Mass Shooting Incidents Research Articles

Mental Illness, Mass Shootings, and the Future of Psychiatric Research into American Gun Violence.

This article outlines a four-part strategy for future research in mental health and complementary disciplines that will broaden understanding of mass shootings and multi-victim gun homicides. First, researchers must abandon the starting assumption that acts of mass violence are driven primarily by diagnosable psychopathology in isolated “lone wolf” individuals. The destructive motivations must be situated, instead, within larger social structures and cultural scripts. Second, mental health professionals and scholars must carefully scrutinize any apparent correlation of violence with mental illness for evidence of racial bias in the official systems that define, measure, and record psychiatric diagnoses, as well as those that enforce laws and impose criminal justice sanctions. Third, to better understand the role of firearm access in the occurrence and lethality of mass shootings, research should be guided by an overarching framework that incorporates social, cultural, legal, and political, but also psychological, aspects of private gun ownership in the United States. Fourth, effective policies and interventions to reduce the incidence of mass shootings over time—and to prevent serious acts of violence more generally—will require an expanded body of well-funded interdisciplinary research that is informed and implemented through the sustained engagement of researchers with affected communities and other stakeholders in gun violence prevention. Emerging evidence that the coronavirus pandemic has produced a sharp increase both in civilian gun sales and in the social and psychological determinants of injurious behavior adds special urgency to this agenda.

The Influence of Media Related to Mass Shootings

Sometimes psychiatrists are confronted with questions regarding the potential role that media may play in influencing mass shootings, and they are asked to assess the risk for targeted violence in certain persons who exhibit potential warning signs of media influence. Additionally, psychiatrists can serve in an important role when interfacing with news media after mass shootings, but they must navigate ethical and professional pitfalls, including inadvertently increasing the risk for contagion. Therefore, it is prudent for psychiatrists to become knowledgeable about the potential impact of media on incidents of mass violence. Drawing from the fields of social psychology, media research, and threat assessment, the authors review contagion in mass shooting incidents, present potential media influence warning signs, and discuss considerations for news media reporting of mass shootings and considerations for psychiatrists interviewed by media after mass shootings. [ Psychiatr Ann . 2020;50(9):393–398.]

Are mass shootings acts of terror? Applying key criteria in definitions of terrorism to mass shootings in the United States from 1982 to 2018

ABSTRACT Scholars and policymakers often make noticeable distinctions between acts of terrorism and mass shooting incidents. In order to assess if these distinctions are generally accurate, we identity four key criteria from standard international and domestic definitions of terrorism. The criteria include: a political, religious, ideological, or social motivation; intent to reach a larger audience; the motivation not involving personal monetary gain; and the manifestation of an ‘enemy/other’. We analyze 105 mass shooting events in the United States from 1982 through October 2018 to assess whether they meet these criteria and find that 41 (39%) incidents meet all four criteria and another 45 (43%) incidents meet three of the criteria to be classified as acts of terrorism. Thus, we contend that mass shooting incidents fit the standard definitions of terrorism to a greater degree than is often reported by government officials, academics, and media outlets. We contend that researchers must be more persistent in investigating the motivations behind mass shooting events in order to accurately label and counter them.

Do Mass Shooters Prefer Large-Capacity Magazines?

There are over 58.9 million firearms magazines holding over ten rounds in private possession in the U.S. and at least 14.8 percent of private guns are equipped with magazines this large, while no more than 15.8 percent of U.S. mass shootings (4+ dead) in 2012-2019 involved a shooter using such a magazine. Thus, mass shooters use LCMs with a frequency not significantly greater than one would expect based on the share of U.S. guns equipped with LCMs. This accords with previous research showing that LCM use is neither necessary nor helpful to offenders trying to shoot large numbers of victims in mass shooting incidents (Kleck 2016).

The Hazards of Data-dredging in Gun Control Research: Comment on Webster et al. (2020)

Webster, McCourt, Crifasi, Booty, and Stuart (2020) recently published an article in which they concluded, based on a panel study of annual state-level data, that the incidence of mass shooting incidents and the total number of fatalities linked with such incidents are reduced by two types of gun control law: bans on large-capacity magazines (LCM) and purchasing licensing laws that require applicants to personally appear at a public safety agency or that require them to be fingerprinted. This comment establishes that the finding regarding the effect of LCM bans is inconsistent with the authors’ own technically soundest findings, and that the finding regarding purchaser licensing is highly sensitive to variations in method, and may have been produced by data-dredging.

Domestic Violence, Firearms, and Mass Shootings.

The strong association between firearms, domestic violence (particularly intimate partner homicide), and additional victimization suggests that prioritization of measures to decrease access to firearms to perpetrators of domestic violence may also reduce the incidence of mass shootings. The majority of mass shootings are associated with domestic violence. The current study by Kivisto and Porter examines whether the use of a firearm in domestic homicide affects the risk that others will also be killed during the same incident. Earlier studies have demonstrated that domestic homicide often extends to additional victims linked to the primary perpetrator or victim, either through a preexisting relationship or through physical proximity to the violence. Based on a national surveillance database, Kivisto and Porter confirm findings from earlier, more limited studies. Firearm use is associated with an increased incidence of multiple homicide victimization, especially in domestic situations. This suggests that additional laws to prevent those who perpetrate domestic violence from purchasing or possessing firearms, and vigorous enforcement of new and existing laws, may decrease the incidence of mass shootings, whether additional victims are inside or outside the home.

Evidence concerning the regulation of firearms design, sale, and carrying on fatal mass shootings in the United States

Research SummaryWe used data from the FBI's Supplemental Homicide Reports and other publicly available databases to calculate state‐level annual incidence of fatal mass shootings for 1984–2017. Negative binomial regression models were used to estimate the associations between changes in key gun laws and fatal mass shootings. Handgun purchaser licensing laws and bans of large‐capacity magazines (LCMs) were associated with significant reductions in the incidence of fatal mass shootings. Other laws commonly advocated as solutions to mass shootings—comprehensive background checks, assault weapons bans, and de‐regulation of civilian concealed carry of firearms—were unrelated to fatal mass shootings.Policy ImplicationsOur findings suggest that laws requiring firearm purchasers to be licensed through a background check process supported by fingerprints and laws banning LCMs are the most effective gun policies for reducing fatal mass shootings.

Assessing the potential to reduce deaths and injuries from mass shootings through restrictions on assault weapons and other high‐capacity semiautomatic firearms

Research SummaryThis article examines the use, impacts, and regulation of assault weapons and other high‐capacity semiautomatic firearms as they pertain to the problem of mass shootings in the United States. High‐capacity semiautomatics (which include assault weapons as a subset) are used in between 20% and 58% of all firearm mass murders, and they are used in a particularly high share of public mass shootings. Mass shootings perpetrated with these firearms result in substantially more fatalities and injuries than do attacks with other firearms, and these differences are especially pronounced for the number of victims with nonfatal gunshot injuries. The federal ban on assault weapons and large‐capacity (>10 rounds) ammunition magazines of 1994 had exemptions and loopholes that limited its short‐term effects, but its expiration in 2004 was followed by an increase in the use of these weapons in mass shootings and other crimes. Growing evidence suggests that state‐level restrictions on large‐capacity magazines reduce mass shootings, but further research is needed on the implementation and effects of these laws.Policy ImplicationsRestrictions on large‐capacity magazines are the most important provisions of assault weapons laws in part because they can produce broader reductions in the overall use of high‐capacity semiautomatics that facilitate high‐volume gunfire attacks. Data on mass shooting incidents suggest these magazine restrictions can potentially reduce mass shooting deaths by 11% to 15% and total victims shot in these incidents by one quarter, likely as upper bounds. It may take several years for the effects of these laws to be fully realized, however, depending on their specific provisions, especially with regard to treatment of pre‐ban weaponry.

Patterns and prevalence of lethal mass violence

Research SummaryMass 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 ImplicationsDespite 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.

Describing a \u201cmass shooting\u201d: the role of databases in understanding burden

BackgroundThe mass shooting phenomenon has gained much attention lately as this form of gun violence appears to increase in frequency. Although many organizations collect information on mass shootings (fatal and nonfatal injuries), no federal definition of this phrase exists. The purpose of this study was to highlight the different statistics that result among databases that define and track “mass shootings.” Establishing definitive guidelines for a mass shooting definition could improve research credibility when presenting evidence to policy makers.MethodsWe obtained data for mass shootings that occurred in 2017 from four sources: Gun Violence Archive, Mother Jones Investigation, Everytown for Gun Safety, and FBI’s Supplemental Homicide Report. We also examined FBI’s Active Shooter Report to compare the mass shootings datasets with active shooter situations, which have been federally defined. First, we examined the overlap among databases. Then, we applied the strictest fatal mass shooting definition to the mass shooting datasets to determine whether the differences in databases could be contributing to differences in fatalities and injuries recorded.ResultsGun Violence Archive recorded the most mass shooting incidents at 346 incidents in 2017, while Mother Jones only recorded 11 cases. Only 2 events were found in all four mass shooting datasets. When the strictest definition – four or more individuals fatally shot – was applied to all datasets, the number of mass shootings in 2017 ranged from 24 (Gun Violence Archive) to 5 (Mother Jones), but incidents collected still varied.ConclusionsThere is much variety in statistics obtained from the different sources that have collected mass shooting information, with little overlap among databases. Researchers should advocate for a standard definition that considers both fatalities and nonfatalities to most appropriately convey the burden of mass shootings on gun violence.

The Effect of Large-Capacity Magazine Bans on High-Fatality Mass Shootings, 1990-2017.

Objectives. To evaluate the effect of large-capacity magazine (LCM) bans on the frequency and lethality of high-fatality mass shootings in the United States.Methods. We analyzed state panel data of high-fatality mass shootings from 1990 to 2017. We first assessed the relationship between LCM bans overall, and then federal and state bans separately, on (1) the occurrence of high-fatality mass shootings (logit regression) and (2) the deaths resulting from such incidents (negative binomial analysis). We controlled for 10 independent variables, used state fixed effects with a continuous variable for year, and accounted for clustering.Results. Between 1990 and 2017, there were 69 high-fatality mass shootings. Attacks involving LCMs resulted in a 62% higher mean average death toll. The incidence of high-fatality mass shootings in non-LCM ban states was more than double the rate in LCM ban states; the annual number of deaths was more than 3 times higher. In multivariate analyses, states without an LCM ban experienced significantly more high-fatality mass shootings and a higher death rate from such incidents.Conclusions. LCM bans appear to reduce both the incidence of, and number of people killed in, high-fatality mass shootings.

Developing a blueprint for a civilian-military collaborative program in trauma training for Northern European countries: A South African experience

BackgroundRecent terrorist attacks and mass shooting incidents in major European and North American cities have shown the unexpected influx of large volumes of patients with complex multi-system injuries. The rise of subspecialisation and the low violence-related penetrating injuries among European cities, show the reality that most surgical programs are unable to provide sufficient exposure to penetrating and blast injuries. The aim of this study is to describe and create a collaborative program between a major South African trauma service and a NATO country military medical service, with synergistic effect on both partners. This program includes comprehensive cross-disciplinary training & teaching, and scientific research. MethodsThis is a retrospective descriptive study. The Pietermaritzburg hospital and Netherlands military trauma register databases were used for analysing patient data: Pietermaritzburg between September 2015 and August 2016, Iraq between May and July 2018 and Afghanistan from 2006 to 2010. Interviews were held to analyse the mutual benefits of the program. ResultsFrom the Pietermaritzburg study, mutual benefits focus on social responsibility, exchange of knowledge and experience and further mutual exploration. The comparison showed the numbers of surgical procedures over a one-month period performed in Iraq 12.7, in Afghanistan 68.8 and in Pietermaritzburg 152. ConclusionThis study has shown a significant volume of penetrating trauma in South Africa, that can provide substantial exposure over a relatively short period. This help to prepare civilian and military surgeons and deployable military medical personnel for casualties with blast – and/or penetrating injuries. The aforementioned findings and the willingness to shape the mutual benefits, create a platform for trauma electives, research, education and training.

Building community resilience: A scalable model for hemorrhage-control training at a mass gathering site, using the RE-AIM framework

In a decade, the US military reduced deaths from uncontrolled bleeding on the battlefield by 67%. This success, coupled with an increased incidence of mass shootings in the US, has led to multiple initiatives intent on translating hemorrhage-control readiness to the civilian sector. However, the best method to achieve widespread population-level hemorrhage-control readiness for civilians has not yet been elucidated. This study evaluates the implementation of American College of Surgeons Bleeding Control training at a National Football League stadium as a prospective model for general mass gathering site implementation. The American College of Surgeons' Bleeding Control Basic layperson hemorrhage-control training was implemented at Gillette Stadium in Massachusetts. The five domains are as follows: reach (demographics of study participants), effectiveness (correct tourniquet application after intervention), adoption (investigator, leadership, and participant efforts for sustainability of intervention), implementation (course details), and maintenance (correct tourniquet application at retention testing at 3 to 9 months). A total of 562 employees were included in the study. Of those included employees, 58.7% reported having taken first-aid training and 17.3% reported having taken hemorrhage-control training. There was an increased mean likelihood to help (4.39 vs 4.09, P < .01) and comfort level to control hemorrhage (4.26 vs 3.60, P < .01) after training compared with before training, on a Likert scale (1-5). The stadium operations team located hemorrhage control kits with automatic external defibrillators, integrated layperson immediate-response awareness into its Web site, and developed a public safety announcement. The training, performed by physicians, nurses, and emergency medical technicians, consisted of a 30-minute lecture and a 30-minute hands-on skills-training course, with a class size of 24. The total number of sessions was 24. Achieving initial hemorrhage-control readiness and maintenance at a mass gathering site through American College of Surgeons Bleeding Control training is feasible but requires significant commitment from training staff, site leadership, and financial resources.

Emergency Medical Services Response to Mass Shooting and Active Shooter Incidents, United States, 2014–2015

Background: The purpose of the current study was to describe the injury patterns, EMS response and interventions to mass shooting (MS) and active shooter (AS) incidents.Methods: Retrospective analysis of 2014–2015 National Emergency Medical Services Information System (NEMSIS) data sets. Date, time, and location for MS incidents were obtained from the Gun Violence Archive and then correlated with NEMSIS data set records. AS incidents were identified through Federal Bureau of Investigation (FBI) data. A de-identified database was generated for final analysis.Results: A total of 608 MS incidents were identified, of which 19 were also classified as AS incidents. NEMSIS patient care data was available for 652 EMS activations representing 226 unique MS incidents. Thirty-four EMS responses to 5 unique AS incidents were similarly identified: 76% of victims were male and 80% of victims were African American. Dispatch complaint did not suggest shooting (potentially dangerous scene environment) in 15.9% of records. The most commonly reported incident locations for MS were Street/Highway (38.2%) and Home/Residence (32.4%). Location of wounds included extremities (49%), chest (12%), and head/neck (13%). Tourniquet use was documented in 6 victims. 35.9% of victims were transported to the closest facility.Conclusions: MS and AS incidents are prevalent in the United States. Despite the fact that extremity wounds were common, documented EMS tourniquet use was uncommon. While MS events are high risk for responders, dispatch information was lacking in almost 15% of records. Responding EMS agencies were diverse, emphasizing the need to ensure all EMS providers are prepared to respond to MS incidents.

Australian Mass Shootings: An Analysis of Incidents and Offenders.

Mass shooting events are relatively underresearched, and most study comes from the United States. Despite significant international interest, little is known about other countries' experiences of these events. The current study examines Australian mass shooting incidents and offenders, with emphasis on mental illness, life strains, and offenders' life histories. Australia had 14 mass shootings between 1964 and 2014. Most offenders experienced acute life stressors and/or chronic strains leading up to the event; however, diagnosed mental illness was less commonly documented. These observations provide new information about mass shooting incidents and offenders, and can help to inform international policy development.

Association Between Gun Law Reforms and Intentional Firearm Deaths in Australia, 1979-2013.

Rapid-fire weapons are often used by perpetrators in mass shooting incidents. In 1996 Australia introduced major gun law reforms that included a ban on semiautomatic rifles and pump-action shotguns and rifles and also initiated a program for buyback of firearms. To determine whether enactment of the 1996 gun laws and buyback program were followed by changes in the incidence of mass firearm homicides and total firearm deaths. Observational study using Australian government statistics on deaths caused by firearms (1979-2013) and news reports of mass shootings in Australia (1979-May 2016). Changes in intentional firearm death rates were analyzed with negative binomial regression, and data on firearm-related mass killings were compared. Implementation of major national gun law reforms. Changes in mass fatal shooting incidents (defined as ≥5 victims, not including the perpetrator) and in trends of rates of total firearm deaths, firearm homicides and suicides, and total homicides and suicides per 100,000 population. From 1979-1996 (before gun law reforms), 13 fatal mass shootings occurred in Australia, whereas from 1997 through May 2016 (after gun law reforms), no fatal mass shootings occurred. There was also significant change in the preexisting downward trends for rates of total firearm deaths prior to vs after gun law reform. From 1979-1996, the mean rate of total firearm deaths was 3.6 (95% CI, 3.3-3.9) per 100,000 population (average decline of 3% per year; annual trend, 0.970; 95% CI, 0.963-0.976), whereas from 1997-2013 (after gun law reforms), the mean rate of total firearm deaths was 1.2 (95% CI, 1.0-1.4) per 100,000 population (average decline of 4.9% per year; annual trend, 0.951; 95% CI, 0.940-0.962), with a ratio of trends in annual death rates of 0.981 (95% CI, 0.968-0.993). There was a statistically significant acceleration in the preexisting downward trend for firearm suicide (ratio of trends, 0.981; 95% CI, 0.970-0.993), but this was not statistically significant for firearm homicide (ratio of trends, 0.975; 95% CI, 0.949-1.001). From 1979-1996, the mean annual rate of total nonfirearm suicide and homicide deaths was 10.6 (95% CI, 10.0-11.2) per 100,000 population (average increase of 2.1% per year; annual trend, 1.021; 95% CI, 1.016-1.026), whereas from 1997-2013, the mean annual rate was 11.8 (95% CI, 11.3-12.3) per 100,000 (average decline of 1.4% per year; annual trend, 0.986; 95% CI, 0.980-0.993), with a ratio of trends of 0.966 (95% CI, 0.958-0.973). There was no evidence of substitution of other lethal methods for suicides or homicides. Following enactment of gun law reforms in Australia in 1996, there were no mass firearm killings through May 2016. There was a more rapid decline in firearm deaths between 1997 and 2013 compared with before 1997 but also a decline in total nonfirearm suicide and homicide deaths of a greater magnitude. Because of this, it is not possible to determine whether the change in firearm deaths can be attributed to the gun law reforms.

The profile of wounding in civilian public mass shooting fatalities.

The incidence and severity of civilian public mass shootings (CPMS) continue to rise. Initiatives predicated on lessons learned from military woundings have placed strong emphasis on hemorrhage control, especially via use of tourniquets, as means to improve survival. We hypothesize that both the overall wounding pattern and the specific fatal wounds in CPMS events are different from those in military combat fatalities and thus may require a new management strategy. A retrospective study of autopsy reports for all victims involved in 12 CPMS events was performed. Civilian public mass shootings was defined using the FBI and the Congressional Research Service definition. The site of injury, probable site of fatal injury, and presence of potentially survivable injury (defined as survival if prehospital care is provided within 10 minutes and trauma center care within 60 minutes of injury) was determined independently by each author. A total 139 fatalities consisting of 371 wounds from 12 CPMS events were reviewed. All wounds were due to gunshots. Victims had an average of 2.7 gunshots. Relative to military reports, the case fatality rate was significantly higher, and incidence of potentially survivable injuries was significantly lower. Overall, 58% of victims had gunshots to the head and chest, and only 20% had extremity wounds. The probable site of fatal wounding was the head or chest in 77% of cases. Only 7% of victims had potentially survivable wounds. The most common site of potentially survivable injury was the chest (89%). No head injury was potentially survivable. There were no deaths due to exsanguination from an extremity. The overall and fatal wounding patterns following CPMS are different from those resulting from combat operations. Given that no deaths were due to extremity hemorrhage, a treatment strategy that goes beyond use of tourniquets is needed to rescue the few victims with potentially survivable injuries. Prognostic/epidemiologic study, level IV; therapeutic/care management study, level V.

The Mental Health Consequences of Mass Shootings

Mass shooting episodes have increased over recent decades and received substantial media coverage. Despite the potentially widespread and increasing mental health impact of mass shootings, no efforts to our knowledge have been made to review the empirical literature on this topic. We identified 49 peer-reviewed articles, comprised of 27 independent samples in the aftermath of 15 mass shooting incidents. Based on our review, we concluded that mass shootings are associated with a variety of adverse psychological outcomes in survivors and members of affected communities. Less is known about the psychological effects of mass shootings on indirectly exposed populations; however, there is evidence that such events lead to at least short-term increases in fears and declines in perceived safety. A variety of risk factors for adverse psychological outcomes have been identified, including demographic and pre-incident characteristics (e.g., female gender and pre-incident psychological symptoms), event exposure (e.g., greater proximity to the attack and acquaintance with the deceased), and fewer psychosocial resources (e.g., emotion regulation difficulties and lower social support). Further research that draws on pre-incident and longitudinal data will yield important insights into the processes that exacerbate or sustain post-incident psychological symptoms over time and provide important information for crisis preparedness and post-incident mental health interventions.

Multiple vantage points on the mental health effects of mass shootings.

The phenomenon of mass shootings has emerged over the past 50 years. A high proportion of rampage shootings have occurred in the United States, and secondarily, in European nations with otherwise low firearm homicide rates; yet, paradoxically, shooting massacres are not prominent in the Latin American nations with the highest firearm homicide rates in the world. A review of the scientific literature from 2010 to early 2014 reveals that, at the individual level, mental health effects include psychological distress and clinically significant elevations in posttraumatic stress, depression, and anxiety symptoms in relation to the degree of physical exposure and social proximity to the shooting incident. Psychological repercussions extend to the surrounding affected community. In the aftermath of the deadliest mass shooting on record, Norway has been in the vanguard of intervention research focusing on rapid delivery of psychological support and services to survivors of the "Oslo Terror." Grounded on a detailed review of the clinical literature on the mental health effects of mass shootings, this paper also incorporates wide-ranging co-author expertise to delineate: 1) the patterning of mass shootings within the international context of firearm homicides, 2) the effects of shooting rampages on children and adolescents, 3) the psychological effects for wounded victims and the emergency healthcare personnel who care for them, 4) the disaster behavioral health considerations for preparedness and response, and 5) the media "framing" of mass shooting incidents in relation to the portrayal of mental health themes.

The impacts of the Virginia Tech and Northern Illinois University shootings on fear of crime on campus

There has been a substantial increase in the number of mass shooting incidents on college campuses in the United States in recent years. Although empirical research examined the impacts of secondary school shootings on student fear, there have been no comparable studies of the impacts of campus shootings. This study began to fill this void by examining responses to surveys administered to convenience samples of students enrolled at the University of South Carolina prior to and following the mass shooting incidents on the campuses of Virginia Tech and Northern Illinois University. Findings indicated that both shootings were associated with modest increases in various measures of fear. Other findings were that the impacts of the shootings depended on both the type of fear measured (e.g., general fear versus fear of being a victim of specific crimes) and student characteristics such as age, sex, and race.