Legal insanity is a peculiar element of criminal law, because it brings together two very different disciplines: psychiatry and psychology on the one hand and the law on the other. One of the basic questions regarding evaluations of defendants concerns the question of who should establish \"true mental disorder,\" the judge or the behavioral expert? This question is complicated, and in this contribution it will be explored based on a Dutch case that was eventually decided by the European Court of Human Rights (ECtHR). We will argue that the ECtHR provides a valuable legal framework. Based on its merits, the framework could also be of interest to countries outside the Court\'s jurisdiction.

A recent governmental report has suggested that the notion of insanity, which has not been a relevant concept in Swedish criminal law for the last 50years, should be reintroduced into the criminal justice system. This move has generated a debate over the most appropriate criteria to be included in a legal standard for insanity. We consider the fundamental question of whether a legal standard is required when introducing insanity, by looking at a legal system in which legal insanity is available but where no standard is used: The Netherlands. Overall, a review of advantages and disadvantages leads to the conclusion that such a standard is necessary. What exactly should that standard be? Is the development of different \"grades\" of insanity desirable? Legal considerations concerning what is essentially a legal notion should predominate in making these determinations-informed by psychiatric and other relevant scientific findings.