Illuminating the Forensic Black Box: Understanding Radicalisation in Secure Settings

This article highlights key themes, research gaps, and areas for further investigation from the 96 reviewed studies, which followed the PRISMA standards (Moher et al, 2009). This included transparent inclusion and exclusion criteria for search strings, outlined databases and quality appraisal.

We know less than we think about radicalisation in forensic settings. Theoretically, two processes can occur:

1. Individuals with no prior history of extremism become radicalised for the first time in the setting; or
2. Radicalised individuals admitted to a forensic facility continue their extremism pathway, or their radicalisation is significantly enhanced.

Of the 96 studies, only five studies from the review exclusively examined psychological dynamics within these environments. Study quality, when assessed in the review for all 96 articles, showed only 56% of studies were rated as good, while the rest were rated fair or poor. For the studies pertaining to forensic settings, three were rated good and two were fair.

While clinical experts possess valuable knowledge concerning the context set by forensic settings, academic research access remains difficult, leading some scholars to describe prisons as potential "breeding grounds for terrorists" (Mulcahy et al., 2013, p. 4). Since then, findings have relativised this notion. While some individuals radicalise behind bars, evidence suggests prison settings can also disrupt radicalisation (Silke et al., 2021). Rehabilitation efforts may be more effective than previously thought (Marsden & Copeland, 2020), though empirical data remains limited. Even less is understood about radicalisation in forensic psychiatric hospitals, and more broadly, the role of mental health in radicalisation remains contentious, with studies both supporting and rejecting a connection (Gill & Corner, 2017).

Overlapping Risk Factors

A central finding from the review was that risk factors for violent extremism significantly overlap with those for general violence. This raises a key question: how do we disentangle those two risk dynamics in risk assessments for an already complex forensic population?

Key risk factors included:

• Criminal history & violent tendencies: Identified in 39 of the 96 studies, prior offences were commonly linked with extremist violence, suggesting shared underlying factors. By definition, everyone in forensic settings has a criminal history, thus posing a unique challenge for clinicians to identify those particularly vulnerable to radicalisation.
• Group processes: Social influences, such as peer networks reinforcing violent ideations, increase radicalisation risk (36 studies). Rigid group norms and violence-endorsing shared narratives, which deepen divisions between groups, are particularly pertinent in forensic settings, in my clinical experience.
• Strain & adversity: Discrimination, marginalisation, and personal grievances heighten susceptibility to radicalisation (29 studies). In forensic populations, perceived strain is naturally high due to involuntary detainment, making this a highly relevant dynamic to consider.

The Role of Ideology: Overestimated?

Extremist attitudes were the most researched topic (41 of 96 studies), yet findings were mixed. Some authors argued ideology drives violent extremism, while others saw it as a post-hoc justification for actions motivated by other factors. The latter ‘post hoc explanation’ is a common occurrence also for individuals who commit non-extremist violence and are then placed in forensic settings, making the presence of violent ideation per se not only a central facet of risk assessments but also a pivotal factor to address in forensic interventions to reduce aggression.

Mental Health: A Murky Picture

Findings from 31 studies remain inconclusive. Some suggest links between conditions like depression, anxiety, and personality disorders with violent extremism, while others find no clear association. Based on my own clinical work experience, it is not the mere presence of a diagnosis and associated symptoms that matters, but whether these symptoms can be plausibly related to extremist behaviours and violence risk (i.e., explaining the relevance of the symptoms is more important than mere presence, as explored in our multi-study that followed this review). A comprehensive examination of how mental health symptoms and violent extremism may interact can be found in ‘Violent Extremism: A Primer for Mental Health Practitioners’, edited by Caroline Logan.

Despite guidance from experts like Al-Attar, uncertainty can still challenge forensic practitioners, especially in how to establish clear care pathways when mental health symptoms and extremism-related attitudes and behaviours coexist. Without stronger evidence, determining best practices remains difficult.

What’s Missing?

Knowledge gaps identified in the radicalisation review included:

1. Forensic populations are understudied: Research overwhelmingly focuses on community samples, leaving a critical gap in understanding radicalisation in secure settings and caring for those individuals.
2. Protective factors are overlooked: Studies emphasise risk factors, but little is known about mitigating influences like resilience, social support, and adaptive coping. Protective factors are likely to be highly relevant in forensic care settings.
3. Lack of primary data: Many studies rely on publicly available information rather than direct engagement with radicalised individuals in forensic settings. However, this is not necessarily due to researchers’ lack of trying but because access is restricted due to national security concerns and ethical barriers. More qualitative research, including interviews, is essential.
4. Mostly Western perspective: Only 14 out of 93 articles had an explicitly non-Western focus. With both international actors and national forensic populations becoming more diverse, the broadening of research input beyond the US and UK is crucial.

Stronger collaboration between researchers and forensic practitioners is key to addressing these challenges and gaps. From the perspective of working in both research and mental health settings, I would suggest there is need for clearer ways to break down the complex behaviours and dynamics encountered in forensic settings, making it easier to understand how radicalisation overlaps with other types of violence. This approach would help understand mental health issues with more clarity and apply insights from community research to forensic settings while identifying emerging challenges across disciplines.

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Dr Sören Henrich is a lecturer and has published papers in Forensic Psychology at the Manchester Metropolitan University. He delivers international training on risk and threat assessment and remains a clinical advisor for secure forensic settings in the UK.