of the defendant’s guilt or innocence. Commonwealth v. Moose, 529 Pa. 218, 602 A.2d 1265 (1992) (citing Giglio v. United States, 405 U.S. 150, 92 S.Ct. 763, 31 L.Ed.2d 104 (1972)). See also Morales, supra (stating to be entitled to new trial for failure to disclose evidence affecting witness’ credibility, appellant must demonstrate that reliability of witness may well be determinative of guilt or innocence). ¶ 40 Additionally, this Court has held that a “conviction obtained by the knowing use of perjured testimony is fundamentally unfair, and must be set aside if there is any reasonable likelihood that the false testimony could have affected the judgment.” Commonwealth v. Romansky, 702 A.2d 1064, 1067 (Pa.Super.1997), appeal denied, 555 Pa. 699, 723 A.2d 670 (1998) (emphasis added) (<HOLDING>). In essence, Brady involves after-trial
holding that the failure to disclose evidence known to the defense cannot form the basis of a brady violation holding prosecutions failure to disclose promise of leniency to witness provided in exchange for that witnesss testimony violated due process holding as brady violation prosecutions failure to disclose to defense that prosecution had agreed not to prosecute key witness in exchange for his testimony at trial holding that prosecutions duty to present all material evidence to the jury was not fulfilled when it became known the government failed to disclose an alleged promise of leniency made to its key witness in return for his testimony holding that the witness had accepted immunity in exchange for no prosecution