Police investigating a deadly attack at a rave in Switzerland have said the gunman appears to have acted as a lone perpetrator, an early conclusion that shapes the direction of the inquiry. The violence shocked a country that rarely experiences such incidents.
Attacks at gatherings meant for celebration carry a particular horror, turning spaces associated with music and community into scenes of tragedy. Survivors and witnesses are often left with lasting trauma alongside their grief.
Investigators typically work to establish motive, planning and whether the attacker had any support, all of which influence both the legal process and public understanding. Determining that a suspect acted alone can ease fears of a wider threat.
Swiss authorities have sought to reassure the public while pressing ahead with their investigation. As details emerge, attention is likely to turn to questions of prevention and how such an attack could have been carried out.
