Appeal by the defendant from a judgment of the County Court, Westchester County (Silverman, J.), rendered May 5, 1988, convicting him of assault in the second degree, after a nonjury trial, and imposing sentence.
Ordered that the judgment is affirmed.
In this case arising out of an altercation between the defendant, an inmate at a State prison, and a corrections officer, we find that contrary to the defendant’s contentions, the prosecution proved the defendant’s guilt beyond a reasonable doubt. Viewing the evidence in the light most favorable to the prosecution (see, People v Contes, 60 NY2d 620), we find that it was legally sufficient to establish the defendant’s guilt of assault in the second degree beyond a reasonable doubt and to disprove the defense of justification beyond a reasonable doubt (see, Penal Law § 120.05 [7]).
Resolution of issues of credibility, as well as the weight to be accorded the evidence presented, are primarily questions to *654be determined by the trier of facts, which saw and heard the witnesses (see, People v Gaimari, 176 NY 84, 94). Its determination should be accorded great weight on appeal and should not be disturbed unless clearly unsupported by the record (see, People v Garafolo, 44 AD2d 86, 88). Upon the exercise of our factual review power, we are satisfied that the verdict was not against the weight of the evidence (see, CPL 470.15 [5]). Balletta, J. P., Miller, Ritter and Copertino, JJ., concur.