The terms violent extremism, mass shootings, and hate crimes can sometimes accurately describe a single incident, but each of these crimes has unique characteristics. Though there can be similar outcomes, means, and motivations for these crimes, each has its own definition and distinctions. Here’s what NIJ-sponsored research tells us about identifying people at risk of committing these offenses, as well as strategies to help mitigate the risk of someone carrying out such acts.
1. There are similarities in age, sex, employment, and criminal histories.
Data on individuals engaged in violent extremism, hate crimes, or mass shootings suggest that they are primarily males in their 20s and 30s who exhibit higher rates of unemployment and longer criminal histories (although this can vary when separated based on bias or ideology).[1] These characteristics could form the basis for general interventions aimed at people susceptible to carrying out such acts. However, these factors are too broad to identify specific at-risk individuals.
| Violent Extremism | Mass Shootings | Bias Crimes |
|---|---|---|
| Includes an ideologically motivated action, be it active support for or association with violent extremist or terrorist groups or actual participation in violent activities to achieve ideological goals. | Considered more common in occurrence and increasing in prevalence in the United States than violent extremist attacks, refers to events involving firearms and characterized by the shooting of multiple individuals within a limited amount of time or within close proximity. | Often less reported, prosecuted, and publicized than violent extremist attacks and mass shootings, these are criminal offenses against a person or property motivated by prejudice against a target’s race, religion, disability, sexual orientation, ethnicity, gender, or gender identity. |
2. Risk factors may vary across and within each offense type.
Background characteristics vary for individuals across (and within) these three offense types.[2] Motives for committing hate crimes are more diverse than for violent extremism or mass shootings. Many hate crimes result from an escalation of disputes that occur during routine daily activities, and there may be no effective way to preemptively measure risk in these cases.
Other notable risk factors:
- Higher levels of education, being unmarried, prior military involvement, and perceptions of victimization.[3]
- High rates of unaddressed mental health issues and previous trauma, in addition to feelings of unrealized expectations,[4] negative personal relationships, and recent personal crises.[5]
- Military involvement, in addition to feelings of “unmet expectations” and disappointment.[6]
See “Notable Risk Factors for Radicalization to Violence Extremism.”
3. Assessing risk is a challenge.
Variation in characteristics makes it difficult to accurately assess someone’s risk of committing these offenses, which underscores the shortcomings associated with using universal risk assessments and other one-size-fits-all profiles. Just as no single pathway into or out of these types of extreme violent lifestyles or acts exists, no agreed-upon or universal risk assessment tool for these specific populations exists. The infrequency of these types of offenses makes it difficult to assign a risk level to an individual. Even among existing risk assessment tools tailored to these populations, structured professional judgment remains the most common tool.[21] This highlights the importance of not just understanding the demographics of people who commit violent offenses, but also how life experiences and perceptions may combine to motivate the decision to do so.
4. Risk-mitigation and prevention strategies must be carefully crafted, tailored to the offense type, and catered to the individual.
Intervention and secondary prevention strategies can be tailored based on the offense and the people involved in its commission, with a focus on individual experiences and trajectories. General violence-prevention frameworks are a good starting point but are insufficient to address these three offense types. We must also account for ideological motivations, cater to local contexts, and address individual needs and grievances.
- Programs designed to prevent targeted mass casualty hate crimes should be based on a nuanced understanding of the individual risks that produce feelings of disappointment, anger, and societal rejection.[22] These strategies must be flexible and designed to address risks in highly diverse populations, and they should focus on prejudice type, levels of ideological commitment, and the location being targeted.
- Individuals who carry out K-12 school shootings usually leak their plans directly to peers or through social media before implementing them,[23] which can be seen as a cry for help and critical intervention point.[24] Mass shooters are also more likely to leak their plans.[25]
- Those closest to the individual are often first to notice early warning signs [26] of radicalization to violent extremism. However, these same peers are also the least likely to report these signs. Removing barriers to reporting (e.g., through training and trust building between law enforcement and the community) and bolstering multidisciplinary services in communities (e.g., mental/behavioral health, social services, education) are crucial to facilitating reporting on violent extremism, and ultimately mitigating risk and aiding prevention.[27]
5. Data limitations may impact our understanding.
Comparing NIJ-sponsored data on violent extremism, mass shootings, and hate crimes makes it clear how difficult it is to collect data on these behaviors. Datasets collating information on each type of offense — such as The Global Terrorism Database [28], The Violence Project, [29] and the FBI’s Hate Crimes Statistics Program [30] — may collect different information about the offenses and the people that commit them or may report that information in different ways.
For example, the definition of a crime varies across jurisdictions.[31] Not all events meeting the definitions of these crimes are observed, not all observed crimes are reported, and not all official records are accessible. It’s important to remember that research on these topics often relies on publicly available information — which is subject to its own biases, as not all crimes receive the same level of media attention.[32] Therefore, the ability to develop policy and practice recommendations is inherently limited.
Notable Risk Factors for Radicalization to Violence Extremism
Education -
Individuals who engage in violent extremism have higher levels of education and lower rates of previous trauma than those who commit mass shootings or hate crimes.[7]
Mental Health -
Individuals engaged in violent extremism displayed the lowest rates of mental health issues, while individuals carrying out mass shooter offenses displayed the highest, in aggregate.[8]
Military Involvement -
People engaged in hate crimes and far-right violent extremism may be more likely to have served in the military[9] than individuals engaged in mass shooting offenses and non-far-right violent extremist behaviors.[10]
Married vs. Unmarried -
Less than one-third of individuals engaged in lone actor violent extremist behavior, mass shootings, and hate crime offenses are married at the time of the offense.[11]
Social Interactions and Grievances -
Mass casualty actors are more likely diverse in terms of their risk profiles, even though they may be linked by general feelings of strain or unrealized expectations.[12]
Grievances brought on by unemployment, negative personal relationships, and unaddressed mental health concerns are the primary motivations for people engaged in mass shootings and lone actor extremism.[13]
People demonstrating violent extremist behavior may be more likely to be affiliated with like-minded groups and cliques, although there is also evidence to suggest that individuals engaged in hate crimes also have group affiliations.[14]
Social isolation does not seem to be widespread among individuals engaged in these offenses. Even lone actors show evidence of some social ties15 and may communicate their intent or plans prior to an offense.[16]
Precipitating Factors -
Individuals who engage in a mass shooting experience recent personal crises to a high degree before the act[17] and often leak their plans to others.[18]
Community crisis (or the perception that one’s community has been victimized) may contribute to conditions in which radicalization to violence occurs.[19]
A combination of feelings of “unmet expectations” and disappointment are potentially associated with the commission of mass casualty acts motivated by hate or bias.[20]
Learn more:
A Pathway Approach to the Study of Bias Crime Offenders
Final Report: Empirical Assessment of Domestic Radicalization (EADR)
A Multi-Level, Multi-Method Investigation of the Psycho Social Life Histories of Mass Shooters
Opinions or points of view expressed in this document represent a consensus of the authors and do not necessarily represent the official position, policies, terminology, or posture of the U.S. Department of Justice on domestic violent extremism. The content is not intended to create, does not create, and may not be relied upon to create any rights, substantive or procedural, enforceable at law by any party in any matter civil or criminal.