P.R. Laws Ap. tit. 34A, § II, Rule 155
Upon a trial for having obtained, with an intent to cheat or defraud another, by any false pretenses, the signature of any person to a written instrument, or having obtained from any person any money, personal property or valuable thing, the defendant shall not be convicted if the false pretense was expressed in language unaccompanied by a false token or writing, unless the pretense, or some note or memorandum thereof, is in writing, subscribed by or in the handwriting of the defendant, or unless the pretense is proven by the testimony of two witnesses, or that of one witness and corroborating circumstances. But this Rule shall not apply to a prosecution for false pretenses or personating another for the purposes of marrying or of receiving any money or property in such assumed character.