1. Whether, to establish "suppression" under Brady
v. Maryland , 373 U.S. 83 (1963), and the parallel
"cause" to excuse procedural default of a Brady
claim, a defendant must show that he could not
have discovered the fav orable evidence through
his own independent due diligence, as the Fifth
Circuit and five other circuits have held, or
whether the defendant's diligence is irrelevant to
the analysis of "suppression" and "cause ," as the
remaining six courts of appeals have held.
2. Whether a petitioner may present separate and
distinct causes excusing the procedural default of claims that have been found to relate back to an
original federal habeas petition under Mayle v.
Felix, 545 U.S. 644 (2005), or whether a p etitioner is restricted to presenting a single cause
excusing default where claims relate back.

Whether a defendant must show inability to discover favorable evidence through due diligence to establish 'suppression' under Brady v. Maryland