The insanity defense in Shelby County,Tennessee

The purpose of this investigation was threefold: to document the number of cases in Shelby County, Tennessee where an insanity defense was possible: to follow cases through to disposition to determine what percentage of defendants use the defense successfully; and to examine the type of charges for insanity cases. Of the 25.000 individuals processed through the Criminal Courts. 685 (2.7%) were referred for insanity evaluations and 45 defendants (6.6%) were returned to the court with a recommendation from the Midtown Mental Health Center's Forensic Team that an insanity defense was possible. Of the 45 insanity defendants identified, 49% (n=22) pleaded guilty, 31% (n=14) went to trial, and 20% (n=9) were dismissed. Overall, 22% (n=10) of the insanity defendants were adjudicated not guilty by reason of insanity. Thus, of all defendants processed (25,000), 04% (n=11) were adjucated not guilty by reason of insanity. While no one type of offense predominated, two general categories were observed: murder and related offenses (33%) and property crimes (27%). The findings are discussed with reference to procedures for handling insanity cases in Tennessee and the position that extreme caution should be exercised before investing substantial resources to effect sweeping changes in laws that effect so few criminal defendants.