"The court noted that, “The overall principle that emerges from the High Court’s decisional law is that federal due process permits States to place a burden on the defendant to prove an affirmative defense by a preponderance of the evidence, so long as the defendant is not thereby required to negate an element of the offense” (that’s right, given Martin v. Ohio). The court declined to reconsider Cropper in this case, stating, “appeal was not allowed in this case to reconsider or adjust the rule arising from Cropper; we decide the appeal in conformity with existing law concerning self-defense, which provides that, where self-defense is properly joined, the Commonwealth has the burden to disprove that defense beyond a reasonable doubt.” But in footnote 10, either the Court or just the Chief Justice (depending on how one reads the “This author would note” sentence) writes,

Appellee’s failure to offer any evidence to support the subjective aspect of his claim of self-defense highlights the difficulties associated with assigning the Commonwealth the burden to disprove a defense where necessary facts are peculiarly within the knowledge and control of the defense. In any event, the fact that the burden has been assigned to the Commonwealth — erroneously, as addressed in Part I supra — not only to affirmatively prove the elements of the offenses charged, but also to disprove self-defense where it is at issue, does not remove the necessity that there be some actual evidence to support the elements of the defense when proffered."

Commonwealth v. Mouzon (Pa. 2012), http://scholar.google.com/scholar_ca...27240067110102