetrators of other types of mass violence. The five school shooters are Eric Houston, Eric Harris, Seung Hui Cho, Adam Lanza, and Elliot Rodger. The other perpetrators are Timothy McVeigh, Clay Shrout, Anders Breivik, James Holmes, and Dylann Roof. The article was originally published in Criminology and Public Policy and is posted here with permission.
This article documents Eric Harris’s self-contradictions and vacillating attribution of responsibility for the attack, demonstrating that his justifications cannot be taken at face value.
Eric Harris left records documenting his admiration for Hitler, Hobbes, and Nietzsche. He also may have admired Charles Manson. This article explores parallels between the ideas of these men and those of Harris in an attempt to trace possible influences on his thinking.
This article appeared in the journal Aggression and Violent Behavior (published by Elsevier) and is reprinted with their permission. The article provides a brief overview of the scholarly literature on school shooters, followed by a presentation of my typology.
This article first demonstrates multiple types of problematic reporting, showing that many statements made about Eric Harris and Dylan Klebold cannot be taken at face value. The article then seeks to present a more accurate picture of Harris and Klebold based primarily on the thousands of pages of Jefferson County Sheriff’s Office (JCSO) documents.
These two documents were found online, compiled by an unknown researcher. I have attempted to obtain permission from the researcher to post this material, but have been unsuccessful. I am posting the documents here to preserve this meticulous work. These two documents provide a page-by-page listing of the contents of the first 11,000 pages of JCSO documents.
This diagram portrays the apparent lines of influence from Columbine through subsequent attacks. All of the post-Columbine perpetrators included here either explicitly cited Columbine as an influence or made oral or written references that suggest it influenced their own attacks. The lines of influence illustrate links between those who were influenced by Columbine and later perpetrators whom they influenced in turn. The New York Times described an earlier version of this document: “Langman has created a mass-shooter diagram tracking the influence Columbine has had on more than 30 other rampage attacks at schools and elsewhere, from California to Germany. The diagram resembles a corporate flowchart, with lines branching out and intersecting, but all of them flowing out of two names: the Columbine killers.” This document may be downloaded as a large-scale poster or in smaller tabloid format. This is a companion document to “Role Models, Contagions, and Copycats: An Exploration of the Influence of Prior Killers on Subsequent Attacks.”
This large-format poster shows all attacks influenced by Columbine, arranged in a timeline format, with attack details and lines of influence.
This 11-by-17-inch version of the diagram features a compact representation of the lines of influence between perpetrators.
This document is an index to thousands of pages of documents compiled by the Jefferson County Sheriff’s Office (JCSO) related to the attack at Columbine High School. This is a guide to summaries of hundreds of interviews organized first by the first name of the interviewee and then by the last name of the interviewee. The original document was found online with no indication of who created it. It has been redesigned for this site.
The attack at Columbine generated over 27,000 pages of documents for the Jefferson County Sheriff’s Office (JCSO), most of which have been made public. These include reports from thousands of interviews with people who knew Harris and Klebold, as well as the killers' personal journals, school planners, academic assignments, yearbook inscriptions, and more. I have organized an index to assist people in locating references by theme. For example, there are pages listing references to Harris and Klebold being harassed, as well as references to Harris and Klebold not being harassed, and references to Harris and Klebold harassing others. There are 10 categories divided into additional subcategories.
Though Klebold drank alcohol and smoked marijuana, the autopsy noted no trace of drugs or alcohol; thus, he was not under the influence at the time of the attack. The report also documents the clothing he wore, including a black t-shirt with the word “Wrath” on it, as well as a “red star medallion containing a sickle and a hammer” on his left boot—a symbol used in Communist Russia.
After Klebold was arrested on January 30, 1998, he participated in a diversion program to keep young, first-time offenders out of the legal system. This document contains his intake paperwork, questionnaires, notes of probation meetings, and assorted forms.
Dylan maintained a handwritten journal. This document is a transcription of the journal and miscellaneous other writings that were found after his death, along with explanatory comments.
This is a collection of pages from several Jefferson County Sheriff's Office (JCSO) documents, including the 1997 and 1998 pre-attack records, as well as the massive collection of post-attack materials. There is some redundancy in these sources, but I have chosen to include different versions of the same content rather than choose one version over another. Note: immediately after the attack, someone posted a fake webpage claiming to be Eric Harris. As far as I know, any online content that is not included in the JCSO material is fraudulent.
This document contains three school assignments in which Harris wrote about his childhood, highlighting the many fun times and pleasant memories he had of his younger years.
Despite Harris’s use of marijuana and alcohol, the autopsy revealed no substances in his system other than fluvoxamine (Luvox), a prescription medication he had been taking for approximately a year. The report also notes that he wore a shirt that read “Natural Selection.” Finally, Harris had a medical condition called pectus excavatum, which means he had a sunken chest. He had surgery at ages 12 and 13 to repair this. Despite the surgery, the autopsy notes that the pectus excavatum was still observable.
After Harris was arrested on January 30, 1998, he participated in a diversion program to keep young, first-time offenders out of the legal system. This document contains his intake paperwork, questionnaires, notes of probation meetings, and assorted forms.
Eric kept a handwritten journal that was discovered after his death. This document is a transcription of the journal with explanatory comments.
These are original source documents from the FBI investigation of Columbine.
On August 7, 1997, a complaint was made to JCSO regarding Eric Harris. Printouts of his web pages, including his log of ‘Rebel Missions' of mischief and vandalism, are included.
On March 18, 1998, another complaint was made regarding Eric's bomb-making activities, violent writings, and threat to kill a specific student. Printouts of Eric's web pages are included.
In 1998, after the Brown family notified the Jefferson County Sheriff’s Office (JCSO) of Eric Harris’s webpages where he documented his bomb-making activity as well as expressed his homicidal urges, an affidavit was written requesting a search warrant to allow law enforcement to search the Harris residence. For some reason, there was no follow through and the search never occurred.
Following the attack at Columbine, the Jefferson County Sheriff's Office (JCSO) took charge of investigating the incident and accumulated approximately 27,000 pages of documents. Most of these have been released to the public and are available below, but there are some gaps in the sequence of documents. These and other materials (such as videos by Harris and Klebold) can be purchased from JCSO. Note: This massive document has been broken into several approximately 1000-page segments, each of which may be downloaded individually. Each segment is about 20 Mb.
This file of 946 pages (25,923–26,859) contains some of the most important pages in the JCSO material, including the journals of Eric and Dylan, school papers, etc.
This was written several weeks before the attack at Columbine. Dylan’s English teacher was concerned about the content and addressed this with him, his parents, and a guidance counselor, but Dylan argued that it was just a piece of fiction. The narrator in the story recounts witnessing a man kill multiple students. The killer is described as 6’4”, left-handed, and wearing a black trenchcoat. Dylan himself was approximately 6’4”, left-handed, and wore a black trench coat.
This document is a collection of quotes from Harris's writings, organized by theme. The themes include his preoccupation with being original and beyond all influence, his grandiose (at times god-like) self-image, his fascination with natural selection and destroying humanity, and more.
In the weeks leading up to the attack at Columbine High School, Eric Harris and Dylan Klebold filmed themselves talking about their violent intentions. The videos have been shown to a few people, but never released to the public. This description of them, along with some quoted passages, was compiled and posted online. It has been reformatted for this site.
This is the final report from the Jefferson County Sheriff's Office regarding the attack at Columbine High School. (Note: The report was published as a website. This is a PDF version of the entire site. As of October 2014, the original site no longer seems to be accessible. We have added bookmarks to this document; we recommend downloading it and using the bookmarks pane in your PDF viewer to navigate. Most of the audio and video links are still functional; clicking on a link will download the audio or video media to your computer.)
This is the official report from May 2001 on the attack at Columbine.
This report reviews all the known law enforcement contacts relating to Eric Harris and Dylan Klebold prior to their attack. Most of these involved Harris and occurred in 1997 and 1998.
As stated in this document, “This report is an analysis of the fire service and emergency medical service (EMS) operations and the overall response to the assault on Columbine High School at Littleton, Colorado, on April 20, 1999. Incident command, special operations, and mass casualty emergency medical services are featured.” The report was produced by the U.S. Department of Homeland Security.