Mass Shootings, Part I

Sadness. Frustration. Anger. Fear. Among the reactions we're having to Tuesday's massacre in Uvalde, surprise doesn't seem very high on the list. Many of us were still grieving the Buffalo shooting 10 days earlier, which, sadly, wasn't that surprising either.  

One thing I find utterly horrifying is that, in my lifetime, mass shootings in the U.S. have become a statistical phenomenon. In other words, there are so many of them, we're become able to create databases where patterns can be analyzed.

(If mass shootings were rare, we wouldn't have statistical data. We'd have isolated incidents, with little basis for generalization.)

In this newsletter I'll share some of what statistics have taught us about the characteristics of  mass shootings and shooters. Next week I'll take a close look at causes and potential solutions, including steps each of us can take to promote change.

What is a mass shooting?

Definitions vary across researchers and agencies.

For example, the highly influential Gun Violence Archive (GVA) , a non-profit group that tracks every instance of gun violence in the U.S., defines a mass shooting as a single incident in which one perpetrator (or a small group) shoots 4 or more people (not necessarily fatally).

Other definitions set 3 or 5 victims as the minimum, and may exclude shootings where victims were specifically targeted (examples of targeted victims include family members, people being robbed, and members of rival gangs). In some instances, no specific definitions are given. For example, the FBI defines mass killings but not mass shootings.

Does it matter how "mass shooting" is defined?

Yes. The extent of the problem varies according to definition.

For example, if mass shootings are defined as a minimum of 5 victims, and targeted shootings are excluded, then America has experienced roughly 1 mass shooting per month, on average, every year for the past decade.

Using the GVA definition (see above), America has experienced between 1 and 2 mass shootings per day, on average, every year for the past decade.

So, take your pick: 1 per month, or 1+ per day, depending on definition. Either way, the stats look pretty grim.

How bad is the mass shooting problem in the U.S.?

One way to address this question is to look at frequencies, as I described above. Another way is through comparison to other countries.

When using the GVA definition (but restricting it to fatalities), and considering data from 1966 through the present, we find that the U.S. leads the world in total numbers of mass shooters and shootings. We're home to about 5% of the world's population but 31% of its mass shootings.

Per-capita statistics tell a nearly identical story. Specifically, the U.S. ranks second in the world, behind Yemen, in mass shooters per capita (28 vs. 40 shooters per million citizens, respectively). And, regardless of definition, our mass shooting rates are much higher than those of any other "developed" or "first-world" country, which are, arguably, the countries we should be comparing ourselves to.

Finally, however you characterize the severity of the problem, it's clearly getting worse. Using a GVA-type definition of mass shooting, for example, over a third of all mass shootings since 1966 have occurred in the past decade alone, and there was a spike at the beginning of the pandemic that has continued through the present month.

(Evidence also suggests that the average number of victims is increasing, but I don't trust these statistics, because the sample size is still small enough for the averages to be misleadingly influenced by a few extreme cases.)

In sum, I suspect most people would agree that mass shootings are a big problem in the U.S., according to most definitions of "mass shooting" and "big". I haven't found reliable data on mass shootings per se, but a 2021 survey conducted by the renowned, non-partisan Pew Research Center showed that 72% of American adults consider gun violence in general to be a "very big" or "moderately big" problem in our country. I certainly agree.

What characteristics do U.S. mass shootings have in common?

In 2001, the U.S. Secret Service and the U.S. Department of Education collaborated on a study of all school shootings documented in the U.S. For a number of years, I required my M.Ed. students to read this study, because the methodology was superb.

I was sad to discover this week that current studies don't tell us much more about mass shootings than that 2001 study did, even though it's nearly two decades old and focused exclusively on school settings.

For instance, according to The Violence Project, the most comprehensive database of mass shootings, nearly all mass shooters in the U.S. thus far have been males and share four characteristics:

—childhood trauma and early exposure to violence

—a current grievance or emotional crisis

—knowledge of the actions of prior shooters and of "narratives" that justify their feelings and plans

—access to guns

In addition, many shooters exhibit warning signs, including communication with others about violent intent, and/or signs of emotional crisis (increased agitation, aggressiveness, etc.), although the majority of shooters showed no signs of specific mental health disorders such as schizophrenia.

This is useful information, but not very actionable, because the overwhelming majority of males who have experienced trauma, nurture a grievance, etc. don't become mass shooters. When a teenager texts someone about plans to shoot up a school, that's actionable, but we don't need a research study to tell us that.

Are U.S. mass shootings distinctive?

Yes, to some extent. Mass shootings in the U.S. tend to differ from those in other countries in three ways:

(i) In the U.S., more than half of mass shooters use multiple guns. In other countries, it's much more common for the shooter to only use one.

(ii) In the U.S., mass shootings are more common in school settings (and, until recently, in the workplace). In other countries, they're more common near military installations.

(iii) In the U.S., each incident is associated with slightly fewer victims on average. We may not notice this, given media attention to larger-scale incidents. Using GVA-type definitions of mass shootings, for example, incidents in the U.S. average 6.9 victims, versus 8.8 victims in all other countries combined.

Is it important that U.S. mass shootings are distinctive?

Yes, because the characteristics of our mass shootings are thought to be informative about both causes and potential remedies.

Consider again each of the three characteristics I mentioned in the previous section.

(i) The fact that American mass shooters are more likely to use multiple guns is treated, by some, as evidence that our high rate of mass shootings reflects widespread access to guns. (Indeed, America has, by far, more guns per capita than any other country – roughly one per citizen.)

(ii) Those who subscribe to "copycat" theories of mass shootings take, as one line of evidence, the relatively high prevalence of shootings in American schools, a tradition that extends all the way back to Columbine (whose perpetrators continue to be idolized by some of the more recent shooters).

(iii) Some experts hold that our mass shootings have fewer victims, because American police receive more training specifically focused on how to handle mass shootings. This is taken by some as evidence that mass shootings have become normative in the U.S., and, thus, the problem is in part a cultural one.

Next week I'll have more to say about these and other explanations that have been proposed for mass shootings, and for why they're so prevalent in the U.S. I will also describe steps each of us can take to help address the problem.

Stay tuned, and stay safe.