After finding petitioner Stringer guilty of capital murder, a Mississippi jury, in the sentencing phase of the case, found that there were three statutory aggravating factors. These included the factor the murder was "especially heinous, atrocious or cruel," which had not been otherwise defined in the trial courts instructions. Stringer was sentenced to death, the sentence was affirmed by the State Supreme Court on direct review, and postconviction relief was denied in the state courts. The Federal District Court then denied him habeas corpus relief, rejecting his contention that the "heinous, atrocious or cruel" aggravating factor was so vague as to render the sentence arbitrary, in violation of the Eighth Amendments proscription of cruel and unusual punishment. The Court of Appeals ultimately affirmed, holding that Stringer was not entitled to rely on Clemons v. Mississippi, 494 U.S. 738, or Maynard v. Cartwright, 486 U.S. 356, in his habeas corpus proceedings because those decisions, which were issued after his sentence became final, announced a "ne