Research Impact


Improving identification and management of Violent Extremists

Led by Professors Paul Gill and Noémie Bouhana’s, the UCL Counter Terrorism Research Group has provided the scientific evidence needed to better identify, assess and manage violent extremists.

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28 April 2022

Professors Gill and Bouhana’s belief is that terrorist behaviour should be examined like any other criminal behaviour: through robust, problem-oriented, and interdisciplinary science. Incorporating insights from diverse disciplines including life-course criminology, psychology and political science, their research has provided important new insights into the characteristics and behaviours of those who engage in violent extremism and has transformed how these complex crimes are tackled. 

Working closely with Greater Manchester Police and using police and intelligence files, Professor Gill and Dr Emily Corner’s early analysis offered new insights into lone-actor terrorists. They revealed the need to focus on behaviour rather than socio-demographic factors, demonstrated the importance of criminal histories and provided a finer-grained understanding of online behaviours associated with radicalisation. Crucially, the research also revealed that friends and family often knew about the offender’s grievance or violent intent, an insight offering new avenues for early detection and intervention. 

Through analysis of first-hand terrorist accounts, Professor Gill, Professor Bouhana, Dr Corner and Zoe Marchment uncovered the how terrorists choose particular targets including their response to deterrents like CCTV and police patrols, and insights into how terrorists can be detected and disconcerted in the build up to attacks. 

Professor Gill and Dr Corner also gained important insights into the mental state of lone-actor terrorists. Their research found lone-actors to be 13.4 times more likely than co-offending terrorists to have a diagnosed mental health disorder prior to offending, and identified a range of co-morbidities, behaviours and traits which could be used for risk assessment and management.  

Professors Gill and Bouhana’s findings highlighting similarities between violent extremism and other forms of targeted violence such as mass shootings have influenced the US Department of Homeland Security (DHS)’s Office for Targeted Violence and Terrorism Prevention to redefine their definition of ‘targeted violence’ to incorporate both types of acts.  

National risk assessment tools have also benefitted from the incorporation of the team’s insights.  For example, Fixated Threat Assessment Centres in Australia use a ‘Risk Aide-Mémoire’ tool, designed to help manage intervention and monitoring requirements associate with lone, fixated individuals. This tool, which has been used to assess behaviour, motivations, mental states and the risk of radicalisation in over 2,000 cases, draws heavily on the UCL team’s research, particularly in relation to mental health. The Terrorist Radicalization Assessment Protocol 18 (TRAP-18) tool used in Canada, Europe and the US to assess persons of concern for ideologically-motivated violence has also used Professor Gill’s research on lone-actor terrorists, citing the work extensively in its guidance manual.  

Professors Gill and Bouhana’s finding that families and communities are often aware of radicalisation or violent intent has also been highly influential, with counter terrorism units in the UK now recognising the need to work closely with communities through a public health approach. This is typified in Counter Terrorism Policing’s ‘ACT Early’ safeguarding prevention campaign launched in November 2020, which provides advice, guidance and support for adults who are concerned a young person may be vulnerable to radicalisation. This insight has also been instrumental in setting up Counter Terrorism Vulnerability Hubs to support those with mental health vulnerabilities who may be at risk of radicalisation, and collaboration with the UK’s North-West Counter Terrorism Unit (Project Regulus) has promoted more evidence-based and effective working across the UK counter-terrorism network.   

Research synopsis 

Improving identification and management of Violent Extremists 

Risk assessment and management are core to counter-terrorism practices worldwide, influencing the outcome of almost every referral into counter-terrorism practice. Led by Professors Paul Gill and Noémie Bouhana’s, the UCL Counter Terrorism Research Group has provided the scientific evidence needed to better identify, assess and manage violent extremists including through the UK Counter Terrorism Unit’s PREVENT and ACTEarly campaigns, and the Terrorist Radicalization Assessment Protocol (TRAP-18) used in Australia, Europe and the US.