Whether the State's failure to disclose impeachment evidence constitutes cause sufficient to excuse the petitioner's prior non-presentation of due process violations, and whether a court conducting the Brady prejudice inquiry must consider the entirety of the suppressed evidence?

QUESTIONS PRESENTED The State built its death penalty case against Christopher Collings on the credibility of its primary law enforcement witness, Wheaton Police Chief Clinton Clark, regarding incriminating statements Clark obtained from Collings. Clark’s testimony was the only evidence to all other available evidence—that Collings received a Miranda warning prior to his interrogation by Clark, and the statements Clark obtained directly contradicted the victim’s stepfather’s confession admitting to being the only person who committed the fatal act. However, although Clark had four prior criminal convictions for AWOL, the State did not disclose Clark’s convictions during Collings’s trial, direct appeal, or initial state post-conviction proceedings. Instead, the State did not disclose them until after the conclusion of these proceedings. The State’s failure to disclose Chief Clark’s prior criminal convictions prevented Collings’s trial counsel from using the convictions to impeach Clark at the suppression hearing and trial proceedings, including that the convictions may have disqualified Clark from serving as a police officer at all. Similarly, the State’s failure to disclose prevented post-conviction counsel from investigating the relationship of Clark’s convictions to his service as a police officer as well as any due process claims under Brady v. Maryland, 373 U.S. 83 (1963), stemming from the State’s failure to disclose the convictions. Although prior counsel did not have grounds to present Brady violations to the Missouri Supreme Court until the State finally disclosed the convictions, the State nonetheless contended in the court below that Collings could not show cause for failing to present the Brady violations earlier. The State further contended Collings could not show prejudice because of the age of the prior convictions. The Missouri Supreme Court accepted these arguments and ignored both the State’s duty to disclose and the import of the prior convictions as impeachment evidence. This case raises the following questions: Whether the State’s failure to disclose impeachment evidence constitutes cause sufficient to excuse the petitioner’s prior non-presentation of the due process violations stemming from the State’s failure to disclose? Whether a court conducting the Brady prejudice inquiry must consider the entirety of the suppressed evidence? i