The trial court did err when it failed to follow the mandates of Penry v. Lynaugh (1989) 492 U.S. 302, (“Penry I”), by failing to instruct the jury in a manner which would allow them to consider and give effect to evidence of mental retardation as mitigating evidence. Reversal of the penalty phase was therefore required. J. Rehnquist, Scalia and Thomas dissented on the mental retardation issue.