“ Regardless of a State's obligation to provide a competency hearing, it is clearly error for a federal court to accord deference to state-court findings when the state hearing is procedurally inadequate. ”

“ I believe that we shirk our responsibility if we do not articulate standards by which the adequacy of procedures in state competency hearings may be judged. I would grant the petitions for certiorari and the corresponding applications for stay of execution. Indeed, four Members of this Court have voted to grant certiorari in this case, but because a stay cannot be entered without five votes, theexecution cannot be halted. For the first time in recent memory, a man will be executed after the Court has decided to hear his claim. ”

“ In addition, Justice MARSHALL observed that " [c] ross-examination of the psychiatrists, or perhaps a less formal equivalent, would contribute markedly to the process of seeking truth in sanity disputes by bringing to light the bases for each expert's beliefs, the precise factors underlying those beliefs, any history of error or caprice of the examiner, any personal bias with respect to the issue of capital punishment, the expert's degree of certainty about his or her own conclusions, and the precise meaning of ambiguous words used in the report." ”