Countering Lone Actor Terrorism: Data Collection & Analysis


As intelligence agencies and law enforcement have become increasingly adept at detecting and disrupting large-scale terrorist plots, potential attackers have instead turned to smaller scale, less sophisticated assaults. In part, this trend reflects a decision by extremist groups to adopt lone actor terrorism as a tactic, with groups trying to inspire their supporters to carry out such attacks. In other cases, individuals, dyads or triads judge that a lone actor attack will have greater chance of success, or perhaps lack connections to a wider network. Whatever the case, there is a growing trend of individuals or small cells acting in isolation from a wider group to conduct terrorist activity. Such lone actor terrorists are perceived as presenting acute challenges for law enforcement practitioners in detection and disruption; acting without direct command and control from a wider network, it is assumed that without such communications they may evade the traditional “trip-wires” that would bring them to the attention of the authorities.

Through the construction and analysis of a database of 120 perpetrators from across Europe, the Countering Lone Actor Terrorism (CLAT) project seeks to improve understanding of lone actor terrorists, their behaviour, and their activities in the period leading up to their intended attack, therefore assisting European governments and frontline workers to counter the threat.


Literature Review

Definitional Workshop

Database Workshop

Analysis Paper

Policy Paper 1: Personal Characteristics of Lone-Actor Terrorists

Policy Paper 2: Attack Methodology and Logistics

Policy Paper 3: Motivations, Political Engagement and Online Activity

Policy Paper 4: ‘Leakage’ and Interaction with Authorities

Analysis Paper

Toolkit Paper 2

Final Report

Project Activities & Goals

The CLAT project will not only focus on data collection and analysis related to lone actor terrorism in Europe, but will also attempt to operationalise these findings in policy recommendations and practitioner training. The aim is to produce conceptual clarity on the subject of lone actor terrorism. The current lack in this regard has had a negative effect on the understanding of the phenomenon, whilst also hindering the gathering of data. This makes it difficult to develop and implement effective policies on countering lone actor terrorism. Several policy briefs will be produced throughout the project and frontline workers and practitioners will be trained in identifying risk indicators and ways to respond to these.

The project kicked-off on 5 September 2014 in London and runs for 18 months. In early 2015, ICCT & Leiden University convened a two-day expert consultation with 30 academics and practitioners to develop a working definition of lone actor terrorism. In March, ISD hosted a follow-up workshop to further define the nature, scope and development of the database.

At the end of the data-collection phase, Chatham House hosted a workshop in September 2015 to analyse and discuss the findings thus far and prepare for the next phase of the project.

Project Partners

The initiative is funded by the Prevention of and Fight against Crime Programme of the European Union and is implemented by a consortium consisting of the Royal United Services Institute (RUSI), ICCT’s co-founding institution Leiden University, The Royal Institute of International Affairs Chatham House, and the Institute for Strategic Dialogue (ISD), in collaboration with the Netherlands National Coordinator for Security and Counterterrorism (NCTV)Polish Institute for International Affairs (PISM), and the UK Association of Chief Police Officers (ACPO). Research Fellow Prof. Dr. Edwin Bakker is responsible for implementing various parts of the project on behalf of ICCT & Leiden University.

In the Media

The Guardian (22 June 2016) ‘Rightwing ‘lone wolves’ kill more than Islamic terrorists acting alone, says report’

Trouw (12 March 2016) ‘Onderzoek: terreur door extreemrechtse ‘lone wolves’ wordt onderschat’ (in Dutch)

International Business Times (1 March 2016) ‘Neo-Nazi lone-wolf attacks in Europe are more deadly than ISIS-inspired terrorist plots’

Wiredgov (1 March 2016) ‘RUSI: New Study: European governments neglecting the threat of extreme right lone actor terrorists’

Additional Information

For more information please contact Research Fellow Ms. Jeanine de Roy van Zuijdewijn.