By Roberto Uchôa de Oliveira Santos

In recent decades, the global debate on gun control has been prominent, with many countries adopting more restrictive policies. Brazil followed this trend by implementing stringent measures in 2003; however, the presidency of Jair Bolsonaro in 2019 introduced normative changes aimed at facilitating public access to firearms and ammunition. Throughout his term, the legal firearms market doubled, allowing access to weaponry previously restricted to the general public. The analyzed hypothesis suggests that these normative changes, especially those related to the quantity and authorization of acquisition of previously restricted firearms, altered the types of firearms in circulation, strengthening the interaction between legal and illegal markets. Using data from the mandatory firearms re-registration, a total of 962,782 firearms were analyzed. The assessment of the increase in circulation of these firearms in the illegal market was conducted through the analysis of seizures in the states of Rio de Janeiro and São Paulo, revealing a significant growth in seizures of these types of firearms, possibly correlated with the increase in their circulation. Three police investigations were selected to exemplify how the connection between markets intensified, allowing criminals to obtain firearms in the legal market that were previously only accessible through international trafficking or diversion from state agencies.

Journal of Illicit Economies and Development, 6(1): pp. 16–29. 2024

By Roberto Uchôa de Oliveira Santos

In recent decades, the global debate on gun control has been prominent, with many countries adopting more restrictive policies. Brazil followed this trend by implementing stringent measures in 2003; however, the presidency of Jair Bolsonaro in 2019 introduced normative changes aimed at facilitating public access to firearms and ammunition. Throughout his term, the legal firearms market doubled, allowing access to weaponry previously restricted to the general public. The analyzed hypothesis suggests that these normative changes, especially those related to the quantity and authorization of acquisition of previously restricted firearms, altered the types of firearms in circulation, strengthening the interaction between legal and illegal markets. Using data from the mandatory firearms re-registration, a total of 962,782 firearms were analyzed. The assessment of the increase in circulation of these firearms in the illegal market was conducted through the analysis of seizures in the states of Rio de Janeiro and São Paulo, revealing a significant growth in seizures of these types of firearms, possibly correlated with the increase in their circulation. Three police investigations were selected to exemplify how the connection between markets intensified, allowing criminals to obtain firearms in the legal market that were previously only accessible through international trafficking or diversion from state agencies.

Journal of Illicit Economies and Development, 6(1): pp. 16–29. 2024

By Gary Klein

In light of the difficulty achieving consensus about gun violence prevention at the federal level in the current political climate, leadership and innovation on gun violence prevention must come at the state and local levels. State legislators, law enforcement leaders, and state attorneys general must take the lead to find the pathway that most effectively protects their residents in collaboration with concerned communities. There is substantial evidence that states with comprehensive and effective gun laws have fewer incidents of gun homicides, gun suicides, and unintentional shooting deaths. These 50 proposals for state or local action have demonstrated success where they have been enacted and are a starting point for states interested in promoting public safety by addressing preventable gun violence.  

Washington, DC: Violence Policy Center, 2022. 24p.

By The Violence Policy Center

Large capacity ammunition magazines are the common thread running through most mass shootings in the United States. Since 1980, there have been at least 106 mass shootings (three or more fatalities not including the shooter) where the shooter used large capacity ammunition magazines containing more than 10 rounds. A total of 959 people were killed in these shootings, and 1,309 were wounded. This number is likely a significant undercount of actual incidents as there is no consistent collection or reporting on this data. Even in many high-profile shootings, information on magazine capacity is neither released nor reported. The Violence Policy Center has compiled this list of incidents by analyzing news reports and follow-up investigative reports on mass shootings. Only shootings in which there is specific information that large capacity magazines were used are included.  ( This document was last updated on January 11, 2024.

Washington, DC: Violence Policy Center, 2024. 17p. 

By R. Blake Brown  

This report provides a legal history of firearm regulation to help understand the current debate over gun control policy in Canada, particularly regarding semi-automatic firearms. Debate over the regulation of such guns has been particularly heated since 1 May 2020, when Prime Minister Justin Trudeau announced that the federal cabinet had issued an Order in Council (PC 2020-298) to ban several models of semi-automatic firearms. 1 This report describes some of the key technological developments in handguns and long guns that have spurred debates about the kinds of firearms that should be available for certain uses in Canada. It identifies weapons employed in mass casualty events in Canada with reference to specific examples and notes the policy response to those events. The report explains the legislative tools used to address the dangers associated with semi-automatic firearms and considers the public policy debates about these regulatory approaches. It also identifies the strengths and shortcomings of past legislative approaches and considers policy options concerning the availability of semi-automatic weapons. This report demonstrates that the federal government has used a somewhat piecemeal approach to regulating handguns and semi-automatic firearms. Governments have historically sought to balance public safety and the interests of gun collectors, hunters, and target shooters. Efforts to limit the availability of some kinds of firearms have often resulted from their use in domestic and international mass shootings. Changes in firearm technology have contributed to attempts to limit the ownership or use of firearms deemed especially dangerous. The federal government has prohibited some semi-automatic rifles, declared others to be restricted firearms,   and left others as non-restricted firearms. This has complicated the enforcement of Canada’s gun laws. It has also permitted firearms with the capability to cause substantial harm to remain in circulation. Similarly, the federal government has prohibited some handguns but left many others available for purchase, thus contributing to the movement of firearms from the legal market to those wanting handguns for illegal purposes.

Halifax, NS: The Joint Federal/Provincial Commission into the April 2020 Nova Scotia Mass Casualty, 2022. 112p.

By John J. Donohue

The January 6 attack on the U.S. Capitol has important lessons for much of the widespread, current Second Amendment litigation designed to eradicate beneficial gun safety regulation across the country. First, the value of Washington, DC, laws in constraining the gun carrying of the riotous crowd was evident and likely saved many lives. Second, flirtations with the idea that armed citizens should be ready to fight the federal government were shown to be absurd: there is no circumstance in which private citizens in modern America could promote democracy by using assault weapons to kill government employees to show their disapproval of what they perceive to be “tyrannical” government. Third, the idea that gun owners can be expected to oppose rather than support a tyrant was dealt a fatal blow by the violence at the U.S. Capitol. The time has come to earnestly acknowledge and embrace the wise restraints on firearms that make the American public free and to reject the specious mask of zeal for unlimited gun rights that has become a mainstay of too many American politicians.

New York: Brennan Center for Justice at New York University School of Law, 2021. 11p.

By Jaclyn Schildkraut and H. Jaymi Elsass

An Updated Look at Mass Public Shootings in America Over the last two years, there have been a number of high-profile mass public shootings in the United States that have dominated the headlines and captured the attention of the public and policymakers alike—from Buffalo, New York (May 14, 2022; 10 dead) to Uvalde, Texas (May 24, 2022; 21 dead), Highland Park, Illinois (July 4, 2022; 7 dead), Monterrey Park, California (January 21, 2023; 11 dead), and Louisville, Kentucky (April 10, 2023; 5 dead). Although mass public shootings rarely made headlines during the height of the pandemic, the frequency of events has since rebounded to pre-COVID levels. Consequently, these and other mass public shootings have reinforced the need to do more to prevent these tragedies from occurring and to mitigate the harms to individuals and communities if and when they happen. To achieve these goals, it is important to understand the trends associated with the phenomenon of mass public shootings.

The Regional Gun Violence Research Consortium (the Consortium) first published a report in 2018 analyzing 51 years (1966–2016) of mass public shootings data.1 In order to better understand the phenomenon of mass shootings, the report presented information on the location of shootings, weapons used, and demographics of the perpetrators. A follow-up report released in 2021 integrated an additional four years of data (2017–20).2 These reports were based on a comprehensive database of US mass public shootings from researchers Jaclyn Schildkraut and H. Jaymi Elsass.3 As the United States continues to face record rates of gun violence,4 with mass public shootings also increasing in frequency, the need for evidence-based policies is all the more important. A starting point, however, is understanding the different contexts and characteristics of various forms of firearm violence. Mass public shootings, although among the rarest forms of gun violence, require different strategies for prevention and response from other incidents. These shootings often involve considerable planning, which can provide important opportunities for identification, intervention, and de-escalation of the threat before it is carried out, unlike other forms of more spontaneous gun violence.5 Additionally, mass public shootings often are random in nature and occur in large, open public spaces, which present different challenges— including preventative security measures and law enforcement responses—from targeted incidents and those that occur in private locations.

Albany, NY: Rockefeller Institute of Government, 2023. 28p.

By Elise White, Basaime Spate, Javonte Alexander, and Rachel Swaner

In 2020, while the world was wrestling with how to keep safe from a new contagious respiratory virus, many young, urban Americans were navigating how best to protect themselves from another public health crisis: a steep increase in gun violence. Long before these dual pandemics came to dominate media coverage, researchers at the Center for Justice Innovation [the Center] had been grappling with understanding gun violence in cities around the country: Why are young people carrying and using guns? What factors—social and structural—are creating and impacting gun culture? What cultural strategies do youth develop in response to gun culture, and how can those strategies be leveraged to stem the violence? To answer these questions and build on the Center’s previous study of New York City youth gun carrying (Swaner et al. 2020), the Center received funding from the National Collaborative on Gun Violence Research to conduct an exploratory, participatory action research study of the socio-cultural roots of gun violence in four cities (Brooklyn, NY; Wilmington, DE; Philadelphia, PA; Detroit, MI) that will each produce site-specific findings. This report focuses on the findings from the Brooklyn, NY site, where we conducted interviews with 103 youth ages 15-24 who had carried a gun in the previous year. Data were collected between February 27, 2020, and March 30, 2021.

New York: Center for Justice Innovation , 2023. 72p.

Suzanna Fay

Gun reform after a major mass shooting in Australia has largely been heralded as a success. However, understanding how compliance is encouraged among the gun owning community with a history of opposing regulation is currently limited in systematic sociological research. Gun dealers in particular appear to be important for understanding levels of compliance and possibilities for promoting compliance, as they are simultaneously involved in the compliance process and subject to its enforcement as members of the gun owning community. This paper positions gun dealers as street-level bureaucrats responsible for implementing gun regulations and uses a Compliance Motivation framework to explore the possible motivations for compliance and their role in promoting compliance within the gun owning community. Findings are based on 28 in-depth interviews with gun dealers across Australia and demonstrate the challenging but important role that gun dealer’s play in enacting gun control policy

Sociological Perspectives. Volume 65, Issue 1: Special Issue: Sociological Perspectives on Guns in AmericaFeb 2022. Pages5-235

By Ari Davis, Rose Kim, Cassandra Crifasi

Gun violence is an ongoing public health crisis in the United States that impacts the health and wellbeing of all of us. In 2020, during the first year of the COVID-19 pandemic, the U.S. experienced an unprecedented spike in gun homicides. Many believed that this spike would be short-lived; levels of gun violence would subside as institutions effectively responded to the pandemic and people returned to their daily routines. This, unfortunately, was not the case. In 2021, for the second straight year, gun deaths reached the highest number ever recorded. Nearly 49,000 people died from gun violence in the U.S. in 2021. Each day, an average of 134 people died from gun violence—one death every 11 minutes. Gun homicides continued to rise in 2021, increasing 7.6% over the previous year. Gun suicides reached record levels, increasing 8.3%, the largest one-year increase recorded in over four decades. Guns, once again, were the leading cause of death among children and teens in 2021 accounting for more deaths than COVID-19, car crashes, or cancers. Coincident with the rise in gun-related deaths were record gun sales. Millions of first-time purchasers, including Black and Hispanic/Latino people, and women of all races and ethnicities, bought guns during the pandemic at unprecedented levels. Many of these purchasers were motivated by gun industry marketing claims that guns make you safer. Yet, this is far from the truth; gun ownership greatly increases the risk of dying by suicide and homicide. While it is too early to tell whether this surge in gun purchases contributed directly to the rise in gun violence the country is experiencing, we know that over the long run this influx of guns will only exacerbate the public health crisis of gun violence and worsen health disparities

Baltimore, MD: Johns Hopkins Center for Gun Violence Solutions. Johns Hopkins Bloomberg School of Public Health 2023. 45p.

Sarah Moshary, Bradley Shapiro & Sara Drango

This paper estimates consumer demand for firearms with the aim of predicting the likely impacts of firearm regulations on the number and types of guns in circulation. We first conduct a stated-choice-based conjoint analysis and estimate an individual-level demand model for firearms. We validate our estimates using aggregate moments from observational data. Next, we use our estimates to simulate changes in the number and types of guns in circulation under alternative regulations. Importantly, we find that bans or restrictions that specifically target “assault weapons” increase demand for handguns, which are associated with the vast majority of firearm-related violence. We provide distributions of consumer surplus under counterfactuals and discuss how those distributions could be useful for crafting policy.

Cambridge, MA: National Bureau of Economic Research (NBER), 2023. 

by Sierra Smucker, Max Griswold, Amanda Charbonneau, Rose Kerber, Terry L. Schell, Andrew R. Morral

Among researchers, policymakers, and advocates, momentum is growing to better understand the impact of firearm laws on a variety of outcomes (e.g., suicide, crime, defensive gun use, homicide). There is also a growing interest in data that can shed light on these relationships. One source of these data is the National Instant Criminal Background Check System (NICS). This system includes information used in background checks, the number and type of background checks processed, and details on the number of and reason for denials when NICS finds that an individual is prohibited from purchasing a firearm. In this tool, researchers provide detailed information about data associated with NICS and discuss the data's strengths and weaknesses for various gun policy evaluation objectives. The researchers also outline the substantial limitations to interpreting these data to assist researchers in this field. Finally, they provide these data to researchers to encourage further exploration and evaluation of how NICS data might be used for policy analysis.

Santa Monica, CA: RAND, 2022. 65p.

By Christoph Koenig and David Schindler 

  Do firearm purchase delay laws reduce aggregate homicide levels? Using variation from a 6-month countrywide gun demand shock in 2012/2013, we show that U.S. states with legislation preventing immediate handgun purchases experienced smaller increases in handgun sales. Our findings indicate that this is likely driven by comparatively lower purchases among impulsive consumers. We then demonstrate that states with purchase delays also witnessed comparatively 2% lower homicide rates during the same period. Further evidence shows that lower handgun sales coincided primarily with fewer impulsive assaults and points towards reduced acts of domestic violence.   

Discussion Paper 20 / 730  

Bristol, UK: Bristol University, School of Economics, 2020. 70p.

By Jonathan Colmer, Jennifer Doleac:

Gun violence is a major problem in the United States, and extensive prior work has shown that higher temperatures increase violent behavior. In this paper, we consider whether restricting the concealed carry of firearms mitigates or exacerbates the effect of temperature on violence. We use two identification strategies that exploit daily variation in temperature and variation in gun control policies between and within states. Our findings suggest that more prohibitive concealed carry laws attenuate the temperature–homicide relationship. Additional results suggest that restrictions primarily decrease the lethality of temperature–driven violent crimes, rather than their overall occurrence, but may be less effective at reducing access to guns in more urban areas.

 Bonn: IZA – Institute of Labor Economics, 2023. 67p,  

Benjamin L. Cavataro

This article argues that the status quo is unacceptable, and proposes a clear, workable solution. Congress should empower the Commission to regulate the safety of guns as products, without granting the Commission authority over "gun control" as traditionally understood. This approach resolves the inadequacies of industry self-regulation, tort, and state consumer law; appropriately leverages the existing Consumer Product Safety Act framework; and is consistent with the Commission’s longstanding oversight of holsters, gun locks, and gun safes. Under this approach, the firearms industry would be obligated to report safety defects, recall dangerously defective firearms, and offer remedies to consumers. The Commission could also consider adopting common-sense product safety standards (such as regulations to ensure that new firearms have functional safety devices, and do not discharge without a trigger pull), just as the Commission adopts safety standards for many other consumer products. But the Commission would be precluded from regulating guns to curtail gun violence or suicide, or to reduce guns’ prevalence.

This approach is fully compatible with the Second Amendment in light of New York State Rifle and Pistol Association v. Bruen (2022). And lifting the firearms industry’s immunity from product safety law—thereby regulating guns as products—has helpful implications for broader debates on gun law and policy. By establishing that Commission regulation could simultaneously protect the public from harm and facilitate the right to lawful self-defense, this Article’s proposal demonstrates that some gun regulations can concurrently respect gun rights, uphold consumers’ rights, and protect lives—and, in doing so, reveals fissures between the interests of the gun industry and gun owners.

 Forthcoming in George Washington Law Review, Vol. 92 (2024),

By Nicolas Florquin

This article reviews research undertaken over the past two decades to support international policy on small arms and light weapons (SALW) – which include firearms – and discusses its relevance to academic debates and policy on gun violence. It examines whether SALW research generated a greater understanding of the most problematic uses and users of firearms, and of the role of different weapons as instruments of violence. SALW research helped shift international policy from armed conflicts to gun violence occurring in a range of developing and post-conflict settings, and in Europe following the 2015–16 terror attacks. This work underscored the proximate weapons sources that armed groups often utilise, and the importance of flows of certain weapons – such as converted firearms – and ammunition in fuelling violence. Undertaking impact evaluations of novel interventions, monitoring the impact of new technologies, and investigating the relationship between ammuni-tion supply and violence are suggested ways forward.

Global Crime, Volume 22, 2021 - Issue 4

By Joel Negin, Philip Alpers and Rebecca Peters   

The Australian experience with firearm regulation provides important lessons for other jurisdictions with high rates of gun violence. This example demonstrates that taking a public health approach to firearm injury prevention by reducing access, strengthening regulation, and engaging the community can reduce gun deaths. Along with emerging evidence in New Zealand after the Christchurch mosque massacre, it also shows that a mass shooting incident can be a galvanising event for a country to improve policies on a wide scale.. Australia’s sweeping policy change used a substantial amount of the political capital of the relatively new, right-leaning Prime Minister. The support of many conservatives was crucial and was secured by overwhelming pro-firearm regulation opinion polls and media pressure. Gun policy reforms were supported by all major political parties, whereas conservative parties in many other countries staunchly oppose such reforms. The success of firearm regulation has since become a source of pride for many Australians. Mass shootings account for a small proportion of firearm-related deaths, but they tend to receive a substantial amount of media coverage and can focus the attention of the public and politicians on gun violence more broadly. Although preventing gun deaths is essential, focusing on deaths obscures another tragic reality of firearm violence. Beyond the people killed with firearms, a larger number are injured and have life-changing pain, disability, and psychological distress, which leads to substantial expenses related to medical care, mental health care, and rehabilitation. Australian firearm policy now focuses more than it did in the mid-1990s on domestic and family violence, which often involves additional victims besides intimate partners, including children. While firearm injury prevention has been a notable public health success in Australia, the field of firearm injury prevention is remarkably under-researched and poorly understood. This public policy gap undermines gun control successes. Data on firearms and firearm violence in Australia is patchy, inconsistent, and incomplete. Most studies are based only on deaths and ignore injuries completely. Eight jurisdictions store widely variable data, often in obsolete and inaccurate firearm registers. In order to support the policy response, strong data collection and data use, as well as data-sharing across jurisdictions, are required. This can allow the monitoring of trends and impacts as well as the analysis of the impact of policy changes over time    

Halifax, NS: The Joint Federal/Provincial Commission into the April 2020 Nova Scotia Mass Casualty, 2022. 49p.

By Everytown for Gun Safety and Johns Hopkins Center for Gun Violence Solutions. ( 

Extreme Risk Protection Order (ERPO) laws create an opportunity to intervene and prevent firearm violence when there are warning signs that an individual poses a risk of harm to self or others. While ERPO laws are relatively new, a growing body of research demonstrates the potential for these laws to prevent firearm violence, particularly firearm suicide, and multiple victim/mass shootings. Interest in ERPO laws has increased in recent years, with 16 states having enacted these laws between 2018 and 2023. Implementation varies widely across and within states. As a result of strong ERPO implementation efforts in some jurisdictions, more information is now available for state and local leaders about how to implement and adapt ERPO laws for their own communities. In addition, the Bipartisan Safer Communities Act of 2022 included $750 million in new federal grant funding for states, some of which is designated to support ERPO implementation. To meet this moment, the Everytown for Gun Safety Support Fund and the Johns Hopkins Center for Gun Violence Solutions have partnered to compile this guide of the best available practices and promising approaches to effective implementation of extreme risk laws. These recommendations are informed by conversations with individuals who are pioneering ERPO implementation, in addition to the best practices shared at a December 2022 convening of ERPO leaders from around the country.   

New York; Baltimore: The Authors: 2023. 52p.  

By Ye Liu ; Michael Siegel; Bisakha Sen

Question  How are states’ firearm laws associated with firearm-related deaths in nearby states?

Findings  In this pooled cross-sectional analysis involving firearm laws and firearm-related deaths from 2000 to 2019 in the 48 contiguous states, a permit requirement for purchasing all firearms had an interstate association with decreased total firearm-related deaths and homicide, whereas the prohibition of firearm possession for individuals who have committed a violent misdemeanor had an interstate association with decreased firearm suicide.

Meaning  These findings suggest that synergic legislative action to implement firearm laws in proximate states may help prevent firearm-related deaths.

  AMA Network Open. 2022;5(11):e2240750. doi:10.1001/jamanetworkopen.2022.40750 (Rep  

By Ye Liu, Michael Siegel, Bisakha Sen 

Introduction: Firearm injury is a major U.S. public health concern. This study aims to evaluate whether the relationship between state firearm laws and state firearm deaths are affected by comparatively lenient firearm laws in neighboring states.

Methods: This observational study used 2000‒2017 data on firearm deaths and firearm laws of the 48 contiguous states of the U.S. (Alaska, Hawaii, and the District of Columbia excluded). The associations among state firearm deaths, state firearm laws, and presence of neighboring states with more lenient laws were analyzed using negative binomial regression models with state- and year-fixed effects. Analyses were conducted in 2019‒2020.

Results: There were 578,022 firearm deaths of all intents during the study period or 11.1 firearm deaths (IQR=8.5-14.0) per 100,000 population. The presence of more state firearm laws was associated with decreased firearm deaths (incident rate ratio=0.991, 95% CI=0.987, 0.996). However, weaker firearm laws in neighboring states correlated with more firearm deaths within a state (incident rate ratio=1.016, 95% CI=1.004, 1.028). Failing to account for weaker laws in neighboring states led to the underestimation of the impact of 1 additional law on state's own firearm deaths (incident rate ratio=0.994, 95% CI=0.989, 0.998 vs 0.991, 95% CI=0.987, 0.996) by approximately 20%.

American Journal of Preventive Medicine: 59(5): 648-657, 2020.