The assessment of volition in insanity cases in Japan

In theory, Japan's two-pronged insanity defence offers a defence to a wider range of offenders, considering the narrow nature of the wrongness limb. However, the assessment of the volitional prong presents a significant challenge in murder trials. This assessment appears to rely more on the defendant's general circumstances and the nature of the crime rather than the mental disorder. There seems to be a disregard for the influence of mental disorders, and the courts seem to emphasise defendants' free will and alternative options. The ambiguity of the guidelines affords broad discretion to judges, as a result of which mentally disordered offenders are often sentenced to death. Drawing on case examples and legal guidelines, this article provides an overview of the assessment of the volitional prong in Japan, exploring its evaluation in conjunction with mental disorders and demonstrating the need for a clear and consistent approach to prevent the execution of mentally disordered offenders.