Criminal couples. From "madness shared by two" to the mental illness: A review of brutal crimes

The criminal couple is an uncommon phenomenon, since criminals act alone or involving other individuals in a fortuitous manner. The murders committed in pairs represent a rather rare eventuality (it is estimated that in Italy they are about 5%). At the base of this very particular dynamic there is the c.d. folie à deux, otherwise indicated in the psychiatric nosography as "Shared Psychotic Disorder" and ICD-10 as "Induced Delusional Disorder". Described for the first time in 1887 by Lasègue and Falret, it is characterized by the appearance of a delirium in a subject called the Primary Case, shared by the induced subject. The delusional couple lives in close correlation and at the same time isolated from the social context, conditions that facilitate the influence of the incube, bearer of a more serious mental pathology, on the succubus not necessarily affected by a psychotic pathology, nor, by force coming from a criminal subculture. The succubus therefore welcomes the delirious ideas of the incube and makes them its own, giving life not to the simple sum of two individuals but to a quid novi represented by the couple, united by a very strong pathological dependence. This contribution aims to highlight, through the analysis of some famous homicidal couples, the recognition or otherwise of the perpetrators of crimes, a total or partial defect of mind and the consequent imputability not omitting considerations on the social reintegration of them; once the prison sentence has been expiated.