A notario in Mexico is very different from a notary public in the US. In addition to having a law degree, a notario has completed additional legal studies specifically related to the work and responsibilities of a notario, and has even competed for the title. They are appointed by the governor of each state based on population. 

Unlike regular attorneys, they are the only ones authorized to sign off on and record real estate transactions, last wills and testaments, and other legal documents. Their records are kept in their office for life and are property of the state. 

By law, notarios are required to be neutral in every transaction.