“…In 2010, Singh, Serper, Reinharth, and Fazel (2011) identified more than 120 risk assessment tools for clinical and/or professional judgment. Tools that might be relevant in terms of extremism include the Multi-Level Guidelines (MLG: Cook, 2014; Cook, Hart, & Kropp, 2013), the Violent Extremism Risk Assessment (VERA-2: Pressman, 2009; Pressman & Flockton, 2014), the Extremist Risk Guidelines (ERG-22+: Lloyd & Dean, 2015), and, specifically for lone actors, the Terrorist Radicalization Assessment Protocol (TRAP-18: Meloy & Gill, 2014). The MLG comprises 20 risk factors with four nested domains (individual, individual-group, group, and group-societal), the VERA-2 31 factors, and the ERG 22+ (22 factors are identified but it is acknowledged that more may be added).…”