A person commits forgery if, with intent to defraud, the person: 1. Falsely makes, completes or alters a written instrument; or 2.§ 13-2002 defines Arizona's forgery law. Forgery occurs when somebody alters a written document so that it is false with the intent to defraud another person. Most types of forgery are categorized as class 4 felonies. A conviction could mean up to 15 years in prison plus 3 more years of probation. A successful forgery prosecution in Arizona can subject you to a maximum of eight years and hefty fines. Any document that has been falsified or altered for the purpose of deceiving others is considered a forgery in Arizona. ARS 13-2002 is the Arizona law that defines the crime of forgery.