By Marzia Giambertoni

lthough U.S. policymakers face a variety of complex challenges in addressing transnational terrorism, one underappreciated aspect is Hezbollah's evolving presence in Latin America. Academic literature and government reports almost universally indicate that Hezbollah's activities in the region pose potential threats to U.S. national security. However, there is a significant knowledge gap in existing assessments. In this paper, the author offers an initial exploration of Hezbollah's operational footprint in Latin America, focusing on illicit funding mechanisms, violent operations, and key operational hubs — particularly in the Tri-Border Area and Venezuela. The analysis situates these activities within the broader context of Iran's regional diplomatic, economic, and cultural activities, which partially facilitate conditions amenable to Hezbollah's operations.

The author draws from a variety of open-source materials and reviews publicly available information to provide a foundation for understanding how Hezbollah's networks in Latin America are characterized and discussed publicly. By analyzing the group's operational strategies and historical precedents, the author's framing identifies actionable considerations for U.S. Department of Homeland Security (DHS) and U.S. Department of Defense (DoD) leadership while raising awareness of the organization's presence among a broader community of stakeholders. These findings are significant for both DHS and DoD, given the former's counterterrorism mandate in Latin America and the latter's strategic interests in the region. Hezbollah's evolving presence warrants careful consideration from defense planners to effectively address potential challenges to U.S. interests and regional stability.

Santa Monica, CA: RAND, 2025, 20p.

By Kateira Aryaeinejad and Thomas Leo Scherer

Over the years, the National Institute of Justice’s (NIJ) funding for research has provided important opportunities to advance our understanding of topics related to crime and justice within the United States. Drawing from this portfolio, this synthesis paper compares and contrasts the data and findings from NIJ-sponsored research projects on violent extremism, mass shootings, and bias crimes. This comparison focuses both on the content of the data and on the creation and coverage of the data, examining findings from four research projects: ■ The Profiles of Individual Radicalization in the United States (PIRUS) database of 2,226 individuals who demonstrated at least 1 of 5 extremist or radicalized behaviors. ■ The Bias Incidents and Actors Study (BIAS) database of 966 adults arrested or indicted for bias crimes. ■ The National Hate Crime Investigation Study (NHCIS) database of 1,230 hate crime cases. ■ The Violence Project dataset of 172 mass shootings. This synthesis first reviews the creation of each dataset and the types of information that are collected to better understand their generalizability and the ability to make comparisons across separate datasets. There are significant differences in the size, time span, and information of the four datasets, which limits the comparisons that can be made between the individuals described in each dataset and necessitates caution in drawing strong conclusions from such comparisons. With that caution in mind, the datasets suggest some similarities in the individuals who commit bias crimes and mass shootings and display violent extremist behavior. These individuals are primarily males in their 20s and 30s and unmarried at the time of their offenses. They may exhibit higher rates of unemployment than the general population and often have prior criminal histories. However, that is not to say that these characteristics should be used as a profile to determine who is at risk of or more likely to commit any of these types of offenses or behaviors. Rather, it calls into question what other factors may be impacting individuals with these characteristics who go on to commit these types of offenses. The datasets also suggest some differences in the individuals who commit each type of offense or behavior. Individuals associated with violent extremism tend to be more educated than those who commit mass shootings or bias crimes. Individuals who commit mass shootings exhibit higher rates of mental health issues than those who commit bias crimes or participate in violent extremism offenses. The comparison of individuals across categories also highlighted differences among individuals who committed the same type of offense. Among individuals who supported violent extremism, for example, those acting in support of far-right ideologies were more likely to have military experience than those following other ideologies. Comparing these datasets highlights their potential and their limitations, suggesting paths forward for future research. The different collection methods show the importance of precisely describing the data collection method, discussing which behaviors are missed by that method, and triangulating among data with different methods to understand what is missing. The differences in the types of information that each dataset collects about each individual and action suggest that future collections could have greater overlap and comparability. The establishment of potential similarities in demographics and life experiences also allows for more targeted data collection focusing on why most individuals who fit that profile do not commit an offense, while others do. In this way, these projects not only contribute to our current understanding of these types of offenses and behaviors but also allow future research and programming to be conducted more effectively.

Washington, DC : U.S. Department of Justice, Office of Justice Programs, National Institute of Justice, 2024. 43p.

By Noémie Bouhana | Caitlin Clemmow | With contributions from Philip Doherty

Post 9/11, research on radicalisation and involvement in terrorism and violent extremism (henceforth, ITVE) has focussed on the role of individual-level attributes, such as the psychological characteristics, socio-economic background, demographic features, experiences, beliefs, past behaviours and criminality, and the social embeddedness of radicalised individuals and people involved in acts of terrorism (Borum, 2011; Stern, 2016; McCauley & Moskalenko, 2017; Sageman, 2008; Wiktorowicz, 2005). Likewise, existing processes, methods and tools to identify and evaluate the risk of ITVE operate largely at the individual level. The Vulnerability Assessment Framework (VAF) used in the context of Channel is the best example of this. Comparatively less attention has been devoted to identifying and evaluating the characteristics of the socio-physical contexts which may contribute to the emergence of the risk of ITVE, or, conversely, to its suppression. Yet research on crime, arguably a closely related problem space, makes a strong case that many of the causes and enabling conditions of criminal development (of which ITVE is an instantiation) are found in the environment: crime and criminals concentrate in space and time. Modifying the environment in which crime occurs and the specific settings in which criminals develop and act has been shown at length to be an effective approach to crime prevention and disruption (Weisburd et al., 2012). In crime prevention, as in other areas of behavioural change, one size does not fit all: to design effective programs, the ability to tailor interventions to the socio-physical context is paramount, which means that the effect of key contextual features on the outcome of interest must be understood (Sampson et al., 2013); notably, the effect of exposing (susceptible) individuals with particular kinds of characteristics to (criminogenic) places with particular kinds of features. Situational Action Theory [SAT] is a theory of crime causation, which, as its name suggests, puts context at the centre of the explanation of crime (P.- O. H. Wikström et al., 2009). In 2010, ahead of the revision of the Prevent Strategy, the UK Home Office commissioned a Rapid Evidence Assessment of the cause of al-Qaeda-influenced radicalisation seen through the lens of SAT (Bouhana & Wikström, 2011), which identified the key levels of analysis in a causal model of radicalisation as relating to individual vulnerability to radicalising influence, exposure to radicalising settings, and the mechanisms of emergence of said settings. In the decade since, this theoretical model has been refined and now underpins a research programme concerned chiefly with going beyond "who" and "why" to the "where" of terrorism involvement. It has inspired, notably, the EU FP7-funded international PRIME project on lone actor terrorism, which, among other findings, has shown that individual-level risk indicators are multifinal (i.e., their meaning determined by the context in which they arise), and has provided support for a formulation of individual vulnerability which encompasses susceptibility to exposure to radicalising settings, as well as cognitive susceptibility to moral change with significant implications for prevention efforts (Corner et al., 2018). It has also produced evidence for distinct configurations of individual/ context interaction patterns leading to the emergence of lone actor risk, with further implications for risk assessment (Clemmow et al., 2019). To better support policy strategy and counter-terrorism practice, the theoretical SAT model of radicalisation was reformulated and expanded into a risk analysis framework for lone actor terrorism [PRIME RAF] (Bouhana et al., 2016, 2018) and a systemic inference framework to inform counter-extremism strategies [S5], commissioned by the UK Counter-Extremism Commission (Bouhana, 2019). Both of these integrate SAT with the broader behavioural and socio-cognitive knowledge-base to refine our understanding of personenvironment interaction. While the RAF is concerned specifically with the effect of situational interaction on the motivation and capability of lone actors to act (behaviour), S5 is more broadly focused on explaining the acquisition of extremist propensities (beliefs). Both frameworks are analytically related and can be logically integrated. However, these remain general frameworks. Inherent in their interactionist logic is the fact that, while environmental processes of risk can be set out in generic terms, specific risk (or protective) factors and – crucially – their observable indicators must be elicited with regards to a particular context. This is because indicators are subject to change over space and time (P. O. H. Wikström & Bouhana, 2017) and because risk assessment is most effective when calibrated to context (Hamilton et al., 2021). A recently completed, Home Office-funded project guided by S5 (State of the Union [SOTU]; Bouhana and Schumann, 2021), which aimed to assess the observability of key analytical concepts of mainstream models of terrorism involvement, demonstrated the difficulty, yet also the necessity of translating said concepts into observable indicators, inasmuch as any model is intended to guide risk assessment or intervention design and evaluation. It also suggested that environmental indicators may be more reliably observed than susceptibility-related indicators using commonly available sources of information, and it tentatively provided further support for the notion that susceptibility and exposure interact in specific ways, leading to the emergence of risk. This project investigated the feasibility of developing a framework to assess the risk of involvement in terrorism and violent extremism at the level of place, with a view towards – further down the line – designing an assessment tool along the lines of the Vulnerability Assessment Framework, intended to assess environments instead of individuals. As a first step towards establishing this feasibility, this project investigated whether the mechanisms articulated in the S5 framework could be operationalised; in other words, to what extent they could be associated with a set of observable indicators relevant to the UK ITVE context. Given the relative scarcity of empirical research into the characteristics of extremist social ecologies and settings in the UK (and largely elsewhere) – which would be prerequisite to the conduct of a systematic review – the researchers elected to carry out an e-Delphi exercise with U.K. Prevent practitioners, the results of which are presented at length in this report.

London: CREST - Centre for Research and Evidence in Security Threats (CREST), 2025. 50p.

By Noor Huda Ismail

Violent extremist groups exploit societal grievances, including climate-related disasters, to gain legitimacy and recruit members by positioning themselves as the true protectors of vulnerable communities. Strategic communication, including AI driven tools, is essential to counter extremist narratives and build resilience against manipulation. There is an urgent need for proactive, transmedia storytelling approaches to address both climate change and violent extremism, ultimately strengthening trust and promoting community unity.

S. Rajaratnam School of International Studies, NTU Singapore, 2025. 4p.

By Iftekharul Bashar

Hizb ut-Tahrir Bangladesh, an extremist organisation banned since 2009, is swiftly expanding by recruiting Bangladeshi youth through social media and educational institutions. The group’s recent rally in Dhaka, attended by over 2,000 supporters, underscores its resurgence and the growing challenge for the government. Bangladesh must recalibrate its response to this threat by strengthening law enforcement measures, enhancing counter-radicalisation programmes, and creating job and entrepreneurship opportunities for its youth.

S. Rajaratnam School of International Studies, NTU Singapore, 2025. 4p.

By Remadji Hoinathy, Malik Samuel and Akinola Olojo

  Some Lake Chad Basin countries (Cameroon, Chad, Niger and Nigeria) have been dealing with violent extremism for over a decade. Disarmament, demobilisation, repatriation, reintegration and resettlement processes in these countries may offer useful lessons for other West African contexts, including Mali and Burkina Faso, or more recently affected countries such as Benin, Côte d’Ivoire and Togo. Such lessons include incentivising defections, coordinating at national and regional levels, gender sensitivity, appropriate legal frameworks and community engagement.

Key findings Understanding the circumstances that lead people to join and leave violent extremist groups, and their experiences in those groups, is key to crafting incentives for disengagement. The willingness to leave violent extremist groups is often clouded by uncertainty, as well as long waiting periods between disengagement and enrolment in programmes for disarmament, demobilisation, repatriation, reintegration and resettlement (DDRRR). Waves of defection from Boko Haram caught Lake Chad Basin (LCB) states unprepared. DDRRR processes were thus implemented under pressure, hindering early coordination at a regional level. Women are treated mainly as victims, despite some voluntarily joining and playing active roles in Boko Haram, including volunteering as suicide bombers. DDRRR implementation in the LCB has revealed gaps in legal frameworks that require revisions. DDRRR lacks public support in some LCB countries, as many people view it as blanket amnesty for Boko Haram members. 

Recommendations Non-military means of countering violent extremism should incorporate incentives and opportunities for associates to leave these armed groups. By depleting these groups’ human resources, their fighting capacity is reduced. To encourage defection, clear processes for screening, prosecution and integration are needed. National ownership of these processes, inclusivity, adaptation to local context and adequate resourcing are key, from inception to implementation. National ownership should not lead to isolated approaches, but rather create bridges between countries to enable a cohesive regional approach. Organisations such as the Economic Community of West African States, the Liptako-Gourma States Integrated Development Authority, the G5 Sahel and the Accra Initiative could offer relevant regional frameworks for this. Authorities in charge of DDRRR programmes should consider the diverse needs and backgrounds of ex-associates. Distinguishing individuals according to why they joined and their roles within the groups is important for providing appropriate treatment. The specific needs of women and children should be taken into account. Affected West African countries should proactively formulate relevant legal and institutional frameworks. International and regional provisions and standards should be taken into account, including the need for transparent and predictable screening, prosecution and rehabilitation processes. Due to their position connecting the LCB and West Africa, Niger and Nigeria could play a key role in sharing lessons learned from DDRRR implementation. Community organisations, platforms, and media should be used by the DDRRR authorities to raise public awareness of the reintegration process. This would help prevent perceptions of general amnesty for Boko Haram members and preconceived ideas about the disengaged from undermining the process. 

Pretoria: Institute for Security Studies, 2023. 12p.

By Andrew Gilligan and Paul Stott

  • The Government’s “Rapid Analytical Sprint” to determine its policy on extremism has been leaked to Policy Exchange. • It says the UK’s approach to extremism should no longer be based on “ideologies of concern” but on a very wide range of “behaviours,” including violence against women and girls, “spreading misinformation and conspiracy theories,” an interest in gore or extreme violence, misogyny, or involvement in “an online subculture called the manosphere.” It admits itself that many who display such behaviours are not extremist. • This approach could swamp already stretched counter-extremism staff and counter-terror police with thousands of new cases, increasing the risk that genuinely dangerous individuals are missed. It risks addressing symptoms, not causes. • The Sprint de-centres and downplays Islamism, by far the greatest threat to national security. It acknowledges “left-wing, anarchist and single issue (LASI) extremism,” “environmental extremism” and Hindu extremism as distinct phenomena that counter-extremist policy should tackle. The left may object to the first two; others will welcome it. • The Sprint will raise concerns over freedom of speech. It says claims of two-tier policing are a “right-wing extremist narrative.” It recommends the reversal of moves to cut police use of “non-crime hate incidents.” A new crime of making “harmful communications” online – rejected by the previous government on freedom of speech grounds - is floated. • The Sprint may have been influenced by the events of Southport. But as in the Prime Minister’s remarks after the killer’s guilty pleas last week, it risks confusing extreme violence with extremism, or extremism with any shocking crime, bad belief or nasty social phenomenon about which we are worried. • What happened in Southport was more an operational than a policy failing. The murderer had shown he was dangerous many times over several years before he killed anyone. In a more operationally effective policing and justice system, action would have been taken against him sooner, even without having to first label him an extremist. • There is a case, as the former counter-terror policing chief Neil Basu has said, for creating a “non-extremist” version of Prevent aiming to interdict people, such as the Southport killer, with an interest  in violence but no obvious ideological or political motivation. The recommendation by a previous reviewer of Prevent, William Shawcross, that the current programme is the wrong place for dealing with the psychologically unstable has been ignored, even repudiated, in the Sprint. It should be acted on. • There are several sensible proposals, including the creation of a new Ministerial Counter-Extremism Board to coordinate policy.   

London: Policy Exchange, 2025. 30p.

ByJoe Whittaker, Elizabeth Pearson, Ashley A Mattheis, Till Baaken, Sara Zeiger, Farangiz Atamuradova, Maura Conway

Drawing from interviews with 39 online extremism and terrorism researchers, this article provides an empirical analysis of these researchers’ experiences with institutional ethics processes. Discussed are the harms that these researchers face in the course of their work, including trolling, doxing, and mental and emotional trauma arising from exposure to terrorist content, which highlight the need for an emphasis on researcher welfare. We find that researcher welfare is a neglected aspect of ethics review processes however, with most interviewees not required to gain ethics approval for their research resulting in very little attention to researcher welfare issues. Interviewees were frustrated with ethics processes, indicating that committees oftentimes lacked the requisite knowledge to make informed ethical decisions. Highlighted by interviewees too was a concern that greater emphasis on researcher welfare could result in blockages to their ‘risky’ research, creating a ‘Catch 22’: interviewees would like more emphasis on their (and colleagues’) welfare and provision of concomitant supports, but feel that increased oversight would make gaining ethics approval for their research more difficult, or even impossible. We offer suggestions for breaking the impasse, including more interactions between ethics committees and researchers; development of tailored guidelines; and more case studies reflecting on ethics processes.

New Media & Society Online First, February 28, 2025

By Irfan Idris and Kusumasari Ayuningtyas

The ideological influence of Jemaah Islamiyah continues to be a threat to security even after its disbandment in June 2024. Some of its former members may align with other extremist groups, while others may seek to operate as lone-wolf terrorists. The possibility of JI’s former members transitioning into lone wolf actors stems from the enduring power of its ideology and indoctrination process.

S. Rajaratnam School of International Studies, NTU Singapore, 2025, 3p.

By Noor Huda Ismail

The concept of asabiyya – group solidarity – originally articulated by Ibn Khaldun, has been hijacked by extremist groups in Southeast Asia to create division and promote radical ideologies. Reclaiming asabiya is crucial, redefining it as a tool for social cohesion and unity by drawing on cultural values that foster mutual respect and collective responsibility. Regional cooperation and digital counter-narratives are essential in countering extremism and fostering long-term peace in the region.

S. Rajaratnam School of International Studies, NTU Singapore, 2025. 4p.

By Piotr Bąkowski

Faced with a persistent terrorist threat, the European Union (EU) is playing an increasingly ambitious role in counter-terrorism. While primary responsibility for combating crime and ensuring security lies with the Member States, the EU provides cooperation, coordination and (to some extent) harmonisation, as well as financial support, to address this borderless phenomenon. Moreover, awareness of the connection between development and stability, as well as between internal and external security, has come to shape EU action beyond Union borders. EU spending on counter-terrorism has increased over the years, to allow for better cooperation between national law enforcement authorities and enhanced support by the EU bodies in charge of security and justice, such as Europol, eu-LISA and Eurojust. The many new rules and instruments that have been adopted in recent years focus, among other things, on harmonising definitions of terrorist offences and sanctions, sharing information and data, protecting borders, countering terrorist financing and regulating firearms. However, implementing and evaluating the various measures is a challenging task. The European Parliament has played an active role not only in shaping legislation, but also in evaluating existing tools and gaps through the work accomplished by its Special Committee on Terrorism (TERR) in 2018. In line with the Parliament's recommendations, as well as the priorities set by the European Commission and its counter-terrorism agenda presented in December 2020, EU counter-terrorism action has focused on doing more to anticipate threats, counter radicalisation, and reduce vulnerabilities by making critical infrastructures more resilient and improving the protection of public spaces. The EU will also continue to address the online dimension of various forms of extremism, in line with the regulations on dissemination of terrorist content online and on the provision of digital services in the EU. This briefing updates an earlier one, entitled Understanding EU counter-terrorism policy, published in 2023.

Brussels: EPRS | European Parliamentary Research Service, 2025. 12p.

By Alana Ford

An examination of the threat of disinformation and cognitive warfare in the Indo-Pacific, the brief unpacks how these tactics are reshaping national security and undermining democratic institutions. Drawing on global examples, it highlights the implications for regional stability and democratic resilience.

The briefing paper outlines Australia’s multipronged approach, including legislative reforms, international partnerships, and public education efforts, offering practical insights to counter these evolving security threats and safeguard democratic values across the Indo-Pacific.

Key messages

Disinformation and cognitive warfare are evolving security threats that undermine democratic institutions, polarise societies, and manipulate public trust at a global scale.

The digital revolution has amplified the speed, precision, and scale of disinformation campaigns.

Russia’s invasion of Ukraine demonstrates how cognitive warfare is deployed to legitimize unlawful acts of aggression and manipulate international narratives.

Democracies in the Indo-Pacific, including Australia, face heightened risks of disinformation and cognitive warfare due to their open information environments and the region’s complex geopolitical dynamics.

Effective countermeasures require coordinated domestic and international efforts, leveraging regulation and multilateral partnerships like AUKUS and the Quad.

Australia: Perth USAsia Centre, 2025.

By Alexander Palmer, Skyeler Jackson, and Daniel Byman

Despite the recent attack in New Orleans, longer-term trends suggest that jihadist terrorism in the United States is not resurgent. The number of jihadist plots and attacks in the United States has been low since the territorial defeat of ISIS. The average lethality of jihadist terrorist attacks has also fallen since the peak of the caliphate. International groups such as the Islamic State and al Qaeda have filled more of an inspirational role rather than directly orchestrating attacks on the United States. Although formal links between attackers and plotters in the United States appear to be rare, this has not prevented individuals from carrying out lethal “lone wolf” attacks. Overall, jihadist terrorism in the United States does not merit additional resources at this time; however, international terrorism organizations continue to merit counterterrorism efforts.

Washington, DC: The Center for Strategic and International Studies (CSIS) , 2025. 12p.

By Iftekharul Bashar

In 2024, Bangladesh faces a growing threat of radicalism fuelled by political instability, security vacuums, and weakened counterterrorism infrastructure. Unless the interim government adopts a zero-tolerance policy and strengthens law enforcement and intelligence efforts, extremist groups may gain further ground, leading to long-term instability. COMMENTARY Bangladesh is facing an increasing threat of radicalism and terrorism. The political violence and instability of 2024 have worsened the situation, with extremist elements exploiting the security vacuum created by the regime change. Weakened law enforcement and intelligence agencies, along with the rise of armed groups and radical ideologies, pose a serious threat to the country’s stability. Bangladesh risks long-term insecurity with broader regional implications without swift and decisive action.

Singapore: S. Rajaratnam School of International Studies (RSIS), NTU , 2024. 4p.

By Yannick Deepen and Sabine Kurtenbach

Non-state armed actors (NSAAs) come in a variety of shapes and sizes, including warlordled groups, insurgencies, militias, and organised-crime syndicates to name just the most prominent examples hereof. In war or lower-level armed conflict, as well as violence-prone contexts, these groups pose acute problems for peacebuilding, democratic governance, and sustainable development. They control resources and territories, as well as compete, cooperate, or align with political and economic elites both within and beyond the state to promote the unstable status quo that serves their interests. Various challenges arise when dealing with NSAAs. Prevailing strategies vary between repression, co-optation, and submission to the rule of law. This analysis maps cross-regional trends regarding NSAAs based on available datasets. On this basis we develop a typology for NSAAs and a conceptual frame for their transformation. We then apply this to three paradigmatic case studies – Colombia, Mali, the Philippines – and formulate recommendations for the designing of improved strategies vis-à-vis development cooperation and other external actors.

GIGA Working Papers, No. 337,

By Omar Ashour

How did ISIS – a widely hated, massively outnumbered and ludicrously outgunned organisation – manage to occupy over 120 cities, towns and villages from the Southern Philippines to Western Libya? Seeking to understand ISIS’s combat effectiveness, Omar Ashour analyses the military and tactical innovations of ISIS and their predecessors in Iraq, Syria, Libya and Egypt. He shows how their capacity to mix conventional military tactics with innovative guerrilla warfare and urban terrorism strategies allowed ISIS to expand and endure beyond expectations.

Edinburgh: Edinburgh University Press, 2021.

By Rohan Gunaratna

The conflicts in Israel, Gaza, Lebanon, Yemen and Syria will have a generational impact. The 7 October 2023 attack against Israel in Gaza and its consequences have set back the prospects of a two-state solution to the Palestinian issue and may attract a new wave of foreign fighters to embark on terrorist activities like what was seen following the military debacles in Afghanistan, Iraq and Syria. What can be done to stem another rise of the terrorist fighters?

S. Rajaratnam School of International Studies, NTU Singapore, 2025. 3p.

Edited by Katharina Karcher, Yordanka Dimcheva ,· Mireya Toribio Medina. Mia Parkes

This open access book sheds light on collective practices of remembering, imagining and anticipating in relation to recent acts of urban terrorism in Europe. Analysing a range of personal and collective responses to urban terrorism in contemporary Europe, this book shows that current debates on this issue are shaped by multiple co-existing and intersecting memories of political violence in the past. Moreover, despite public declarations of unity and solidarity, collective memories of urban terror in contemporary Europe are far from consensual - memory can be both a catalyst for and an impediment to social and political change. Drawing on case studies from a range of European countries and creative responses by survivors, artists, and poets, this interdisciplinary volume introduces readers to key methods (e.g. discourse analysis and (auto-)ethnography) and concepts (e.g. Lieux de Mémoire and ‘grassroots memorials’) for the study of the memorialization of terror attacks.

Cham: Palgrave Macmillan, 2024. 317p.

By Michael Jensen, Sheehan Kane, and Elena Akers

Profiles of Individual Radicalization in the United States (PIRUS) is a database of 3,203 Islamist, far-left, far-right, and single-issue extremists who have radicalized to violent and non-violent extremism in the United States from 1948 through 2021. This update adds 955 subjects to the database who were charged with committing extremist crimes in the United States from 2019-2021.1 The database is freely available for download on START’s webpage at https://www.start.umd.edu/profiles-individual-radicalization-united-states-pirus-keshif. The analysis for this research brief draws on the full dataset and illustrates the important differences that exist across ideological groups and highlights recent trends in the data.

College Park, MD: START , 2023. 10p.

By Michael Jensen, Sheehan Kane, and Elena Akers

Included with the current update to the Profiles of Individual Radicalization in the United States (PIRUS) data are a suite of variables that allow users to investigate extremist offenders who plotted to commit, or committed, mass casualty attacks in the United States from 1990-2021. A mass casualty plot is defined as an event in which the perpetrator(s) intended to kill or injure four or more victims. Unlike other data resources on mass casualty events, PIRUS allows users to investigate successful mass casualty attacks as well as unsuccessful plots where the perpetrators clearly intended to kill or injure four or more people but failed. The inclusion of failed and foiled mass casualty plots in PIRUS gives users a more accurate estimate of how often extremists plan to cause significant harm. It also allows users to compare ideological groups and offenders on measures of plot success. This research brief provides an overview of the mass casualty crimes in PIRUS, including their frequency, links to ideological and sub-ideological groups, and a comparison of their perpetrators.

College Park, MD: START (March). 2023, 4p.