Study analyzes differences among lone, pair and group terror attackers

Analysis of more than 140 individuals convicted of extremist offenses in England and Wales has revealed how terrorists who act alone, in pairs, or in a group differ in background, social influence and activity.

The study of specialist files was carried out by Nottingham Trent University (NTU), His Majesty's Prison and Probation Service (HMPPS) and Bournemouth University and builds on a previous report into internet radicalization, which was the first to use closed source data of this kind of analysis.

It aims to identify the risk posed by each of these sub-groups based on in-depth professional risk assessments rather than the severity of their offense, as previously inferred.

In total, 44 lone actors, 20 lone pairs and 79 group actors were identified in the sample. Both lone and group actors were typically male (over 90%) with the figure lower for lone pairs (75%). The average age for all perpetrators at sentencing was under 30 and the majority were born in the U.K. Over time, lone-actor attacks have become increasingly prominent, while the opposite is true for group attacks.

The research, "An Analysis of Terrorist Attack Perpetrators in England and Wales: Comparing Lone Actors, Lone Dyads and Group Actors," has been published in the Journal of Threat Assessment and Management.

Findings showed that attackers affiliated with the Extreme Right Wing were more likely to commit attacks alone or in pairs, in contrast to Islamist extremists who were more likely to attack as a group.

The internet was also found to play an important role in radicalization pathways and attack preparation for lone actors and lone pairs, but a lesser role for group-based attackers. Lone-attackers were more likely to signal their intent online, which may make it easier to detect them and to counter attacks at an earlier stage.

Whether the attack progressed or failed was also analyzed in the research, showing that lone actors were least effective. While 30% of lone attackers completed their plan, this was the case for 40% of lone pairs and 41% of group actors. Across all three groups the majority of plots were thwarted by police and security services.

In addition, the study investigated prevalence of mental health issues and found that these were highest among lone actors and lone pairs. Using a wider definition of mental health, lone terrorists were the most likely to have mental illness, neurodivergence or a personality disorder based on percentages—at 57% of cases compared to 45% of lone pairs and 10% of group actors respectively.

Dr. Jonathan Kenyon, lead author of the study and working for HMPPS Counter Terrorism—Assessment and Rehabilitation Center, said, "One way of protecting the public more effectively against terrorist violence is to develop insight to support identification of potential attackers and evaluate risk more effectively.

"The high prevalence of a range of mental health issues suggests that we need more preventative responses to deter would-be attackers from their path. For example, particular attention should be paid to those with mental health concerns who are expressing support for extreme views, especially those supporting an Extreme Right Wing ideology."

Dr. Jens Binder, Associate Professor of Psychology at NTU's School of Social Sciences, said, "This study gives us an increased understanding of different attacker profiles, which can help guide counter-terrorism approaches and future policy. In particular, our analysis shows that online activity is no longer an effective shield against detection."