By K.D. Browne , K. Green , S. Jareno-Ripoll , E. Paddock

Knives and sharp objects are tools used in a wide range of violent offences. However, knife offending may have different risk factors than general violence, thus requiring tailored interventions. This systematic review aims to synthesise evidence on the characteristics of knife offenders and interventions aimed at the reduction of knife crime. After screening 1352 titles and abstracts, 344 articles were fully considered of which 21 papers met the inclusion criteria and were quality assessed. These consisted of 15 offender characteristic studies and six intervention studies. Findings suggested that knife crime may be associated with illicit drug use, exposure to any violence as a witness, victim or perpetrator and mental health problems. Males were more at risk of engaging in knife crime in the community and females in domestic settings. Different risk factors were found between gang involved and non-involved knife offenders. Primary prevention strategies, such as stop and search, knife amnesties, media campaigns and curfews did not show a significant impact in reducing knife crime. By contrast, increasing offenders' access to tailored support regarding housing, education, and employment showed an impact in reducing weapon carrying. Further research is required in the area to support the reliability of outcomes.

Aggression and Violent Behavior. Volume 67, November–December 2022, 101774

By Sara Haylock, Talia Boshari, Emma C. Alexander, Ameeta Kumar , Logan Manikam and Richard Pinder

Background: Since 2013, the number of violent crimes and offences by sharp instruments have increased continually, following a previous decrease, with the majority of cases occurring among young people and in London. There is limited understanding surrounding the drivers influencing this change in trends, with mostly American-based research identifying risk factors. Methods: The aim of this review is to identify and synthesise evidence from a range of literature to identify risk factors associated with weapon-related crime, for young people (aged 10–24 years) within the UK. A search strategy was generated to conduct a systematic search of published and grey literature within four databases (EMBASE, Medline, PsycINFO, and OpenGrey), identifying papers within a UK-context. Abstracts and full texts were screened by two independent reviewers to assess eligibility for inclusion, namely study focus in line with the objectives of the review. Weight of Evidence approach was utilised to assess paper quality, resulting in inclusion of 16 papers. Thematic analysis was conducted for studies to identity and categorise risk factors according to the WHO ecological model. Results: No association was found between gender or ethnicity and youth violence, contrasting current understanding shown within media. Multiple research papers identified adverse childhood experiences and poor mental health as positively associated with youth and gang violence. It was suggested that community and societal risk factors, such as discrimination and economic inequality, were frequently linked to youth violence. A small number of studies were included within the review as this is a growing field of research, which may have led to a constrained number of risk factors identified. Due to heterogeneity of studies, a meta-analysis could not be conducted. As many studies displayed positive results, publication bias may be present. Conclusions: Several risk factors were identified, with evidence currently heterogeneous with minimal high-quality studies. However, findings highlight key areas for future research, including the link between poor mental health and knife-crime, and the trajectory into gangs. Risk factors should help identify high-risk individuals, targeting them within mitigation strategies to prevent involvement within crime. This should contribute to efforts aimed at reducing the rising crime rates within UK.

BMC Public Health (2020) 20:1451

By Hannah Gaffney, Darrick Jolliffe and Howard White

This technical report reviews the evidence on the effect of knife crime education interventions on the involvement of children and young people in crime and violence. This report is based primarily on a recent systematic review by Browne et al. (2022). Knife crime education interventions are implemented with children and young people in order to raise awareness of the legal implications of knife carrying as well as the physical and emotional implications. These interventions also aim to change attitudes about knife carrying and use in order to prevent and reduce the involvement of children and young people in crime and violence. Key components of these interventions include the delivery of educational sessions with groups of children and young people, the provision of workshops, and group discussions. Knife crime education interventions may adopt a ‘norms approach’, where the intervention content focuses on challenging children and young people’s perceptions that it is ‘normal’ to carry a knife. Other types of interventions to reduce knife crime, in particular media campaigns, have used real life stories to illustrate the profound impacts and consequences of carrying knives. For example, in 2017 the #knifefree campaign by the Home Office (2017) used stories from young people who had made the decision to not carry a knife. Knife crime education interventions would typically be implemented in settings where children and young people attend or gather, for example, schools or community centres. They could also be implemented in hospitals or Youth Offender Institutions. Interventions can be implemented by a range of personnel, including nurses working in emergency medicine (England & Jackson, 2013) or NonGovernment Organisations (Gilbert & Sinclair, 2019). The presumed causal mechanisms in knife crime education interventions are that by raising awareness around the impact and/or consequences of knife carrying and knife use for themselves and their friends and family, young people may be deterred. There can also be peer effects, if participants are less accepting of knife carrying by their friends, and by word of mouth to friends and siblings. There may be an adverse effect if the education creates a misperception regarding the prevalence of knife ownership and so encourages participants to carry

Youth Endowment Fund, 2023. 17p.

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.

By Leslie M. Barnard, Erin Wright-Kelly, Ashley Brooks-Russell; Marian E. Betz

The US has more than 10 times the number of mass shooting events as other developed countries.1 Mass shootings in the US have increased in frequency, with more than half occurring since the year 2000.2 These events have a direct toll on individuals injured or killed, as well as a psychological impact on families, friends, and society.3 Little research has examined the types and distribution of mass shooting events across the US.4 A geographic analysis by type may inform if specific events have disproportionately occurred in particular states or regions of the US. This may generate hypotheses about the contextual (policy, environmental, or sociocultural) factors that may be associated with the distribution of types of mass shooting events and may suggest recommendations for tailored prevention. The purpose of this study was to examine state rates of mass shooting event types and total injuries and deaths in the US.

JAMA Open 2023.

By Ariel Bogle

As mainstream social media companies have increased their scrutiny and moderation of right-wing extremist (RWE) content and groups,1 there’s been a move to alternative online content platforms.2 There’s also growing concern about right-wing extremism in Australia,3 and about how this shift has diversified the mechanisms used to fundraise by RWE entities.4 This phenomenon isn’t well understood in Australia, despite the Australian Security Intelligence Organisation (ASIO) advising in March 2021 that ‘ideological extremism’5 now makes up around 40% of its priority counterterrorism caseload.6 Research by ASPI’s International Cyber Policy Centre (ICPC) has found that nine Australian Telegram channels7 that share RWE content used at least 22 different funding platforms, including online monetisation tools and cryptocurrencies, to solicit, process and earn funds between 1 January 2021 and 15 July 2021. Due to the opaque nature of many online financial platforms, it’s difficult to obtain a complete picture of online fundraising, so this sample is necessarily limited. However, in this report we aim to provide a preliminary map of the online financial platforms and services that may both support and incentivise an RWE content ecosystem in Australia. Most funding platforms found in our sample have policies that explicitly prohibit the use of their services for hate speech, but we found that those policies were often unclear and not uniformly enforced. Of course, there’s debate about how to balance civil liberties with the risks posed by online communities that promote RWE ideology (and much of that activity isn’t illegal), but a better understanding of online funding mechanisms is necessary, given the growing concern about the role online propaganda may play in inspiring acts of violence8 as well as the risk that, like other social divisions, such channels and movements could be exploited by adversaries.9 The fundraising facilitated by these platforms not only has the potential to grow the resources of groups and individuals linked to right-wing extremism, but it’s also likely to be a means of building the RWE community both within Australia and with overseas groups and a vector for spreading RWE propaganda through the engagement inherent in fundraising efforts. The funding platforms mirror those used by RWE figures overseas, and funding requests were boosted by foreign actors, continuing Australian RWEs’ history of ‘meaningful international exchange’ with overseas counterparts.

Barton, ACT: The Australian Strategic Policy Institute Limited, International Cyber Policy Centre 2021.36p.

By Kathryn M. Roberts

Countering the radical Islamist narrative remains a high-profile priority of the United States in its ongoing efforts to counter domestic violent extremism. Since mid-2014, government officials have condemned the United States as unable to muster a satisfactory counter-narrative, and emphasize the potentially devastating consequences of failure. Experts inside and outside the government describe the Islamic State as masters of the internet capable of reaching into the United States and turning its people into hate-filled, violently inspired terrorists at will. The idea that the United States must aggressively work to counter these messages domestically remains a given but should it The focus of this thesis is to examine current U.S. efforts in counter-messaging to determine why the United States believes it is failing, and what, if any, evidence supports the idea that a counter-narrative or counter-messaging should be part of domestic countering violent extremism CVE programs. Review of official documents found little basis to assess U.S. programs, as no meaningful published strategy, objectives, or performance data exist for current efforts. Moreover, the foundational assumptions underlying current programs suggest malalignment between what U.S. officials desire a counter-messaging effort to accomplish and what is realistically achievable. Based on these findings, it is recommended that domestic CVE programs eliminate counter-messaging from their portfolio.

Monterey, CA: Naval Postgraduate School, 2020. 119p,

By HM Inspectorate of Probation, Inspectorate of Constabulary and Fire & Rescue Services and HM Inspectorate of Prisons (UK)

His Majesty’s Inspectorate of Probation has led an inspection, alongside HM Inspectorate of Constabulary, Fire & Rescue Services (HMICFRS), and HM Inspectorate of Prisons – looking at the work of the Probation Service’s National Security Division (NSD) and multi-agency arrangements for the management of terrorist offenders in the wake of terrorist attacks.

In response to terrorist attacks in 2019 and 2020, by known terrorist offenders who were subject to licence supervision, the NSD was created as a separate division of the Probation Service, working alongside police Counter Terrorism Nominal Management (CTNM) arrangements. Together with existing prison and probation services, these bodies are responsible for managing those convicted of terrorist offences or suspected of potential terrorist activity, even if they have no related convictions.

What we found

• This inspection looked at the management and progress of the strategy to supervise these offenders. It found:

• NSD, probation, police and prison services worked well together and are approaching managing counter terrorism cases collectively

• supervision within the community was robust overall, balancing rehabilitative needs with tight risk management

• probation practitioners within NSD were well trained specialist officers, holding a small and restricted caseload, delivering high quality case assessment and supervision

• terrorist offenders were subject to additional oversight throughout their sentences

• the arrangements to protect others from harm from terrorist cases in custody were effective

• there has been significant financial investment to improve services dealing with counter terrorism, and staffing levels were appropriate

• prison governors and directors were clear about the terrorist risk posed in their prisons and were actively managing this

• leadership across the NSD and CTNM was strong, and there were clear lines of accountability, enhanced by national multi-agency governance arrangements.

Manchester: His Majesty’s Inspectorate of Probation, 2023. 65p.

By Riza Kumar

Protracted insurgencies and the growing threat by local affiliates of the global terrorism networks of al-Qaeda and the Islamic State (ISIS) throughout Nigeria, Somalia, and Burkina Faso have transformed on-the-ground responses to violent extremism throughout Sub-Saharan Africa. Somalia continues to grapple with the unrelenting force of the al-Qaeda affiliated al-Shabaab; Burkina Faso contends with al-Qaeda in the Islamic Maghreb (AQIM), Jama’at Nusrat al-Islam wal Muslimeen (JNIM), ISIS in the Greater Sahara (ISGS), and Ansarul Islam; and Nigeria remains encumbered by Boko Haram’s 14-year insurgency and the increasingly violent Islamic State West Africa Province (ISWAP). As serious and sustained militant and terrorist movements continue to kill thousands and displace millions, the three respective governments have altered their responses to violent extremists and terrorism, integrating civilian-led, community-based security strategies into their national counterterrorism programs. National armies and their international partners have offered some reprieve from enduring violent conflicts, but in many cases have failed to offer comprehensive protections to all civilians. Civilian counterterrorism militias emerged to provide security to vulnerable communities and were quickly recognized as an alternative to state-sponsored counterinsurgency campaigns. However, once these counterterrorism militias were enlisted and absorbed into the national security apparatus, new—albeit long-established—challenges quickly emerged. Localized counterterrorism campaigns have at times devolved into vengeful operations against ethnic rivals as well as opportunities to carry out illicit activities such as extortion, drug trafficking, and looting. The benefits and drawbacks of civilian counterterrorism militias remain consistent across different regions. The strategy is cost-effective and practical as civilian defense forces are often cheaper than formal security units, such as the national army and the police. There is a ready pool of potential local recruits to safeguard vulnerable communities, and they are knowledgeable about the communities they protect. Most importantly, civilian troops establish a level of community loyalty that can be difficult to achieve with national armies. Significant drawbacks of civilian forces are that troops can become unreliable and difficult to control if not properly managed. Furthermore, without strong and effective oversight mechanisms, civilian troops are capable of undermining government authority, rule of law, and governance. Unfortunately, if not carefully executed, civilian forces could deteriorate into armed criminal networks,1 transforming from vanguards of safety into long-term sources of instability and insecurity.

Berlin: Counter Extremism Project, 2023. 24p.

By Anna Kruglova

This policy brief analyses the phenomenon of conspiracy theories, and how they fit in the realm of research on violent extremism. Using the case study of QAnon, this Policy Brief looks at how the movement mobilises people to violence on social media and attempts to determine how different this process is from any other process of radicalisation to violence. By combining discourse analysis of the movement’s Gab posts, interviewing former supporters, and analysing three illustrative case studies, this Policy Brief identifies five discourses - such as revenge, “the Other”, chosenness/ specialness, apocalypse, and urgency for action and altruism - that are used to bring people into the violent mindset. It emphasises the similarity of these discourses to the ones used by other extremist organisations and argues against exceptionalising the threat of QAnon and other conspiracy theories. It concludes by making recommendations about how to tackle QAnon propaganda.

The Hague: International Centre for Counter-Terrorism (ICCT) , 2023. 22p.

By Benjamin V. Allison

Given the potential economic, psychological, and human consequences of such attacks, it seems terrorists would attack US bridges and tunnels regularly. After all, terrorists have attacked such critical infrastructure in other countries; why not in the United States? Shockingly, while there has been some discussion of the risk of such attacks, there is a lack of research addressing why they have not happened. Using foiled plots as case studies, I present several major explanations as to why these plots fail—and, more importantly, what deters terrorists from pursuing them. These include counter-terrorism measures, perceived structural soundness and target hardness, expense, and terrorist preference for high body counts.

The Hague: International Centre for Counter-Terrorism, 2022. 35p.

By Theo Clement | Hans-Jakob Schindler

The nexus between terrorist and transnational organized crime (TOC) networks in West Africa presents one of the most significant security challenges. Both networks undermine governance and the rule of law and cooperate on a multitude of levels in a complex web of mutual beneficial arrangements. Therefore, this nexus presents a mutually enforcing mechanism that supports and accelerates regional destabilization. This paper argues that the risks emanating from this cooperation are not limited to terrorism financing alone as terrorist groups also use their cooperation with TOC networks to gain access to resources needed for their activities, such as arms and ammunition. Finally, such cooperation also allows terrorist groups to carve out spaces that allow them to control the local population while at the same time provide security for local licit and illicit economic activities. Therefore, this cooperation is in some cases also a tool through which terrorist groups can gain support and acceptance among the local population. Therefore, tackling this nexus must involve both the regaining of territorial control from terrorist groups by the respective governments as well as the strengthening of governance structures. Both aims should also be attempted concurrently. This paper presents a range of recommendations for German and European decision-makers that primarily aim to disrupt the entry as well as exit points of the flows of illicit goods of the region. Given the current challenges European and German projects face when cooperating with some of the governments in the region, an emphasis on increasing regional cooperation in West Africa seems advisable. In particular, the paper suggests strengthening national and regional law enforcement and border control capabilities, especially within the coastal states of the Gulf of Guinea. Increased cooperation with the Intergovernmental Action Group Against Money Laundering in West Africa (GIABA), increased support to strengthen the management and control mechanisms for national parks, and intensified exchange mechanisms, such as the West Africa Police Chief Committee (WAPCC) of Economic Community of West African States (ECOWAS), could be contemplated. In addition, German and European decision-makers could encourage and support governments in the region in their efforts to intensify the use of existing regional mechanisms such as the ECOWAS sanctions mechanism, as well as increase the participation of regional states in the United Nations Office on Drugs and Crime (UNODC)-World Customs Organization (WCO) Container Control Program and INTERPOL’s West African Police Information System (WAPIS) as possible priorities.

Berlin: Counter Extremism Project Germany GmbH ,2023. 16p

By Dele-Adedeji | Sofia Koller

This policy paper summarizes the current state of affairs regarding the linkages of terrorist groups in West Africa with terrorist networks in other African regions. It also provides recommendations for policymakers and security agencies. The paper looks at linkages of JNIM, IS West Africa Province (ISWAP), and IS in the Greater Sahara (ISGS) with terrorist groups in North, West-Central, Eastern, and Southern Africa. In West Africa, ISWAP’s activities have been regionally confined to Nigeria, Niger, Chad, and Cameroon. There is no indication that ISWAP intends to expand its territorial base beyond these countries or that it has any transregional linkage with terrorist groups in other parts of Africa. JNIM and ISGS have demonstrated that they possess the intention and capability of regional expansion across West Africa. Increasing attacks further southwards in West Africa and their presence in the neighboring regions of Ivory Coast, Ghana, Togo, and Benin suggests that both groups intend to expand their geographical zone of influence to the Gulf of Guinea. There is, however, no indication of either JNIM or ISGS forming a transregional linkage with terrorist groups in other African sub-regions. ● In North, West-Central, East, and Southern Africa, there are also currently no indications that terrorist groups have developed linkages with other terrorist networks beyond their own region. ● Terrorist groups in West Africa are pragmatic in their approach to collaborations. Their choice of network linkages is guided by local dynamics and their own particular agenda rather than ideology. Hence, existing linkages are driven by the involvement in transnational organized crime (TNCO), potential financial gains as well as the potential of financing terrorism via local and international sources, training of fighters, foreign terrorist fighters from other African countries, and weapons smuggling and use of small arms and light weapons (SALWs).

Berlin: Counter Extremism Project Germany GmbH ,2023. 16p.

By Anders Strindberg

This report provides an overview of Social Identity Theory (SIT) and its utility as an integrative framework for the qualitative study of terrorism and violent extremism. SIT is a sociological theory for understanding the effects of social identification on group membership, group behaviour, and intergroup relations. It was designed specifically for the study of intergroup conflict, but scholars have developed a comprehensive analytical apparatus for improving our understanding of multiple aspects both of inter- and intragroup relations and conflict. SIT can serve as scaffolding for organizing our knowledge about terrorism and violent extremism, but also as a foundation for new analytical tools and structures. Following a preface, chapter one demonstrates the need for an integrative analytical framework in the qualitative study of terrorism and violent extremism. Chapter two discusses why SIT is suitable as such a framework, and also the main criticisms against it. Chapters four through seven examine the basic hypotheses and implications of SIT and each chapter identifies some to the key implications for the study of terrorism and violent extremism. Chapter eight outlines a particularly influential SIT-derived structure for organizing analysis of terrorism – Fathali Moghaddam’s “staircase to terrorism” – and chapter nine provides a brief summary and conclusion.

Sweden: Swedish Defence Research Agency, 2020. 80p.

By Anne R. Bradley , Christopher J. Coyne and Abigail R. Hall

Abstract: This Element explores the topics of terrorism, counterterrorism, and the US government’s war on terror following the September 11, 2001 terror attacks. It draws on insights from Austrian and public choice economics. First, it discusses the foundations of the economics of terrorism, emphasizing that the behaviors of terrorists and counterterrorists are purposeful and goal-oriented. It then considers the economics of counterterrorism policies and the importance of institutional change for reducing demand for terrorism. Next, it focuses on three dilemmas facing liberal societies in relation to counterterrorism efforts. The Element then provides an assessment of the US government’s war on terror. It discusses the origins of the war, whether it can be judged a success or a failure, and some of the main effects both abroad and within the United States. The Element concludes by putting forward several areas for future research.

NY. Cambridge University Press. 2023. 85p.

By James D. Wright, Peter H. Rossi, Kathleen Daly with the assistance of Eleanor Weber-Burdin

FRON THE JACKET: “The United States is one of the most heavily armed private populations in world history; one-half the households in the country possess at least one firearm, and the total number of firearms in private hands is well over 100 million. The rates of criminal violence in the United States are among the highest in the world. What, if anything, is the relationship between these facts? UNDER THE GUN provides -for the first time a comprehensive review and analysis of both the published and the unpublished literature on weapons, crime, and violence in the U.S.

Each chapter explores the issues and trends which have been widely debated over the years. Some of the topics covered include: the number of guns in private hands, recent upward trends in firearms sales, demographic characteristics of gun owners, uses of guns in self-defense, patterns of violent crimes committed in the U.S., characteristics of weapons used in crimes, public opinion on gun control issues, and the effectiveness of gun control laws.”

"Wright/Rossi/Daly bring balanced judgment, the best data available, and careful analysis to each issue. They outline an agenda for research which is sensi ble and critical to the matters at hand. The book is more than 'state of the art.' It separates data from inference, logic from value-based argument, and identifies the sorts of issues which cannot be settled by empirical inquiry..” — James Short.

NY. Aldine Publishing Company. 1983. 350p.

By Konaev, Margarita; Fedasiuk, Ryan; Corrigan, Jack; Lu, Ellen; Stephenson, Alex; Toner, Helen; Gelles, Rebecca.

From the webpage: "This data brief uses procurement records published by the U.S. Department of Defense and China's People's Liberation Army between April and November of 2020 to assess, and, where appropriate, compare what each military is buying when it comes to artificial intelligence. We find that the two militaries are prioritizing similar application areas, especially intelligent and autonomous vehicles and AI applications for intelligence, surveillance and reconnaissance."

Georgetown University. Walsh School Of Foreign Service. Center For Security And Emerging Technology. 2023.

By Nowrasteh, Alex

From the document: "Terrorism is a hazard to human life and material prosperity that should be addressed in a sensible manner whereby the benefits of actions taken to contain it outweigh the costs. A total of 219 foreign-born terrorists were responsible for 3,046 murders on U.S. soil from 1975 through the end of 2022. The chance of a person perishing in a terrorist attack committed by a foreigner on U.S. soil over the 48-year period studied here is 1 in 4.3 million per year. The hazard posed by foreigners who entered on different visa categories varies considerably. For instance, the annual chance of an American being murdered in a terrorist attack by a refugee is about 1 in 3.3 billion, while the annual chance of being murdered in an attack committed by an illegal immigrant is zero. Looking at this spectrum of risk, any government response to terrorism must consider the wide range of hazards posed by foreign-born terrorists who entered under various visa categories. There were 219 foreign-born terrorists who planned, attempted, or carried out attacks on U.S. soil from 1975 through 2022. Of those, 67 percent were Islamists, 16 percent were foreign nationalists, 6 percent were right-wing extremists, 5 percent were non-Islamic religious terrorists, 4 percent were left-wing extremists, and the rest were separatists, adherents of other or unknown ideologies, or targeted worshippers of specific religions. The federal government has an important role in screening all foreigners who enter the United States and excluding those who pose a threat to the national security, safety, or health of Americans, as foreign-born terrorists explicitly do. This focused terrorism risk analysis can aid in the efficient allocation of scarce government-security resources to best counter the small threat of foreign-born terrorists."

CATO Policy Analysis No. 958. 2023.

By Jonathan Jay • Luke W. Miratrix • Charles C. Branas • Marc A. Zimmerman • David Hemenway

Although multiple interventions to remediate physical blight have been found to reduce urban firearm violence, there is limited evidence for demolishing vacant buildings as a violence reduction strategy. Starting in 2014, Detroit, MI launched a large-scale program that demolished over 10,000 buildings in its first 3 years. We analyzed the pre-post effects of this program on fatal and nonfatal firearm assaults and illegal drug violations at the U.S. Census block group level, using propensity score matching and negative binomial regression. Receiving over 5 demolitions was associated with a 11% reduction in firearm assaults, relative to comparable control locations, 95% CI [7%, 15%], p = 0.01. The program was associated with larger reductions in firearm assaults for the locations receiving moderate numbers of demolitions (between 6 and 12) than for locations receiving high numbers of demolitions (13 and over). No effects were observed for illegal drug violations and no evidence of spatial crime displacement was detected. These findings suggest that vacant building demolitions may affect gun violence.

J Behav Med (2019) 42:626–634