Appeal by defendant, as limited by his brief, from so much of a judgment of the County Court, Suffolk County (Sherman, J.), rendered June 8, 1983, as convicted him of forgery in the second degree, upon a jury verdict, and imposed sentence.
Judgment affirmed, insofar as appealed from.
Where the prosecution’s expert witness testified that two of the three signatures found on the certificate of title were written by defendant, but as to the third he could only state that it very probably was written by defendant, a prima facie case of forgery in the second degree by falsely completing a commercial instrument has been made out. It is for the jury to determine the weight and credibility to be given expert testimony (United States v Williams, 583 F2d 1194, cert denied 439 US 1117), and the jury may make a comparison between a writing sample and a disputed writing whether or not the expert offers an opinion (CPLR 4536; People v Hunter, 34 NY2d 432).
In the instant case, in viewing the evidence in the light most favorable to the People, as we must, we find that sufficient evidence was adduced to prove defendant’s guilt beyond a reasonable doubt. “The resolution of questions relating to the credibility of witnesses is properly a function of the jury and said determination may not be overturned lightly on appeal (see People v Gruttola, 43 NY2d 116)” (People v Rodriguez, 72 AD2d 571).
We have reviewed defendant’s other contention and find it equally without merit. Weinstein, J. P., Rubin, Lawrence and Kunzeman, JJ., concur.