Inside the Mind of the Active Shooter

July 16, 2013
Knowing your adversary is the first step to stopping your school’s worst enemy

On April 16, 2007, Seung-Hui Cho, an undergraduate student at Virginia Tech, became infamous for perpetrating the deadliest mass shooting by an individual in U.S. history. After his first two murders, he returned to his dorm room, and in between the first round and the next 30 murders followed by suicide when he was cornered, Cho was calm enough to collect and mail a package including videos and a manifesto to NBC news.

In the material he sent to NBC, he gave a glimpse into the thoughts of one active shooter. On one video, Cho said that the massacre could have been avoided. “You had a hundred billion chances and ways to have avoided today. But you decided to spill my blood. You forced me into a corner and gave me only one option. The decision was yours. Now you have blood on your hands that will never wash off.”

Those charged with providing safety and security to public or to private organizations must try to understand active shooters — they must come to know the adversary. Motives are sought, but in devastating mass murders, those motives often seem inadequate. For example, police found a note in Cho's room in which he criticized “rich kids,” “debauchery" and “deceitful charlatans,” which is no different than the resentment of many a bitter and resentful person who is not at risk of committing horrific crimes. Stating that others “forced” him to do it rings equally hollow, and is not a rare feeling for many an immature child or adult.

On Dec. 14, 2012, 20-year-old Adam Lanza fatally shot 20 children and six adult staff members at Sandy Hook Elementary School in Newtown Conn., the second worst mass murder by a single individual in U.S. history. Like Cho, there were two separate periods in his shooting spree. Before driving to Sandy Hook, Lanza shot and killed his mother who was sleeping in her Newtown home. Like Cho, he had a second wind; Lanza went to Sandy Hook to wreak massive devastation of innocents, primarily 6-year olds. Similar to Cho, as first responders arrived, he committed suicide by shooting himself. But unlike Cho, Lanza did not conduct a PR campaign to justify his actions, and he did not mail or leave behind videos or manifestos.

This young man who had always tried to remain hidden was extraordinarily careful in hiding most of his thoughts. And he was careful to destroy his computer, leaving few clues behind. One item left behind, however, was a telling — a 7-foot-long, 4-foot-wide, 9-point font spreadsheet that was so detailed, it required a special printer to print vast amount of material on a single page. Lanza’s highly organized document was a spreadsheet of worldwide mass murderers and attempted murders, showing meticulously detailed research into prior shooters. It listed more than 500 victims. One theory by the Connecticut State Police is that this spreadsheet was really a video-gamer’s score sheet. According to this theory, his ambition was to move to the top of the chart by having the highest number of kills in history.

Lanza was well-prepared. During his active shooting episode, after shooting the occupants of a room in the elementary school he dumped his unused ammo to have a full clip when he entered the next room, a tactical reload possibly learned from his video games. When the strap broke on his first weapon, an AR-15, he was prepared and went to his handgun. The Connecticut State Police believe he shot 6 year-olds because they would be easy kills for someone wanting to get the highest numbers of any killer.

On April 20, 1999, in Littleton Colo., (only a few miles from the Denver street where I grew up), two senior students, Eric Harris and Dylan Klebold, murdered 12 students and one teacher. They injured 24 additional students prior to committing suicide. The Columbine High School massacre remains the deadliest mass murder at an American High School.

Much has been written about the motives of these self-described outcasts, which was fueled by Harris’s website that included blog postings documenting his growing anger at society. Harris’s website included numerous death threats. Klebold gave access to this private website to one of Harris’s intended targets, which led to the Jefferson County Sheriff's Office finding numerous threats directed against the students and teachers at Columbine, his hatred of society, and a wish to kill those who annoyed him. Also on his website, Harris stated that he made pipe bombs and discussed his gun count. The Jefferson County Sherriff’s investigator wrote a draft Affidavit for a search warrant, but it was not filed. Eventually Harris posted his and Klebold's progress in acquiring guns and making the bombs which were used at Columbine. Journals of both Harris and Klebold documented their competition with McVeigh in their bomb’s destructiveness, plans to inflict maximum damage at Columbine, and an escape plan.

The Role of Mental Illness in Mass Shootings
What is the role of mental illness in the commission of mass murder? Cho, the Virginia Tech shooter, had a long history of mental illness that was concealed when he applied to Virginia Tech. Cho was painfully shy since his earliest years and the level to which he would not interact socially, participate in group activities or speak aloud, even in class (selective mutism) was dramatic and rare, and noted from the earliest years of his education.

His first mental health contact occurred during the summer before Cho started 7th grade, due to the severity of his social isolation and his unwillingness to discuss his thoughts or feelings. He was diagnosed with severe Social Anxiety Disorder, and Cho’s shyness and awkwardness was painful to watch. Psychological testing showed immaturity and a lack of verbal skills, but his IQ was above average. Cho continued to isolate in middle school but had no reported behavioral problems and did not get into any fights. In the middle of 8th grade, Cho suddenly became more withdrawn and showed symptoms of depression. His therapist was concerned about suicide despite no verbal indication by Cho.

One month after his therapist expressed concern, right after the Columbine devastation, Cho wrote a paper discussing generalized suicidal and homicidal thoughts, and said he wanted to repeat Columbine. Cho, who was already in therapy, was again seen by a psychiatrist who diagnosed Cho with Selective Mutism and Major Depression, and prescribed an antidepressant. Cho did well on the medication, smiled more and seemed brighter, but the psychiatrist discontinued it one year later as Cho no longer seemed depressed.

In 10th grade, Cho was placed in a Special Education Program for Emotional Disabilities. He was permitted to eat lunch alone and to provide verbal responses in private sessions with teachers rather than in front of the class. With this arrangement, Cho’s grades were excellent. He had Advanced Placement and Honors classes, but Cho’s thinking began to appear confused. In the 11th grade, Cho’s weekly sessions at the mental health center came to an end because he resisted continuing and there was a gradual, if slight, improvement over the years.

Cho was strongly advised to attend a small college near his home, as he needed a great deal of support and school and family interaction. Cho ignored this advice and went to a much larger and more distant school, Virginia Tech. At Virginia Tech, only minimal interaction occurred with mental health. He was psychiatrically hospitalized for one night after uttering suicidal comments to his roommate, but he was let go. Cho’s grades deteriorated in his sophomore year and he became convinced his acne was not pimples, but the bites of mites (This was probably delusional thinking).

In his junior year, Cho’s social withdrawal became increasingly severe, his writing became hostile and violent and his behavior became threatening. During this year, he and his roommates went to a female’s dorm room where Cho started stabbing her rug with a knife. After being criticized, Cho wrote, “You low-life barbarians make me sick to the stomach that I wanna barf over my new shoes. If you despicable human beings who are all disgraces to [the] human race keep this up, before you know it you will turn into cannibals — eating little babies, your friends. I hope y’all burn in hell for mass murdering and eating all those little animals.”

Cho began taking unauthorized and unwelcomed pictures of other students, and some of these students stopped coming to class out of fear of Cho. His poetry teacher felt he was uncooperative and that he was trying to bully her. She refused to allow Cho back into class, stating she would resign if she was required to allow him to come back to class. The department chair took over on a one-to-one basis. Cho’s writings were of shooting or harming people. A roommate found a very large knife in Cho’s property and discarded it. Unfortunately, this information was not shared in any central or common setting — it was pieced together after the massacre.

Adam Lanza had multiple mental illness diagnoses from an early age with a form of autism being the predominant diagnosis; however, it should be noted that autism is not correlated with violent or criminal actions. Like Cho, he was painfully shy and avoided contact with others at all cost, even when the avoidant behavior made him appear very odd.

In contrast to Cho and Lanza, Harris was not widely thought to have mental illness; but he is now believed to have a Psychopathic Personality Disorder. Klebold often appeared depressed and more troubled than Harris.

Threat Assessment
What does studying events such as these tell us about the psychology of the most dangerous of the active shooters? First, there is a widely discussed but inaccurate belief that these mass murderers had significant stress which, combined with mental illness, caused them to “snap” — implying that when events became overwhelming, they lost their footing and more or less impulsively, committed horrific acts. The idea of suddenly snapping when stress got too high does not fit with the facts in most cases of mass murders, including these three examples.

Most school shootings (as opposed to mass murders) are less planned and more impulsive, often done either in sudden bursts of anger or in retaliation for a perceived slight. In contract to relatively sudden and impulsive acts of violence, mass murderers usually demonstrate extremely careful planning and careful execution of plans which were conducted in a calm manner. This repeated observation changed the field of Threat Assessment.

We now know that most mass murders are not the product of stress tipping the scale to a point where someone suddenly snaps, but the product of a person or persons capable of planning what Meloy (1997) calls “Predatory Violence.” Is this a form of mental illness? That question may not be fully answerable at this time, but if it is, it is not mental illness as we usually define it.
What is in the mind of an active shooter? Research has shown that an active shooter’s mind is focused on the violent act, and especially on their plan as to how to carry it out. Active shooters often verbalize multiple justifications for the perceived wrongs and injustices that were done to them — justifications which seem immature or ludicrous to us.

How to Recognize the Warning Signs
How do security professionals recognize active shooters? In most cases, active shooters give clues to their plans — frequently only to those close to them. Usually, the only way to recognize an active shooter is to obtain information from those who have access to clues left by, and behaviors of the shooter.

Holders of information, therefore, can be quite varied. In Cho’s case, other students, teachers, former school officials, mental health professionals and family all had pieces of the puzzle. Increased communication is greatly facilitated by the development of Threat Assessment Teams within an organization or school. Due to the varied nature of shooters and informants, Threat Assessment Teams function best if they are represented by multiple disciplines, usually including Security, HR, Administration, Student Representatives (if a school), Legal Departments, and a consultant Threat Assessment Expert who may be trained as a Forensic Psychologist. Threat Assessment Teams may include other disciplines to fit the structure and culture of an organization or school.

These teams are developed to create and continually encourage communication of concerning or threatening material. They collect and share information to facilitate rapid and effective assessment and responses to threats or perceived threats when they occur. By obtaining, sharing and assessing threatening communication, Threat Assessment Teams often prevent a threat from becoming an active incident, and successfully deescalate and manage threats and their effect on a corporation, school or organization.

Mark Siegert, PhD is a Clinical and Forensic Psychologist and a principal in Threat Assessment Experts ( He is a former faculty member at Harvard University, Harvard Medical School and Columbia University. He will be presenting his work on “Direct, Indirect and Perceived Threats: Challenges posed by the American’s with Disabilities Act (ADA)” at the Association of Threat Assessment Professionals (ATAP) 23rd Annual Threat Management Conference on Aug. 14, in Anaheim, Calif. His decades of experience in Forensic Psychology ( include extensive evaluations of violent perpetrators, Violence Risk Assessment and Fitness-for-Duty Examinations for employees, students and defendants. His expertise has led him to be interviewed on The O'Reilly Factor, Connie Chung, Paula Zahn, Crossfire, and NPR.

Beth Siegert, M.S., is an organizational psychologist and consultant and a principal in Threat Assessment Experts ( She has expertise facilitating a team's focus and collaboration with threat assessment professionals, private security, law enforcement, HR, Executives and Administration, and other professionals. She is a seasoned leader and team developer with more than 25 years experience.