In the case of forgery, the culpable mental state requires proof of knowledge that the check is forged. Section 32.31(b) of the Texas Penal Code required the State to prove beyond a reasonable doubt that a person: (1) with intent to defraud or harm another; (2) passed; (3) a writing; (4) that purported to be the act of another; (5) that other person did not authorize the act. See Williams v. State, 688 S.W.2d 486, 488 (Tex. Crim. App.1985); Oldham v. State, 5 S.W.3d 840 (Tex. App.-Houston [14th Dist.] 1999, pet. ref'd); see also TEX. PEN. CODE ANN. 32.21(a) & (b) (Vernon 1989). The intent to defraud or harm may be established by circumstantial evidence. Williams, 688 S.W.2d at 488. Proof of intent to defraud is also derivative of other elements. If there is sufficient evidence to establish an actor's theft of the instrument ultimately forged, the evidence is deemed sufficient to show knowledge of the forgery, and therefore sufficient to show an intent to defraud or harm. See Wallace v. State, 813 S.W.2d 748, 751 (Tex. App.-Houston [1st Dist.] 1991, no pet.).