In the last month, the United States has seen four mass shootings in public places that killed at least four people aside from the perpetrator, including yesterday's attack at a FedEx warehouse in Indianapolis. Prior to the Atlanta spa shootings on March 16, more than a year had elapsed without such a crime, which is the definition of public mass shootings used by the Congressional Research Service.
That pattern is consistent with data indicating that public mass shootings tend to happen in clusters, suggesting that one such crime makes others more likely. "One happens, and you see another few happen right after that," Hamline University criminologist Jillian Peterson noted in a 2019 interview with NPR.
A 2015 PLOS One study seemed to confirm that impression. Statistician Sherry Towers and her collaborators looked at 232 "mass killings" (defined as "incidents with four or more people killed") from 2006 through 2013, based on USA Today's database. They also considered 188 school shootings—defined as incidents on campus (including college campuses) during school hours, on school buses, or at school-related events (such as football games) in which at least one person was shot—from 1998 through 2013.
"We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past," Towers and her co-authors reported. "On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents….We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents." The researchers did not find such evidence when they looked at a broader category of shootings that included attacks in which at least three people were injured or killed.
What is the mechanism of the "contagion" described in this study? Towers et al. say "stressed individuals may have, consciously or sub-consciously, been inspired to act on previously suppressed urges by exposure to details of similar events." They argue that "such contagious ideation is not implausible," since "vulnerable youth have been found to be susceptible to suicide ideation brought on by influence of reports and portrayal of suicide in mass media" and "media reports on suicides and homicides have been found to apparently subsequently increase the incidence of similar incidents in the community."
In a 2016 paper, Western New Mexico University psychologist Jennifer Johnston and graduate student Andrew Joy say "recent analyses of media coverage followed by copycat incidents," including the Towers study, "indicate a media contagion effect." Consistent with that hypothesis, other studies have "found that most shooters desired fame and wished to emulate a previous mass shooter." Johnston and Joy argue that "identification with prior mass shooters made famous by extensive media coverage, including names, faces, writings, and detailed accounts of their lives and backgrounds, is a more powerful push toward violence than mental health status or even access to guns."
Northeastern University criminologist James Alan Fox, a leading expert on mass shootings, is skeptical of that argument. "Some bunching just happens," he told The Washington Post in 2016. "Yes, there is some mimicking going on, but the vast majority of mass killers don't need someone else to give them the idea."
In a 2013 Homicide Studies article, Fox said there was a "paucity of hard evidence about the exact magnitude of copycatting." But he also noted that "there are many curious examples of copycat offending," including the series of shootings by U.S. Postal Service workers that began in 1986, which gave rise to the expression "going postal." He also cited the perpetrator of the 2012 attack at Sandy Hook Elementary School in Newtown, Connecticut, who reportedly was "obsessed" with the mass shooter who had killed 77 people in Norway the previous year.
"Whatever the extent of imitation," Fox wrote, "it is important that media coverage not obsess over large and especially record-setting body counts and avoid the tendency to sensationalize already sensational events….There is a critical distinction between shedding light on a crime and a spotlight on the criminal."
University of North Carolina sociologist Zeynep Tufekci likewise argues that news organizations should exercise restraint in covering mass shootings. "I am increasingly concerned that the tornado of media coverage that swirls around each such mass killing, and the acute interest in the identity and characteristics of the shooter—as well as the detailed and sensationalist reporting of the killer's steps just before and during the shootings—may be creating a vicious cycle of copycat effects similar to those found in teen and other suicides," she writes in a 2012 Atlantic article.
Tufekci notes that news outlets changed the way they covered suicides in the hope of weakening the copycat effect—for example, by omitting the word suicide from headlines, by refraining from describing the method of suicide, and by not portraying it as "an inexplicable act of an otherwise healthy person." She suggests that similar self-restraint could help prevent clusters of mass shootings.
Some of Tufekci's specific recommendations are debatable. She suggests, for example, that information about "which guns exactly were used" should not be reported. Yet that information is of keen interest to people on both sides of the gun control debate, especially because politicians and activists always react to mass shootings by pushing the firearm policies they already favored, such as "assault weapon" bans and expanded background checks for gun buyers. The relevance of such proposals is hard to evaluate without knowing what weapon was used or how the perpetrator obtained it.
Tufekci's recommendation that there should be "no reporting of the killer's words or actions before or during the shooting" is similarly problematic, especially when those words and actions illuminate the shooter's motivation. When a killer might have been driven by racism or anti-Semitism, for instance, interest in the views or sentiments he expressed goes beyond morbid curiosity or sensationalism and is legally relevant when prosecutors are contemplating hate crime charges (whether the law should allow such charges is another matter).
Tufekci also suggested that mass shooters' social media accounts should be taken down right away, which has since become common practice, and that perpetrators' names should not be immediately revealed. The latter recommendation, insofar as it implies that police should withhold that information "for weeks" (as Tufekci suggests), seems inconsistent with principles of transparency and accountability, since we are talking about public records concerning newsworthy events with implications for public safety.
But the fact that such information is available does not mean it has to be included in every article about a mass shooting. Likewise with photographs of mass shooters. I try to do my own small part by omitting the perpetrator's name and picture when I write about mass shootings, which has been my practice in recent years. When the subject is something like the wisdom of public policy solutions proposed by politicians, there is no need for those details. And even in straightforward news coverage, reporters and editors really should be thinking about how often and how conspicuously they need to name and show the mass shooter.
More generally, the sheer volume of coverage that tends to follow mass shootings not only makes the perpetrators more famous; it creates a distorted sense of how often these crimes occur. Despite the impression left by the attention they receive, mass shootings remain rare events that account for a tiny share of annual gun homicides, and policies proposed in response to them may be ill-suited to the broader problem. Leaving aside the illogic of "assault weapon" bans, for example, they plainly have nothing to do with run-of-the-mill gun homicides, which overwhelmingly involve ordinary handguns (which are also the type of weapon most commonly used in mass shootings, including some of the deadliest).
In addition to cautioning against obsessive coverage of mass shooters, Tufekci argues that "the intense push to interview survivors and loved ones in their most vulnerable moments should be stopped," which "may help reduce the sense of spectacle and trauma." That too is more a matter of proportion, tone, and emphasis than a yes-or-no question. But if the news media contribute to the copycat effect by dwelling on the suffering of victims and relatives, so do the activists and politicians who endlessly highlight those stories while pushing firearm restrictions.
That is another reason (in case we needed one) to emphasize logic and evidence rather than emotional appeals in debates about gun control. Public officials could do their part by not reflexively pushing their pre-existing agenda after every mass shooting, even when the details of the crime are still unclear or make the supposed solution irrelevant. But if expecting self-control by click-hungry journalists seems unrealistic, expecting politicians to think before they speak is an even taller order.