are typically poor witnesses, and their demeanor may create an unwarranted impression of lack of remorse for their crimes.” Id. at 320-21, 122 S.Ct. at 2251-52, 153 L.Ed.2d at 350. Further, the Court found, reliance on mental retardation as a mitigating factor, a device frequently employed in capital sentencing, may be counterproductive, since jurors may construe the existence of the condition, instead, as enhancing the likelihood of future dangerousness, a commonly-employed aggravating factor. Id. at 321, 122 S.Ct. at 2252, 153 L.Ed.2d at 350. Mentally retarded defendants in the aggregate face a special risk of wrongful execution. Ibid. The Court’s decision in Atkins forms a part of a trilogy, consisting also of Ford v. Wainwright, 477 U.S. 399, 106 S.Ct. 2595, 91 L.Ed.2d 335 (1986) (<HOLDING>) and Roper v. Simmons, 543 U.S. 551, 125 S.Ct.
holding that the eighth amendment prohibits the punishment of death for a defendant convicting of raping a child holding that the eighth amendment prohibits states from inflicting the death penalty upon a defendant who is insane holding that the eighth amendment prohibits execution of persons whose mental illness prevents them from comprehending the reasons for the penalty and its implications holding that the eighth amendment to the united states constitution prohibits the execution of mentally retarded individuals recognizing that the eighth amendment protects individuals from a lingering death