N.Y. Fam. Ct. Act § 249-A
A minor who is a subject of a juvenile delinquency or person in need of supervision proceeding or in any proceeding where a minor is detained under or governed by the interstate compact for juveniles established pursuant to section five hundred one-e of the executive law shall be presumed to lack the requisite knowledge and maturity to waive the appointment of an attorney. This presumption may be rebutted only after an attorney has been appointed and the court determines after a hearing at which the attorney appears and participates and upon clear and convincing evidence that (a) the minor understands the nature of the charges, the possible dispositional alternatives and the possible defenses to the charges, (b) the minor possesses the maturity, knowledge and intelligence necessary to conduct his or her own defense, and (c) waiver is in the best interest of the minor.
N.Y. Family Court Law § 249-A