In the summer of 2009, a sixty-three-year-old professional bass fisherman from Florida named Hugh Crumpler III was arrested for selling guns illegally. For years, he’d been buying weapons, legally, at gun shows, and then reselling them to individuals from Latin America who wanted to smuggle the guns back to their home countries. Crumpler was what’s known as a “straw buyer.” “I developed a group of customers,” he said later, in an interview with Univision. “And it dawned on me one day that they were all Hondurans; and that they all seemed to want the same type of guns; and they all seemed to want more and more.” By the time he was caught, Crumpler had resold roughly a thousand guns, including Glocks and AR-15 assault rifles. He eventually agreed to coöperate with American authorities in exchange for a two-and-a-half-year prison sentence. According to the Bureau of Alcohol, Tobacco, and Firearms, some of the guns Crumpler sold were used in crimes in Honduras, Puerto Rico, and Colombia, including in at least one homicide.

The ready availability of guns in America is often discussed as a domestic-policy matter. But it is an international issue, too. Every year, guns that were initially sold in the U.S. are used in thousands of crimes in Canada, Central America, and the Caribbean, according to the Center for American Progress. It’s estimated that some two hundred thousand American guns are smuggled across the southern border each year. The region that’s been hit the hardest is Central America, where gun laws are relatively strict yet homicide rates are among the highest on earth. Gang wars, massive state corruption, and murderous criminal syndicates are to blame for the violence, but American firepower facilitates it. “Unlike other forms of contraband, American weapons don’t just pass through Central America but engulf it in storms of violence,” Mark Ungar, a political-science professor at Brooklyn College and an expert in the region’s gun violence, told me. This violence, in turn, has fuelled a refugee crisis. Since 2014, more than a hundred and fifty thousand unaccompanied immigrant children from countries in the region have fled to the U.S. seeking some form of asylum.

Mexico, Guatemala, El Salvador, and Honduras do not have substantial gun industries of their own. The governments of these countries rely on imports from abroad to supply their militaries and security forces. Most of the guns otherwise in circulation on the street are illegal and unregistered—and many come from sellers in the United States. Seventy per cent of guns recovered by authorities in Mexico, for instance, were originally sold in the U.S.—most of them in Texas, California, and Arizona, according to a Government Accountability Office report. Forty-nine per cent of weapons recovered in El Salvador came from the U.S., compared to forty-six per cent in Honduras and twenty-nine per cent in Guatemala. Harry Penate, an American adviser to the A.T.F. based in San Salvador, told The New Republic, “I feel as bad about guns going into Central America and Mexico as good, hard-working Colombians feel about cocaine going into the U.S.” There are at least seven hundred licensed gun dealers along the U.S.-Mexico border, and the illegal firearms trade in Mexico generates more than a hundred million dollars in annual revenue for U.S. gun makers.

To get guns across the border, traffickers often disassemble the weapons and stash them, in pieces, in other objects like microwaves, toys, or appliances. Criminal syndicates are usually behind the larger transactions. Crumpler, the man from Florida, sold his guns to a group of undocumented Hondurans living in Orlando, who received tens of thousands of dollars through wire transfers originating in Honduras to pay for the weapons. One of Crumpler’s buyers told him that, as he later put it, “I was dealing with . . . the two largest gun-dealing families in Honduras.” Other times, criminals carry weapons south in backpacks. “Sometimes there are specific, small-scale missions that the gang members arrange to buy the guns easily in the U.S., and then travel back home, through Mexico, with them,” Carlos García, an expert in the Salvadoran-American gang MS-13, told me. Weapons preferences vary. In Mexico, semiautomatic rifles are in high demand—half of the guns from the U.S. recovered in the country are “long guns,” of the AR-15 or AK-47 variety. Central American gangsters like 9-millimetre handguns. A popular purchase from Crumpler’s trove was a semiautomatic pistol known, in the region, as a matapolicías, or cop killer, because it can fire armor-piercing bullets.

Earlier this week, I spoke with José Luis Hernández, a thirty-two-year-old Honduran from San Pedro Sula who now lives in Los Angeles. When he was sixteen, Hernández travelled north and attempted to cross the U.S. border. “It was a case of forced migration,” he said. Local gangs were pressuring him to join their ranks. “You live like a prisoner in your own house. Everyone’s terrified. No one even wants to go to the police because the gangs will find out and kill you,” he said. He failed to reach the U.S. on his first trip, was sent back home, and attempted another crossing, this time travelling on a network of freight trains in Mexico known as “the beast” because they’re so dangerous to ride. After fainting and falling onto the tracks, Hernández lost an arm, half of one leg, and part of his left hand. It took a year for him to recover in a Mexican hospital before he was deported back to Honduras. In 2015, he joined a group of disabled Honduran refugees who called themselves the Caravan of the Mutilated. Together they made it to Texas and were eventually granted asylum. (Hernández’s story was previously written about by Alex Yablon, in The Trace.)

“The violence crosses from here, in the U.S., to Central America,” Hernández told me. “It’s the opposite of what the politicians say. Gangs and guns—those all go south.” He felt an affinity for the young organizers of this weekend’s March for Our Lives. “This demonstration is necessary. We young people are dying because of all this. And at the end of the day, it’s the people, and not the President, who have the power.” The March for our Lives organizers were making a case to acknowledge the policies that allow mass shootings to happen. Hernández believes the wider ramifications of those policies deserve attention, too. In Honduras, Hernández said, “it seems like the hitmen and gangsters have better weapons than the police.”

This article has been updated to correctly reflect the charges brought against Hugh Crumpler III.