Neuroimaging offers great potential to clinicians and researchers for a host of mental and physical conditions. The use of imaging has been trumpeted for forensic psychiatric and psychological evaluations to allow greater insight into the relationship between the brain and behavior. The results of imaging certainly can be used to inform clinical diagnoses; however, there continue to be limitations in using neuroimaging for insanity cases due to limited scientific backing for how neuroimaging can inform retrospective evaluations of mental state. In making this case, this paper reviews the history of the insanity defense and explains how the use of neuroimaging is not an effective way of improving the reliability of insanity defense evaluations.