The Limited Relevance of Neuroimaging in Insanity Evaluations

Forensic evaluations of insanity have recently borne witness to an influx of neuroimaging methods, especially structural and functional magnetic resonance imaging and positron emission tomography, to assist in the development of explanations that help to excuse legal responsibility for criminal behavior. The results of these scanning methods have been increasingly introduced in legal settings to offer or support a clinical diagnosis that in turn suggests that an individual was incapable of knowing right from wrong, or to pinpoint brain dysfunction suggestive of an inability to control behavior. This paper examines how neuroimaging has been employed in insanity evaluations. After addressing the contentious use of neuroimaging scans in insanity evaluations and synthesizing relevant research, we conclude that such scans presently hold limited applicability for forensic determinations of insanity. Furthermore, they can in some cases distract the trier of fact, potentially leading to erroneous conclusions.