“ The principle that a State may not knowingly use false evidence, including false testimony, to obtain a tainted conviction, implicit in any concept of ordered liberty, does not cease to apply merely because the false testimony goes only to the credibility of the witness. The jury's estimate of the truthfulness and reliability of a given witness may well be determinative of guilt or innocence, and it is upon such subtle factors as the possible interest of the witness in testifying falsely that a defendant's life or liberty may depend. ”

“ Had the jury been apprised of the true facts, however, it might well have concluded that Hamer had fabricated testimony in order to curry the favor of the very representative of the State who was prosecuting the case in which Hamer was testifying, for Hamer might have believed that such a representative was in a position to implement (as he ultimately attempted to do) any promise of consideration. ”

“ As stated by the New York Court of Appeals in a case very similar to this one, People v. Savvides, 1 N.Y.2d 554, 557, 154 N.Y.S.2d 885, 887, 136 N.E.2d 853, 854-855:
'It is of no consequence that the falsehood bore upon the witness' credibility rather than directly upon defendant's guilt. A lie is a lie, no matter what its subject, and, if it is in any way relevant to the case, the district attorney has the responsibility and duty to correct what he knows to be false and elicit the truth. ”