Adapting risk assessments to a changing terrorism landscape: Revising the extremism risk guidance.

The Extremism Risk Guidance-Revised (ERG-R) updates and expands the ERG22+ framework, which has guided terrorism risk assessment in prison and probation across England and Wales since 2011. Developed by His Majesty's Prison and Probation Service (HMPPS) Counter Terrorism-Assessment and Rehabilitation Centre (CT-ARC), the ERG-R responds to key shifts in the terrorism landscape, including the growth of online radicalization, greater involvement of younger individuals, an increase in extreme right-wing convictions, and more fluid ideological affiliations. The revised framework comprises 36 factors, building on the original three dimensions (engagement, intent, and capability) by adding a fourth dimension addressing protective and risk-mitigating factors, enhancing alignment with Structured Professional Judgment (SPJ) methodology. Its development drew on a comprehensive literature review, consultation with the Correctional Services Advice and Accreditation Panel (CSAAP), external peer review, and a 12-month pilot across custodial and community settings. The ERG-R enhances operational guidance for assessing dynamic risk, including tracking change over time and informing case prioritization, replacing fixed risk levels with more nuanced case management. Following practitioner training, the ERG-R was formally implemented across HMPPS in March 2025. This technical report outlines its theoretical foundations, development process, and practical application and considers its adaptability to jurisdictions beyond England and Wales.