To see the words 'Mexico and legal' in the same sentence is ironic. EVERYTHING AND ANYTHING is 'legal' in Mexico including murder, depending on who you are, how much money you have, and who you pay. There is no objective 'Law' in Mexico. "Legality" in Mexico and South America is all based on money and power, nothing else.
It is like that in America too, but it is not yet as institutionalized here as it is in other parts of the world. At least in America we still try to at least 'pretend' to have objective law enforcement. Even though we all know that politicians and the super-rich do not have to abide by the same laws as the 'commoners' do.