Judgment unanimously affirmed. Memorandum: Defendant appeals from his conviction upon a plea of guilty to escape, third degree, in satisfaction of a charge of escape, second degree, arising from his act of leaving Gowanda Psychiatric Center. (He had been committed by court order to the custody of the Commissioner of Mental Hygiene, pursuant to CPL 330.20, after a jury had found him not guilty by reason of mental disease or defect of a charge of assault, first degree.) He now argues that the court below erred in denying his motion to dismiss the indictment, claiming, inter alia, that the evidence before the Grand Jury was not sufficient to establish commission of the offense charged (CPL 210.30). The issue of sufficiency of the proof to support the indictment may not be raised on appeal after a guilty plea (see People v Thomas, 74 A.D.2d 317, 321, affd 53 N.Y.2d 338; People v O'Neal, 44 A.D.2d 830). In any event, the court's denial was proper because CPL 210.20 permits dismissal of an indictment on the ground of insufficiency of the evidence before the Grand Jury only where the evidence is "not legally sufficient to establish the offense charged or any lesser included offense" (CPL 210.20, subd 1, par [b]; emphasis added). It appears clearly that the evidence establishes defendant's commission of escape, third degree, a lesser included offense of escape, second degree, in that defendant escaped from the custody of the Commissioner of Mental Hygiene, a public servant under whose restraint he was placed by court order (see Penal Law, § 205.00, subd 2; § 205.05). We do not reach defendant's argument, on appeal, that the acts the indictment accuses him of performing do not constitute the crime of escape, second degree, and that therefore the indictment was defective (see People v Iannone, 45 N.Y.2d 589, 600). Inasmuch as defendant pleaded guilty to escape, third degree, the point is moot.