Order, of disposition, Family Court, New York County (Mary Bednar, J.), entered August 10, 1994, adjudicating respondent a juvenile delinquent and placing him in a nonsecure facility operated by the Division for Youth for up to 18 months and a minimum of 6 months, following a fact-finding determination, based upon respondent’s plea of guilty, that respondent committed acts which, if committed by an adult, would constitute the crime of attempted grand larceny in the second degree, unanimously affirmed, without costs.
Respondent’s claim that the finding of probable cause was erroneous was waived by his plea of guilty (see, People v Brothers, 50 NY2d 413, 418, citing People v Dodson, 48 NY2d 36), and there is no merit to his claim that the plea was defective. While respondent did not admit to having heard the threat made to the complainant in an effort to extort money and there was otherwise no elaboration of respondent’s individual behavior, the minutes of the allocution show that regardless of whether respondent actually heard the threat and, in view of respondent’s close physical proximity to the other youths involved in the extortion scheme, it strains credulity to believe that he did not. Respondent was well aware of the reason for the visit to the complainant’s store, intended personally to benefit therefrom and, consequently, intentionally and knowingly aided in the commission of a crime (Penal Law § 20.00). Respondent’s claim that Family Court, which rejected his request for probation, failed to conduct an adequate and proper inquiry into the matter of his disposition, is improperly raised for the first time on appeal, *229and in any event, there was ample evidence to justify placement. We have considered respondent’s remaining arguments and find them to be without merit. Concur—Murphy, P. J., Sullivan, Rubin, Asch and Williams, JJ.