Legal research in Sweden has traditionally focused on a systematization of the legal rules and their practical application, while the task of studying the effects of the application of the laws has been handed over to other branches of the social sciences. In contrast, new legal theories focusing on proactive and therapeutic dimensions in law have gained increasing attention in the international arena. These approaches may be better suited for evaluating legislation governing compulsory psychiatric care. Theoretical discussions and studies of causal mechanisms underlying criminal behaviour, as well as the implementation and value of instruments for predicting behaviour, are relevant to contemporary criminological research. Criminal behaviour varies across different groups of perpetrators, and the causes can be sought in the interplay between the individual and social factors. Multi-disciplinary efforts, integrating research from forensic psychiatry, psychology, sociology, and criminology, would be beneficial in leading to a better understanding of the causes underlying criminal behaviour.