Violent extremism and terrorism in its different forms are an important security issue in Europe (European Union, 2020) and in the rest of the world. Terrorist attacks such as in Oslo, Paris, Nice, London, Brussels, Orlando and New-Zealand also with violent extremist assassinations of politicians create fear and upheaval in society. Therefore, an evidence-based approach to violent extremism and terrorism is urgently needed.

Scientific knowledge and evidence-based risk assessment and risk management of violent extremism and terrorism are important for policy issues and for all professionals involved. We need more knowledge about the related personal and contextual risk factors (Borum, 2015; Monahan, 2017). Therefore, the European Database of Terrorist offenders (EDT) was developed (Alberda et al, 2021). The Violent Extremist Risk Assessment tool (VERA-2R) has been actualised in 2018 and translated in four languages. More than 1000 professionals have been trained in Europe, and possibly 700 professionals elsewhere in the world.