Order of disposition, Family Court, Bronx County (Harold J. Lynch, J.), entered on or about January 13, 2004, which adjudicated appellant a juvenile delinquent, upon a fact-finding determination that he committed an act which, if committed by an adult, would constitute the crime of attempted assault in the third degree, and placed him on probation for a period of 12 months, unanimously affirmed, without costs.
The court’s finding was based on legally sufficient evidence and was not against the weight of the evidence (see People v Bleakley, 69 NY2d 490 [1987]). There is no basis for disturbing the court’s determinations concerning credibility. Appellant’s course of conduct before, during and after the assault, including the fact that he assisted his companions in surrounding the victim, was inconsistent with that of a mere bystander and *188established his accessorial liability (see e.g. Matter of Marc H., 284 AD2d 211 [2001]; Matter of Taalib B., 273 AD2d 27 [2000], lv denied 95 NY2d 764 [2000]). Concur — Saxe, J.E, Friedman, Marlow, Sullivan and Williams, JJ.