Investigating the Puzzles Behind American Mass Shootings

Print More

Illustration by Kostya Vacuum via Flickr

Mass shootings in the United States are rare events statistically, but their shocking impact can be devastating for generations.

This week is the 20th anniversary of the Columbine High School massacre in Colorado, in which two students shot to death 12 fellow students and a teacher on April 20, 1999.

Considering that there were nearly 40,000 deaths by firearm in the U.S. in 2017 (two-third of which were suicides), the 13 who died at Columbine does not sound like many, but the episode has had an outsized symbolic effect.

Five years ago, ABC News calculated that Columbine was mentioned by perpetrators in at least 17 attacks and another 36 alleged plots or serious threats against schools after the Columbine attack.

Perhaps surprisingly, the phenomenon has not been subjected to a comprehensive academic study, until now.

Last week, the National Science Foundation sponsored what it called a workshop on “An Evidence-Based Approach to Understanding and Countering Mass Violence in America.”

Nearly 50 experts, both academics and law enforcement officers, gathered at George Mason University in northern Virginia for the meeting, which was co-sponsored by George Mason’s Center for Evidence-Based Crime Policy and Heinz College of Carnegie Mellon University. It was led by criminologists Daniel Nagin of Carnegie Mellon and Christopher Koper of George Mason.

Fourteen academics presented papers on various aspects of the subject. The Crime Report was invited to observe the session on the condition that experts not be quoted directly because they are revising their work on the basis of discussion at the gathering. The papers will be published in the American Society of Criminology’s journal Criminology & Public Policy.

While one purpose of the project is to assess whether authorities can do a better job of anticipating and preventing mass violence, experts readily conceded that it will be difficult.

One major reason is that mass-casualty events come in different forms. In addition to school shootings, there have been a number of attacks motivated by terrorism. In some, such as the Las Vegas concert massacre in 2017, no conclusive evidence could be found of the shooter’s motive.

The role of firearms present another set of issues. Many mass shooters exhibited no publicly available signs of planning such events and had no criminal record, making it virtually impossible to keep them from obtaining guns.

Some perpetrators did have records of mental treatment, such as the shooter in Connecticut’s Sandy Hook Elementary School and the Aurora, Co., movie theater, but most people with mental problems do not become involved in mass shootings and cannot be denied access to firearms.

Another major category being considered by the experts is mass deaths resulting from domestic violence incidents, which get much less public attention than do shootings in schools and other public places.

One myth mentioned at the meeting was that mass shootings in the U.S. are much more frequent than they were in earlier years.

Grant Duwe of the Minnesota Department of Corrections, a participant in the ongoing project, wrote in 2017 that such events at that point were “roughly as common now as they were in the 1980s and ’90s. And the data offer a stark finding: Over the past decade, mass public shootings haven’t become particularly more prevalent, they’ve simply become deadlier.”

George Mason’s Koper has focused on this issue in studies of the impact of the federal ban on some kinds of assault weapons, which was in effect only from 1994 to 2004.

He said after the Las Vegas massacre, in which the shooter legally modified about a dozen smiautomatic rifles to fire like automatic weapons, that , “In general, you’d expect that if less lethal weapons were available, you could perhaps reduce the severity of some of the mass shooting incidents.”

Last week’s session included commentary by law enforcement professionals who have investigated cases of mass violence.

One of them was Daniel Oates, Police Chief in Miami Beach, Fl., who was chief in Aurora, Co., at the time of the theater shooting on July 20, 2012, in which 12 people were killed at random.

Oates does not believe that anything could have been done to prevent the Aurora killings, observing that there never was an explanation for what the shooter did.

He also expressed doubts about a new trend of “risk protection orders,” in which several states have enacted laws permitting police to seize guns possessed by people deemed threats to themselves or others. Oates said the bureaucratic process involved in obtaining and enforcing such orders make them “not much of a solution.”

He urged the experts to focus on effective responses to mass shootings, noting that paramedics and others involved in Aurora saved the lives of “everyone with a pulse” who hadn’t died at the scene.

Other researchers writing papers include Richard Berk of the University of Pennsylvania, Dewey Cornell of the University of Virginia, Arie Croitoru of George Mason, Joshua Freilich of John Jay College of Criminal Justice, Lin Huff-Corzine of the University of Central Florida, Peter Langman of Langman Psychological Associates, Adam Lankford of the University of Alabama, Hannah Laqueur of the University of California Davis, James Silver of Worcester State University, Jennifer Skeem of the University of California Berkeley, Daniel Webster of Johns Hopkins University and April Zeoli of Michigan State University.