By John J. Donohue, Samuel V. Cai, Matthew V. Bondy, Philip J. Cook

We analyze a sample of 47 major US cities to illuminate the mechanisms that lead Right-to-Carry concealed handgun laws to increase crime. The altered behavior of permit holders, career criminals, and the police combine to generate 29 and 32 percent increases in firearm violent crime and firearm robbery respectively. The increasing firearm violence is facilitated by a massive 35 percent increase in gun theft (p=0.06), with further crime stimulus flowing from diminished police effectiveness, as reflected in a 13 percent decline in violent crime clearance rates (p=0.03). Any crime-inhibiting benefits from increased gun carrying are swamped by the crime-stimulating impacts.

Cambridge Mass. National Bureau Of Economic Research. 2022. 36p.

By Rajeev Ramchand, Jessica Saunders

Australia’s 1996 National Firearms Agreement (NFA) banned several types of firearms and resulted in the government buying hundreds of thousands of the banned weapons from their owners. Studies examining the effect of removing so many weapons from the community have found that homicides, suicides, and mass shootings were less common after the NFA was implemented, although such incidents were declining prior to 1996. The strongest evidence is consistent with the claim that the NFA caused reductions in firearm suicides, mass shootings, and female homicide victimization. However, there is also evidence that raises questions about whether, for at least firearm suicides, those changes can be attributed to the NFA or to other factors that influenced rates of these outcomes around the time the NFA was implemented.

Rand Corp. 2021. 27p.

By RAND

Good public policies are based on facts and data, and the most effective laws are written when policymakers understand the effects of such laws on a range of outcomes and can weigh the inherent trade-offs. As part of the RAND Gun Policy in America initiative, we conducted rigorous and transparent reviews of what current scientific knowledge could tell the public and policymakers about the true effects of many gun policies that are frequently discussed in state legislatures. Our first review, released in 2018, synthesized the available scientific data from studies published between 2004 and 2016 examining how 13 classes of state-level gun policies affect firearm-related deaths, violent crime, the gun industry, participation in hunting and sport shooting, and other outcomes. In 2020, we released an expanded and updated review, which added five new classes of gun policies and extended the period over which we conducted our literature search to span from 1995 to 2018. In 2023, we incorporated those studies in our updated analyses, drawing new or revised conclusions about the quality of evidence available to support claims about the effects of various policies.

RAND Objective Analysis Effective Solutions. 2023. 9p.

By United States. Bureau Of Alcohol, Tobacco, Firearms, And Explosives

From the Introduction: "The National Firearms Commerce and Trafficking Assessment (NFCTA) is a comprehensive examination of commerce in firearms in the United States and the diversion of firearms to illegal markets. Produced by a team comprised of ATF [Bureau of Alcohol, Tobacco, Firearms and Explosives] subject-matter experts, academics from a variety of disciplines specializing in research relating to firearms, and other law enforcement professionals, the NFCTA is designed to provide the public, researchers, and policymakers with analysis of data lawfully collected by ATF as part of its regulatory and law enforcement missions to inform the dialogue on firearm law and policy. To ensure comprehensive analysis, the NFCTA is being produced in several volumes. In May 2022, ATF published Volume I, 'Firearms in Commerce'. [...] ATF routinely generates bulletins for law enforcement and industry, and issues public safety advisories for all citizens. This Volume of the NFCTA, however, represents the first comprehensive report incorporating crime gun information from the full range of sources used by ATF in more than twenty years. Advancements in ballistic analytical technology and information processing during this period have enhanced ATF's capacity to support law enforcement efforts to identify, investigate, and prosecute those who use firearms to commit violent offenses and the traffickers who illegally divert those crime guns to criminals. Volume II describes in detail the sources of information that constitute CGI [Crime Gun Intelligence], and how CGI is leveraged to promote effective investigation of firearm-related violence. Finally, the information and analysis in NFCTA Volumes I and II set the foundation for the subject that will be addressed in Volume III, 'Firearms Trafficking.'"

Washington DC. United States. Bureau Of Alcohol, Tobacco, Firearms, And Explosives. 2023. 9p.

BY National Integrated Ballistic Information Network (NIBIN

In 1997, ATF initiated the National Integrated Ballistic Information Network (NIBIN) program. Through this program, ATF provided for the first time comprehensive national automated ballistic imaging services to local, state, territorial, tribal, and federal law enforcement agencies across the country. NIBIN technology captures images of ballistic evidence, including cartridge casings1 recovered in shooting investigations (also referred to as “casings”) and test-fired cartridge casings2 from recovered crime guns (also referred to as “test-fires”), and stores those images in the NIBIN national database that conducts automated analysis for further review by expert technicians. Since 1997, law enforcement agencies have been submitting recovered ballistic evidence to ATF for entry into the NIBIN system, building a national and robust network of ballistic data. As of December 2021, approximately 5.2 million pieces of ballistic evidence have been entered into the system.

Washington D.C. ATF. 2021. 19p.

By The ATF National Tracing Center (NTC) and ATF International Affairs Division (IAD)

ATF and IAD cooperate with international law enforcement partners to disrupt transnational firearms trafficking and reduce violent gun crime in other countries. A central component of this effort is the use of ATF’s eTrace system to provide information on crime guns recovered and submitted for tracing by LEAs in foreign countries. Between 2017 and 2021, ATF received trace requests from an average of 75 countries involving approximately 33,000 crime gun trace requests on an annual basis. ATF continuously works to improve the tracing of crime guns recovered in other countries by completing formal tracing agreements with new international law enforcement partners and training them on the appropriate use of the eTrace system. As of 2021, ATF had eTrace Memorandum of Understandings (MOUs) with LEAs in 47 countries, representing 1,843 eTrace user accounts. To improve accessibility, Spanish language eTrace is available and currently used by law enforcement agencies in Mexico and other Central and South American countries.

The ATF National Tracing Center (NTC) and ATF International Affairs Division (IAD). 2021. 27p.

By Smart, Rosanna; Morral, Andrew R.; Ramchand, Rajeev; Charbonneau, Amanda K.; Williams, Jhacova; Smucker, Sierra; Cherney, Samantha; Xenakis, Lea

3rd. Edition. From the Webpage: "In this report, part of the RAND Corporation's Gun Policy in America initiative, researchers seek objective information about what scientific literature reveals about the likely effects of various gun laws. In the third edition of this report, the authors incorporate more-recent research in their synthesis of the available scientific data regarding the effects of 18 state firearm policies on firearm deaths, violent crime, suicides, the gun industry, defensive gun use, and other outcomes. By highlighting where scientific evidence is accumulating, the authors hope to build consensus around a shared set of facts that have been established through a transparent, nonpartisan, and impartial review process. In so doing, they also illuminate areas in which more and better information could make important contributions to establishing fair and effective gun policies."

RAND Corporation. 2023. 104p.

By Macdonald, Stuart Keith, 1979-; Staniforth, Andrew

From the Executive Summary: "Cooperation between law enforcement and tech companies is widely regarded as necessary to tackle online terrorist content. Both sectors have publicly stated their commitment to working together and there are examples of mutual cooperation. Yet there are also impediments to such collaboration, including different cultures and operating practices, and there have been high-profile instances of non-cooperation. The informality of existing collaborations has also led to concerns about censorship, mission creep and a lack of accountability and oversight. The focus of this report is on how to resolve the impediments to closer cooperation between law enforcement and the tech sector in order to realise the benefits of mutual collaboration, while simultaneously addressing concerns about due process and accountability. The report utilises an interview-based methodology to examine the experiences and opinions of personnel from both sectors who have first-hand experience of mutual cooperation. It provides empirically grounded insights into this under-researched topic."

Global Network On Extremism And Technology (Gnet). 2023. 38P.

By Alathari, Lina; Drysdale, Diana; Driscoll, Steven; Carlock, Arna L.; Cutler, Meagan; Besser, Jason

From the Executive Summary: "As law enforcement agencies, workplaces, and other community organizations implement behavioral threat assessment programs, the approach should be guided by the research findings contained in this report. When conducted properly, a behavioral threat assessment will involve promoting bystander reporting to identify warning signs of potential violence, systematically gathering information about the circumstances and behaviors of concern, assessing the possibility of violence as an outcome, and implementing preventive management strategies to make positive and safe outcomes more likely. The 173 attacks contained in this report impacted a variety of locations, 'including businesses/workplaces, schools, houses of worship, military bases, nonprofit service providers, residential complexes, public transportation, and open spaces'. In many cases, the attacker had a known affiliation with the site of the attack. The analysis is intended to provide critical information to a cross-sector of community organizations that have a role in preventing these types of tragedies."

Washington. US. United States. Secret Service. National Threat Assessment Center. 2023. 70p.

By Wang-Sheng Lee and Sandy Suardi

The 1996-97 National Firearms Agreement (NFA) in Australia introduced strict gun laws, primarily as a reaction to the mass shooting in Port Arthur, Tasmania in 1996, where 35 people were killed. Despite the fact that several researchers using the same data have examined the impact of the NFA on firearm deaths, a consensus does not appear to have been reached. In this paper, we re-analyze the same data on firearm deaths used in previous research, using tests for unknown structural breaks as a means to identifying impacts of the NFA. The results of these tests suggest that the NFA did not have any large effects on reducing firearm homicide or suicide rates.

Melbourne. University of Melbourne. Melbourne Institute Working Paper Series Working Paper No. 17/08. 2008. 29p.

Edited ny Updesh Kumar and Manas K. Mandal

In the recent years, more so after the 9/11 twin towers and the 26/11 Mumbai attacks, there have been numerous discourses on terrorism and counterterrorism. Terrorism as a phenomenon does not originate in isolation; rather it is, generally, a reaction to certain specific social and contextual circumstances leading to grievances among people. Therefore, in order to understand the roots and basis of terrorism, there is a pressing need to analyze specific social, cultural, political, and psychological contexts in which it flourishes. Countering Terrorism: Psychosocial Strategies works on this premise and penetrates into this psycho-socio-cultural milieu that serves as a context for the proliferation of violence through acts of terror. With contributions from experts from the developed as well as developing countries of the world, the book has ecumenical focus on terrorism from all possible angles and covers the multiplicity of perceptions and interpretations on the issue. The volume will ignite the mind of the reader toward latent variables that may be considered while carrying out research in this area. This book brings together the minutest aspects related to the burning issue of terrorism, which exploits the precious resources of nations and scars the minds of the people.

New Delhi. Sage Publications.2012. 450p.

By United States. Congress. House. Select Committee To Investigate The January 6Th Attack On The United States Capitol.

From the document: "This Report supplies an immense volume of information and testimony assembled through the Select Committee's investigation, including information obtained following litigation in Federal district and appellate courts, as well as in the U.S. Supreme Court. Based upon this assembled evidence, the Committee has reached a series of specific findings[.] [...] This Report begins with a factual overview framing each of these conclusions and summarizing what our investigation found. That overview is in turn supported by eight chapters identifying the very specific evidence of each of the principal elements of President Trump's multi-part plan to overturn the election, along with evidence regarding intelligence gathered before January 6th and security shortfalls that day."

House of Congress Report 117-000. 2022.

By Elizabeth P. Shulman, Jordan Beardslee, Adam Fine, Paul J. Frick, Laurence Steinberg & Elizabeth Cauffman

  Objective: To examine whether at-risk male youth experience increases in anxiety, depressive symptoms, and aggression during years when they are exposed to gun violence, adjusting for relevant covariates. Method: Participants were 1,216 male, justice-involved adolescents who were recently arrested for the first time for a moderate offense. They were interviewed 9 times over 5 years. Fixed effects (withinindividual) regression models were used to estimate concurrent associations between exposure to gun violence and three outcomes: depressive symptoms, anxiety symptoms, and aggression (both overall and separately for proactive and reactive aggression). The reverse direction (anxiety, depressive symptoms, and aggression predicting gun violence exposure) was also modeled. Results: After controlling for covariates, exposure to gun violence was significantly associated with increases in reactive aggression and, to a lesser extent, increases in proactive aggression. In addition, gun violence exposure was associated with increased anxiety but not depressive symptoms. We found no support for the reverse direction. Conclusions: At-risk males experienced significant increases in anxiety and aggression (particularly reactive aggression) during years when they are exposed to gun violence, even after accounting for several potential confounding factors. The greater impact on reactive aggression suggests that exposure to gun violence may affect self-regulation and/or social information processing. The analyses shed light on the less-visible damage wrought by gun violence and underscore the importance of mental health screening and treatment for youth who have been exposed to violence – especially gun violence – both to assist individual youths and to disrupt cycles of violence.  

Journal of Clinical Child & Adolescent Psychology, 50:3, 353-366, 2021.,

By Regional Gun Violence Research Consortium

As the 2021-22 academic year came to a close, the United States was rocked by the news of another school mass shooting, this time at Robb Elementary School in Uvalde, Texas. Nineteen fourth-grade students and two of their teachers were killed when an 18-year-old former student entered the school through an unlocked door, made his way to his former fourth-grade classroom, and opened fire during a 77-minute rampage. Seventeen others were injured in the attack. The tragedy in Uvalde conjured up memories of the shooting at Sandy Hook Elementary School in Newtown, Connecticut. Nearly 10 years earlier, 20 first-grade students and six of their educators, including the school’s principal, were killed after a 20-year-old shot his way into the building. Two others were injured during the six-minute attack.

In the aftermath of the shooting in Uvalde, administrators and policymakers struggled to implement policies and procedures that would prevent a similar attack in their schools or minimize the loss of life if one did occur. These included, but were not limited to, increases in the numbers and presence of school resource officers, authorization to arm teachers, and even supplying schools with ballistics shields, despite the lack of evidence to suggest these measures would achieve their intended goals in situations like Uvalde. Amid growing fear and apprehension about another Sandy Hook or Uvalde happening and the proliferation of purported school safety measures, two questions occupy the minds of many: Are schools a safe place for children to be? And what actually works to make them safer?

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  As policymakers, school administrators, and other vested stakeholders continue to grapple with these questions, it is critical to plan for every instance of firearm violence on school grounds. In doing so, it is important to implement strategies that are based in research where evidence supports their efficacy in achieving prevention and/or harm mitigation. At the same time, it is imperative to consider not only the short-term effects but also longer-term impacts of both gun violence and the associated strategies for prevention and response on students. Researchers will be key in cultivating this evidence and must continue to work closely with policymakers, school administrators, and the public to protect children from the harmful effects of gun violence.

Albany, NY: Rockefeller Institute of Government, 2022. 64p.

By Alexander D. McCourt,  Cassandra K. Crifasi, Elizabeth A. Stuart, Jon S. Vernick, Rose M. C.Kagawa, Garen J. Wintemute and Daniel W. Webster

Objectives. To estimate and compare the effects of state background check policies on firearm-related mortality in 4 US states. Methods. Annual data from 1985 to 2017 were used to examine Maryland and Pennsylvania, which implemented point-of-sale comprehensive background check (CBC)laws for handgun purchasers ; Connecticut. which adopted a handgun purchaser licensing law; and Missouri, which repealed a similar law. Using synthetic control methods, we estimated the effects of these laws on homicide and suicide rates stratified by firearm involvement. Results. There was no consistent relationship between CBC laws and mortality rates. There we re-estimated decreases in firearm homicide (27.8%) and firearm suicide (23.2%–40.5%) rates associated with Connecticut’s law. There were estimated increases in firearm homicide (47.3%), non-firearm homicide (18.1%), and firearm suicide (23.5%)rates associated with Missouri’s repeal. Conclusions. Purchaser licensing laws coupled with CBC requirements were consistently associated with lower firearm homicide and suicide rates, but CBC laws alone were not. Public Health Implications. Our results contribute to a body of research showing tha tCBC laws are not associated with reductions in firearm-related deaths unless they are coupled with handgun purchaser licensing laws. 

American  Journal of   Public Health.2020;110:1546–1552. doi:10.2105/AJPH.2020.305822

By Cassandra K. Crifasi,  Alexander D. McCourt and Daniel W. Webster

There is a major flaw in federal firearm laws in the U.S. and in most states’ laws; prohibited purchasers can acquire firearms from unlicensed private sellers without subjecting themselves to background checks and record-keeping requirements. Violent criminals and traffickers exploit this weakness with fatal consequences. A logical and popular approach to fixing this flaw is to extend background check requirements and procedures used for transfers by licensed firearm dealers to transfers from private unlicensed sellers. Research shows that these so-called comprehensive background check (CBC) laws curtail the diversion of guns for criminal use, but have not resulted in significant reductions in firearm-related deaths. Fortunately, there is good evidence showing that when states augment CBC laws with mandatory licensing or permitting of handgun purchasers, lives are saved by lower rates of firearm-involved homicides6, and suicides. Why are comprehensive background checks more effective when augmented by handgun purchaser licensing? The most likely reasons center on the more direct interface between prospective purchasers and law enforcement and more robust systems for verifying the identity of applicants and their criminal records. In most states with handgun purchaser licensing, applicants must apply in person at a law enforcement agency and be fingerprinted. In some cases, applicants must also provide proof of completion of certified safety training. These procedures may deter individuals who might otherwise make impulsive decisions to acquire a gun to harm others or themselves, and in fact studies have found that the presence of licensing laws is associated with lower levels of gun homicides and suicides. Further, the licensing requirements may also deter straw purchases (when an eligible person buys a firearm for a prohibited person or for someone who does not want their name attached to the transfer).  

Baltimore, MD: The Johns Hopkins Center for Gun Violence Solutions, 2019. 8p.

By Michael Siegel

In 2017, there were 14,542 firearm-related homicide deaths in the United States. Despite constituting only 13% of the U.S. population, Black persons made up 59% of these victims. Many states have addressed the problem of firearm-related homicide by enacting stronger firearm laws. While many studies have already been conducted on the effectiveness of various firearm laws in reducing overall population homicide rates, the vast majority of these studies do not distinguish between victims of different races/ethnicity. In failing to do so, these studies assume that state-level firearm laws produce homogeneous effects, even while Black communities continue to bear the undue burden of firearm violence. The purpose of this research was to fill this critical gap by rigorously evaluating the differential impact of state-level firearm laws on homicide rates among White, Black, and Hispanic populations. This project sought to answer two major research questions: (1) Is there heterogeneity in the effect of different state firearm laws on homicide rates by race/ethnicity? (2) To what extent are any differences in the impact of firearm laws by race/ethnicity explained by contextual differences in homicide victimization across urban vs. non-urban settings, as opposed to differences among racial groups per se?

Report to the U.S. National Institute of Justice, 2020. 13p.

By The Philadelphia Interagency Research and Public Safety Collaborative (PIRPSC)

Firearm violence in Philadelphia is a public health crisis. In 2021, Philadelphia suffered a record number of fatal criminal shooting victims (501) and non-fatal criminal shooting victims (1,850). Philadelphia has also experienced extraordinary recent increases in arrests for illegal firearm possession and crime guns recovered, while the Commonwealth has recorded record gun sales in 2020. Despite this crisis in gun violence, shooting arrest rates remain low, conviction rates in illegal gun possession cases have been declining since 2015, and conviction rates in shooting cases declined between 2015 and 2019 and increased modestly in 2020 and 2021.

Firearm violence in Philadelphia is a racial justice crisis. Shootings disproportionately impact Black communities: in Philadelphia over 80% of shooting victims and 79% of arrestees have been Black since 2015. Both victims and arrestees overwhelmingly come from disadvantaged neighborhoods that are majority non-white, have high rates of poverty and unemployment, and less likely to have a high school degree or diploma. Endemic violence in these communities means that the vast majority of those arrested for gun violence have themselves been previously traumatized, often as a witness to previous violent acts; over 80% have previously accessed or been screened for behavioral health services through the City. Because the causes of gun violence are complex and varied, so are the solutions. Addressing the gun violence crisis requires a comprehensive strategy with elements of enforcement, intervention, and prevention to achieve both short-term and long-term reductions in gun crimes. Collaboration among city agencies, including law enforcement and non-law enforcement agencies is critical to successfully implement such a comprehensive strategy. Reviews of evidence-based practices, along with data analysis of local data, have helped us to come to key findings related to gun violence in Philadelphia and have informed recommendations to stem that violence. Readers are encouraged to read both the summary, below, as well as the report in its entirety to understand the context of our recommendations as well as the limitations in both our data and data analyses. 

Philadelphia: Philadelphia Interagency Research and Public Safety Collaborative (PIRPSC)    2022. 196p.  

By Giffords Law Center

The United States accounts for just 4% of the global population but a startling 25% of the world’s prisoners. The mass incarceration crisis that is bloating our nation’s prisons disproportionately affects Black and Brown Americans, tearing apart families and communities—often because of crimes that didn’t involve violence. Data has shown that this “tough on crime” mentality doesn’t actually reduce crime or enhance public safety. While the public is increasingly aware of the harmful impact of failed policies like the war on drugs, a lesser-known yet still significant driver of mass incarceration is the criminal legal system’s response to nonviolent illegal gun possession. Tens of thousands of Americans are arrested and incarcerated each year on nonviolent weapon possession charges. Given that the majority of violent crime in any city is driven by a very small percentage of individuals, we can improve public safety and reduce mass incarceration by rethinking our approach to nonviolent gun possession. This report explores prosecutor-led diversion programs and makes the case for expanding this promising alternative to incarceration.

Washington, DC: Giffords Law Center, 2021. 3 p,

By Rosanna Smart, Andrew R. Morral, Sierra Smucker, Samantha Cherney, Terry L. Schell

In this report, part of the RAND Corporation's Gun Policy in America initiative, researchers seek objective information about what the scientific literature reveals about the likely effects of various gun laws. In this second edition of an earlier work, the authors add five gun policies to the 13 examined in the original analysis and expand the study time frame to incorporate a larger body of research. With those adjustments, the authors synthesize the available scientific data on the effects of 18 policies on firearm deaths, violent crime, the gun industry, defensive gun use, and other outcomes. By highlighting where scientific evidence is accumulating, the authors hope to build consensus around a shared set of facts that have been established through a transparent, nonpartisan, and impartial review process. In so doing, they also illuminate areas where more and better information could make important contributions to establishing fair and effective gun policies.

Monterey CA: RAND, 2020. 412p.