Whether a habeas petitioner is entitled to a certificate of appealability when the state trial court and federal district court agree that the petitioner has pleaded a claim that, if true, would warrant relief, and reasonable jurists could debate whether the district court erred in limiting discovery

QUESTION PRESENTED Harvey Windsor was convicted of capital murder during a robbery on a theory of accomplice liability, and he was sentenced to death following a penalty phase in which the State presented only one aggravating circumstance, the one established by the jury’s guilt-phase verdict, and his defense counsel presented only a single, brief witness. In state postconviction and federal habeas proceedings, Mr. Windsor alleged that trial counsel were constitutionally ineffective because they did not present available and compelling mitigating evidence regarding a head injury caused by a motorcycle accident he was involved in three years before the offense. Both the original trial judge and the district court below recognized that, if he could establish that the head injury provided a mitigating explanation for the crime, Mr. Windsor’s death sentence likely would not stand. Yet, in federal habeas proceedings, despite well-taken motions for extensions of time in which to complete the discovery about his head injury, to which Mr. Windsor was found entitled, the district court ended the discovery process as habeas counsel was continuing to engage in good faith efforts to complete it. The district court denied Mr. Windsor’s habeas petition without an evidentiary hearing and denied him a certificate of appealability. Without opinion, the Court of Appeals for the Eleventh Circuit likewise denied him a certificate of appealability. The question presented is: Whether, when both the state trial court and the federal district court agree that a habeas petitioner has pleaded a claim that, if true, would warrant relief and when reasonable jurists could debate whether the district court erred in limiting discovery, a Court of Appeals should issue a Certificate of Appealability. i