Abstract: Among the United States’ 237 Islamic State-linked federal cases to date, the nexus between crime and terrorism has a subtle but vital impact on law enforcement’s counterterrorism efforts, and provides both challenges and opportunities. Drawing from new and old cases, this article examines the criminal history of every federal Islamic State defendant and deceased attack perpetrator and highlights the consistent prevalence of past violent crimes. It evaluates criminality that was integral to the financing or logistics of Islamic State activity in the United States, and assesses the role of gangs and prison on defendants’ and perpetrators’ pathways to terrorism. Moving beyond the Islamic State, the crime-terror nexus appears more pronounced in other parts of the ideological spectrum, particularly for racially and ethnically motivated violent extremists in the United States, underscoring its potential wider salience for practitioners and researchers.
Jason Brown, the leader of the Chicago-area “AHK” street gang that was heavily involved in drug trafficking, was sent to prison for a June 2016 gang-related firearms offense. Search warrants obtained for Brown’s seized phones revealed extensive communication with Jamaican jihadi ideologue Sheikh Abdullah el-Faisal, and that Brown regularly visited Faisal’s extremist “Authentic Tauheed” online forum in the month prior to his firearms arrest.1 Brown’s time in a Georgia state prison and his communication prior to that with Faisal both reportedly contributed to his radicalization.2 Upon his release from prison in June 2018, Brown, who also used the name Abdul Ja’Me, forced fellow gang members to convert to Islam and distributed Islamic State propaganda to them while using his leadership position to recruit and radicalize new gang members to support the Islamic State as part of his own personal “jihad.”3 Brown, who had plans to travel to Syria, was ultimately arrested in November 2019 for sending money overseas that he believed was intended to support the Islamic State, while six fellow gang members were concurrently arrested for drug trafficking.4 a Brown’s case is a vivid U.S. example of the nexus between crime, prison, gangs, and terrorism seen more often in the European context.
Extensive prior research has revealed that those involved in devastating Islamic State attacks in Europe in the last decade often had lengthy criminal records and were involved in criminal networks that fundraised for an attack or facilitated travel of aspiring foreign fighters.5 Prior involvement in crime provided perpetrators with plot-relevant know-how, and relationships forged through street crime, gangs, or in prison were instrumental in the recruitment, radicalization, planning, and preparation for attacks. Some of Europe’s most lethal Islamic State attacks have been the result of the convergence of criminal and terrorist networks at the grassroots level.6
This phenomenon differs from formal organizational collaboration or alliance formation between criminal and terrorist groups often found in areas of weak state governance.7 It is more individualized, fluid, and unstructured than formalized organizational collaboration.8 Salman Abedi, the perpetrator of the 2017 Manchester Arena suicide bombing, was aided by associates who were members of a British-Libyan drug trafficking gang in south Manchester. One gang member allowed Abedi to store a vehicle packed with explosive materials at his residence; another “wiped down” the vehicle in the wake of the bombing; and two others, each with extensive criminal pasts and one of whom was later arrested for fraud, allegedly assisted Abedi in the research and procurement of chemicals used to build the bomb.9 Several members of the gang allegedly had combat experience in Libya’s civil war, others had visited a convicted Libyan jihadi imprisoned in the United Kingdom prior to the attack, while Abedi’s father had reported ties to senior Libyan jihadi figures.10 Abedi and his brother also likely used a student loan and public benefits fraud to fund the attack.11 At the official government inquest after the bombing, it was revealed that the security services had expressed concern with the “close proximity” of gangs and violent extremists in south Manchester and the difficulty distinguishing gang-related drug-dealing and fraud from that of national security interest.12 Elsewhere, the perpetrators of the November 2015 Paris attacks leveraged a fraudulent document ring led by a criminal underworld figure to procure identity cards used to travel, wire funds, rent getaway vehicles, and acquire safehouses for preparing the attack.13 In December 2020, a French court convicted 14 people for involvement in the January 2015 attacks in Paris on the Charlie Hebdo office and the Hypercacher kosher supermarket. At least seven of those 14 were also found guilty of being members of criminal networks in Lille, France, and Ardennes, Belgium, that procured firearms used in the attack or provided logistical or financial support to the perpetrators.14
Based on Europe’s experience, the crime-terror nexus can be conceptualized as involving four components. First, those involved in terrorist activity often had a prior criminal record. Second, crime was utilized to finance or logistically support terrorism. Third, some of those involved in terrorist activity were involved with street gangs; and fourthly, some served time in prison—often regarded as “melting pots” where criminal and terrorist networks converge—where relevant skills were acquired, members were radicalized, and relationships of utility for the future attack were developed.15
While the prevalence of criminal history and plot-relevant criminal activity in the U.S. Islamic State cases is indeed less pronounced than in Europe, a number of important trends and practical considerations are evident that inform the crime-terror nexus. This article updates a larger study by the author that assessed the interplay of crime and terrorism in U.S. Islamic State cases and ultimately illustrated how the U.S. experience acts as a counterpoint to Europe.16 This article updates the original dataset, which examined the criminal past of every publicly identified individual charged in U.S. federal court for activity associated with the Islamic State up until June 1, 2020, by including two more years of cases. The updated dataset comprises 237 individuals, including all 227 federal Islamic State defendants and all 10 individuals killed by law enforcement while carrying out Islamic State-related attacks in the United States, from the first case brought by the U.S. Department of Justice in March 2014 to June 1, 2022.b All data and defendant criminal records were ascertained from Justice Department documents, official court records, and open-source accounts.c
This article reviews developments in the crime-terror nexus, drawing from new and old Islamic State cases. It provides an updated examination of the criminal histories of U.S. Islamic State defendants, looks at the recurrence of repeat criminal offenders, and highlights the consistent prevalence of violent crimes, especially domestic violence and firearm offenses, among individuals in the dataset. It examines criminality that was integral to the financing or logistics of Islamic State activity in the United States and assesses the role of gangs and prison on defendants’ pathways to terrorism. Moving beyond the Islamic State, it suggests that the crime-terror nexus appears more pronounced in other parts of the ideological spectrum, particularly for racially and ethnically motivated violent extremists (REMVEs) in the United States. While a systematic examination of right-wing extremist cases is beyond this article’s scope, it intends to highlight avenues for future research so that scholars and practitioners may endeavor to better understand the relevance and wider salience of the crime-terror nexus in the United States. This article will now examine, in turn, the four components of the crime-terror nexus relating to U.S. Islamic State cases before discussing the crime-terror nexus in U.S. REMVE cases and providing some practical implications and conclusions.
In the wake of a terrorist incident, a dreaded realization for counterterrorism practitioners may be that the perpetrator was “known to law enforcement” due to the presence of a criminal record or prior interactions with police. It is conventional wisdom in law enforcement that while prior arrests do not directly predict a subject’s risk, arrest records are a valuable tool and source of information for counterterrorism analysts and investigators that can shed light on prior violent behavior.17 Criminologists have long regarded criminal history to be one of the best predictors of future criminal activity.18 One of the few studies to explore the relationship between criminal history and involvement in terrorism (published in Criminology in 2018) found that those with a criminal record were more likely than those with no criminal record to engage in violent political extremism (terrorism), and ultimately concluded that a criminal history is a reliable predictor for future engagement in violent extremist behavior.19
In the United States, 31 percent of Islamic State defendants and perpetrators killed in an attack have a prior criminal record, defined as having at least one arrest by a law enforcement agency (73 of 237). This trend has remained relatively consistent as the number of Islamic State cases rose between March 2014 and June 2022 (though the rate of cases has slowed in recent years as the group has declined in Syria): In 2016, 28 percent of all Islamic State defendants had prior criminal histories;20 in 2017, 26 percent;21 and in 2020, 32 percent.d As of June 2022, more than half (53 percent) had no criminal history. The records of the remaining 16 percent could not be determined due to a lack of open-source data.
Many U.S. Islamic State defendants were repeat criminal offenders: 63 percent (38) of defendants with a criminal recorde had more than one prior arrest, which means there is a likelihood of recurrent contact with law enforcement that provides additional data points for counterterrorism investigators attempting to gain an understanding of a subject of concern’s propensity for violence. The average number of prior arrests per U.S. Islamic State defendant with a criminal record remains approximately three per defendant. A non-trivial percentage of U.S. Islamic State defendants appear to have a fairly lengthy criminal background, with 28 percent (17) of those with a criminal record having at least three arrests, which includes 10 defendants with more than six arrests and several with 11-14 arrests.f
Criminological studies that examined the prevalence of a criminal record over different timeframes in the general U.S. adult population found that roughly one-quarter to one-third had at least one arrest.22 This indicates that the prevalence of a criminal record in U.S. Islamic State cases (31 percent) does not differ significantly from national averages in the United States. However, not all criminality should be considered equal. The nature and type of criminal history of an individual exhibiting signs of extremism or radicalization can be a more important diagnostic indicator for counterterrorism investigators than the presence of criminal history alone, and may enable investigators to paint a more complete picture of a subject, recognize signs of mobilization, and better gauge the subject’s propensity for violence.g
Twenty percent (47) of all U.S. Islamic State defendants have a history of violent crime. This signifies that two-thirds (64 percent) of defendants with a criminal record have at least one previous arrest for a violent crime.h Many defendants were arrested for both violent and non-violent crimes. One-third (36 percent) of defendants with a criminal record had previously been arrested for only non-violent crimes.
Nationwide, federal repeat offenders with prior violent offenses recidivate at a higher rate and are more likely than repeat offenders with non-violent prior offenses to commit a violent offense in the future.23 For law enforcement, the prevalence of violent crime in the Islamic State dataset has analytical and investigative importance, as an individual’s demonstrated proclivity to resort to violence may suggest an enhanced risk of future violence.24 This is informed by existing criminological research that found that violent criminal history is predictive of subsequently more severe behavior.25 The 2018 Criminology study that examined the relationship between crime and terrorism found that individuals with a criminal history prior to radicalization (regardless of whether the crime was violent or non-violent) are more likely to attempt or commit an act of violence post-radicalization.26
Several violent crimes remain consistently prevalent in the criminal history of the U.S. Islamic State defendants. One-third (36 percent) of all Islamic State defendants with a criminal history had prior arrests for domestic abuse and/or assault, which correlates to 11 percent of all Islamic State defendants.i Domestic violence appears to be somewhat correlated with additional criminal history: In all but one case, a defendant with a domestic violence history had at least one additional arrest for another violent crime.j Academic literature on the psychology of terrorism has pointed to the pervasiveness of domestic abuse and family violence in the personal history of terrorist offenders.27 The National Counterterrorism Center (NCTC) has noted that “outbursts/fights with family, peers, or authority figures, while advocating violent extremist ideology” and “outbursts or behavior, including violent behavior, or advocacy that results in exclusion or rejection by family or community” are both observable long-term indicators of concern.28
Ahmad Rahami, the perpetrator of the 2016 bombings in New York City and New Jersey who was sentenced to life in prison, was previously involved in two domestic incidents, including one called in to local police in Elizabeth, New Jersey, by his own father. In the 2014 dispute, Rahami stabbed a family member in the leg with a knife, which resulted in a three-month imprisonment. The incident occurred three months after Rahami returned from a year-long trip to Pakistan and coincided around the time Rahami’s father raised concerns to the FBI about his son’s possible radicalization.29
Just a few hundred miles away in Lackawanna, New York, Arafat Nagi, who in 2018 was sentenced to 15 years in prison for attempting to provide material support and resources to the Islamic State,30 had been involved in two domestic incidents. In the second incident which occurred in 2013, he threatened to kill and behead his daughter while brandishing a military-style knife outside the family home.31 In 2014, around a year after the second domestic incident, a community member reported to the FBI that Nagi spoke often about violent jihad and that he commonly got into verbal disputes over his jihadi beliefs with community members. His history of domestic violence (and specific statements regarding beheadings) provides context to the accusations. It was later revealed that Nagi had pledged allegiance to the Islamic State, traveled to Turkey in 2012 and 2014 to meet Islamic State members, and had purchased military combat items.32
In 2021, NCTC updated its assessment of violent extremist mobilization indicators, highlighting “a history of notable noncompliance with restrictions, boundaries, or laws,” which may, but need not, be reflected in a subject’s criminal history. More concretely, this may be coupled with “a history of stalking, harassing, threatening, or menacing behavior,” and/or a “history of violence (not necessarily related to terrorism),” which are all indicators of concern.33 An FBI report that examined lone offender terrorists from across the ideological spectrum noted most offenders had previously exhibited behavior that was hostile or aggressive, and more than half engaged in physical battery or violence as reflected in their arrest history or in accounts of individuals close to the offender.34 For practitioners, one challenge is that the crimes that appear to be most prevalent in the Islamic State cases—assault and domestic violence—are chronically underreported to law enforcement, and therefore may be underestimated and difficult to detect.35
The prevalence of prior firearms offenses is another important trend observed in the criminal history of U.S. Islamic State defendants. Nineteen percent (14) of all defendants with a criminal history had prior arrests for firearm offenses, including criminal possession of a firearm, firearm trafficking, or firearm-related violence. The pervasiveness of prior firearms offenses by the U.S. Islamic State defendants is significant, as firearms are the preferred weapon of choice in a large number of plots. The NCTC noted that while “it is important to consider the totality of circumstances when observing potential indicators, as some factors may increase the risk of extremist violence in a given situation,” one possible factor is the “possession of, access to, or familiarity with weapons or explosives.”36
Terrorism offenses are difficult and complex charges to prosecute, which may contribute to law enforcement’s pursual of firearms charges as a means to disrupt a terrorist plot. Islamic State defendants with a criminal history are roughly twice as likely to be charged specifically with firearms offenses as part of their terrorism prosecution compared to those Islamic State defendants with no criminal history. Specifically, 10 of 13 defendants (77 percent) with a history of firearms offenses were later charged with firearms offenses as part of their terrorism prosecution, often related to attempts to obtain a firearm for use in an attack.k This suggests that a subject’s prior familiarity with firearms may impact a subject’s weapon choice for use in an attack.
The prevalence of prior firearm offenses by the U.S. Islamic State defendants provides one specific opportunity for law enforcement: Prior felons are generally prohibited from possessing a firearm under federal law.l At least 11 U.S. Islamic State defendants with prior felony convictions (15 percent of all defendants with a criminal history) attempted to purchase a firearm as part of their plot, and were subsequently arrested and charged specifically with “possession of a firearm as a felon” as part of their terrorism prosecution. Evidently, for law enforcement, this strategy has yielded results.
Highlighting its utility for law enforcement nationwide, the number of convictions for possession of a firearm as a felon has risen steadily over the last several years.37 Illustrating the usefulness of the charge to interdict would-be attackers, in 2015 Yusuf Wehelie, a Somali-American from Virginia, met an undercover officer as part of a cigarette trafficking operation. In the meeting, he expressed his desire to shoot up a military recruitment center on behalf of the Islamic State and willingly agreed to transport firearms. Wehelie, who had previously been placed on a “no fly” list by the federal government due to possible ties to jihadi groups in Yemen,38 had a felony criminal history related to a past burglary conviction, and was ultimately arrested in 2016 and convicted for illegally transporting firearms as a convicted felon rather than on terrorism charges.39 Elsewhere, Ohio native Amir al-Ghazi, who had a lengthy felony criminal record including nine drug convictions, pledged his support to the Islamic State in 2014 on social media and expressed his desire to carry out a beheading, perpetrate an attack on a police station, and derail a train in the United States.40 Al-Ghazi was later arrested after purchasing an AK-47 assault rifle as a felon from an undercover officer in order to carry out an attack. He was also concurrently engaged in the sale and distribution of narcotics.41 He later pleaded guilty to providing material support to the Islamic State, as well as possession of firearm as a felon.42
The Utility of Crime
Criminality has been an integral component of the financing or logistics of at least 15 Islamic State cases (five percent) in the United States. Some of those planning to perpetrate attacks, join the Islamic State overseas, or materially support the group have engaged in criminal activity to support their plans. Nine defendants engaged in various kinds of financial fraud to fund their plans. Only a small number of cases involved other types of criminality such as armed robbery, drug dealing, or illegal firearms sales. These findings are corroborated by recent findings that appeared in this publication that highlighted Islamic State supporters’ use of financial fraud to fundraise for the group.43
Counterintuitively, most plot-relevant criminality has been perpetrated by individuals without any criminal history. For example, nearly all defendants who engaged in financial fraud to materially support the Islamic State in the United States had no criminal history.m Conversely, in the small subset of Islamic State defendants with prior arrests for financial fraud, three out of the four did not utilize fraud as part of their terrorist activity. While the subset is indeed small, this suggests the possibility that the U.S. Islamic State defendants generally do not use their “old skills” acquired from a criminal past as part of terrorist activity, which differs from the European experience.44 n
Financial fraud may be appealing because it requires few resources, little know-how, is not dependent on personal interactions with co-conspirators, and can be done remotely via computer.45 Zoobia Shahnaz, a 27-year-old Pakistani-American female from Long Island, New York, who pled guilty in 2018 to providing material support to the Islamic State, obtained a fraudulent loan for $22,500, used dozens of fraudulently obtained credit cards to purchase $62,000 of cryptocurrencies, and then wired $150,000 to Islamic State shell entities in Pakistan, China, and Turkey.46 Amer Alhaggagi from Berkeley, California, claimed to an undercover officer that he purchased poison online with a stolen credit card as part of an aspirational plan to distribute poison-laced cocaine in San Francisco on behalf of the Islamic State, and sought to use a fake identity he procured to obfuscate his real identity in order to perpetrate an attack. He was convicted of terrorism offenses, and two years of his 15-year sentence were for identity theft and credit card fraud.47 o At least four other defendants with minimal to no criminal history utilized fraud specifically related to their federal student financial aid to materially support the Islamic State.
Research has noted the small financial footprint of the U.S. Islamic State members who have generally fundraised legally via donations, asset sales, or new credit lines.48 Within a cohort of Somali-American teens from Minnesota that sought to join the Islamic State, travel to Syria was funded by both legal means and fraudulent use of federal student aid, highlighting the complexity of the task for law enforcement in detecting criminal activity or other observable behaviors that indicate a subject’s terrorist intent.49
A few cases sought to use other types of criminality to fund terrorism, such as armed robbery; however, criminal activity was rarely “outsourced” to unaffiliated criminal networks. Marchello and Douglas McCain, brothers from San Diego who both had violent criminal histories, were part of a like-minded network that raised funds obtained from theft to support the travel of North Americans to Syria.50 The network was led by Abdullahi Ahmed Abdullahi, a fellow San Diegan who moved to Edmonton, Canada, and who encouraged members of the network to commit crimes against “infidels.”51 Douglas McCain, who became one of the first Americans to die fighting for the Islamic State in 2014, received $3,100 from an armed robbery of a jewelry store in Edmonton perpetrated by Abdullahi.52 Abdullahi was eventually extradited to the United States in October 2019 for facilitating the travel of at least five North American foreign fighters, and pled guilty in 2021 to funding Islamic State activity in Syria.53 Marchello McCain, who planned to join his brother in Syria, pled guilty in 2016 to possessing nine firearms as a felon and making false statements involving international terrorism concerning his visit to a gun range with Douglas before his departure.54
Some research has suggested that the Islamic State has broad organizational similarities to street gangs, as both thrive in marginalized areas with weak social trust or cohesion.55 In the United States, similar group dynamics, community characteristics, and underlying mechanisms draw individuals to extremist groups and gangs, but they generally do not share the same recruitment pool and there is only occasional transition of members between groups.56 A study that examined jihadi recruits and human trafficking gangs in the Somali-American community found that both groups shared some common push and pull factors, especially related to recruitment.57 However, it appears there was generally little organizational overlap. This highlights that the “mere coexistence” of terrorists and criminals in the same physical space does not always indicate a genuine connection or alliance.58 A 2018 Justice Quarterly study noted that since 1980, 6.5 percent of violent extremists from across the ideological spectrum had a history of gang involvement, which indicates the possibility of links between gangs and extremists, though at a relatively low rate.59 There were also significant demographic differences related to age and ethnic background between both groups.60
There are a small number of important cases where Islamic State defendants with a prior gang membership did eventually gravitate to terrorism, often after prison time. Notably, nearly all Islamic State defendants with a prior gang affiliation made a clean break from criminal life and withdrew from the gang upon their radicalization.p For example, Sajmir Alimehmeti joined a Bronx street gang as a teenager called the “Albanian Boys, Inc.”61 He was arrested several times and subsequently radicalized while serving a state prison sentence for assault. He rejected members of his former gang upon his release from prison, and later sought to join the Islamic State and was in contact with a network of Islamist extremists overseas. He was later arrested for his attempts to assist an individual who was purportedly traveling from New York to Syria to fight with the Islamic State, and pleaded guilty to providing material support to the Islamic State in 2018.62 Elsewhere, Yosvany Padilla-Conde of Milwaukee was arrested at age 17 for armed robbery as a member of the “Rolling 60’s Crips” gang and later converted to Islam in prison under the influence of his friend Jason Ludke.63 Padilla-Conde left the gang and reestablished his life after his release from prison, but Ludke later sought out and radicalized him, leading to their plot to travel to Syria together to join the Islamic State.64 Both men were later convicted of providing material support to the Islamic State.65 The case of Chicago gang leader Jason Brown, as described in the introduction, who sought to radicalize fellow gang members by distributing Islamic State propaganda is an intriguing outlier, and the most vivid example of a direct association between gang membership, radicalization, and terrorism.
Prison has been described as a “melting pot” where vulnerable criminals are radicalized and where terrorist and criminal networks converge to transfer knowledge, learn new skills, or develop relationships that can be leveraged upon release.66 Prisons have played a role in a select number of Islamic State cases in the United States.q The prison experience has contributed to the radicalization of several subsequent U.S. Islamic State defendants and has occasionally solidified relationships later relevant to a terrorism plot. For context, more than half never previously served time in prison. Of those defendants with a criminal history, at least 40 percent (29 defendants) were previously incarcerated at least once, which corresponds to around 12 percent of all U.S. Islamic State defendants. The length of prior prison time varies widely.
A reexamination of the subset of U.S. Islamic State defendants who previously served time in prison affirms that at least five radicalized inside prison, representing 17 percent of the 29 U.S. Islamic State defendants who previously served time in prison on criminal convictions. Furthermore at least two other incarcerated defendants radicalized others.r A recurring trend helps explain this phenomenon, as each case of prison radicalization in the U.S. Islamic State dataset can be partially attributed to the role of a charismatic, non-isolated terrorist prisoner who acted as a key radicalizer of other inmates. Overall, it must be stressed that the number of prisoners in the general U.S. prison population who radicalize and gravitate to terrorism remains low.67
According to a 2020 Federal Bureau of Prisons audit, there are approximately 500 incarcerated inmates with a known nexus to domestic or international terrorism.s The United States generally concentrates its terrorism offenders in high-security facilities despite skepticism among critics of its benefits.68 In the United States, when terrorism inmates (regardless of ideology) were not isolated and given opportunities to interact with other inmates, there is evidence that some of these high-profile offenders acted as charismatic figures inside prison and became nodes of radicalization that successfully inculcated other inmates who later became involved in terrorist activity.69 A charismatic leader in prison who inherently derives authority and credibility from fellow inmates is assessed by criminologists to be more important than other prison “push” factors associated with radicalization such as overcrowding, poor conditions, or a lack of rehabilitative programs.70 In fact, recent high-profile attacks by those who radicalized in prison has led to the United Kingdom to announce plans to separate “charismatic” or influential terrorist prisoners from the general inmate population.71
Overall, few U.S. Islamic State plots were directly reliant on personal relationships forged inside correctional facilities. Several U.S. Islamic State defendants were discovered to be plotting attacks while incarcerated during their court proceedings or while serving their terrorism sentences. Most of these plots consisted of violent attacks against prison staff. For example, 28-year-old New Yorker Ali Saleh was sentenced in 2021 to 30 years in prison for material support to the Islamic State after attempting to travel to join the group on four occasions between 2014 and 2015. He also funded the travel of a Mali-based Islamic State supporter to Syria, and had researched making explosives from fireworks and purchased 29 machetes. While detained at the Metropolitan Detention Center in Brooklyn, Saleh assaulted correctional officers, crafted weapons from materials in prison, broke cell windows, initiated false emergency alarms, and set fires, and was cited for more than 90 disciplinary infractions, including slashing a correctional officer with an improvised knife, to which he pleaded guilty.72 Europe has experienced a similar trend, as there have been at least six attacks planned inside prison by Islamic State inmates between 2016 and 2020 that typically targeted prison guards, and were usually carried out by offenders with violent pasts.73 A recent CTC Sentinel study found that several European offenders imprisoned for extremist-related offenses were later involved in attacks on prison staff that had an apparent terrorism dimension.74
Most U.S. Islamic State plots planned from inside prison were thwarted by other inmates notifying prison officials, often motivated by self-interest and reduced prison time for cooperation. At least five U.S. Islamic State inmates made attempts to kill the undercover officer or cooperator who contributed to their prosecution.75 Former New York resident Fabjan Alameti was arrested in 2019 for plotting an attack against army recruitment facilities, federal buildings, and a gay nightclub after moving to Montana, where he believed it would be easier to obtain explosives.76 Prior to his sentencing after pleading guilty for making false statements relating to international terrorism, another inmate informed prison officials that Alameti had asked about getting guns and explosives while inside Crossroads Correctional Center in Shelby, Montana. During a search of Alameti’s cell, officers found extremist messages written on his walls and a razor blade hidden in a book.77
Most plots by incarcerated U.S. Islamic State defendants from inside prison were relatively primitive, and overall, there is generally little indication of a meaningful knowledge or skills transfer inside prison that contributed to a plot. However, there are outlier cases where Islamic State defendants attempted to plan more ambitious attacks while incarcerated for terrorism offenses. Amer Alhaggagi (referenced earlier) researched retaliatory plots to blow up a federal building in San Francisco from inside jail and sought to arrange the killing of police officers.78 Alex Hernandez, an inmate at Old Colony Correctional Center in Massachusetts serving a sentence for state firearms offenses, plotted to kill President Obama and sought to obtain false travel documents to flee the country after the attack. Hernandez, a convert to Islam, claimed to have researched explosives, wanted to become a member of the “mujahedeen” and a martyr, and sought to kill the president who was targeting the “brothers [who] are fighting to uphold the laws and structure of the caliphate in the Middle East.” Items discovered in Hernandez’s cell included Islamic State propaganda.79 He was later sentenced to 37 months of additional prion time for threatening to kill and inflict bodily harm on the U.S. president.80
A Comparison with Racially and Ethnically Motivated Violent Extremists
The four components of the crime-terror nexus—criminal history, the utility of crime, gangs, and prison—may have wider relevance beyond the Islamic State experience. On a different part of the ideological spectrum, there are several noteworthy areas for future research pertaining to racially and ethnically motivated violent extremists (REMVEs), defined by the FBI as those who use the “threat of force or violence in furtherance of ideological agendas derived from bias, often related to race or ethnicity, held by the actor against others or a given population group.”81
To contextualize the relatively low prevalence of criminal history among U.S. Islamic State defendants, an FBI study that assessed the typology of U.S. “lone offender terrorists” from across the ideological spectrum found that 70 percent had a prior criminal history, which is more than double the 31 percent of Islamic State cases identified in this study.82 This stark discrepancy may be because more than half (54 percent) of the FBI sample were anti-government, racially motivated extremists advocating the superiority of the white race, or anti-abortion violent extremists.83 This compels an exploration of the wider relevance of the crime-terror nexus to extremists across the ideological spectrum.
Several well-regarded academic studies have similarly noted that right-wing violent extremists are more likely to be less educated and have a criminal history than their Islamist extremist counterparts. Paul Gill and his co-authors examined sociodemographic characteristics and antecedent behaviors of lone-actor terrorists from across the ideological spectrum and found that al-Qa`ida-inspired lone actors were less likely to have criminal convictions (26.9 percent) than their extremist right-wing counterparts (50 percent), and were also 10 years younger, better educated, and more likely to have a professional job.84 In an analysis of lone-actor terrorists, Mark Hamm and Ramon Spaaij argued that historically, white supremacist movements have tended to produce terrorists from the lower classes, while “religious” terrorist groups such as al-Qa`ida appear to draw from all classes and may be better educated.85 It appears that socioeconomic and educational differences between Islamist extremists and right-wing extremists may impact the prevalence of prior criminal history.
In several high-profile REMVE cases in the United States, dozens of defendants were heavily involved in crime and had extensive criminal histories. For example, as part of a massive federal investigation of the Aryan Brotherhood of Texas and associated groups’ role in organized crime, 89 group members were arrested and prosecuted in 2017. The Justice Department noted that in some instances, “the white supremacy ideology of each of these groups had taken a backseat to traditional criminal ventures such as drug-dealing.”86 In fact, an internal debate within the Aryan Brotherhood about the group’s primary identity as a crime syndicate versus a white supremacist group remains unresolved and has been hotly debated among members inside Texas prisons since the 1980s.87
Highlighting the pervasive criminal background of some REMVEs, based on publicly released law enforcement information, the 89 Aryan Brotherhood defendants arrested in the 2017 federal takedown were previously convicted of a combined 736 crimes: 234 were drug-related offenses, 76 were violent offenses; 36 were gun offenses, 37 were burglaries, seven were sex or child abuse offenses, and one was a murder conviction. Some defendants were career criminals with more than 25 prior convictions, while only six of the 89 (6.7 percent) had no prior criminal history.88 It was noted elsewhere that the Aryan Brotherhood was responsible for at least 33 murders in Texas between 2000 and 2015 that were carried out for traditional criminal motives, internal killings of suspected informants or rules-breakers, and hate-related (ideological) motives directed against minorities.89
The Aryan Brotherhood case raises many interesting questions pertaining to the role of criminal history in recruitment, retention, and acculturation of REMVEs into extremist groups. However, the picture is not so clear-cut, as high-profile REMVE attack perpetrators at the Tree of Life Synagogue in Pittsburgh in 2018 and Chabad Jewish Center of Poway, San Diego in 2019 had no criminal record.90 Complicating things further, the racially motivated 2022 Buffalo supermarket shooter was “known to law enforcement” but never formally arrested; he underwent a mental health evaluation by New York State Police after making a school shooting threat in June 2021, and spent two days in a mental hospital, but was never charged with a crime.91 Further exploration of divergent trends concerning the contrasting criminal past of older REMVE gang members and the recent wave of internet-inspired extremist youths radicalized in online forums could be a fruitful initiative. It would also shed light on differences in criminal history between lone attack perpetrators and REMVE group members, and would provide nuance to understanding the diagnostic importance of criminal history on extremists’ mobilization to violence.
The lack of a federal domestic terrorism statute often means that REMVEs, even those who are actively plotting ideologically motivated crimes or have perpetrated an attack, may only be prosecuted for purely criminal offenses, rather than terrorism offenses more frequently seen in Islamic State cases (given “material support to a foreign terrorist organization” by definition is not applicable to domestic groups). Barring changes to federal law, prosecutors will continue pursuing criminal charges against REMVEs, highlighting the interplay between crime and terrorism, but also underscoring the challenges for law enforcement in prosecuting future domestic terrorism and racially motivated crimes.
White supremacist criminal gangs are prolific in the United States, with at least 100 groups active inside the nation’s prison system.92 The influence of gangs and prison on the pathways of REMVEs appears more pronounced than in the U.S. Islamic State cases. The prison system is often a primary gateway for recruitment into white supremacist gangs, as recruits are often motivated by poor or dangerous conditions inside prison and are seeking protection.93 For example, in Florida, 16 members of “Unforgiven,” a white supremacist prison gang guided by Aryan philosophy that partly sought to rebel against the perceived victimization of white inmates, were charged in 2021 with racketeering, murder, kidnapping, robbery, and obstruction of justice.94 Elsewhere, 20 members of the Alaska-based neo-Nazi prison gang “1488” were charged with murder, narcotics, and weapons trafficking in 2019-2020, and also explicitly recruited prospective extremists by offering protection to white inmates.95
REMVEs, including white supremacist and “skinhead” motorcycle gangs, have a longstanding documented involvement in narcotics and firearms trafficking in the Midwest to fund their illegal activities. For example, in Utah, 21 white supremacist gang members who were members of groups such as Soldiers of Aryan Culture and Silent Aryan Warriors were charged in 2020 with firearms trafficking and methamphetamine production. Many of the defendants had extensive criminal histories which allowed for federal sentencing enhancements of prior felons.96 Much like the utility of the “Felon in Possession of a Firearm” charge in interdicting would-be Islamic State attackers, REMVE felons’ engagement in firearms trafficking has clear implications for the crime-terror nexus. While such high-profile cases are only illustrative of a much wider and deeper phenomenon, it is evident that criminal history, gangs, and prisons are important elements of the crime-terror nexus across the ideological spectrum, and further comparisons to the U.S. Islamic State cases and an exploration of associated challenges and opportunities would be fruitful.
As the number of Islamic State defendants has increased in the United States, albeit at a slower rate in recent years given the group’s decline, criminal trends have remained consistent. The prevalence of prior violent crime in 20 percent of U.S. Islamic State defendants may provide indicators to law enforcement related to the propensity for violence of a subject exhibiting signs of extremism. Criminal history may also occasionally offer clues about ideological leanings, but rarely on terrorist intent. In the United States, there appears to be little organizational overlap between gangs and Islamic State extremists despite some similarities related to recruitment patterns and underlying mechanisms that draw individuals to such groups. Most U.S. Islamic State defendants with a gang affiliation withdrew from the gang upon radicalization, and there were few concrete examples in the United States of any attempted “outsourcing” of critical aspects of an Islamic State terrorist plot to unaffiliated gangs or criminal networks. In prison, relationships formed by U.S. Islamic State inmates only occasionally had plot relevance, but exposure to charismatic or high-profile terrorist inmates was a key factor in the cases of prison radicalization.
The REMVE prison-gang ecosystem is vast and appears to run comparatively deeper in the United States, although the criminal pasts of perpetrators of REMVE attacks varies. Lone-actor REMVEs with no criminal past who radicalize on the internet with few in-person ties pose a different challenge than hardened career criminals who are part of white supremacist prison gangs involved concurrently in narcotics trafficking and racially motivated violence against minorities and law enforcement. Further research should also explore how the criminal past of lone-actor extremists differ from those with more formalized ties to extremist groups across the ideological spectrum, though it is more useful to view such ties on a continuum of connectivity to a group.97
The crime-terror nexus in the United States is observable in about one-third of Islamic State cases and had an impact on defendants’ pathway to terrorism. While seemingly less pronounced compared to REMVEs, criminal history, gang membership, and prison time are important elements of the crime-terror nexus—pertaining to the Islamic State and beyond—and demand attention as to how each fits into the larger picture regarding drivers of radicalization and mobilization to violence across the ideological spectrum. CTC
Raphael D. Marcus is a supervisory intelligence research specialist at the NYPD Intelligence Bureau, where he oversees a team of analysts that support counterterrorism investigations that focus primarily on the Middle East and South Asia. He is also a non-resident research fellow in the Department of War Studies at King’s College London, where he received his Ph.D. He is the author of Israel’s Long War with Hezbollah: Military Innovation and Adaptation Under Fire published by Georgetown University Press in 2018.
The views expressed in this article are strictly the author’s and do not necessarily represent the views of the NYPD.
© 2022 Raphael D. Marcus
[a] As of August 2022, Brown’s case is still pending in federal court. Defendants are presumed innocent until proven guilty in a court of law. In addition to official court records, a useful resource for tracking the judicial disposition of U.S. federal Islamic State-related cases is George Washington University’s Project on Extremism “Extremism Tracker.”
[b] Even though 10 of those in the dataset were not charged in connection with their terrorist crimes because they were killed by law enforcement, this article refers to the entire group of 237 individuals as “U.S. Islamic State defendants.”
[c] The dataset primarily includes cases related to the Islamic State where the defendant is arrested and charged with a “federal crime of terrorism” (which includes statues associated with international terrorism as codified in U.S. law). Defendants charged with “general crimes” not inherently associated with international terrorism are included (statutory violations such as firearm offenses, making false statements, and obstruction of justice), but only when the Department of Justice specifically alleges a link to the Islamic State. It is important to note that defendants are often (but not always) charged with both categories of offenses. The study only includes cases where the Islamic State association is publicly alleged in official court records, and excludes defendants arrested on purely criminal charges whose terrorism association is not publicly revealed, or when an indictment is filed “under seal” without it becoming public record. The small number of Islamic State cases prosecuted outside the U.S. federal system (i.e. state, county, or juvenile court) are not included.
[d] This article revises and abridges sections of an earlier study: Raphael D. Marcus, “ISIS and the Crime-Terror Nexus in America,” Studies in Conflict and Terrorism, 2021.
[e] The data on repeat offenders is drawn from a subset of 60 U.S. Islamic State defendants where the exact number of prior arrests was available. Thirteen defendants (out of 73 with a criminal record) were excluded from the statistics on repeat offenders only due to imprecise information concerning the total number of prior arrests. All other statistics relating to criminal records in the study are drawn from the 73 defendants with a criminal record.
[f] Twenty-two U.S. Islamic State defendants (37 percent of those with a criminal record) had only one arrest. Twenty-one defendants (35 percent) had two prior arrests. Seventeen defendants (28 percent) had at least three arrests.
[g] The National Counterterrorism Center (NCTC) noted that such indicators “may involve constitutionally protected activities and might be insignificant on their own. However, when observed in combination with other suspicious behaviors, these indicators may raise suspicion in a reasonable person. … Law enforcement action should not be taken solely based on the exercise of constitutionally protected rights, or on the apparent or actual race, ethnicity, national origin or religion of the subject, or on any combination of these factors.” Homegrown Violent Extremist Mobilization Indicators (Washington, D.C.: National Counterterrorism Center, 2019), p. 2.
[h] Thirty-seven percent of 73 U.S. Islamic State defendants with a criminal record committed only violent crimes. Twenty-seven percent of these 73 defendants committed both violent and non-violent crimes. The sum totals 64 percent.
[i] Twenty-six individuals were arrested for assault or domestic violence or both. Fourteen U.S. Islamic State defendants had arrests for domestic violence, and 18 had arrests for assault. Six of these defendants had arrests for both domestic violence and assault.
[j] The one exception is Safya Roe Yassin who was arrested only once and charged with criminally threatening the father of her children in a 2001 domestic incident. USA vs. Safya Roe Yassin, “Government Sentencing Memorandum,” June 1, 2018, pp. 10-11.
[k] The 10 cases are Donald Ray Morgan, Marchello McCain, Leon Nathan Davis, Miguel Moran Diaz, Abdul Malik Abdul Kareem, Amir Said Rahman Al-Ghazi, Khalil Abu Rayyan, Dayne Antani Christian, Yousef Mohammad Ramadan, and Muhammed Momtaz Al-Azhari.
[l] 18 U.S.C. § 922(g) is the federal statute that “prohibits certain persons from shipping, transporting, possessing, or receiving a firearm or ammunition while subject to a prohibition from doing so, most commonly because of a prior conviction for a felony offense.” See “Quick Facts – Felon in Possession of a Firearm” (FY 2019), U.S. Sentencing Commission, May 2020.
[m] Those cases are Muhanad Badawi, Guled Ali Omar, Akram Musleh, Mahmoud ElHassan, Amer Sinan Alhaggagi, and Zoobia Shahnaz.
[n] Those defendants with prior arrests for financial fraud are Yousef Wehelie, Houcine Ghoul, Youssef Mohammad Ramadan, and Kim Vo.
[o] It was never conclusively proven in court that the credit card fraud supported his acquisition of materials for the attack.
[p] The four cases with confirmed gang affiliation are Jason Brown, Emanuel Lutchman, Yosvany Padilla-Conde, and Sajmir Alimehmeti.
[q] According to the U.S. Department of Justice, jails are confinement facilities usually administered by a local law enforcement agency for confinement before and after adjudication. Inmates sentenced to jail usually have a sentence of one year or less. “Compared to jails, prisons are longer-term facilities owned by a state or by the federal government. Prisons typically hold felons and persons with sentences of more than 1 year. However, sentence length may vary by state. Six states (i.e., Connecticut, Rhode Island, Vermont, Delaware, Alaska, and Hawaii) have an integrated correctional system that combines jails and prisons.” See “Frequently Asked Questions,” “What is Prison?” Bureau of Justice Statistics, U.S. Department of Justice. In this article, when discussing radicalization while incarcerated, the term “prison radicalization” is used generally for the sake of simplicity.
[r] The seven cases are Ahmad Rahami, Sajmir Alimehmeti, Jason Brown, Mohamad Ibrahim Ahmed, Clark Calloway, Casey Charles Spain, and Alex Hernandez. All defendants were convicted except for Jason Brown, whose case is still pending.
[s] Of these inmates, 431 were classified as international terrorists, and 103 were classified as domestic terrorists. See Audit of the Federal Bureau of Prisons’ Monitoring of Inmate Communications to Prevent Radicalization (Washington, D.C.: U.S. Department of Justice, Office of the Inspector General, 2020), p. 5.
 USA vs Jason Brown aka Abdul Ja’Me, “Criminal Complaint,” November 13, 2019, pp. 5-7.
 Ibid., p. 5.
 Ibid., pp. 5-6.
 Ibid., pp. 13-14, 24; USA vs. Tristan Clanton, Randall Langston, Brandon Langston, Hezekiah Wyatt, Lenolis Muhammad-Curtis aka Naheem, and Frank Thaxton, “Criminal Complaint,” November 13, 2019.
 For an overview, see Kacper Rekawek, Viktor Szucs, Martina Babikova, and Enya Hamel, European Jihad: Future of the Past? From Criminals to Terrorists and Back? (Bratislava: Globsec Defense and Security Program, 2019) and Rajan Basra and Peter R. Neumann, “Crime as Jihad: Developments in the Crime-Terror Nexus in Europe,” CTC Sentinel 10:9 (2017). For country-specific research, see Anton Weenik, “Adversity, Criminality, and Mental Health Problems in Jihadis in Dutch Police Files,” Perspectives on Terrorism 13:5 (2019), pp. 130-142; Marc Hecker, “137 Shades of Terrorism: French Jihadists Before the Courts,” IFRI Focus Stratégique 79 (2018).
 Alexander Kupatadze and Javier Argomaniz, “Introduction to Special Issue – Understanding and Conceptualizing European Jihadists: Criminals, Extremists or Both?” European Journal of Criminology 16:3 (2019): pp. 261-277.
 Cyrille Fijnaut, Letizia Paoli, and Jan Wouters, “Introduction to the Nexus between Organized Crime and Terrorism” in The Nexus Between Organized Crime and Terrorism: Types and Responses (Cheltenham, U.K.: Elgar, 2022), pp. 9-10.
 Kupatadze and Argomaniz, pp. 263-270; Rajan Basra, Peter R. Neumann, and Claudia Brunner, Criminal Pasts, Terrorist Futures: European Jihadists and the New Crime-Terror Nexus (London: International Center for the Study of Radicalization, 2016).
 Daniel De Simone, “Manchester Arena Attack: Man Arrested Over Bombing Wanted in Drugs Probe,” BBC, January 14, 2022; Duncan Gardham, “Manchester Arena Attack: Bomber’s Friend Sentenced Over Fraud to Buy Chemicals,” Sky News, November 26, 2020.
 Eran Benedek and Neil Simon, “The 2017 Manchester Bombing and the Libyan-Jihadi Nexus,” CTC Sentinel 13:5 (2020). For details of Abedi’s family ties to senior Libyan jihadi figures, including Abu Anas al-Libi, see pp. 30-31. See also Daniel de Simone, “The Road to the Manchester Arena Bombing,” BBC, March 17, 2020.
 John Scheerhout, “How Hashem Abedi, his Bomber Brother and their Family Raked in a Fortune in Benefits,” Manchester Evening News, August 20, 2020.
 See the UK Government Manchester Arena Inquiry, “INQ022846/8 – Extract from the witness statement of Witness X, provided on behalf of the Security Service, dated 15/07/2019,” Evidence 27 October 2021.
 Basra, Neumann, and Brunner, p. 37.
 “Charlie Hebdo: Fourteen Guilty in 2015 Paris Terror Attacks Trial,” BBC, December 16, 2020. For more on the perpetrators’ weapons procurement from criminal networks, see Basra, Neumann, and Brunner, pp. 36, 44-45.
 Basra, Neumann, and Brunner, p. 3; Kupatadze and Argomaniz, p. 265. For a concise review, see Basra and Neumann, “Crime as Jihad.”
 Raphael D. Marcus, ISIS and the Crime-Terror Nexus in America: A Counterpoint to Europe (New York: Center on National Security at Fordham Law, 2020).
 Lauren Richards, Peter Molinaro, John Wyman, and Sarah Craun, Lone Offender: A Study of Lone Offender Terrorism in the United States (Quantico, VA: FBI National Center for the Analysis of Violent Crime, 2019), p. 22.
 Gary LaFree, Michael A. Jensen, Patrick A. James, and Aaron Safer-Lichtenstein, “Correlates of Violent Political Extremism in the United States” Criminology 56:2 (2018): pp. 242-243.
 Ibid., pp. 242-243, 251-254.
 Case by Case: ISIS Prosecutions in the United States: March 1, 2014 – June 30, 2016 (New York: Center on National Security at Fordham Law, 2016), p. 25.
 The American Exception: Terrorism Prosecutions in the United States – The ISIS Cases: May 2014 – May 2017 (New York: Center on National Security at Fordham Law, 2017), p. 21.
 Robert Tillman, “The Size of the ‘Criminal Population:’ The Prevalence and Incidence of Adult Arrest,” Criminology 25:3 (1987): pp. 561-597. The timeframe in this longitudinal study covers 1974-1985 and reports the 24 percent of American 18-year-olds had at least one arrest over a 12-year period. See also J.C. Barnes, Cody Jorgensen, Kevin M. Beaver, Brian B. Boutwell, and John P. Wright, “Arrest Prevalence in a National Sample of Adults: The Role of Sex and Race/Ethnicity,” American Journal of Criminal Justice 40 (2015): pp.457-465. This study looked at a nationally representative sample of individuals aged 24-34 drawn from the National Longitudinal Study of Adolescent Health, which covers the mid-1990s and 2000s. The latter study was also cited in the FBI’s Lone Offender Terrorism study (p. 20, footnote 23), regarding the lifetime prevalence for an American adult being arrested (30 percent). See also Robert Brame, Michael G. Turner, Raymond Pater-noster, and Shawn D. Bushway, “Cumulative Prevalence of Arrest From Ages 8–23 in a National Sample,” Pediatrics 129:1 (2012): pp. 21-27, which reported that the arrest prevalence for a U.S. 23-year-old lies between 30 percent and 41 percent.
 Report to the Congress: Career Offender Sentencing Enhancements (Washington, D.C.: U.S. Sentencing Commission, 2016), pp. 2-3. For a summary, see “Federal Sentencing of Career Offenders – Report to the Congress: Career Offender Sentencing Enhancements,” U.S. Sentencing Commission, 2016, p. 2.
 Lone Offender, p. 22.
 LaFree, Jensen, James, and Safer-Lichtenstein, p. 254.
 Ibid., 257.
 For example, Joan Smith, Home Grown: How Domestic Violence Turns Men into Terrorists (London: Quercus, 2019).
 Mobilization Indicators (2019 ed.) (Washington, D.C.: National Counterterrorism Center), pp. 14, 18.
 First reported publicly by Marc Santora and Adam Goldman, “Ahmad Khan Rahami Was Inspired by Bin Laden, Charges Say,” New York Times, September 20, 2016, and Eyder Peralta, “FBI: Bombing Suspect Bought Material Online, Left Fingerprints on Devices,” NPR, September 20, 2016. For the sentencing, see “Chelsea Bomber Ahmad Khan Rahimi Sentenced to Life in Prison for Executing September 2016 Bombing and Attempted Bombing in New York City,” U.S. Department of Justice, February 13, 2018.
 “Lackawanna Man Sentenced For Attempting To Provide Support To ISIS,” U.S. Department of Justice, June 11, 2018.
 USA vs. Arafat Nagi, “Decision and Order,” July 31, 2015, p. 4. For incident details, see Mark Belcher, “Accused Terrorism Suspect Arrested in 2011 for Assaulting Daughter,” WIVB4, July 30, 2015, and Mark Belcher, “Accused ISIL Terrorist Threatened his Child with Large Knife in 2013,” WIVB4, July 30, 2015.
 “Lackawanna Man Sentenced for Attempting to Provide Support To ISIS.”
 US Violent Extremist Mobilization Indicators (2021 ed.) (Washington, D.C.: National Counterterrorism Center), p. 21.
 Lone Offender, p. 22.
 Brian A. Reaves, “Police Response to Domestic Violence, 2006-2015,” Special Report, Office of Justice Programs, Bureau of Justice Statistics, U.S. Department of Justice, May 2017.
 Mobilization Indicators (2019 ed.), p. 21.
 “Quick Facts – Felon in Possession of a Firearm” (FY 2019), U.S. Sentencing Commission, May 2020, p. 1.
 Scott Shane, “American Man in Limbo on No-Fly List,” New York Times, June 15, 2010.
 USA vs Yusuf Abdirazak Wehelie, “Affidavit in Support of Criminal Complaint and Arrest Warrant,” July 7, 2016; “Virginia Man Sentenced for Felon in Possession of Firearms,” U.S. Department of Justice, July 14, 2017.
 USA vs Amir Said Abdul Rahman Al-Ghazi, “Criminal Complaint,” June 19, 2015.
 Ibid., p. 26; Ida Lieszkovszky, “Sheffield Lake Terrorist Suspect Said He’d Behead his Non-Muslim Son, FBI Reports,” Cleveland.com, June 19, 2015.
 “Ohio Man Pleads Guilty to Attempting to Provide Material Support to ISIL and Possessing Firearms as a Felon,” U.S. Department of Justice, March 16, 2016.
 Lorenzo Vidino, Jon Lewis, and Andrew Mines, “Dollars for Daesh: The Small Financial Footprint of the Islamic State’s American Supporters,” CTC Sentinel 13:3 (2020): p. 25.
 Javier Argomaniz and Rut Bermejo, “Jihadism and Crime in Spain: A Convergence Settings Approach,” European Journal of Criminology 16:3 (2019): pp. 355-358.
 Author personal communication, NYPD intelligence analysts, November 2020.
 “Long Island Woman Indicted for Bank Fraud and Money Laundering to Support Terrorists,” U.S. Department of Justice, December 14, 2017; “Long Island Woman Sentenced to 13 Years’ Imprisonment for Providing Material Support to ISIS,” U.S. Department of Justice, March 13, 2020.
 USA vs. Amer Sinan Alhaggagi, “Government Sentencing Memorandum,” December 4, 2018, pp. 1-14, 27, 51-52. See also Frances Dinkelspiel, “FBI Alleges Berkeley High Graduate, ISIS Sympathizer, Planned to Set Fires, Plant Bombs,” Berkeleyside, July 27, 2017.
 Vidino, Lewis, and Mines, p. 24.
 For example, USA vs. Mohamed Amiin Ali Roble, “Criminal Complaint,” August 24, 2016, p. 14; USA vs Hamza Naj Ahmed, “Government Sentencing Memorandum,” November 3, 2016, p. 22; USA vs. Guled Ali Omar, “Government Sentencing Memorandum,” November 3, 2016, pp. 10, 19.
 USA vs. Marchello Dsuan McCain, “Government Response and Opposition to Defendant’s Motion for Discovery,” March 30, 2015, pp. 2-3.
 USA vs. Abdullahi Ahmed Abdullahi, “Indictment,” March 10, 2017, p. 2.
 “Brother of San Diego Man Killed Fighting for Isis Sentenced to 10 Years for Terrorism-Related Charges and Illegal Firearms Possession,” U.S. Department of Justice, January 12, 2018.
 “Former San Diego Resident Pleads Guilty to Funding ISIS Terrorist Activities in Syria,” U.S. Department of Justice, December 17, 2021.
 “Brother of San Diego Man Killed Fighting for ISIS Sentenced to 10 Years for Terrorism Related Charges and Illegal Firearms Possession,” U.S. Department of Justice, January 12, 2018.
 Matthew Valasik and Matthew Phillips, “Understanding Modern Terror and Insurgency through the Lens of Street Gangs: ISIS as a Case Study,” Journal of Criminological Research, Policy and Practice 3:3 (2017): pp. 192-207.
 David C. Pyrooz, Gary LaFree, Scott H. Decker, and Patrick A. James, “Cut from the Same Cloth? A Comparative Study of Domestic Extremists and Gang Members in the United States,” Justice Quarterly 35:1 (2018): pp. 4-5.
 Stevan Weine, Edna Erez, and Chloe Polutnik, Transnational Crimes among Somali-Americans: Convergences of Radicalization and Trafficking (Washington, D.C.: National Institute of Justice, May 2019), pp. 32-38.
 Kupatadze and Argomaniz, p. 266.
 Pyrooz, LaFree, Decker, and James, p. 16, footnote 6.
 Ibid., pp. 17-18, 24.
 USA vs. Sajmir Alimehmeti, “Defense Sentencing Memorandum,” November 21, 2019, p. 15.
 USA vs. Sajmir Alimehmeti, “Government Sentencing Memorandum,” December 2, 2019, p. 45. For further details of Alimehmeti’s prison radicalization, see Raphael D. Marcus, “ISIS and the Crime-Terror Nexus in America,” Studies in Conflict and Terrorism, 2021, pp. 13-15. For his guilty plea, see “New York Man Pleads Guilty to Attempting to Provide Material Support to ISIS and Passport Fraud,” U.S. Department of Justice, February 21, 2018.
 USA vs. Yosvany Padilla-Conde, “Government Sentencing Memorandum,” August 2, 2019, p. 1.
 USA vs Yosvany Padilla-Conde, “Defense Sentencing Memorandum,” August 1, 2019, pp. 3-4.
 “Milwaukee Man Convicted Of Aiding and Abetting An Attempt to Provide Material Support to ISIS,” U.S. Department of Justice, April 22, 2019.
 Rajan Basra and Peter R. Neumann, “Criminal Pasts, Terrorist Futures: European Jihadists and the New Crime-Terror Nexus,” Perspectives on Terrorism 10:6 (2016): p. 31; Argomaniz and Bermejo, p. 361.
 This corroborates existing literature: for example, Mark S. Hamm, The Spectacular Few: Prisoner Radicalization and the Evolving Terrorist Threat (New York: NYU Press, 2013), p. 46 and Andrew Silke, “Physical Facilitating Environments – Prisons and Madrassas as Mechanisms and Vehicles of Violent Radicalisation?” in Anthony Richards, Devorah Margolin, and Nicolo Scremin eds., Jihadist Terror: New Threats, New Responses (London: I.B. Tauris, 2019), pp. 169-178.
 Andrew Silke and Tinka Veldhuis, “Countering Violent Extremism in Prisons: A Review of Key Recent Research and Critical Research Gaps,” Perspectives on Terrorism 11:5 (2017): pp. 4-5.
 Mark Hamm, Terrorist Recruitment in American Correctional Institutions: An Exploratory Study of Non-Traditional Faith Groups (Washington, D.C.: National Institute of Justice, 2007).
 Ibid., p. 107.
 Gavin Cordon, “Charismatic’ Terrorist Prisoners to be Isolated in Jail ‘Separation Centres,’” Independent, April 27, 2022.
 “Man Sentenced to 30 Years in Prison for Attempting to Provide Material Support to ISIS,” U.S. Department of Justice, November 17, 2021.
 Rajan Basra and Peter R. Neumann, Prisons and Terrorism: Extremist Offender Management in 10 European Countries (London: ICSR, 2020), p. 15.
 Robin Simcox and Hannah Stuart, “The Threat from Europe’s Jihadi Prisoners and Prison Leavers,” CTC Sentinel 13:7 (2020): p. 25.
 For further details, see Marcus, ISIS and the Crime-Terror Nexus, pp. 45-47.
 “New York City Man Admits to Making False Statements Involving International Terrorism,” U.S. Department of Justice, August 28, 2019.
 Ibid.; Searborn Larson, “Pro-ISIS Writing Found in Inmate’s Cell at Montana Prison,” Missoulian, December 13, 2019.
 Frances Dinkelspiel, “23-year-old Man who Set up Email Accounts for ISIS Sent to Prison for 15+ Years,” Berkeleyside, February 27, 2019.
 “Inmate Charged with Plotting to Kill President,” U.S. Department of Justice, May 23, 2016.
 “Prison Inmate Sentenced for Threatening to Kill the President of the United States,” U.S. Department of Justice, July 26, 2017.
 “Domestic Terrorism: Definitions, Terminology, and Methodology,” FBI and the U.S. Department of Homeland Security, November 2020, p. 2.
 Lone Offender, pp. 20-21.
 Ibid., 29-30.
 Paul Gill, John Horgan, and Paige Deckert, “Bombing Alone: Tracing the Motivations and Antecedent Behaviors of Lone-Actor Terrorists,” Psychiatry & Behavioral Sciences 59:2 (2014): p. 431. This study examined prior criminal convictions rather than arrests.
 Mark Hamm and Ramon Spaaij, The Age of Lone Wolf Terrorism (New York: Columbia University Press, 2017), pp. 49-51.
 “Last of 89 Members/Associates of Aryan Brotherhood of Texas and Aryan Circle Sentenced to 20 years in Federal Prison,” U.S. Immigration and Customs Enforcement, November 10, 2017.
 Mary E. Pelz, James W. Marquart, and C. Terry Pelz, “Right-Wing Extremism in the Texas Prisons: The Rise and Fall of the Aryan Brotherhood of Texas,” Prison Journal 71:2 (1991): p. 34.
 “Last of 89 Members/Associates of Aryan Brotherhood of Texas and Aryan Circle Sentenced to 20 years in Federal Prison.” Information on past convictions appeared in the press release.
 “White Supremacist Prison Gangs in the United States: A Preliminary Analysis,” Anti-Defamation League Center on Extremism, 2015, p. 1.
 Tom Jones, “Suspect in Poway Synagogue Shooting Accused in Escondido Mosque Arson,” NBC San Diego, April 30, 2019; Kaelyn Forde, Emily Shapiro, Matt Gutman, and Matt Seyler, “Pittsburgh Synagogue Shooting: What We Know about Alleged Mass Shooter Robert Bowers,” ABC News, October 29, 2018.
 “Buffalo Shooting Suspect’s Prior Threat Sent Him to Mental Hospital,” CBS News, May 16, 2022. For background, see Amarnath Amarasingam, Marc-Andrew Argentino, and Graham Macklin, “The Buffalo Attack: The Cumulative Momentum of Far-Right Terror,” CTC Sentinel 15:7 (2022).
 “White Supremacist Prison Gangs.”
 Hamm, Spectacular Few, p. 53.
 “Sixteen Members of a White Supremacist Gang Indicted for Violent Crimes In Aid Of Racketeering,” U.S. Department of Justice, July 15, 2021. See also Kathryn Varn, “Florida White Supremacist Gang Members Indicted on Kidnapping, Assault Charges,” Tampa Bay Times, July 15, 2021.
 “Multi-Agency Investigation Results in Charges Against 18 Members and Associates of Violent White Supremacist Gang,” U.S. Department of Justice, March 27, 2019.
 “Members, Associates of White Supremacist Gangs Charged in Methamphetamine and Firearms Trafficking Cases,” U.S. Department of Justice, October 16, 2020.
 Raphael D. Marcus, “Lone Actor Terrorism” in Scott Romaniuk ed., The Handbook of Homeland Security (New York: CRC Press-Taylor Francis, forthcoming).