How a Loophole in US Law Helps Drug Cartels Sneak Guns Into Mexico

The cartels are using a nearly undetectable method of getting weapons parts across the border.

Ammunition sits on a table in front of alleged members of a drug cartel in Guadalajara, Mexico.Carlos Jasso/AP

Let our journalists help you make sense of the noise: Subscribe to the Mother Jones Daily newsletter and get a recap of news that matters.


The same routes that Mexico’s drug cartels use to smuggle drugs into the United States are also used to run American guns into Mexico, according to a new report from the Government Accountability Office (GAO).

The report, commissioned by Rep. Eliot Engel (D-N.Y.) and published yesterday, reveals that 70 percent—more than 73,000—of the guns recovered from crime scenes in Mexico and traced by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) from 2009 to 2014 originated in the United States. These weapons have fueled the ongoing war among the drug cartels and between the cartels and Mexican security forces, contributing to the more than 100,000 killings in the country since 2007.

The cartels’ weapons of choice are high-caliber rifles*, as well as AR-15 and AK-47-type semiautomatic rifles, which can be easily converted into fully automatic machine guns. The cartel’s gunrunners often buy firearms legally in the United States, either at gun shops, gun shows, or in private sales. The firearms are then illegally shipped across the border.

Increasingly, the cartels are shipping weapons parts into Mexico to be assembled into  firearms. It’s especially difficult to detect.

But increasingly, the cartels are shipping weapons parts into Mexico to be assembled into finished firearms. It’s a discreet process that is especially difficult to detect. Firearm manufacturers or importers in the United States are not required to stamp serial numbers on gun parts. Retailers do not have to report when they buy and sell parts kits with everything needed to complete a gun except a receiver. Receivers, which house the mechanical components of a firearm, like trigger groups and magazine feeds, can be purchased separately. To avoid detection, gunrunners will often use unfinished, or “80-percent” receivers—receivers that are mostly complete but require some further machining to be functional.

As I previously reported when I attended a gun building party in California, unfinished receivers are not classified as firearms. They don’t require serial numbers and generally have no markings, which makes firearms assembled with them untraceable. “They are also easy to conceal,” the GAO report noes, “making it more challenging for customs authorities to detect illicit shipments of such parts.” As Rep. Engel noted in a statement, the ATF has discretion over how it defines a receiver. Yet, as Engel puts it, “far too often, unfinished gun receivers are minimally modified to avoid regulation.”

The ATF has long been hindered by a lack of funds and agents, a problem that President Obama addressed in the executive action he announced last week that includes adding 200 new ATF agents and investigators. Engel said Congress could do more to “stop the illegal flow of guns across the U.S.-Mexico border” but accused his Republican colleagues of being “much more concerned with loosening already lax gun regulations than protecting citizens in both of our countries from gun violence.”

The GAO report also notes that collaboration between American and Mexican authorities is fraught. In 2012, joint US-Mexico efforts to stem firearms trafficking were scaled down when Mexican President Enrique Peña Nieto sharply limited law enforcement collaboration. In the past year, US officials reported to the GAO that collaboration is gaining momentum, but concerns over corruption among Mexican officials is still a problem. The report notes that Immigration and Customs Enforcement officials in the United States “are concerned about sharing information with ICE officials based in Mexico, fearing that the information may unintentionally reach corrupt Mexican authorities and compromise their investigations.”

Correction: This article previously misclassified the caliber of AK-47 and AR-15-type rifles.

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. It's our first time asking for an outpouring of support since screams of FAKE NEWS and so much of what Trump stood for made everything we do so visceral. Like most newsrooms, we face incredibly hard budget realities, and it's unnerving needing to raise big money when traffic is down.

So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

IT'S NOT THAT WE'RE SCREWED WITHOUT TRUMP:

"It's that we're screwed with or without him if we can't show the public that what we do matters for the long term," writes Mother Jones CEO Monika Bauerlein as she kicks off our drive to raise $350,000 in donations from readers by July 17.

This is a big one for us. So, as we ask you to consider supporting our team's journalism, we thought we'd slow down and check in about where Mother Jones is and where we're going after the chaotic last several years. This comparatively slow moment is also an urgent one for Mother Jones: You can read more in "Slow News Is Good News," and if you're able to, please support our team's hard-hitting journalism and help us reach our big $350,000 goal with a donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate