Some things change, but I'll bet you that Mexican prisons are still alot like when I did eight months in one in 1970. I mean, I know they change some, because the one I was in was over 100 years old at the time, and something new has been built to replace it. I'll bet you, though, that the form of management is still to place guards only on the outside, and to leave internal matters pretty much solely to the inmates.
Oh, and I shouldn't say prison. The official name was "Escuela de Readaptacion". School of readaptation, and the "crazy" section was a large stone bay with no mental health professionals, bars across the front, little if any medication, and a system where a crew of "normal" inmates would wander by occasionally and hose down the folks in the name of cleanliness. Somehow, they never looked like they appreciated that.
The regular units each had one inmate who the Warden appointed as "El Presidente". He, then, created a "police force", armed them with knives, and assigned each one a different area of contraband to be in charge of administering. Man, those guys made a ton. The presidents, I mean, but the police/enforcers did real good also. The presidents got a cut off of all drugs, gambling, and prostitution. They also made money off of renting the private cells, which meant they got a cut of the profits from the various stores, because a private cell was needed to set up a grocery, restaurant, tortilla factory, etc. If you had one (and I was one of the very few americans too poor to afford it), you could even rent it out on weekends for conjugal visits. (One guy was on his sixteenth year inside for killing his high school teacher, and had fathered eight kids with a wife he originally met by hollering down to the womens section.)
The tenure of a president was dependent on the inmates staying inside, and the maintenance of peaceful living conditions. Interestingly, this profit incentive, and the rifles on the walls was all there was to control breakouts, because Mexican law had no penalty for escape. It was recognized that the human condition contains a yearning for freedom, and the act of trying to regain it, unlike here, was not penalized. I knew one guy who got out for a while and, after he got caught, the only thing he got prosecuted for was destruction of property over the bars he cut. (I also ran across a guy who drove truck for a circus and killed an elephant when he ran off of the road. He had to stay locked up until he got the elephant paid for because mexicans do take destruction of property more seriously than we do.)
We had a change of presidents on my floor once. The riot started as soon as the doors opended, and we were wakened to the sound of a shit load of pop bottles exploding off of the walls and floor of the coutryard. One of the mellow old timers advised that americans stay neutral, and, as best we could, invisible. The problem came from a guy who just came up from "the hole", where he sat long enough to heal from the bad beating the President gave him for selling unauthorized pot. It seems he took advantage of a huge market opening provided when the greed of the President caused him to cut the size of the "quartitos" in half. Anyway, this dude had some sympathizers, and things were off and running. Calm was restored by a police assault, almost the only thing I ever saw them do to earn their pay to that point. And then we got a new president, and all of the internal "police" were replaced by his buddies, because the Warden had no room to tolerate disturbances.
Guards were not only notoriously under paid, but they even had to pay for their own bullets for their rifles. (Outside family could pay these guys a little something to throw contraband in, but not to help an escape, because they had to take the place of the absconder if they were on duty.) The word was that they couldn't hit shit, but most of us hippies weren't into testing the system, because standard procedure was for us to sit a spell, and then get deported before our cases got finished. Not a vacation by any means but all the pot we could smoke sure made things more bearable.
And then there was Magoo. First he got caught with a truck load at the Border. Then he had a pistol in an escape attempt up north in the Nogales jail, a definite no-no. A hell of a nice guy, but he did have a problem with authority. And he had way too much time to just sit it out. He hit the streets running for all of twenty minutes once during my tenure, and claimed even the beating was worth the taste of freedom. When we hooked up a while after I got out, he introduced me to a gentleman called "El Jeffe" who had loads needing to be moved, and had put the right amount of money in the hands of the right judge for Magoo to start working on it.
Oh, at the time, I had been charged with having some pot in a backpack at the beach.
A funny old world, ain't it.