Is it possible to identify behaviors or expressions that can betray the intent of individuals or groups to commit acts of terrorism? With that question the Dutch authorities approached Leiden University’s Center for Terrorism and Counterterrorism in 2011. The two-year collaboration that followed aimed to uncover possible ‘indicators’ of terrorism and radicalization. It did so by conducting seven in-depth, primary-sources based case studies of homegrown jihadism in three western countries. This project was geared towards providing practical insights and tools that could assist police and security services in the early detection and prevention of terrorist plots.

The existing literature on this topic is limited in size and, some important exceptions notwithstanding, has produced few in-depth analyses. This means that there is little in the way of a theoretical or empirical basis on which to build. As a consequence, research on potential indicators of terrorism and radicalization is largely exploratory in nature. The authors do not claim to have uncovered causal relationships between certain behavior or certain expressions and the intention of individuals or groups to commit terrorist attacks. Instead, they identify behaviors and expressions that, when analyzed in conjunction with each other and within the context of an active investigation of a group or individual of interest, can provide important guidance for establishing a terrorist threat assessment.

The indicators research project proceeded from a literature study which identified that; a) terrorist groups do frequently produce observable behaviors and expressions that betray their intent and b) such information has a proven utility when it comes to law enforcement and intelligence agencies’ ability to detect and prevent terrorist plots. These findings were used to create a preliminary analytical framework of the different stages leading up to a terrorist attack, along with potential indicators of those different stages. The framework’s categories encompass the individual characteristics of the persons of interest, the ideological convictions of these individuals or groups, organizational development, attack planning, attack preparation, operational security and related activities that may yield important clues that can lead to the detection of suspect individuals or groups.

Ultimately, the authors hope that this framework and the associated indicators can make a modest contribution to the early detection and prevention of homegrown jihadist terrorist plots.

This topic will be presented at the annual Society for Terrorism Research conference in Boston on September 18^th.