Mad or bad? Una riflessione comparata su imputabilità ed insanity defense a partire dalla sentenza della Corte Suprema degli Stati Uniti Kahler v. Kansas

On March 23, 2020, in the Kahler v. Kansas judgment, the U.S. Supreme Court ruled that the AmericanConstitution does not impose on states a duty to provide that a person suffering from a mental illness, whichrendered them unable to appreciate the wrongfulness of the act, should go exempt from criminal liability. Infact, the state of Kansas adopted the mens rea approach in 1996, abandoning far more popular variations of the insanity defense (e.g., the M’Naghten test). According to this approach, the presence of mental illness is only relevant (for a successful insanity defense) if it negates the mens rea required for the crime. With this inmind, the paper aims to use the findings of the Kahler v. Kansas ruling to provide insights into matches andmismatches between the regulation of criminal insanity in Italy and in the United States. Hence, the inquiry will deal with two pillars of criminal science – the insanity defense and the notion of « imputabilità » – in a comparative manner. In order to conduct this analysis, the paper will first situate the different formulations
of the insanity defense from a dogmatic perspective, as well as account for the ambiguity of the termmens rea in American legal doctrine. Based on these findings, the paper will then present critical observations regarding the narrow interpretation of such a concept as conveyed in the analyzed judgment.