In 2013 Earl Campbell, along with 18 others, was arrested for running a gun trafficking operation that had helped flood New York City with more than 250 handguns and assault weapons, as well as “cop-killer” bullets, in the previous year. It was the largest seizure of illegal weapons in New York City’s history. Campbell isn’t from New York, though — he’s from Rock Hill, South Carolina. He and his associates reportedly made several trips north over the course of a year, traveling a well-worn path to unload their illegal guns.

Every year, Southern traffickers send thousands of illegal firearms to Northeastern cities. They’re usually driven in from Georgia, Virginia, Florida, and the Carolinas – states with comparatively lax gun laws – through the famed gun-trafficking corridor along Interstate 95, dubbed “The Iron Pipeline.”

South Carolina exports illegal guns at more than twice the national average and is the third biggest supplier of guns among the Iron Pipeline states.

“Ninety percent of the guns we recover, the origin is down South,” Sgt. Luke Laterza, a firearms examiner in the ballistics lab at the Newark Police Department, tells The Trace. “I rarely get a gun where the trace comes back that it’s from Jersey.”

Laterza, whose ballistics lab sits just across the river from New York City, noted that Iron Pipeline states rarely have stringent reporting methods for lost or stolen firearms. “We’re talking about down South, where there’s different gun laws,” he says. “There’s no accountability.”

In 2012, the last year for which figures are available, 5,718 guns were reported stolen in South Carolina. But since there are no mandatory reporting laws, that number might be much higher.

“One gun can do so much damage in the hands of the wrong criminal,” Charles Mitchell, a licensed concealed carrier and member of a group called Stop the Violence, told a local news outlet after 18 handguns were stolen from a gun range in Jasper County, South Carolina, in February. “We need to do what we can to get these guns off of the streets.”

Illegal firearms from South Carolina are also acquired by straw purchases, in which a person without a criminal record buys a gun for someone who can’t pass a federal background check. Like stolen guns, such weapons are then sold at steep markups in northern states, where more restrictive laws make guns harder to come by for people not permitted to own them.

For three decades, South Carolina limited handgun purchases to one per month in an effort to curb straw buying. In 2004, that law was repealed.

[Photo: Flickr user R∂lf Κλενγελ]