It is notoriously difficult to distinguish between those who simply espouse radical beliefs and those who are prepared to commit acts of extremist-related violence. This poses a problem for those responsible for counter terrorism (CT) needing to discriminate between the two. The present study adopted an empirical approach to compare violent extremists (VEs) and nonviolent extremists (NVEs). In-depth case studies on 40 extremist individuals were developed and analyzed for key themes, subthemes and underlying variables. VEs and NVEs were compared to understand where similarities and differences lie. Identified were a number of variables that distinguish between VEs and NVEs; this has implications for CT in terms of prevent, pursue, and intervention. Results can, for example, assist those responsible for CT and law enforcement to focus on variables that distinguish between VEs and NVEs to identify those who are most high risk (i.e., likely to actively facilitate and/or commit acts of extreme violence) and focus their efforts on these, rather than on those who are not. Results can also inform CT practitioners and policymakers on the development of tailored interventions for different types of extremist individuals and groups.