Types of forgery crimes in California include check fraud, identity theft, counterfeiting, and falsifying financial documents. California law considers various acts as forgery.Forgery can come in many forms. 470 PC defines the California crime of forgery, which is falsifying a signature or seal or counterfeiting documents when doing so with fraudulent intent. Counterfeiting and Forgery Crimes in California. Forgery involves the altering of certain documents with the intent to defraud.