Nearly Every Mass Shooter Since 1966 Has Had Four Things In Common

by : Cameron Frew on : 19 Nov 2019 15:29
Nearly Every Mass Shooter Since 1966 Has Had Four Things In CommonNearly Every Mass Shooter Since 1966 Has Had Four Things In CommonPA

A superlative US government-funded study of mass shooters has found nearly all perpetrators since 1966 have four traits in common. 

The findings were compiled by The Violence Project, ‘a nonpartisan think tank dedicated to reducing violence in society and improving related policy and practice through research and analysis’.


The Department of Justice-funded endeavour looked to analyse every ‘mass murder’ – in accordance with the FBI’s definition, where four or more people are killed in a public place excluding the shooter – to provide a ‘better understanding or preventing mass shootings’.

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The widely-spread stereotype for a mass shooter is that of a white male with a history of mental health issues and/or domestic violence. While that is no doubt true in some cases, The Violence Project nailed down four particular traits recurring among those listed in its database.

As per the study, the traits are: 


Although mass shooters have different profiles, nearly all mass shooters have four things in common: (1) early childhood trauma and exposure to violence at a young age; (2) an identifiable grievance or crisis point; (3) validation for their beliefs, have studied past shootings to find inspiration; and (4) the means to carry out an attack.

Each one of the four themes represents an inflection point – an opportunity for intervention.

Researchers used the University of Texas shooting in 1966 as a starting point, when a former Eagle Scout and Marine shot and killed 15 people from an observation deck at the Austin campus.

Gun Control ProtestGun Control ProtestCameron Frew

While there were other incidents prior to this day, ‘what set the Texas clocktower shooting apart was that it unfolded live over the radio and the new medium of television – reporters on the scene described the events as they happened’.


The findings of the study are terrifying: of the 167 incidents logged, 20% have occurred in the last five years, and half since 2000.

The study elaborates: 

The fact that mass shootings account for fewer than 1% of all firearm homicides does not diminish their extraordinary tragedy – mass shootings cause damage and devastation far beyond that which is measured in lives lost.

Mass shootings are focusing events. And while they are statistically rare… in the US they are certainly routine.

In the past five years, the number of mass shootings driven by racism, religious hate and misogyny has increased dramatically – for example, there’s the Charleston church shooting, in which nine African Americans were killed.

Charleston Mass ShootingCharleston Mass ShootingCameron Frew

The study was also careful to point out while mental health is a factor – two-thirds had a documented history of mental health issues – it can’t be attributed as the main cause.

While 70% of shooters were suicidal before or after the shooting, the percentage of shooters whose actions were directly influenced by symptoms of a mental disorder, such as hallucinations via psychosis, was roughly 16%.

Jillian Peterson, a psychologist at Hamline University and co-author of the study, told Vice the findings ‘shows us that there are opportunities for intervention – this doesn’t just happen out of the blue’.

Gun Control USGun Control USPA

‘We know a lot more about suicide prevention than we do about this issue, and we know what works – things like limiting access to weapons, directly asking the question, connecting people with outside resources, not talking about it in the news,’ Peterson added.

While acknowledging there is no single profile for a mass shooter, researchers found certain individual characteristics were often tied to the particular locations of an incident.

The study lists five categories: 

1. K-12 school shooter: a white male student of the school with a history of trauma who is suicidal. Leaks his plans ahead of time, high degree of planning, and has an interest in guns. Uses multiple guns that he stole from a family member.

2. College and university shooter: a non-white male current student with a history of violence and childhood trauma who is suicidal. Uses handguns that he legally obtained and leaves something behind to be found (like a video or ‘manifesto’).

3. Workplace shooter: a male in his 40s, no racial profile, but is an employee of the blue-collar shooting site and having trouble at work. Uses a handgun and assault rifles that he legally owns.

4. House of worship shooter: a white male in his 40s who is suicidal with a prior criminal record and violent history. Uses in a handgun in a Christian church where he knows victims. Low degree of planning, motivated by domestic spillage and hate.

5. Retail/restaurant/bar shooter: a white man, aged 30, with a criminal record and violent history and no connection to the location. Uses one legally owned handgun. One-third show evidence of a thought disorder.

To read the full study, click here.

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Cameron Frew

After graduating from Glasgow Caledonian University with an NCTJ and BJTC-accredited Multimedia Journalism degree, Cameron ventured into the world of print journalism at The National, while also working as a freelance film journalist on the side, becoming an accredited Rotten Tomatoes critic in the process. He's now left his Scottish homelands and taken up residence at UNILAD as a journalist.

Topics: News, Crime, Gun Control, Gun violence, Mass Shooting


The Violence Project and 1 other
  1. The Violence Project

    Database of Mass Shootings in the United States, 1966–2019

  2. Vice

    Nearly All Mass Shooters Since 1966 Have Had 4 Things in Common