The insanity defense in cases of homicide involving post-mortem dismemberment

• Published in: Forensic science international. Mind and law 2020-11, Vol.1, p.100033, Article 100033
• Main Authors: Tidrick, Molly, Brucato, Gary, Petreca, Victor, Burgess, Ann W., Stone, Michael H.
• Format: Article
• Language: English
• Subjects: Dismemberment; Insanity; Motive; Murder; Posthumous
• ISSN: 2666-3538; 2666-3538
• DOI: 10.1016/j.fsiml.2020.100033

Little is known about the success of the insanity defense in homicide cases involving posthumous dismemberment. Such seemingly bizarre conduct may suggest, at first glance, aberrant mental states. Drawing from a larger study of cases of single or repeat homicide followed by dismemberment on at least one occasion, we examined 38 in which offenders pleaded the insanity defense. These were compared to 30 cases in which no posthumous dismemberment was observed. Cases were drawn from print and online sources, as well as the Radford/Florida Gulf Coast Universities Serial Killer Database (SKD). Various motivations for both homicide and posthumous dismemberment among defendants who attempted to plead Not Guilty by Reason of Insanity (NGRI) were analyzed. The most common style of mutilation and dismemberment observed was aggressive, occurring in the context of excessive emotion, such as rage or acute psychosis. Among those in the dismemberment group, 52.6% of the NGRI cases proved successful. In comparison, 33.3% of the NGRI cases were successful among those in the non-dismemberment group. A relationship between NGRI outcomes and motive for homicide was observed in both comparison groups. Our findings suggest that posthumous dismemberment may be an important characterological description in homicide offending, representing murderous impulses that may help to identify a sub-group of homicide offenders. Examination of posthumous dismemberment vis-a-vis NGRI verdicts also helps elucidate the degree to which posthumous dismemberment is, at least in some cases, a psychopathology-driven action. •The Aggressive style of dismemberment was the most common style displayed from our sample.•A significant relationship was observed between dismemberment style and motives for murder.•In the dismemberment group, 75% of successful NGRI cases involved motives associated with the offenders’ mental status and wellbeing.•In comparison, 47% of cases which were motivated by emotions or anger were not successful.•While 92% of the offenders displayed either aggressive or offensive styles of dismemberment, only about 52% successfully pled insanity.