The U.S. Supreme Court made two landmark rulings regarding the death penalty during the month of June. In the decision Atkins v. Virginia, the Supreme Court ruled that executing prisoners with mental retardation was unconstitutional, reversing its 1989 ruling that upheld the executions of such offenders. Twenty of the 38 death penalty states had permitted the execution of mentally retarded capital offenders. Days after the Atkins decision, in the decision Ring v. Arizona, the Supreme Court decided that juries, not judges, must determine whether defendants may receive the death penalty.