Mexican prisons operate under an entirely different set of rules than facilities in the United States, and our experience and knowledge base is built around the American correctional system. What we can tell you honestly is that we do not have reliable firsthand knowledge of conditions, policies, or privileges inside Mexican federal or state prisons.
What is widely documented is that Mexican prisons, particularly at the state level, have a reputation for operating with significant informality compared to U.S. facilities. Conditions vary enormously from one institution to another, and the level of privilege available to an inmate can sometimes be influenced by factors that would not exist in the American system. Whether smoking is permitted, whether phones are accessible, and what any of that costs depends heavily on the specific facility.
The most reliable sources of information for your situation would be organizations that work with foreign nationals in Mexican custody, such as the nearest U.S. consulate if your husband is an American citizen, or human rights organizations that monitor detention conditions in Mexico. If he is a Mexican national, his family members who can visit in person will have the most current and accurate picture of what the specific facility allows.
InmateAid's services and expertise are focused on the U.S. correctional system. We would not want to give you information about Mexican prisons that turns out to be inaccurate when the stakes are this personal.