Judgment unanimously reversed on the law and facts and a new trial granted. Memorandum: The indictment charged appellant with uttering a forged doctor's prescription with intent to defraud and with knowledge that it was forged (Penal Law, §§ 880, 889-b). Where the utterer and the forger of the instrument are one and the same person his knowledge of the forgery is obvious (2 Burdick, Law of Crime, § 671), but otherwise guilty knowledge must be proved ( People v. Underhill, 142 N.Y. 38, 46; People v. Petty, 14 A.D.2d 16; People v. Abeel, 45 Misc. 86, 93). While such knowledge may be established by the circumstances of the case ( People v. Valentine, 147 App. Div. 31, 35), there is here no such proof. It might have been found from the proof that the prescription was forged and appellant presented it to the druggist to be filled. Completely lacking is proof from which it might be inferred that defendant knew the writing was a forgery.