PT - JOURNAL ARTICLE AU - Felthous, Alan R. TI - Rationality Was Lost on the United States Supreme Court in Its <em>Kahler</em> Decision AID - 10.29158/JAAPL.210054-21 DP - 2021 Dec 21 TA - Journal of the American Academy of Psychiatry and the Law Online PG - JAAPL.210054-21 4099 - http://jaapl.org/content/early/2021/12/21/JAAPL.210054-21.short 4100 - http://jaapl.org/content/early/2021/12/21/JAAPL.210054-21.full AB - In its recent Kahler decision, the U.S. Supreme Court ruled that Kansas’ abolition of the state’s insanity defense was constitutional. It did so by framing the matter as a choice between the state’s mens rea defense and a moral capacity defense, then mischaracterizing the mens rea defense as a type of insanity defense. In analyzing the two approaches, the Court missed the fundamental importance of rationality in criminal mental responsibility, a constitutional requirement for other criminal competencies, and a condition well described in the Court’s Panetti ruling. The Court’s acceptance of the abolition of a special insanity defense is a public policy in the direction of further criminalizing and punishing rather than providing prompt and proper treatment to those with serious mental illness, at a time when increasing modern research demonstrates the success of insanity acquittee dispositions with improved treatment and management resulting in lower rates of relapse and criminal recidivism.