Marcel Emanuel Johnson v. Pennsylvania

On post-conviction review in this capital murder case, the state court held that the prosecution’s failure to disclose exculpatory impeachment evidence from the prison file of a jailhouse informant – a key witness who provided the only direct evidence of guilt by testifying that Petitioner had confessed to him – did not violate Petitioner’s due process rights under Brady v. Maryland, 373 U.S. 83 (1963). The state court held that there was no prosecutorial duty to disclose because the evidence could have been obtained by the defense using reasonable diligence and that the nondisclosure was not material because other circumstantial evidence was “sufficiently compelling” to sustain the conviction and sentence. The questions presented are:

1. Should this Court resolve the deep circuit split about whether a prosecutor’s duty to disclose exculpatory evidence under Brady v. Maryland, is excused when the evidence could have been discovered with the exercise of reasonable diligence by the defense?

2. Did the Pennsylvania Supreme Court’s materiality determination apply a standard that was contrary to this Court’s precedent and in conflict with the trial prosecutor’s arguments to the jury about the importance of the jailhouse informant’s testimony?