How Not to Cover Mass Shootings

Illustration: Doug Chayka

The often sensationalistic media attention given to perpetrators is central to why massacres are happening more.

N. Schulman reports: It isn’t your imagination: Mass shootings are getting deadlier and more frequent. A recent FBI report on “active shooters” from 2000 to 2015 found that the number of incidents more than doubled from the first to the second half of the period. Four of the five deadliest shootings in American history happened in the past five years, and 2017 already far exceeds any previous year for the number of casualties.

Though we seem to be plunging ever deeper into a dark night, researchers now have a far clearer view of a key factor in the violence. A long-standing theory has matured into a body of evidence that can no longer be dismissed: The level of attention paid to mass shootings is central to why they keep happening.

The idea that some crimes might be self-spreading, like a disease, was proposed as early as 1890, when the French sociologist Gabriel Tarde labeled murders copying Jack the Ripper “suggesto-imitative assaults.” For mass shootings, the effect was well known among researchers by the early 2000s, when a wealth of information allowed forensic psychiatrist Paul E. Mullen to conclude, “These massacres are acts of mimesis, and their perpetrators are imitators.”

But the research has solidified in just the last few years. In 2015, a pair of studies analyzed databases cataloging nearly all U.S. mass shootings. They produced the first comprehensive statistical evidence that shootings occur in clusters rather than randomly across time.

[Read the full story here, at WSJ.com]

One of the studies, led by mathematician Sherry Towers of Arizona State University, used a contagion model previously applied to analyze viral videos and terrorist attacks. It found that the likelihood of a mass shooting is significantly higher when another mass shooting has recently occurred. The period of increased probability lasts, on average, for 13 days, the study found. (Notably, Dr. Towers did not find a contagion effect for shootings in which three or fewer people were killed.) The other study, conducted by Fresno State criminologist Jason Kissner, employed a different statistical modeling technique but also found an increased likelihood lasting for a similar period.

These findings are not yet conclusive. A study published in July by criminologist Adam Lankford and psychologist Sara Tomek, both of the University of Alabama, claimed that the clustering effects were not significantly different from random variation. Read the rest of this entry »