DescriptionThis conclusion paper summarises the main outcomes of the fourth meeting of Thematic Panel 5, hosted online on 11 December 2025. The gathering explored lessons learned in cooperation and evaluation, deepening into practical cases and insights on evaluation from real scenarios. In this sense, the management of multi-stakeholder cooperation in preventive efforts and useful tools andrecommendations in the evaluation of the prevention of radicalisation were addressed, with particular emphasis in cases of lone actor attacks. Thus, this meeting elaborated on the aforementioned issues in an interactive and collaborative dynamic.Related topicLone Actors and Mental Health IssuesLinkRead the document