Comparing Significant Acts of Anti-Government Violent Extremism: A Research Note

By Michael K. Logan, Clara Braun, Seamus Hughes

Abstract

In 2021, the Federal Bureau of Investigations (FBI) and Department of Homeland Security (DHS) put forth a five-category typology of domestic violent extremism. One of these categories, referred to as anti-government/anti-authority violent extremism, clusters together anarchist violent extremism (AVE), sovereign citizen violent extremism (SCVE), and militia violent extremism (MVE). While there is conceptual debate regarding this typology, few researchers have assessed if, and how, any commonalities exist between the three ideological subtypes. In this research note, we examine the utility of this new anti-government/anti-authority violent extremism category by comparing event-level characteristics of domestic terrorism incidents committed by AVEs, SCVEs, and MVEs. Data for this study derived from fifty-nine acts of anti-government/anti-authority violent extremism identified as significant by the FBI and the DHS. Our findings suggest that the focus on targeting law enforcement and preference for lone offending are shared characteristics across AVEs, SCVEs, and MVEs. However, there were differences in weapons selection across the three subtypes indicating that the anti-government/anti-authority violent extremism category is not completely homogenous at the incident-level. Despite the small sample size, the results of this study highlight the general utility of classifying AVE, SCVE, MVE under the umbrella anti-government/anti-authority violent extremism typology.

In the current research note, we provide a descriptive analysis of 59 (n = 59) “significant” acts of domestic anti-government/anti-authority violent extremism highlighted in the May 2021, October 2022, and June 2023 Strategic Intelligence Assessment and Data on Domestic Terrorism report put forth by the Federal Bureau of Investigations (FBI) and Department of Homeland Security (DHS).[1] By definition, anti-government/anti-authority violent extremists encompasses the potentially unlawful use or threat of force or violence in furtherance of political and/or social agendas, which are deemed to derive from anti-government or anti-authority sentiment, including opposition to perceived economic, social, or racial hierarchies, or perceived government overreach, negligence, or illegitimacy.[2] As shown in Figure 1, we pay specific attention to similarities and differences at the event-level (e.g., target and weapon selection) across the three subtypes of anti-government/anti-authority violent extremism found in the FBI and DHS’s recent reclassification of domestic violent extremism, including anarchist violent extremist (AVE), sovereign citizen violent extremist (SCVE), and militia violent extremism (MVE).

Despite the small sample size, there are two important contributions of this research note to domestic terrorism research and policy. First, the domestic terrorism incidents examined in this study were determined to be significant by counterterrorism professionals within the FBI and DHS.[3] This is important because, although no inclusion criteria are made available, the 59 incidents examined in this study provide valuable insights into the perceptions of counterterrorism professionals. At the same time, counterterrorism professionals within the FBI and DHS also classified each incident by the offenders’ primary ideology (i.e., AVE, SCVE, MVE). Prior research has shown that categorizing acts of domestic terrorism by ideology is an inherently political task and that some datasets on domestic terrorism include “serious missteps in their coding of the data that obscure the nature of certain threats.”[4] Since the incidents in this study were already classified by individuals within the FBI and DHS, the presence of any researcher bias is limited.

Second, findings from this study assess the viability of the FBI and DHS’s recent reclassification of the typologies of domestic violent extremism with a particular focus on anti-government/anti-authority violent extremism. Despite the general anti-government sentiment shared between AVE, SCVE, and MVE, little is known about if, and how, attacks committed by these actors compared to one another.  While typologies are oftentimes a useful tool for organized complex information, there is a risk of obscuring nuances between actors when developing broad, all-encompassing typologies. Moreover, the presence of any nuance between extremist types has important implications for law enforcement and counterterrorism professionals. For instance, Lundberg notes that typologies are “essential for describing an event in law or policy and typologies of events can be useful for identifying scenarios to exercise”.[5] Subsequently, if all three extremist types have a similar tactical profile, then it is reasonable to suggest that a universal training program is the best approach to orient law enforcement to the threat posed by anti-government/anti-authority violent extremists. However, if differences exist, it may be worthwhile to develop customized training programs with an individual focus on one form of anti-government/anti-authority violent extremism.

In the next section, we discuss the three subtypes of anti-government/anti-authority violent extremism: AVE, SCVE, and MVE.

Subtypes of Anti-Government/Anti-Authority Violent Extremism

For the purposes of this study, anarchist violent extremism (AVE) is defined as individuals who advocate for violence to restructure society and eliminate oppressive hierarchies and authorities with a particular focus on institutions of the state, capitalism, white supremacy, bureaucracy, militarism, and environmental domination in favor of deliberately small collectives and affinity groups.[6] Although elements of anarchist ideology are central features of various contemporary social movements, such as the animal and earth liberation movement or anti-fascism, anarchism is not tied to a specific auxiliary cause. Rather, “anarchists view anarchy itself as the main cause or objective for which they advocate; it is not merely a means to an end.”[7] In the United States, anarchist violence emerged in the early 1900s when revolutionary anarchists conducted dozens of assassinations and bombings in an attempt to disrupt modern society. Most notably, anarchist extremists were responsible for the assassinations of President William McKinley in 1901 as well as a spree of 40 bombings on prominent political figures and businesspeople in 1919. More recently, AVEs are typically associated with the use of “black bloc” tactics against law enforcement and/or counter-protesters at events such as the riots at the 1999 World Trade Organization conference in Seattle, WA, the 2008 Republican National Convention in Minneapolis, MN, the “Occupy” movement in the early 2010s, and the 2020 protests against police brutality across the United States.

Next, sovereign citizen violent extremism (SCVE) refers to individuals who subscribe to the belief that the United States government and most forms of institutions and authorities are illegitimate.[8] The roots of SCVEs can be traced back to the Posse Comitatus Act and tax protesters, and its adherents are known for engaging in paper terrorism, which involves filing pseudolegal claims accusing government officials of wrongdoings.[9] In fact, Sullivan and colleagues found that out of the 215 financial schemes identified in the U.S. Extremism Financial Crime Database, approximately one-third were committed by sovereign citizens.[10] In addition to financial crimes, SCVEs have also demonstrated a willingness to utilize lethal violence, particularly against law enforcement.[11] For example, Gruenewald and colleagues found that 40 percent of incidents in which a law enforcement officer was killed by a far-right extremist were committed by an offender with antigovernment sentiments or sovereign citizens.[12] At the same time, Sarteschi found that 27 law enforcement officers were killed by sovereign citizens between 1983 and 2020. In most cases, these deadly encounters occurred during routine traffic stops, ambushes, or police standoffs.[13]

Finally, militia violent extremism (MVEs) refers to individuals who overtly participate in or support the use of violence to overthrow or resist the United States government in response to the perception that it is surpassing powers limited by constitutional authority.[14]Although the militia movement has diverse political goals, the majority of those who participate in the movement have at least two shared features. First, MVEs share the perception that the federal government is becoming increasingly tyrannical and threating the rights and liberties of Americans.[15] Second, MVEs view themselves as “patriots” and share the belief that they have a duty to defend the nation. As part of this obligation, MVEs often engage in combat and survival training with other militia members and stockpile weapons and food.[16] Prior research has shown that violent acts by MVEs are typically geared toward law enforcement and government officials.[17] For example, a Michigan-based militia group known as the Wolverine Watchman were responsible for the plot to kidnap Gretchen Whitmer, the governor of Michigan, in 2020. Furthermore, several individuals associated with high profile militia groups, such as the Oath Keepers, have pleaded guilty or charged with crimes in connection to the January 6th attack on the U.S. Capitol.

The Current Study

The current study examines the incident-level characteristics of significant acts of domestic terrorism perpetrated by AVEs, SCVEs, and MVEs. Despite their shared anti-government stance and general opposition to the state, it is unknown if, and how, these three ideologies compare to one another at the incident level. If similarities are found, then our study lends support for the inclusion of all three subtypes within anti-government/anti-authority violent extremism typology. However, if substantive differences are found, it would be reasonable to question the usefulness of the anti-government/anti-authority violent extremism typology in favor of treating one or more extremist type as its own category. We now turn to the methods section.

Methodology  

Data from this study comes from the May 2021, October 2022, and June 2023 Strategic Intelligence Assessment and Data on Domestic Terrorism published by the FBI and DHS. In total, 59 incidents of domestic terrorism were designated as “significant” and attributed to anti-government/anti-authority violent extremists between 2015 and 2022.[18] This includes incidents that were carried out as well as plots that were foiled by law enforcement. Each incident included a short narrative description and details on when and where the incident took place, which was used by our research team as a starting point to complete a more comprehensive assessment of each incident via publicly available sources. Like other datasets that rely upon publicly available sources, we collected information from media reports, watchdog groups, court records, and Department of Justice press releases.[19]

In the current study, we focused on five main variables: (1) target type, (2) multiple target types, (3) weapon type, (4) multiple weapon types, and (5) # of offenders. These variables were selected given their prevalence in research focused on the incident characteristics of extremist violence.[20] Furthermore, while other variables could have been assessed (e.g., attack planning), the five variables examined in this study are advantageous since they require little interpretation and subsequently minimize any potential reliability issues.[21] For both the target type and weapon type variables, we employed the attributes used to code incidents in the Global Terrorism Database (GTD).[22] Target type is a categorical variable representing the general type of target or intended victim of the attack. Although the GTD houses 22 different target types, only seven emerged in this study, including: (1) police, (2) private citizens, (3) government general, (4) business, (5) religious institutions, (6) utilities, and (7) unknown. Multiple target types is a binary measure representing whether the offender attacked or planned to attack more than one target type during a single incident (1 = multiple incidents). For example, during the early morning hours of April 24, 2019, Daniel Hector Mackinnon, a suspected AVE, set fire to the home of a San Diego real estate agent and a Raytheon building. This incident was coded as including multiple targets since the offender targeted a private civilian and a business.

Weapon type is a categorical variable representing the primary type of weapon used in each incident. The GTD includes 13 different weapon type categories; however, only eight were found in this study, including: (1) firearms, (2) explosives, (3) no weapon, (4) incendiary device, (5) melee, (6) vehicle, (7) sabotage equipment, and (8) unknown. Multiple weapon types is a binary measure representing whether the offender used or planned to use more than one weapon type during a single incident (1 = multiple weapon types). For example, Willem Van Spronsen, an alleged AVE, was shot and killed by law enforcement after throwing Molotov cocktails and attempting to ignite a propane tank at an ICE detention center in Washington state. This incident was classified as involving multiple weapon types since Van Spronsen was armed with a rifle in addition to the incendiary devices. Finally, # of offenders is a categorical measure reflecting the total number of offenders involved or plan to be involved in the attack. Incidents were coded as including, (1) one offender, (2) two offenders, (3) three offenders, (4) four or more offenders, or (5) unknown.

Our analysis seeks to descriptively capture patterns of target selection, weapon choice, and co-offending associated with significant acts of domestic anti-government/anti-authority violent extremism. Given the limited sample size coupled with the exploratory nature of this research note, intent is simply to describe the nature of the incident-level data within and across the different types of anti-government/anti-authority extremism.

The findings are broken into two parts. First, we assess similarities in the incident characteristics across the three subtypes of domestic anti-government/anti-authority violent extremism. Second, we explore incident-level differences across the three ideological subtypes.

Findings

Table 1 presents descriptive statistics for the target type, weapon type, and number of offenders for 59 significant incidents of anti-government/anti-authority extremism between 2015 and 2022. There are three attack characteristics that are relatively similar across the three violent extremist subtypes to discuss. First, Table 1 suggests that many significant acts of anti-government/anti-authority extremism targeted police. Collectively, police were targeted in just under half (44 percent) of all significant government/anti-authority extremism incidents, which was more than double any other target type. When examining target selection across the individual subtypes, police were the most frequently attacked target for AVEs (44 percent), SCVEs (69 percent), and MVEs (30 percent). The disproportionate focus on law enforcement among anti-government/anti-authority extremists likely reflects the core ideological view that police are enforcers of an unjust, illegitimate government.

Second, Table 1 indicates that few significant incidents of anti-government/anti-authority extremism attacked or planned to attack multiple target types (14 percent) or use multiple weapon types (12 percent). In other words, most incidents focused on a single target type and utilized a single weapon type. Across the three subtypes, Table 1 shows that AVEs were the most likely to target more than one target type (25 percent) or utilize multiple weapon types (19 percent), whereas SCVEs were the least likely to engage multiple target types (6 percent) or weapon types (0 percent).

Third, Table 1 illustrates that most significant anti-government/anti-authority extremist incidents involved or planned to involve one offender (75 percent). Across the three subtypes, attacks associated with SCVEs were the most likely to involve a lone actor (81 percent), followed by AVEs (75 percent) and MVEs (70 percent). This finding is consistent with the notion that lone actor attacks have become more prevalent over the last several years in the United States.[23] This may be, in part, because lone offending offers a greater opportunity for operational success since there is less opportunity for leakage and subsequent detection and disruption.[24]

Table 1. Comparison of Attack Characteristics Across Anti-Government/Anti-Authority Ideological Subtypes
	All Types (n = 59)		AVE (n = 16)		SCVE (n = 16)		MVE (n = 27)
Variable	f	%	f	%	f	%	f	%
Target Type
Police	26	44	7	44	11	69	8	30
Private Citizens	10	17	3	19	1	6	6	22
Government General	9	15	0	0	3	19	6	22
Business	7	12	4	25	0	0	3	11
Religious Institutions	2	3	0	0	0	0	2	7
Utilities	1	2	1	6	0	0	0	0
Unknown	4	7	1	6	1	6	2	7
Multiple Target Types	8	14	4	25	1	6	3	11
Weapon Type
Firearms	18	31	2	13	8	50	8	30
Explosives	13	22	3	19	0	0	10	37
No Weapon	15	25	3	19	6	38	6	22
Incendiary Device	8	14	7	44	0	0	1	4
Melee	2	3	0	0	2	13	0	0
Vehicle	1	2	0	0	0	0	1	4
Sabotage Equipment	1	2	1	6	0	0	0	0
Unknown	1	2	0	0	0	0	1	4
Multiple Weapon Types	7	12	3	19	0	0	4	15
# of Offenders
One	44	75	12	75	13	81	19	70
Two	7	12	2	13	2	13	3	11
Three	5	8	0	0	1	6	4	15
> Four	2	3	1	6	0	0	1	4
Unknown	1	2	1	6	0	0	0	0

Despite these commonalties, Table 1 also highlights two notable differences across the three types of anti-government/anti-authority extremism at the incident level. First, MVE incidents had a greater degree of target diversity compared to AVE or SCVE attacks. Specifically, no single target type accounted for more than one-third of significant MVE incidents. In relation to tactical diversity, MVE incidents were also spread across targets typically classified as hard targets, such as police (30 percent) and government targets (22 percent) as well as those often classified as soft targets, such as private citizens (22 percent), businesses (11 percent), and religious institutions (11 percent). In many ways, AVE incidents had a similar degree of diversity in target choice. For example, significant AVE attacks targeted hard targets like police (44 percent) as well as soft targets, including businesses (25 percent) and private citizens (19 percent). SCVE incidents had very little diversity in target selection with steadfast focus on hard targets, including police (69 percent) and government officials (19 percent).

Second, the results suggest that the type of weapon employed varied across the three ideological subtypes. For example, the majority of AVE incidents involved an incendiary device (44 percent), explosives (19 percent), or no weapon (19 percent). The use of incendiary devices, such as Molotov cocktails, illustrates that AVEs are similar to other variations of left-wing extremism, which have general preference for fire setting.[25] For AVEs, the use of incendiary devices is beneficial in that they can be used against a wide range of targets, are easy to hide and handle, simple to use, and require little training to develop and use.[26]

 In contrast, SCVE incidents were likely to use firearms (50 percent) or no weapon (38 percent). For SCVEs, firearms are imperative to their extremist identity or group values surrounding self-protection and self-reliance.[27] That said, the actual use of firearms among SCVEs, particularly against law enforcement, reflects circumstance and opportunity. Since sovereigns engage in a variety of illicit forms of protest against the government (e.g., license plate forgeries), confrontation with law enforcement is somewhat inevitable. In many cases, however, simple traffic stops turn deadly when sovereigns engage in confrontational and conflict-oriented tactics, such as refusing to roll down their vehicle’s window or refusing to answer questions, resulting in law enforcement having to escalate their use of force.[28] Consequently, these encounters can turn lethal when considering sovereigns’ propensity to carry firearms coupled with their view of law enforcement as unjust and illegitimate.

Finally, weapons selection among MVE incidents was the most diverse with most attacks, or would-be attacks, involving explosives (37 percent), firearms (30 percent), or no weapon (22 percent). The use of explosives among significant MVE incidents likely reflects the heightened levels of tactical expertise found among MVE groups. For instance, MVE groups, such as the Oath Keepers, are characterized by their organization and group training, often focusing on implementing military and law enforcement tactics, weapons training, and recruitment from individuals with militia training.[29] Research has shown that even the most rudimentary explosives require operational training to successfully construct and detonate.[30] We suspect that MVE incidents use explosives at a higher rate than AVE or SCVE incidents because they have the tactical knowledge embedded within the group to do so. Similar to SCVEs, firearms usage among MVEs revolves around their values of self-protection and self-reliance as well as the accessibility of firearms compared to other weapon types.

Discussion and Conclusions

The goal of this research note was to examine the incident-level characteristics associated with significant acts of domestic anti-government/anti-authority violent extremism. Given the recent categorization of AVEs, SCVEs, and MVEs under the anti-government/anti-authority violent extremism umbrella, we were particularly interested in determining if, and how, the three subtypes shared a tactical profile. In general, our findings suggest that AVEs, SCVEs, and MVEs were relatively similar across most incident-level metrics, including target selection, multiple target types, multiple weapon types, and number of offenders. Based on our analysis, it appears that significant acts of anti-government/anti-authority violent extremism target law enforcement and involve one offender.

The preference of targeting law enforcement among anti-government/anti-authority violent extremism is generally consistent with the idea that target selection decisions for extremists is largely shaped by ideology.[31] Law enforcement not only represents the state, but successful attacks directly harm those tasks with enforcing the unjust laws put forth by the state. Put another way, law enforcement is an attractive target given their symbolic representation of the state and its capacity to use force.[32] Next, the preference of lone offending among anti-government/anti-authority violent extremists is likely driven by practical concerns over the chance of detection and arrest while offending.[33] Without co-offenders, there is less opportunity for leakage and infiltration by law enforcement.

The primary difference among the three types of anti-government/anti-authority violent extremism revolved around the type of weapon used during an attack. In other words, there was relative consistency in who AVEs, SCVEs, and MVEs targeted, but differences in how weapons were used (see Figure 2). While AVEs seemingly preferred the use of incendiary devices, SCVEs favored firearms, and MVEs drew from a mix of weaponry. These differences in weapon type show that the anti-government/anti-authority violent extremism typology is not uniform at the incident level and that nuances exist between how the different ideological subtypes attack their targets.

Despite the contribution of this study, there are at least three limitations to bear in mind. First and foremost, our sample is relatively small and only included incidents between 2015 through 2022 that were identified as “significant acts of domestic terrorism” by the FBI and DHS. As such, findings are not generalizable to all acts of anti-government/anti-authority violent extremism. Moreover, there are no objective criteria (e.g., number of fatalities) illustrating what makes an act of domestic terrorism significant. It is possible that the incidents defined as significant reflect the predispositions of those working in the counterterrorism field. Second, we only examine a narrow set of characteristics in this study and do not cover the full range of incident-level characteristics examined in previous research. Third, our results are descriptive and do not include higher order statistical techniques necessary to test differences nor causation. However, given the novelty of this research, coupled with the small sample size, descriptive statistics are appropriate for this study.

Findings from this research note offer at least two practical implications to homeland security professionals. First, our findings illustrate that there is some utility in classifying AVEs, SCVEs, and MVEs together under the broader anti-government/anti-authority extremism threat category. Based on the incident-level characteristics, significant acts of anti-government/anti-authority extremism primarily target government representatives, particularly law enforcement. In a recent special issue on anti-government extremism, Bjørgo and Braddock summarize that anti-government extremism “finds different expressions in terms of organizational formations, conspiracy theories, collective action, and violence and threats against politicians and government representatives.”[34] Our findings demonstrate that expressing anti-government extremism via violence and threats against politicians and government representatives is shared among AVEs, SCVEs, and MVEs. Second, findings from this study can be used for training local law enforcement about threats posed by anti-government/anti-authority extremism in their area of responsibility. For example, a training program designed for law enforcement in areas with an increasing number of SCVEs may focus on the threat of violence during traffic stops or serving a warrant. In contrast, a training program in a region where the threat of AVEs is high might focus on identifying and reducing the risk of improvised incendiary devices.

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About the Authors

Michael K. Logan, Assistant Professor, Department of Sociology and Criminal Justice, Kennesaw State University, mlogan21@kennesaw.edu

Clara Braun, Research Scientist, REJIS

Seamus Hughes, Senior Research Faculty, National Counterterrorism, Innovation, Technology, & Education Center, University of Nebraska Omaha

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Bibliography

Allison, Benjamin V. “The Devil’s in the Details—or Is He? The Ethics and Politics of Terrorism Data.” Perspectives on Terrorism 15, no. 2 (2021): 125-141.

Barnum, Timothy C., and Michael K. Logan. “Radicalized Environmental Extremism and Situational Decision Making.” Journal of Research in Crime and Delinquency (2023): Advanced online publication.

Berger, J. M. Without Prejudice: What Sovereign Citizens Believe. Washington DC:Program on Extremism at George Washington University (2016).

Bjørgo, Tore, and Kurt Braddock. “Anti-Government Extremism.” Perspectives on Terrorism 16, no. 6 (2022): 2-8.

Borum, Randy, and Chuck Tilby. “Anarchist Direct Actions: A Challenge for Law Enforcement.” Studies in Conflict & Terrorism 28, no. 3 (2005): 201-223.

Carson, Jennifer Varriale, Gary LaFree, and Laura Dugan. “Terrorist and Non-Terrorist Criminal Attacks by Radical Environmental and Animal Rights Groups in the United States, 1970–2007.” Terrorism and Political Violence 24, no. 2 (2012): 295-319.

Drake, C.J.M. “The Role of Ideology in Terrorists’ Target Selection,” Terrorism and Political Violence 10, (1998): 53–85.

Dudenhoefer, Anne-Lynn, Charlotte Niesse, Thomas Görgen, Laura Tampe, Marcella Megler, Christina Gröpler, and Rebecca Bondü. “Leaking in Terrorist Attacks: A Review.” Aggression and Violent Behavior 58, (2021): 101582.

Federal Bureau of Investigation and Department of Homeland Security. Strategic Intelligence Assessment and Data on Domestic Terrorism. Washington, DC: Federal Bureau of Investigation and Department of Homeland Security, 2021. https://www.fbi.gov/file-repository/fbi-dhs-domestic-terrorism-strategic-report.pdf/view.

Federal Bureau of Investigation and Department of Homeland Security. Strategic Intelligence Assessment and Data on Domestic Terrorism. Washington, DC: Federal Bureau of Investigation and Department of Homeland Security, 2022. https://www.fbi.gov/file-repository/fbi-dhs-domestic-terrorism-strategic-report-2022.pdf/view.

Federal Bureau of Investigation and Department of Homeland Security. Strategic Intelligence Assessment and Data on Domestic Terrorism. Washington, DC: Federal Bureau of Investigation and Department of Homeland Security, 2023. https://www.fbi.gov/file-repository/fbi-dhs-domestic-terrorism-strategic-report-2023.pdf/view.

Freilich, Joshua D., Steven M. Chermak, Roberta Belli, Jeff Gruenewald, and William S. Parkin. “Introducing the United States Extremis Crime Database (ECDB).” Terrorism and Political Violence 26, no. 2 (2014): 372-384.

Gartenstein-Ross, Daveed, Colin P. Clarke, and Samuel Hodgson. Militia Violent Extremists in the United States: Understanding the Evolution of the Threat. The Hague: International Centre for Counter-Terrorism, 2022.

Gibbs, Jennifer C., James Ruiz, and Sarah Anne Klapper-Lehman. “Police Officers Killed on Duty: Replicating and Extending a Unique Look at Officer Deaths.” International Journal of Police Science & Management 16, no. 4 (2014): 277-287.

Gill, Paul. “Tactical Innovation and the Provisional Irish Republican Army.” Studies in Conflict & Terrorism 40, no. 7 (2017): 573-585.

Gruenewald, Jeff, Kayla Allison-Gruenewald, and Brent R. Klein. “Assessing the Attractiveness and Vulnerability of Eco-Terrorism Targets: A Situational Crime Prevention Approach.” Studies in Conflict & Terrorism 38, no. 6 (2015): 433-455.

Gruenewald, Jeff, Kiefer Michael G. Dooley, Michael J. Suttmoeller, Steven M. Chermak, and Joshua D. Freilich. “A Mixed-Method Analysis of Fatal Attacks on Police by Far-Right Extremists.” Police Quarterly 19, no. 2 (2016): 216-245.

Haberl, Ferdinand J. “The Weapons of Choice: Terrorist Armament Culture and The Use of Firearms in Online Propaganda and Identity-Building Through Cyberspace.” Proceedings of the European Conference on Information Warfare and Security, (2020): 126-135.

Hall, Abigail R., Jerod T. Hassell, and Chivon H. Fitch. “Militarized Extremism.” The Independent Review 26, no. 2 (2021): 225-242.

Jackson, Sam. Conspiracy Theories in the Patriot/Militia Movement. Washington, DC: Program on Extremism at George Washington University, (2017).

Jackson, Sam. Oath Keepers: Patriotism and the Edge of Violence in a Right-Wing Antigovernment Group. New York: Columbia University Press, 2020.

LaFree, Gary, and Laura Dugan. “Introducing the Global Terrorism Database.” Terrorism and Political Violence 19, no. 2 (2007): 181-204.

Loadenthal, Michael. ““Eco-Terrorism”: An Incident-Driven History of Attack (1973–2010).” Journal for the Study of Radicalism 11, no. 2 (2017): 1-34.

Loeser, Charles E. “From Paper Terrorists to Cop Killers: The Sovereign Citizen Threat.” North Carolina Law Review 93, (2014): 1106-1139.

Logan, Michael K., and Gina S. Ligon. “Come One, Come All: Individual-Level Diversity among Anti-Fascists.” Dynamics of Asymmetric Conflict 14, no. 2 (2021): 209-224.

Lundberg, Russell. “Archetypal Terrorist Events in the United States.” Studies in Conflict & Terrorism 42, no. 9 (2019): 819-835.

Mandala, Marissa, and Joshua D. Freilich. “Disrupting Terrorist Assassinations Through Situational Crime Prevention.” Crime & Delinquency 64, no. 12 (2018): 1515-1537.

Muibu, Daisy, and Benjamin P. Nickels. “Foreign Technology or Local Expertise? Al-Shabaab’s IED Capability.” CTC Sentinel 10, no. 10 (2017): 33-37.

Perry, Barbara, David Hofmann, and Ryan Scrivens. “Anti-Authority and Militia Movements in Canada.” The Journal of Intelligence, Conflict, and Warfare 1, no. 3 (2019): 1-26.

Phillips, Brian J. “Deadlier in the US? On Lone Wolves, Terrorist Groups, and Attack Lethality.” Terrorism and Political Violence 29, no. 3 (2017): 533-549.

Rose, Miss Menna, and John Morrison. “An Exploratory Analysis of Leakage Warning Behavior in Lone-Actor Terrorists.” Behavioral Sciences of Terrorism and Political Aggression 15, no. 2 (2023): 179-214.

Sarteschi, Christine M. “Sovereign Citizens: A Narrative Review with Implications of Violence Towards Law Enforcement.” Aggression and Violent Behavior 60, (2021). https://doi.org/10.1016/j.avb.2020.101509

Smith, Brent L., Paxton Roberts, Jeff Gruenewald, and B. Klein. Patterns of Lone Actor Terrorism in the United States: Research Brief. College Park, MD: National Consortium for the Study of Terrorism and Responses to Terrorism, 2014.

Sullivan, Brandon A., Joshua D. Freilich, and Steven M. Chermak. “An Examination of the American Far Right’s Anti-Tax Financial Crimes.” Criminal Justice Review 44, no. 4 (2019): 492-514.

Williams, Dana M. “Contemporary Anarchist and Anarchistic Movements.” Sociology Compass 12, no. 6 (2018).

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Notes

[1] Each of the domestic terrorism incidents examined in this study were identified as “significant” by counterterrorism professionals at the FBI and DHS. No definition nor criteria of what made a domestic terrorism incident “significant” was offered in the report.

[2] Federal Bureau of Investigation and Department of Homeland Security, Strategic Intelligence Assessment and Data on Domestic Terrorism (Washington, DC: Federal Bureau of Investigation and Department of Homeland Security, 2021, 2022, 2023).

[3] No conceptual definition of what made a domestic terrorism incident “significant” was offered in the report.

[4] Benjamin V. Allison, “The Devil’s in the Details—or Is He? The Ethics and Politics of Terrorism Data,” Perspectives on Terrorism 15, no. 2 (2021): 125-141

[5] Lundberg, Russell. “Archetypal terrorist events in the United States.” Studies in Conflict & Terrorism 42, no. 9 (2019): 820.

[6] Borum, Randy, and Chuck Tilby. “Anarchist direct actions: A challenge for law enforcement.” Studies in Conflict & Terrorism28, no. 3 (2005): 201-223; Williams, Dana M. “Contemporary anarchist and anarchistic movements.” Sociology Compass 12, no. 6 (2018)

[7] ibid

[8] Sarteschi, Christine M. “Sovereign citizens: A narrative review with implications of violence towards law enforcement.” Aggression and Violent Behavior 60 (2021). https://doi.org/10.1016/j.avb.2020.101509

[9] Loeser, Charles E. “From paper terrorists to cop killers: The sovereign citizen threat.” North Carolina LawL Review. 93 (2014): 1106-1139

[10] Sullivan, Brandon A., Joshua D. Freilich, and Steven M. Chermak. “An examination of the American far right’s anti-tax financial crimes.” Criminal Justice Review 44, no. 4 (2019): 492-514.

[11] Berger, J. M. “Without prejudice: What sovereign citizens believe.”  Program on Extremism at George Washington University (2016).

[12] Gruenewald, Jeff, Kiefer Michael G. Dooley, Michael J. Suttmoeller, Steven M. Chermak, and Joshua D. Freilich. “A mixed-method analysis of fatal attacks on police by far-right extremists.” Police Quarterly 19, no. 2 (2016): 216-245.

[13] Sarteschi, Christine M. “Sovereign citizens: A narrative review with implications of violence towards law enforcement.” Aggression and Violent Behavior 60 (2021). https://doi.org/10.1016/j.avb.2020.101509

[14] FBI & DHS (May 2021). Strategic Intelligence Assessment and Data on Domestic Terrorism

[15] Jackson, Sam. “Conspiracy theories in the patriot/militia movement.” Program on Extremism at George Washington University  (2017); Perry, Barbara, David Hofmann, and Ryan Scrivens. “Anti-Authority and Militia Movements in Canada.” The Journal of Intelligence, Conflict, and Warfare 1, no. 3 (2019): 1-26.

[16] Jackson, Sam. “Conspiracy theories in the patriot/militia movement.” Program on Extremism at George Washington University (2017).

[17] Gartenstein-Ross, Daveed, Colin P. Clarke, and Samuel Hodgson. “Militia Violent Extremists in the United States: Understanding the Evolution of the Threat.” International Centre for Counter-Terrorism (2022); Jackson, Sam. Oath Keepers: Patriotism and the edge of violence in a right-wing antigovernment group. Columbia University Press, 2020.

[18] The Strategic Intelligence Assessment and Data on Domestic Terrorism published in May 2021 included twenty-nine cases of anti-government/anti-authority violent extremism. However, two cases were removed, including the 2017 Berkeley protests and the occupation of the Malheur National Wildlife Refuge in 2016, since these incidents included several different criminal actors and events making them difficult to compare to the other incidents.

[19] Freilich, Joshua D., Steven M. Chermak, Roberta Belli, Jeff Gruenewald, and William S. Parkin. “Introducing the United States extremis crime database (ECDB).” Terrorism and Political Violence 26, no. 2 (2014): 372-384.372-384; LaFree, Gary, and Laura Dugan. “Introducing the global terrorism database.” Terrorism and Political Violence 19, no. 2 (2007): 181-204; Logan, Michael K., and Gina S. Ligon. “Come one, come all: individual-level diversity among anti-fascists.” Dynamics of Asymmetric Conflict 14, no. 2 (2021): 209-224.

[20] Gruenewald, Jeff, Kayla Allison-Gruenewald, and Brent R. Klein. “Assessing the attractiveness and vulnerability of eco-terrorism targets: A situational crime prevention approach.” Studies in Conflict & Terrorism 38, no. 6 (2015): 433-455; Mandala, Marissa, and Joshua D. Freilich. “Disrupting terrorist assassinations through situational crime prevention.” Crime & Delinquency 64, no. 12 (2018): 1515-1537.

[21] Each incident was coded by the first author of the study.

[22] LaFree, Gary, and Laura Dugan. “Introducing the global terrorism database.” Terrorism and Political Violence 19, no. 2 (2007): 181-204.

[23] Phillips, Brian J. “Deadlier in the US? On lone wolves, terrorist groups, and attack lethality.” Terrorism and Political Violence 29, no. 3 (2017): 533-549.

[24] Dudenhoefer, Anne-Lynn, Charlotte Niesse, Thomas Görgen, Laura Tampe, Marcella Megler, Christina Gröpler, and Rebecca Bondü. “Leaking in terrorist attacks: A review.” Aggression and Violent Behavior 58 (2021): 101582; Rose, Miss Menna, and John Morrison. “An exploratory analysis of leakage warning behavior in lone-actor terrorists.” Behavioral Sciences of Terrorism and Political Aggression 15, no. 2 (2023): 179-214.

[25] Carson, Jennifer Varriale, Gary LaFree, and Laura Dugan. “Terrorist and non-terrorist criminal attacks by radical environmental and animal rights groups in the United States, 1970–2007.” Terrorism and Political Violence 24, no. 2 (2012): 295-319; Loadenthal, Michael. ““Eco-Terrorism”: An Incident-Driven History of Attack (1973–2010).” Journal for the Study of Radicalism 11, no. 2 (2017): 1-34.

[26] Barnum, Timothy C., and Michael K. Logan. “Radicalized Environmental Extremism and Situational Decision Making.” Journal of Research in Crime and Delinquency (2023): Advanced Online Publication

[27] Haberl, Ferdinand J. “The weapons of choice: Terrorist armament culture and the use of firearms in online propaganda and identity-building through cyberspace.” In Proceedings of the European Conference on Information Warfare and Security, ECCWS, pp. 126-135. 2020.

[28] Sarteschi, Christine M. “Sovereign citizens: A narrative review with implications of violence towards law enforcement.” Aggression and Violent Behavior 60 (2021). https://doi.org/10.1016/j.avb.2020.101509

[29] Hall, Abigail R., Jerod T. Hassell, and Chivon H. Fitch. “Militarized Extremism.” The Independent Review 26, no. 2 (2021): 225-242; Jackson, Sam. Oath Keepers: Patriotism and the Edge of Violence in a Right-Wing Antigovernment Group. Columbia University Press, 2020.

[30] Gill, Paul. “Tactical innovation and the provisional Irish Republican Army.” Studies in Conflict & Terrorism 40, no. 7 (2017): 573-585;  Muibu, Daisy, and Benjamin P. Nickels. “Foreign technology or local expertise? Al-Shabaab’s IED capability.” CTC Sentinel 10, no. 10 (2017): 33-37.

[31] C. J. M. Drake, “The Role of Ideology in Terrorists’ Target Selection,” Terrorism and Political Violence 10 (1998), pp. 53–85

[32] Gibbs, Jennifer C., James Ruiz, and Sarah Anne Klapper-Lehman. “Police officers killed on duty: Replicating and extending a unique look at officer deaths.” International Journal of Police Science & Management 16, no. 4 (2014): 277-287.

[33] Smith, Brent L., Paxton Roberts, Jeff Gruenewald, and B. Klein. “Patterns of lone actor terrorism in the United States: research brief.” National Consortium for the Study of Terrorism and Responses to Terrorism (2014).

[34] Bjørgo, Tore, and Kurt Braddock. “Anti-Government Extremism.” Perspectives on Terrorism 16, no. 6 (2022): 2-8.

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