Advancement of neuroscience and the assessment of mental state at the time of offense

Neuroscience has the benefit of illuminating the neural correlates of behaviors that are of interest to the legal system. This raises the optimism that neuroscience will be able to considerably and appropriately address some perennial problems besetting the legal system. Notable among them are the determination of: (1) criminal responsibility; (2) mental states at the time of offense; (3) competence to stand trial (also known as fitness to plead or adjudicative competence); and (4) whether a defendant is telling the truth. Whereas previous discussions have focused mainly on criminal responsibility, the present review is limited to the assessment of mental states at the time of offense as a legal pre-requisite for determining criminal responsibility in trials involving defendants claiming mental incapacitation (insanity defense). This is one of the challenging forensic assessment endeavors, attracting public criticisms following acquittals based on the insanity defense. We canvas the relevant neuroscientific evidence to elucidate how neuroscientific advances can be applied to help improve upon the assessment of mental states at the time of offense examinations. We examine neuroscience assessments of intention, knowledge of the nature and quality of an act, knowledge of wrongness of an act, as well as decision-making. We conclude that neuroscience assessments would be useful as a complementary data source in insanity evaluations. Clinical opinion based on neuroscientific findings as well as psychosocial data (biopsychosocial assessment) would help to improve upon assessment results.