Gun-related Homicides Research Articles

State assault weapons bans are associated with fewer fatalities: analysis of US county mass shooting incidents (2014–2022)

BackgroundThe need for evidence to inform interventions to prevent mass shootings (MS) in the USA has never been greater.MethodsData were abstracted from the Gun Violence Archive, an independent online database...

Changes in the Demographic Distribution of Chicago Gun-Homicide Decedents From 2015-2021: Violent Death Surveillance Cross-sectional Study

Homicide is one of the 5 leading causes of death in the United States for persons aged 1 to 44 years. In 2019, 75% of US homicides were by gun. Chicago has a gun-homicide rate 4 times the national average, and 90% of all homicides are by gun. The public health approach to violence prevention calls for a 4-step process, beginning with defining and monitoring the problem. Insight into the characteristics of gun-homicide decedents can help frame next steps, including identifying risk and protective factors, developing prevention and intervention strategies, and scaling effective responses. Although much is known about gun homicide because it is a long-standing, entrenched public health problem, it is useful to monitor trends to update ongoing prevention efforts. This study aimed to use public health surveillance data and methods to describe changes in the race/ethnicity, sex, and age of Chicago gun-homicide decedents from 2015-2021, in the context of year-to-year variation and an overall increase in the city's gun-homicide rate. We calculated the distribution of gun-related homicide deaths by 6 race/ethnicity and sex groups (non-Hispanic Black female, non-Hispanic White female, Hispanic female, non-Hispanic Black male, non-Hispanic White male, and Hispanic male), age in years, and age by age group. We used counts, percentages, and rates per 100,000 persons to describe the distribution of deaths among these demographic groups. Comparisons of means and column proportions with tests of significance set at P≤.05 were used to describe changes in the distribution of gun-homicide decedents over time by race-ethnicity-sex and age groups. The comparison of mean age by race-ethnicity-sex group is done using 1-way ANOVA with significance set at P≤.05. The distribution of gun-homicide decedents in Chicago by race/ethnicity and sex groups had been relatively stable from 2015 to 2021 with 2 notable exceptions: a more than doubling of the proportion of gun-homicide decedents who were non-Hispanic Black female (3.6% in 2015 to 8.2% in 2021) and an increase of 3.27 years in the mean age of gun-homicide decedents. The increase in mean age coincided with a decrease in the proportion of non-Hispanic Black male gun-homicide decedents between the ages of 15-19 and 20-24 years and, conversely, an increase in the proportion of non-Hispanic Black male gun-homicide decedents aged 25-34 years. The annual gun-homicide rate in Chicago had been increasing since 2015 with year-to-year variation. Continued monitoring of trends in the demographic makeup of gun-homicide decedents is necessary to provide the most relevant and timely information to help shape violence prevention efforts. We detected several changes that suggest a need for increased outreach and engagement marketed toward non-Hispanic Black female and non-Hispanic Black male individuals between the ages of 25-34 years.

Federalism, Policy Diffusion, and Gender Equality: Explaining Variation in State Domestic Violence Firearm Laws 1990–2017

AbstractThis work explores the ways that federalism exacerbates gender inequality among women by explaining the adoption of domestic violence laws across different states in the context of policy diffusion. Using an original dataset of domestic violence firearm law (DVFL) enactments across all 50 states in the United States from 1990 to 2017, we analyze the circumstances under which states will adopt these laws. Using a set of political and demographic indicators as independent variables, we find evidence that state and federal factors influence policy adoption. In particular, the number of gun-related homicides, partisan control of the legislature, citizen ideology, federal policy, and election years each influence the likelihood of DVFL enactments. We find support for the effects of vertical policy diffusion on initial enactment of federal laws in this domain, but not for reauthorizations, which raises important questions about the continuous influence of the federal government on state policies.

REDUCING GUN CRIMES: ACTIONABLE POLICIES FOR POLICE ORGANIZATIONS

Over ninety-nine percent of gun-related homicides in the U.S. involved a routinely occurring gun incident. More resources should be dedicated to addressing gun crimes by police organizations, especially those at the local level. Local police bear the brunt of most gun crimes and bulk of their investigations; a strong need thus exists for understanding related policy recommendations. Various policies and recommendations against gun crimes have been put forward resulting from related studies and evaluations. What they are and whether or how they should be adopted are not always clearly understood, however. This article provides a review of various gun-crime policies and programs to provide both a conceptual understanding of different approaches to gun crimes and specific choices of actionable gun crime policies. The results include a categorization of policy recommendations and a discussion of whether particular or more types of policies should be pursued and conditions under which these recommendations can be implemented successfully.

Non-fatal gunshot injuries during criminal acts in Mexico, 2013–2019

IntroductionAs the volume of firearms (legal and illegal) in Mexico grows, gun violence has become a major public health challenge. While studies have focused on gun-related homicides and robberies, there...

Fewer guns, less crime: evidence from Brazil

SUMMARY This paper studies the effects of legislation in Brazil that banned the right to carry guns and provided for a voter referendum regarding whether to ban the sale of all firearms. Using a regression discontinuity design, I find that gun-related homicides decreased by 12.2% and gunshot wounds that were ‘intended to kill’ by 16.3%, with the reduction of the former being especially pronounced in high-crime areas and among black males. There is no evidence of substitution effect as non-gun-related homicides were not affected. Two pieces of evidence suggest that the mechanism explaining this result is a decrease in the number of people carrying guns in response to the legislation: first, the number of cases of illegal gun carrying decreased and second, only gun-related homicides taking place outside the residence were reduced. Analysis of the subsequent voter referendum, which was defeated by a wide margin, shows stronger support for the complete firearms ban in the areas more affected by gun violence.

Explaining the Recent Homicide Spikes in U.S. Cities

Recently, major cities across the country have suffered dramatic spikes in homicides. These sudden spikes are remarkably large and widespread. At this rate, 2020 will easily be the deadliest year in America for gun-related homicides since at least 1999, while most other major crime categories are trending stable or slightly downward. This article attempts to explain why so many cities have seen extraordinary increases in murder during the summer of 2020. A close analysis of the emerging crime patterns suggests that American cities may be witnessing significant declines in some forms of policing, which in turn are producing the homicide spikes. Crime rates are increasing only for a few specific categories—namely homicides and shootings. These crime categories are particularly responsive to reductions in proactive policing. The data also pinpoint the timing of the spikes to late May 2020, which corresponds with the death of George Floyd while in police custody in Minneapolis and subsequent antipolice protests—protests that likely led to declines in law enforcement. The thesis of this article is that the recent spikes in homicides have been caused by a “Minneapolis Effect,” similar to the earlier “Ferguson Effect.” Specifically, law enforcement agencies have been forced to divert resources from normal policing to patrolling demonstrations. And even as the antipolice protests have abated, police officers have scaled back on proactive or officer-initiated law enforcement, such as street stops and other forms of policing designed to prevent firearm crimes. If this thesis is correct, it is reasonable to estimate that, as a result of de-policing during June and July 2020, approximately 710 additional victims were murdered and more than 2,800 victims were shot. Of course, this estimate relies on various assumptions, and further research on the issues surrounding the homicide spikes should be an urgent priority. If this article’s thesis about a Minneapolis Effect is correct, an important implication is that policy makers in major cities should proceed cautiously before taking steps to “defund” the police in ways that might reduce the proactive policing that is important in preventing gun violence.

Evolution of Firearm Violence over 20 Years: Integrating Law Enforcement and Clinical Data

Data linking ballistics to injury are lacking. To address this data chasm, a partnership with law enforcement was developed to describe clinical outcomes from specific firearms. A random sample of patients with gunshot wounds over a 20-year period ending in 2015, was identified. Circumstances of incident, firearm type, and/or caliber were extracted from police reports. Data on demographics, mortality, injury severity, and clinical outcomes were collected from the trauma registry, and these datasets were linked. Firearms were stratified by velocity (high > 2,500 ft/sec; low < 1,200 ft/sec) and caliber (large= .40 and .45; small=.20 and .25) and compared over time. Police reports were obtained on 366 patients who had a gun type or caliber documented. The majority were male (82%) with a median age of 28 years. Twenty-one percent of patients had an Injury Severity Score > 25, 60% required immediate operative intervention, and overall mortality was 13%. The use of large caliber firearms increased from 4% (1996 to 2000) to 33% (2011 to 2015); small caliber guns decreased from 33% to 7% over the same time period (p < 0.0001). High velocity firearm usage significantly increased (p= 0.0320). Recovered shell casings doubled from the first decade to the second (2 vs 4; p= 0.0006). Both median New Injury Severity Score (p= 0.0488) and hospital days (p= 0.0321) increased from 1996 to2015. Larger caliber and higher velocity firearms have significantly increased over the past 20 years in conjunction with injury severity, hospital days, and mean number of gun-related homicides per year (112 in 1996 to 2000 vs 143 in 2011 to 2015). Robust data sharing partnerships can be built between police and trauma centers to address the dearth of data on firearm crime and resulting injury.

SA98GENETIC ANALYSIS OF CADM2, A POSSIBLE LINK BETWEEN MENTAL AND PHYSICAL HEALTH

Data linking ballistics to injury are lacking. To address this data chasm, a partnership with law enforcement was developed to describe clinical outcomes from specific firearms.A random sample of patients with gunshot wounds over a 20-year period ending in 2015, was identified. Circumstances of incident, firearm type, and/or caliber were extracted from police reports. Data on demographics, mortality, injury severity, and clinical outcomes were collected from the trauma registry, and these datasets were linked. Firearms were stratified by velocity (high > 2,500 ft/sec; low < 1,200 ft/sec) and caliber (large = .40 and .45; small = .20 and .25) and compared over time.Police reports were obtained on 366 patients who had a gun type or caliber documented. The majority were male (82%) with a median age of 28 years. Twenty-one percent of patients had an Injury Severity Score > 25, 60% required immediate operative intervention, and overall mortality was 13%. The use of large caliber firearms increased from 4% (1996 to 2000) to 33% (2011 to 2015); small caliber guns decreased from 33% to 7% over the same time period (p < 0.0001). High velocity firearm usage significantly increased (p = 0.0320). Recovered shell casings doubled from the first decade to the second (2 vs 4; p = 0.0006). Both median New Injury Severity Score (p = 0.0488) and hospital days (p = 0.0321) increased from 1996 to 2015.Larger caliber and higher velocity firearms have significantly increased over the past 20 years in conjunction with injury severity, hospital days, and mean number of gun-related homicides per year (112 in 1996 to 2000 vs 143 in 2011 to 2015). Robust data sharing partnerships can be built between police and trauma centers to address the dearth of data on firearm crime and resulting injury.

Crime and Political Effects of a Concealed Carry Ban in Brazil

This paper studies the effects of legislation in Brazil that banned concealed carry nationwide in 2003, and provided for a voter referendum 22 months later regarding whether to ban the sale of all firearms. Using a regression discontinuity design, I find that gun-related homicides decreased by 12.2 percent, with the reduction especially pronounced in high-crime areas and among black males. Other crimes involving guns also declined. There is no evidence of substitution effect as non-gun-related homicides were not affected. Two pieces of evidence suggest that the mechanism explaining this result is a decrease in the number of people carrying gun in response to the legislation: first, the number of illegal gun carrying decreased and second, only gun-related homicides taking place outside the residence were reduced. Analysis of the subsequent voter referendum, which was defeated by a wide margin, shows stronger support for the complete weapons ban in the areas more affected by gun violence.

Infant Deaths and Mortality from Gun Violence: Causal or Casual?

ObjectiveDescribe trends in non-Hispanic black infant mortality (IM) in the New York City (NYC) counties of Bronx, Kings, Queens, and Manhattan and correlations with gun-related assault mortality. MethodsLinked Birth/Infant Death data (1999-2013) and Compressed Mortality data at ages 1 to ≥85 years (1999-2013). NYC and United States (US) Census data for income inequality and poverty. Pearson coefficients were used to describe correlations of IM with gun-related assault mortality and other causes of death. ResultsIn NYC, the risk of non-Hispanic black IM in 2013 was 49% lower than in 1995 (rate ratio: 0.51; 95% CI: 0.43, 0.61). Yearly declines between 1999 and 2013 were significantly correlated with declines in gun-related assault mortality (correlation coefficient (r) = 0.70, p = 0.004), drug-related mortality (r = 0.59, p = 0.020), major heart disease and stroke (r = 0.85, p < 0.001), malignant neoplasms (r = 0.57, p = 0.026), diabetes mellitus (r = 0.63, p = 0.011), and pneumonia and influenza (r = 0.78, p < 0.001). There were no significant correlations of IM with chronic lower respiratory or liver disease, non-drug-related accidental deaths, and non-gun-related assault. Yearly IM (1995-2012) was inversely correlated with income share of the top 1% of the population (r = −0.66, p = 0.007). ConclusionsIn NYC, non-Hispanic black IM declined significantly despite increasing income inequality and was strongly correlated with gun-related assault mortality and other major causes of death. These data are compatible with the hypothesis that activities related to overall population health, including those pertaining to gun-related homicide, may provide clues to reducing IM. Analytic epidemiological studies are needed to test these and other hypotheses formulated from these descriptive data.

On Golden Vaginas and Gun Violence

The article discusses the depictions of gun violence and black women and men in the motion picture Chi-Raq directed by Spike Lee in relation to data from the U.S. Centers for Disease Control and Prevention's National Center for Injury Prevention and Control Web-based Injury Statistics Query and Reporting System regarding gun-related homicides in America. Gang violence and sexual behavior by black women in the U.S. are examined, along with the Black Women’s Health Imperative organization.

The Decision to Carry: The Effect of Crime on Concealed-Carry Applications

Despite contentious debate on the role of concealed-carry legislation in the U.S., little is known about individual decisions to legally carry concealed handguns in public. Using data on concealed-carry permit applications from 1998 to 2012, we explore the degree to which individuals respond to crime by applying for permits to legally carry concealed firearms. We find that recent homicide incidents increase concealed-carry applications in areas relatively near to the event. Our main results suggest that an additional homicide in relatively small cities increases applications by 26 percent over the following two months. We also find effects in larger cities when using neighborhood-level data.Our data allow us to explore specific circumstances of crime incidents and the characteristics of responsive applicants. Our results show that gun-related homicides are particularly relevant and that whites and males are most responsive to homicide incidents. We also find evidence that individuals are more responsive to homicide incidents when they share a common characteristic with the victim, particularly for female applicants.

Lessons From Markey et al. (2015) and Bushman et al. (2015): Sensationalism and Integrity in Media Research

This article presents a response to the comment by B. J. Bushman, D. Romer, and P. E. Jamieson (2015). This reply addresses 2 issues raised by the commenters. First, they claim they and others have not made sensationalistic statements linking violent media to horrific acts of real-world violence. In response, we supply numerous examples of sensationalistic statements made by them and others. Second, they claim they did not expect violence in films to be related to violent behavior among adults, but only among youths. However, by examining homicide arrests and homicide gun mortality rates among youths, we found that as films have become increasingly violent over time, both homicide arrests and gun-related homicides have tended to decrease among this age group.

The effect of firearm restrictions on gun-related homicides across US states

The Newtown massacre has raised the issue of gun violence to a fever pitch. While several states have responded with tough new controls on firearms, most states have loosened restrictions. This study explores what effect such changes might have on gun-related homicides in the United States. The results, based on panel data for the 50 states over the 2007–2010 period and estimated under several alternative model specifications, suggest that looser restrictions will likely do little to lessen the incidence of gun deaths but that tighter restrictions may produce a modest reduction in firearm fatalities.

Repeal of the concealed weapons law and its impact on gun-related injuries and deaths

Senate Bill 1108 (SB-1108) allows adult citizens to carry concealed weapons without a permit and without completion of a training course. It is unclear whether the law creates a "deterrent factor" to criminals or whether it escalates gun-related violence. We hypothesized that the enactment of SB-1108 resulted in an increase in gun-related injuries and deaths (GRIDs) in southern Arizona. We performed a retrospective cohort study spanning 24 months before (prelaw) and after (postlaw) SB-1108. We collected injury and death data and overall crime and accident trends. Injured patients were dichotomized based on whether their injuries were intentional (iGRIDs) or accidental (aGRIDs). The primary outcome was any GRID. To determine proportional differences in GRIDs between the two periods, we performed χ analyses. For each subgroup, we calculated relative risk (RR). The number of national and state background checks for firearms purchases increased in the postlaw period (national and state p < 0.001); that increase was proportionately reflected in a relative increase in state firearm purchase in the postlaw period (1.50% prelaw vs. 1.59% postlaw, p < 0.001). Overall, victims of events potentially involving guns had an 11% increased risk of being injured or killed by a firearm (p = 0.036) The proportion of iGRIDs to overall city violent crime remained the same during the two periods (9.74% prelaw vs. 10.36% postlaw; RR, 1.06; 95% confidence interval, 0.96-1.17). However, in the postlaw period, the proportion of gun-related homicides increased by 27% after SB-1108 (RR, 1.27; 95% confidence interval, 1.02-1.58). Both nationally and statewide, firearm purchases increased after the passage of SB-1108. Although the proportion of iGRIDs to overall city violent crime remained the same, the proportion of gun-related homicides increased. Liberalization of gun access is associated with an increase in fatalities from guns. Epidemiologic study, level III.

Does the Declining Lethality of Gunshot Injuries Mask a Rising Epidemic of Gun Violence in the United States?

Recent mass shootings in the U.S. have reignited the important public health debate concerning measures to decrease the epidemic of gun violence. Editorialists and gun lobbyists have criticized the recent focus on gun violence, arguing that gun-related homicide rates have been stable in the last decade. While true, data from the U.S. Centers for Disease Control and Prevention also demonstrate that although gun-related homicide rates were stable between 2002 and 2011, rates of violent gunshot injuries increased. These seemingly paradoxical trends may reflect the declining lethality of gunshot injuries brought about by surgical advances in the care of the patient with penetrating trauma. Focusing on gun-related homicide rates as a summary statistic of gun violence, rather than total violent gunshot injuries, can therefore misrepresent the rising epidemic of gun violence in the U.S.

Children and adolescents deaths from trauma-related causes in a Brazilian City

IntroductionInjury is the first cause of death worldwide in the population aged 1 to 44. In developed countries, the most common trauma-related injuries resulting in death during childhood are traffic accidents, followed by drowning.MethodsThis retrospective study based on autopsy examinations describes the epidemiology profile of deaths by trauma-related causes in individuals younger than 18 years from 2001 to 2008 in the city of Campinas. The aim is to identify epidemiology changes throughout the years in order to develop strategies of prevention.ResultsThere were 2,170 deaths from all causes in children < 18 years old, 530 of which were due to trauma-related causes, with a male predominance of 3.4:1. The age distribution revealed that 76% of deaths occurred in the 10-17 age group. The most predominant trauma cause was firearm injury (47%). Other frequent causes were transport-related injuries (138 cases-26%; pedestrians were struck in 57.2% of these cases) and drowning (55 cases-10.4%). Asphyxia/suffocation was the cause of death in 72% of cases in children < 1 year old; drowning (30.8%) was predominant in the 1-4 age group; transport-related deaths were frequent in the 5-9 age group (56%) and the 10-14 age group (40.4%). Gun-related deaths were predominant (68%) in the 14-17 age group. 51% of deaths occurred at the scene.ConclusionsThere was a predominance of deaths in children and adolescents males, between 15-17 years old, mainly from gun-related homicides, and the frequency has decreased since 2004 after the disarmament statute and the combating of violence.

Dependence of the Firearm-Related Homicide Rate on Gun Availability: A Mathematical Analysis

In the USA, the relationship between the legal availability of guns and the firearm-related homicide rate has been debated. It has been argued that unrestricted gun availability promotes the occurrence of firearm-induced homicides. It has also been pointed out that gun possession can protect potential victims when attacked. This paper provides a first mathematical analysis of this tradeoff, with the goal to steer the debate towards arguing about assumptions, statistics, and scientific methods. The model is based on a set of clearly defined assumptions, which are supported by available statistical data, and is formulated axiomatically such that results do not depend on arbitrary mathematical expressions. According to this framework, two alternative scenarios can minimize the gun-related homicide rate: a ban of private firearms possession, or a policy allowing the general population to carry guns. Importantly, the model identifies the crucial parameters that determine which policy minimizes the death rate, and thus serves as a guide for the design of future epidemiological studies. The parameters that need to be measured include the fraction of offenders that illegally possess a gun, the degree of protection provided by gun ownership, and the fraction of the population who take up their right to own a gun and carry it when attacked. Limited data available in the literature were used to demonstrate how the model can be parameterized, and this preliminary analysis suggests that a ban of private firearm possession, or possibly a partial reduction in gun availability, might lower the rate of firearm-induced homicides. This, however, should not be seen as a policy recommendation, due to the limited data available to inform and parameterize the model. However, the model clearly defines what needs to be measured, and provides a basis for a scientific discussion about assumptions and data.

Cross-Border Spillover: U.S. Gun Laws and Violence in Mexico

To what extent, and under what conditions, does access to arms fuel violent crime? To answer this question, we exploit a unique natural experiment: the 2004 expiration of the U.S. Federal Assault Weapons Ban exerted a spillover on gun supply in Mexican municipios near Texas, Arizona, and New Mexico, but not near California, which retained a pre-existing state-level ban. We find first that Mexican municipios located closer to the non-California border states experienced differential increases in homicides, gun-related homicides, and crime gun seizures after 2004. Second, the magnitude of this effect is contingent on political factors related to Mexico's democratic transition. Killings increased disproportionately in municipios where local elections had become more competitive prior to 2004, with the largest differentials emerging in high narco-trafficking areas. Our findings suggest that competition undermined informal agreements between drug cartels and entrenched local governments, highlighting the role of political conditions in mediating the gun-crime relationship.