"Innocent until proven guilty beyond a reasonable doubt." There is perhaps no presumption more familiar in the law than the presumption of innocence. What is less familiar to most, however, is how quickly that presumption shifts to a presumption of guilt after a defendant is convicted. Once a conviction and sentence become final, the policy choice in favor of protecting the innocent shifts instead to protecting the finality of convictions.

Although both state and federal law recognize mechanisms to collaterally attack the validity of state convictions, in keeping with the policy favoring finality, these statutes provide very limited avenues to relief. See generally 42 Pa. C.S. Section 9542 et seq.; 28 U.S.C. Section 2254. For example, under Pennsylvania's Post Conviction Relief Act (PCRA), once a defendant's judgment of sentence is final, he/she has only one year to file a motion seeking a new trial. That one-year time period has been interpreted as jurisdictional, meaning that a court has no authority to consider an untimely petition even if there is a good reason the petition was late. See Commonwealth v. Peterkin, 722 A.2d 638 (Pa. 1998). A petitioner seeking to file a PCRA petition seeking a new trial outside that one-year period can do so only if he/she meets certain criteria, one of which is when "the facts upon which the claim is predicated were unknown to the petitioner and could not have been ascertained with the exercise of due diligence." In that situation, PCRA petitioners historically had 60 days from when the claim could have been presented to file their petitions based on newly-discovered facts; in 2018, the General Assembly extended that time to one year. See 42 Pa. C.S. Section 9545(b)(2). If a petitioner successfully invokes this "new facts" exception to the one-year time bar, a court will then review the merits of the petitioner's claim for a new trial—analyzing, among other potential claims, "the unavailability at the time of trial of exculpatory evidence that has subsequently become available and would have changed the outcome of the trial if it had been introduced."