Patterns and prevalence of lethal mass violence

• Published date: 01 February 2020
• Date: 01 February 2020
• Author: Grant Duwe
• DOI: http://doi.org/10.1111/1745-9133.12478

DOI: 10.1111/1745-9133.12478

SPECIAL ISSUE ARTICLE

COUNTERING MASS VIOLENCE IN THE UNITED STATES

Patterns and prevalence of lethal mass violence

Grant Duwe

Minnesota Department of Corrections

Correspondence

GrantDuwe, Minnesota Department of Cor rec-

tions,1450 Energy Park Drive, Suite 200, St.

Paul,MN 55108.

Email:g rant.duwe@state.mn.us

Research Summary: Mass shootings have been identified

as a novel American crime problem. The term is merely

a new name, however, for an older crime problem—mass

murder. The social construction of the mass shooting and

mass murder problems have both been driven by “mass

public shootings”—incidents that occur in the absence of

other criminal activity (e.g., robberies, drug deals, and gang

“turf wars”) in which a gun was used to kill four or more

victims at a public location within a 24-hour period. Using

data on 845 mass shootings, including 158 mass public

shootings, which occurred in the United States between

1976 and 2018, in this study, I analyze trends in their

prevalence and severity (i.e., number of victims killed

and wounded). After controlling for growth in the U.S.

population, the results show the late 1980s and early 1990s

had the highest incidence of mass shootings. Both the

incidence and severity of mass public shootings, on the

other hand, have increased over the last decade. I also

describe the patterns of mass public shootings by reporting

incident and offender characteristics.

Policy Implications: Despite the recent growth in mass

public shootings, the infrequency with which they occur

makes it very challenging to develop broad measures that

will reduce their incidence or severity. It may therefore be

more effective to focus on strategies that that have shown

promise in decreasing violence in general.

KEYWORDS

lethal mass violence, mass murder, mass public shootings

Criminology & Public Policy. 2020;19:17–35. wileyonlinelibrary.com/journal/capp © 2019 American Society of Criminology 17

18 DUWE

During the late 1980s and early 1990s, a string of high-profile public shootings led to claims that mass

murder was on the rise and had become “commonplace” in the United States (Duwe, 2007). More

recently, the occurrence of massacres in places such as Newtown, Connecticut; Orlando, Florida; and

Las Vegas, Nevada, have prompted assertions that mass shootings have grown more prevalent and are

now “routine” (Cohen, Azrael, & Miller, 2014; Korte, 2016). Yet, the emergence of the mass murder

and mass shooting problems have both been fueled by mass public shootings, which are incidents in

which multiple victims are gunned down in a public place for no apparent rhyme or reason (Duwe,

2018).

In part as a result of the surplus of terms that have been used to describe mass violence, there has

been, as Fox and Levin (2015) have pointed out, “mass confusion” over the phrase “mass shooting”.

It is therefore important, at the outset, to clarify the meaning of terms such as “mass murder”, “mass

shooting”, or “mass public shooting”. A mass murder has been defined as an incident in which four

or more victims are killed—with any type of weapon—within a 24-hour period (Duwe, 2007; Fox &

Levin, 2011). A mass shooting, as defined here, is a mass murder carried out with a firearm. Therefore,

a mass shooting is any gun-related mass murder regardless of whether it occurred in a residential

setting or a public location. A mass shooting would thus include incidents such as the 1890 Wounded

Knee Massacre, the 1929 St. Valentine’s Day Massacre, and the recent mass murders in Orlando and

Las Vegas.

A mass public shooting, meanwhile, is a gun-related mass murder that takes place at a public loca-

tion in the absence of other criminal activity (e.g., robberies, drug deals, and gang “turf wars”), military

conflict, or collective violence. Although the Las Vegasmassacre would qualify as a mass public shoot-

ing, the Wounded Knee and St. Valentine’s Day massacres would not. Mass public shootings can thus

be seen not only as a type of mass murder but also as a specific type of mass shooting.

In this study, I describe the patterns and prevalence of mass violence and, in particular, gun-related

mass killings. In doing so, I address not only whether mass shootings have been on the rise but also

the profile of those who commit this type of violence. In the next section, I begin by discussing how

mass murder and, more recently, mass shootings have been socially constructed as crime problems.

Next, given recent concerns over whether mass shootings have increased, I begin by delineating trends

in their prevalence. To describe the patterns of mass public shootings, I conclude by reporting incident

and offender characteristics.

1MASS MURDER: SOCIAL CONSTRUCTION OF A “NEW”

CRIME PROBLEM

Whereas the objectivist approach can be used to define social problems in terms of their objective con-

ditions, the social constructionist perspective can be used to maintain that social problems are the prod-

uct of “the activities of individuals and groups making assertions of grievances and claims with respect

to some putative conditions” (Spector & Kitsuse, 1977, p. 75). The news media are invariably the pri-

mary means through which social problems are constructed, either by making claims directly (i.e.,

primary claimsmaking) or, more frequently, by reporting the claims made by others (i.e., secondary

claimsmaking). Prior research findings have revealed that the “discovery” of a new crime problem

is often triggered by the occurrence of a widely publicized event, or landmark narrative, which ulti-

mately is used to define the essence of the problem (Adler,1996; Cher mak, 2003; Duwe,2007; Nichols,

1997). When claimsmakers construct a social problem, they usually focus on describing the nature of

the problem, how prevalent it is, and what can be done to control it.