WASHINGTON, June 20 — A divided Supreme Court reversed itself Thursday and ruled that executing the mentally retarded is unconstitutionally cruel — a decision that reflects changes in public attitudes on the issue since the court declared such executions constitutional in 1989. THE 6-3 RULING is confined to mentally retarded killers, and does not address the constitutionality of capital punishment in general. When the court first declared such executions constitutional in 1989. Then, only two states that used capital punishment outlawed the practice for the retarded. Now, 18 states prohibit it. “It is not so much the number of these...
