Family Matters: Insanity defense left up to states, high court rules

By Marie Matyjaszek

In mid-March of this year, the United States Supreme Court made a significant ruling regarding the use of insanity as a defense to a crime. In the case of James Kahler v Kansas, the high court ruled that the due process clause of the Constitution does not require a state to acquit a defendant who was found to be insane at the time of the crime.

Kahler was convicted of murdering his family and was sentenced to death in Kansas. His wife had left him, taking their children, causing Kahler great distress. While Kansas provides for mental disease or defect as a defense to a prosecution, it only allows for an acquittal if the defendant could not form the necessary mens rea. Kahler attempted to use his depression as proof he was unable to form the requisite intent to kill. He also introduced evidence in an attempt to reduce his sentence due to mental illness, but was unsuccessful.

Kahler appealed, challenging the fact that Kansas does not allow “an insanity defense that acquits a defendant who could not ‘distinguish right from wrong’ when committing his crime.” Kansas instead provides for cognitive incapacity, not moral incapacity, as a defense. The Supreme Court decided that in order for Kansas’ law to violate due process, it has to “‘[offend] some principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.’” The opinion provided a fascinating look at the insanity defense throughout legal history.

The Court reiterated that it is paramount to allow individual states to determine what can be used as a defense to a criminal act, due to ever changing social policies, morals, and ethics. It is not the duty of the Supreme Court to dictate how the states choose to apply the insanity defense, and the Court noted that opinions on mental illness and criminal behavior vary so widely that it would be unwise for the law to require one rigid standard. Since the research and knowledge on mental conditions change over time, a firm standard for the law would not adapt to the fluidity of the psychiatric field.

The Supreme Court affirmed the lower court in ruling that Kansas and all states have the power to choose how they handle insanity defenses. It seems particularly fitting that this ruling was issued at the beginning of the pandemic – if there was ever going to be a year in which to claim insanity, 2020 would be it.
The author is an Attorney Referee at the Washtenaw County Friend of the Court; however, the views expressed in this column are her own. She can be reached at


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