As the war on drugs fractured large cartels in recent years, smaller and more predatory groups rose in their place. Extortions and kidnappings spiked, targeting not just businesses and the rich but also middle-class workers.
In response, those who could afford it enlisted private security to do what the state could not.
Between 2013 and 2015, the number of private security companies nearly tripled, according to government statistics. Industry analysts believe the real number, including unregistered firms, may be several times higher.
The shift may be worsening Mexico’s notoriously ineffective justice system, which secures convictions for only a tiny fraction of crimes. Armed guards can prevent a murder but they cannot investigate one, much less roll up a local cartel.
Remaining police resources tilt toward the connected. One study estimated that 70 percent of Mexico City’s police work to protect private interests, such as guarding banks.
As powerful classes grow less reliant on the state for security, political pressure for addressing crime or reforming police has declined, even as the murder rate rises.
In moneyed enclaves across Mexico, where guards patrol boutique shops and hip restaurants, the violence rarely comes up in conversation, as if it were happening in another country.
Meanwhile, ordinary citizens are left unprotected. Gangs and organized crime have flowed into poor neighborhoods.
The divide is starkly visible in places like Santa Fe, an affluent neighborhood on Mexico City’s western edge, where glass high-rises and shopping malls overlook slums that sprawl out from their shadows.
On a recent afternoon in one such slum, Andres Ruiz, a sometimes-employed musician, leaned against a wall as he waited for the bus that, though frequently targeted by robbers, was his only way into town.
He squinted across the street at a stone cliff that rises, like a castle battlement, some 20 feet above the shanties. The fresh white walls of a gated neighborhood, built right up to the ledge, seemed to gaze back down at him.
“Security is only for them, for the high people,” he said, using a word that also means elite. Gang members, who openly patrol the streets, crawled past on a motorbike. “We are relegated, forgotten.”
Living outside those walls, Mr. Ruiz said, “is like being in a slaughterhouse.”
Marilena Hernandez, who sells quesadillas and tacos down the street, said it might be for the best that police ignore the robberies that come “at any hour.”
“It can be counterproductive to call them,” she said. The police, for her, were just another form of private security that she could not afford. “If you have money to give the officers, maybe they’ll be more eager to help you, but otherwise they won’t.”