Prisons have been “centres of gravity” for virtually every terrorist group in the modern era. The strategies, goals, and operations of a variety of groups – from Egyptian Islamists to German Marxists and Irish Republicans – have all been heavily influenced by the imprisonment of their members. In many instances, the treatment of imprisoned comrades served as an important rallying cause, and the lives of extremists have been fundamentally shaped by their time in the jail cells of the state. The increase in the number of suspected and convicted terrorist inmates throughout the Middle East, particularly in Iraq and north-eastern Syria, has made prisons even greater focal points in countering Salafi-Jihadi movements. It is vitally important to continue to tailor policy according to the best available evidence in various contexts and to understand the dynamics and consequences of different types of prison management.

This review examines 34 studies (including academic articles, policy reports, programme evaluations, and the grey literature) published in English between 2000 and 2021. The systematic search generated 9,447 articles, of which 25 met the inclusion criteria. The hand search identified an additional nine studies for inclusion.

Key findings

The evidence base for prison-based interventions targeting violent extremists, whether in fragile and conflict-affected states or in the developed world, is very poor. Many existing programmes are in their infancy, and so they have not yet been robustly evaluated. However, there are promising themes. The naming of programmes can affect attitudes towards them, whether of participants or wider society. Involving family members can be beneficial to participants, and relatives can be supportive of deradicalisation/disengagement measures. Using deradicalised/disengaged leaders of extremist groups in interventions can have a positive impact on low-level members. There are promising signs that rapport-building is an effective technique when interviewing terrorist detainees. The same is true of motivational interviewing (MI), especially when applied to detainees who are ambivalent about and resistant to change. These techniques encourage engagement and disclosure of information. There is also some evidence that conducting sessions in informal settings leads to greater engagement. Regarding wholesale programmes, the most effective programmes are ones with a comprehensive array of interventions, which include treating inmates with dignity and respect. The Sri Lankan programme has been most effective, and there are promising aspects of the Saudi Arabian and Pakistani initiatives. Those programmes are comprehensive and multifaceted in approach, including vocational training, psychological support, family support, religious counselling and education, and, in some cases, financial assistance.

This review of evidence was originally published on the International Centre for the Study of Radicalisation’s website.