Breaking research

Over 70% of mass shootings in developed countries happen in the US, international analysis shows

A makeshift memorial site, established near the MLK Commons at Northern Illinois University, within a week of the February 14, 2008 shooting which killed six and injured 18 people
A makeshift memorial site, established near the MLK Commons at Northern Illinois University, within a week of the February 14, 2008 shooting which killed six and injured 18 people

816 deaths from mass shootings in the US between 1998-2019, which is the only country to have such an incident every single year



Mass shootings in the US account for 73% of all 139 incidents occurring in developed countries between 1998 to 2019. During this time, 62% of all 1,318 fatalities from the attacks also happened in the states.

These are the findings of a shocking new study, published in the peer-reviewed International Journal of Comparative and Applied Criminal Justice.

It shows some 101 attacks occurred in the US during this period, leading to 816 deaths.

In comparison, France had the next highest number of mass shootings, with eight; and these lead to 179 deaths.

Half of the 36 developed countries studied have not had a single mass shooting in the last 22 years, and only five had more than two incidents. In stark contrast, the US has a mass shooting every single year – it is the only country to do so.

The research has been carried out by a leading expert on such confrontations, Assistant Professor, Dr Jason R Silva, from William Paterson University, who has analyzed the differences in characteristics between US mass shootings and all other countries – with mass shootings being classified here as “a public incident involving four or more fatalities, with at least some victims chosen indiscriminately”.

Emerging patterns show:

  • 91% of perpetrators were born in the country they attacked
  • 99% were male
  • One-third had military experience
  • 7% had a history of law enforcement experience

The study is calling on further research to help inform policy on the issue. And Dr Silva, based at the University’s Department of Sociology and Criminal Justice, says it is important to learn lessons from incidents for future approaches.

“Many developed countries instituted policies in the immediate aftermath of an attack that may have contributed to stopping the problem, and this can provide lessons for future approaches to US mass shooting intervention and prevention.

“For example, in the wake of three shootings in Finland between 2007-2009, the Finnish government issued new firearm guidelines for handguns and revolvers, which were the primary firearms during these attacks. Applicants for handgun licences are now required to be active members of a gun club and vetted by their doctor and police.”

By analyzing openly accessible data from both developed and developing nations internationally, as well as reviewing previous research on mass shootings, Dr Silva was able to paint a picture of the differences and similarities in the characteristics of mass shootings across the world. Crucially, he is also able to provide insight into the type of person carrying out the attacks; the details of the incident; and, indeed, the motives of why they took place – if such an explanation could be found.

Overall, it was shown that in developed countries (including the US), shootings were more likely to be carried out by those with ideological motives, and fame-seeking motives. As well as schools, attacks in open spaces were also common – and most incidents involved handguns and shotguns.

Looking at the US separately, shooters were more likely to use more than one firearm. The motivation of their attack was also distinct from other countries, with perpetrators facing employment and financial issues, as well as relationship problems.

“American mass shooters were more likely to attack factories, warehouses, and offices than perpetrators in all other combined countries. While individuals from all countries suffer from strain, this particular strain is largely a US mass shooting motive,” explains Dr Silva.

“Security measures should therefore focus on target hardening in high-risk workplaces, modelling other location-based intervention strategies that have effectively decreased incidents and casualties.

“Relationship problems present another distinct form of strain contributing to US mass shootings. This is not to say that relationship problems do not exist in other countries or that they do not result in violence. In fact, many other countries have much higher rates of intimate partner violence and homicide. However, it is uniquely American that relationship problems end in mass shootings: where individuals outside of those contributing to relationship problems were also, or instead, targeted at random.”

In developing countries, mass shootings were more likely to involve perpetrators with a military or police history, and to occur within their place of work – so, an “attack from within”. 64% of all mass shootings involved this type of incident. A motive was often “difficult” to source from within publicly available documents though.

Comparing and summarizing, Dr Silva added: “Mass shootings are a uniquely American problem, particularly in relation to other developed countries.”

His research disqualified incidents involving profit-driven criminal activity, state-sponsored violence, and familicide, as well as incidents involving organized terrorism and/or battles over sovereignty. This was because, he states, “it does not provide a valuable comparison with the US – the primary focus of this study – the US has never had mass shootings rooted in organized terrorism and/or battles over sovereignty”.

Limitations of the research include its “reliance” on open-source data, which “means it is impossible to know if all cases have been captured” – an issue greatest in developing countries with limited data and non-English language news outlets hindering the ability to search and find information.