Tucked deep inside Mexico City’s notorious Tepito barrio — a lawless maze where even police hesitate to tread — lies one of the country’s most dangerous black-market operations.

Run by the Union Cartel, Tepito is a hub for everything illicit: pirated goods, drugs, extortion, and even human trafficking. Here, cartel “hawks,” often young children, stand watch at market entrances, while deep inside, traffickers conduct business under the gaze of Jesús Malverde, the so-called “narco saint.”

The real power of Tepito lies in its hidden armories — private homes and underground bunkers where weapons are sold like street food. Handguns start at $300, AR-15s fetch $1,500, and a 50-caliber rifle can go for $3,000. From low-caliber pistols to grenade launchers, the arsenal is vast, fueling Mexico’s relentless cycle of cartel violence. 

Yet the real question is: From where do these weapons come? And is the United States solely to blame? Weeks after the Trump administration labeled six Mexican cartels as terrorist organizations, Mexico took its fight to the United States Supreme Court, seeking $10 billion in damages from American gun makers. The lawsuit claims these companies knowingly facilitate cartel violence by supplying United States-made weapons that flood across the border, making them complicit in criminal activity. 

The Mexican government alleges that gun companies aided and abetted illegal transactions by disregarding straw purchasers and traffickers, directly contributing to rising cartel violence and forcing the Mexican government to bear the costs of increased law enforcement. Gun manufacturers, however, argue that they have long operated legally and are sheltering under the Protection of Lawful Commerce in Arms Act, enacted in 2005 — a federal shield against liability. 

Gun makers contend that their practices are business as usual and that Mexico’s claims rely on a chain of independent criminal actions — spanning from American dealers to smugglers, traffickers, and cartel enforcers. They insist that manufacturers cannot be blamed for crimes committed with legally sold firearms, much like carmakers aren’t liable for reckless drivers. 

Still, Mexico counters that this case is different: gun companies allegedly knowingly facilitate an illegal trade by ignoring red flags and selling to bad actors. Initially dismissed by a lower court in 2022, a year after its filing, the case, Smith & Wesson Brands v. Estados Unidos Mexicanos, was brought back early last year by the First Circuit of the United States Court of Appeals, which found an exception to the federal liability shield law, prompting an appeal to the Supreme Court. 

This month, the court heard oral arguments. The justices now are expected to weigh whether gun makers should be held responsible for cartel bloodshed — or whether the blame lies elsewhere.

“Mexico tries to deflect blame onto the U.S. gun manufacturers instead of looking at their own borders and corruption. Many of the weapons that end up in the hands of cartels are legally purchased from American manufacturers by the Mexican military, who then sell them or lose track of them. It’s not the fault of the gun manufacturers,” the managing director of strategic advocacy firm Nestpoint Associates, John Thomas, tells the New York Sun. 

“A lot of these guns are legally purchased, unlike drugs, which are illegal from the start. So, blaming U.S. gun manufacturers doesn’t address the root cause.”

Mexico faces a severe violent crime problem, driven by organized criminal groups and drug cartels. In 2019, the country recorded nearly 35,000 homicides, with widespread violence affecting both public safety and governance. 

Seven of the world’s ten most dangerous cities are in Mexico, and incidents like Royal Caribbean halting travel to Manzanillo this year due to escalating violence highlight the widespread insecurity, making it difficult for law enforcement to combat the main drivers of crime.

Sourcing Weapons  

Mexico has some of the world’s strictest gun laws on the planet. The country has only one legal gun store serving a nation of 130 million and fewer than 50 permits issued annually following more than six-month wait periods. Despite the challenge of obtaining a firearm for law-abiding citizens, even though the right to bear arms is enshrined in the country’s constitution, cartels and criminal organizations are awash with weapons. 

The majority of Mexicans assert that easy access to guns in the United States as a driving force behind the violence plaguing their country, fueling cartel operations and criminal activity.

“Our cartels get all their guns, weapons, and everything from the United States. This is a long-standing problem,” a Mexico City-based psychologist and criminological profiler, Mónica Ramírez Cano, tells the Sun. “One side has agreed to curb immigration while the other agreed to address firearm trafficking.” 

Mexico’s Secretariat of Foreign Relations estimates that 70-90 percent of traced firearms originate from or pass through the country’s northern border. Meanwhile, the Department of Justice and the Government Accountability Office report a slightly lower figure of 68 percent, with 50 percent made in the United States and 18 percent imported before ending up in Mexico.

A Mexico-based organized researcher and author of “Blood Gun Money: How America Arms Gangs and Cartels,” Ioan Grillo, tells the Sun that “an overwhelming amount of guns are coming from the U.S.”

“The U.S. could really crack down on these sales by applying more stringent laws. They could designate groups as terrorist organizations and hold people accountable for arming them, but so far, there’s been a lack of action on that front,” he said. 

Alternate Sources for Arms

There are, however, more puzzle pieces in the picture. 

A retired Drug Enforcement Administration agent, Wesley Tabor, tells the Sun that “cartels also obtain weapons from Central America and corrupt military sources with near impunity.”

Intelligence sources in Mexico also tell the Sun that while United States-sourced firearms dominate cartel arsenals, a growing supply of weapons is flowing from elsewhere. 

Smugglers are tapping into Central and South America routes, with bulk shipments coming from Nicaragua and other Latin American countries. Eastern Europe, Russia, China, and even parts of the Middle East have also become sources, as criminal groups diversify supply lines to evade increased scrutiny at Mexico’s northern border.

Additionally, clandestine workshops across Mexico are using sophisticated Computer Numerical Control machines to manufacture firearm components, further complicating efforts to stem the flow of illicit arms. Tepito, Mexico City’s notorious black market, has emerged as the country’s largest hub for underground weapons distribution, fueled by imports from Colombia, Spain, and Pakistan.

Mr. Thomas underscored that “most of the weapons are either coming from Mexico’s own military—where they’re legally purchased but then either sold or lost track of—or from the U.S. via South America.”

“It’s a pretty complicated process, and the corruption on both sides makes it hard to trace,” he continued. 

According to one United States official, who requested only to speak on background, “Mexico uses the fact that guns come from the U.S., and the money gets laundered back into Mexico to leverage the U.S.”

“They talk about how U.S. consumption supports the cartels. In return, when the U.S. complains about drugs being brought in from Mexico, the Mexican government points to U.S. guns and money laundering as the source of the violence. It’s a back-and-forth,” the insider tells the Sun. 

“They do get weapons from the U.S., especially through straw purchases, where people buy guns legally in the U.S. and bring them into Mexico. But they also get Russian-made weapons, like AK-47s. There are cases where U.S. weapons are purchased in other countries and come back into the U.S., adding to the supply chain.”

Corruption and Impunity

Taking the lens off the Unted States, Mexico’s violent crime crisis is exacerbated by rampant impunity and a failing justice system. Human rights abuses, including extrajudicial killings, forced disappearances, torture, and corruption, remain widespread. 

A study by the Center for Impunity and Justice Studies at Universidad de Las Américas underscores the severity of the problem, revealing that only 4.46 percent of reported crimes lead to convictions. Yet with just 7 percent of crimes reported, the real impunity rate exceeds 99 percent. 

Many Mexicans cite the time-consuming legal process and lack of trust in authorities as reasons for not coming forward. As a result, organized crime continues to thrive, operating with near-total immunity while citizens bear the brunt of unchecked violence.

“All of the blame lies with Mexico, not with U.S. gun manufacturers. Radical, American, anti-gun organizations and politicians helped Mexico manufacture this lawsuit to impose additional costs on American gun manufacturers and ultimately put them out of business,” one Second Amendment attorney, Cameron Atkinson, tells the Sun. 

“Mexico needs to fully commit to annihilating the cartels and the violent actors in its country. If it lacks the capability to do so, Mexico should accept our help in getting rid of them.”

Making matters worse is the high levels of corruption. 

“There’s no distinction between politicians, law enforcement, and drug cartels in Mexico. They’re all part of the same system, working together for their own interests,” the United States government source claimed. “Corruption in Mexico is more systematic than isolated—it’s corruption from the top down, rather than just one dirty cop.”

Some Republican lawmakers have even accused American officials of overlooking the sweeping corruption south of the border “in favor of cooperating with and funneling resources to foreign actors” at the expense of human lives and immense taxpayer dollars. 

The lawsuit’s future

If Mexico’s lawsuit against American gunmakers moves forward, it could set a far-reaching legal precedent, extending beyond the firearms industry to any business whose products might be misused for criminal purposes. The Supreme Court’s ruling has the potential to reshape corporate liability in the face of transnational crime, potentially challenging long-standing protections for gun manufacturers under United States law.

During oral arguments, however, the justices appeared unconvinced by Mexico’s argument that American gun makers bear primary responsibility for the country’s escalating violence rather than its own systemic corruption and governance failures. 

While the court’s final decision remains uncertain, it carries significant implications for the Protection of Lawful Commerce in Arms Act, which has shielded the gun industry from litigation since 2005. 

The case also unfolds amid heightened United States-Mexico tensions, with border security and cartel violence remaining central to political discourse.

“The irony is, if Mexico were to win this case, they’d probably set a dangerous precedent for the U.S. to go after their government for cartel activities. Even if they win, it won’t solve their crime problem,” Mr. Thomas added. “It’s a proxy fight for those liberal groups who want to put the manufacturers out of business and stop guns from being so easily available to U.S. citizens.”