¶1OPINION
¶2A jury convicted appellant Walker of first degree murder. On appeal, appellant contends that the prosecution’s failure to reveal a plea bargain agreement with a key witness, one Thomas, denied appellant due process of law. We agree.
¶3Appellant had informed the police that another man, whom he identified as perpetrating the crime, had sold the murder weapon to Thomas. The police found the gun in Thomas’ possession, but Thomas asserted that appellant, rather than the man named by appellant, had sold him the weapon. Thomas’ attorney then negotiated a plea bargain agreement to the effect that, if Thomas were later convicted on certain other criminal charges, the State would recommend probation for Thomas. In *267sum, by testifying against appellant, Thomas not only avoided any charges arising from the murder in question, but also avoided the possibility of imprisonment on the other unrelated felony charges.
¶4At appellant’s trial, Thomas testified pursuant to his counsel’s advice, asserting that he had purchased the murder weapon from the appellant, rather than from the person appellant identified. On cross-examination, Thomas admitted that a felony charge was pending against him; however, he denied the existence of a plea bargain agreement with the district attorney’s office. The State asserts that Thomas’ answers on cross-examination were not perjurious, because neither his attorney nor the district attorney had disclosed the agreement to him. However, it is clear the prosecutor knew that Thomas’ testimony was not true, and that a plea bargain agreement in fact existed.
¶5In Davis v. Alaska, 415 U.S. 308 (1974), the Supreme Court declared:
The partiality of a witness is subject to exploration at trial, and is “always relevant as discrediting the witness and affecting the weight of his testimony.” 3A J. Wigmore, Evidence § 940, p. 775 (Chadbourn rev. 1970). We have recognized that the exposure of a witness’ motivation in testifying is a proper and important function of the constitutionally protected right of cross-examination.
¶6Id., at 316-17. This court has declared that, “[i]f the state knows that its witness has testified falsely on a point relevant to the credibility of that witness, and fails to correct that falsehood, the conviction is constitutionally infirm.” Hanley v. Sheriff, 85 Nev. 615, 617, 460 P.2d 162 (1969).
¶7Here, the prosecution knew that its key witness had testified falsely, although perhaps unwittingly, on a point highly relevant to his credibility. Nonetheless, the prosecution failed to correct that falsehood. Therefore, appellant’s conviction is constitutionally infirm.
¶8Reversed and remanded for a new trial.