The Family Court found that the evidence adduced at a fact-finding hearing proved beyond a reasonable doubt that the appellant, while under 16 years of age, forcibly took property from Stacy Pinsker, the complainant, thereby committing acts which if committed by an adult would have constituted robbery in the third degree.
We see no reason to disturb this adjudication. Upon reviewing the issues of credibility presented in this case, we find that “[t]here is no reason * * * to disturb the findings of the trier of the facts, since only he had the opportunity to observe the demeanor of the witnesses and assess their credibility” (Matter of Derrick C., 52 AD2d 522, 522-523; accord, People v Regina, 19 *704NY2d 65; People v Cook, 99 AD2d 552; People v Rosenfeld, 93 AD2d 872). We have reviewed the record and cannot say that proof beyond a reasonable doubt was not adduced. Mangano, J. P., Brown, Niehoff and Lawrence, JJ., concur.