The VERA and revisions are developed as an evidence-based standardized tool.
Terrorism indicators that were empirically supported by scientific literature on terrorism and empirical experience were used to develop the first VERA and the first revision (Crenshaw, 1995, 2000; DHS, 2007; FBI, 2001; Kreuger, 2007; Bakker, 2006; Kruglanski & Fishman, 2006; Kruglanski et al, 2009; Horgan, 2003, 2005, 2008; Laqueur, 2003, Merari, 2005, Merari, 2010).
Other risk assessment approaches and tools were also reviewed prior to the VERA development (Kropp et al, 1995; Monahan, 1981; Monahan et al., 2001; Monahan & Steadman, 2004; Hare, 1991, 2003; Hanson, 2005; Kruglanski & Fishman, 2006; Hanson, 2005; Hare, 2003; Hart, 1998; Hart & Logan, 2011; Ogloff, 2009).
In the VERA-2R the empirical basis has been improved and actualised. It has Additional indicators, for example criminal history and psychopathology. There is evidence of an important link between crime and terrorism (Reitano, Clarke, & Adal, 2017; Weenink, 2019), and more than half of the European recruits to IS states have criminal pasts (Basra, Neumann & Brunner, 2016; Neumann & Basra, 2018).
Also, psychopathology has been identified as a potential risk factor that may influence an individuals’ engagement with terrorism, especially lone actor terrorists (Gill, 2015; Gruenewald, Chermak, & Freilich, 2013; Gill & Corner, 2017; Duits et al., 2017; Lankford, 2018).