The only practical way to be sure you’re not a victim of a fraud is to go to a true real estate professional, that has a well established business that allows to locate them, a brand or reputation to back them up, and belongs to the highest reputation real estate professional organism in the zone.  One of the most important organisms and with a higher prestige is AMPI (Real Estate Professionals Mexican Association) who has mutual recognized agreements with “Realtor” in USA and with “CREA” in Canada.