Order, Family Court, Bronx County (Harvey Sklaver, J.), entered July 25, 1989, which, after finding that appellant had committed an act which, if committed by an adult, would have constituted fourth degree criminal possession of a weapon, and the act of unlawful possession of a weapon by a person under 16 years of age, conditionally discharged him, unanimously affirmed, without costs.
*311The fact-finding court correctly determined that the prosecutor’s delay in disclosing the Rosario material did not substantially prejudice appellant’s right to a fair hearing (People v Rosario, 9 NY2d 286, cert denied 368 US 866; see, People v Martinez, 71 NY2d 937, 940; People v Ranghelle, 69 NY2d 56, 63). Moreover, the arresting ofiicer’s testimony sufficiently established appellant’s guilt beyond a reasonable doubt. Concur—Ross, J. P., Rosenberger, Ellerin and Wallach, JJ.