Once again, if you possess documents that you know are fake and you do so with the intent to defraud you will face one of these Forged Instrument crimes. Third-degree forgery, a misdemeanor, involves falsely creating, completing or changing a written document to purposely defraud or harm someone.Signature forgery refers to creating or imitating someone else's signature without their permission or authorization, intending to deceive others. There are 3 forgery crimes in New York. Forgery is a crime, not a civil matter. Go back to the police. Deed fraud happens when criminals record fraudulent deeds, mortgages or other liens against a property without the owner's knowledge or consent. Identity document forgery is a criminal act in which a person falsifies an ID document. It is absolutely illegal to forge someone's signature and has jail time upto 2 years with fine. The law defines forgery as the making of a fake document, the modification of an existing document, or the unauthorized signing of a signature.