Well this is the Cartel flexing it's muscle and power it has over Mexico (the government and it's citizens) and whatever goes on in the country from little petty crimes to the bloody events that transpired a few days ago. They own the gangs.
Cartel had nothing to do with those four Black people being attacked by a street gang, but see how they exercised their power and made the gang give back the two surviving hostages and sent out an apology letter, that's called flexing muscle

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This has nothing to do with being afraid of the US or any secret money ties y'all conspiring about, it's more to do with keeping the heat off of Mexico, and preventing the US from getting any ideas to further investigate or dig into their business, because the first thing people would assume is that the Cartel had something to do with this situation and the bosses don't want that kind of attention

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When two of the most powerful cartels the world, Medellín Cartel and the Cali Cartel, in Columbia, had fallen, that sent a message to every Cartel since that the best way to avoid exposure is by keeping a low profile and “working” with government authorities to keep things from escalating into a bloodbath.
As we all know, well hopefully we all know that law enforcement/government doesn't really care about drugs being sold as much as they put on to the general public, because it's a never ending operation they know arresting a few people ain't gonna stop the drugs from flowing. It's the bodies that pile up on the streets is what matters most in convicting narco-traffickers and pretty much any kind of street and drug activity.