Mental Retardation as a Bar to the Death Penalty: Who Bears the Burden of Proof

In holding that the execution of mentally retarded offenders is cruel and unusual punishment,\u27 the instant court followed the current trend of other states. Even before the Supreme Court of the United States rendered its decision in Atkins, state legislatures around the country, including the Missouri legislature, had enacted laws prohibiting the execution of mentally retarded offenders.\u27 Also, the Supreme Court of Missouri\u27s holding that a defendant bears the burden of proving his mental retardation is consistent with the position taken by the vast majority of states. However, the court rendered its holding in the absence of any legislation placing the burden upon the defendant.\u27 In so doing, the court was not acting in conformity with Missouri common law setting forth doctrines of statutory construction.\u27 Furthermore, by not requiring that the burden of proving mental retardation be beyond a reasonable doubt, the court arguably failed to follow precedent of the Supreme Court of the United States. This Note analyzes these issues and concludes that, while the Supreme Court of Missouri\u27s holding in the instant decision followed the trend of other state legislatures, it failed to make its decision in accordance with Missouri common law