Mexican drug cartels pay Americans to smuggle weapons across the border, intelligence documents show

CBS Reports: Mexican drug cartels have been smuggling a vast arsenal of weapons out of the U.S. with the help of American citizens.

Dozens of cartel gunrunning networks, operating like terrorist cells, pay Americans to buy weapons from gun stores and online dealers across the country, sources say.

The free flow of American guns across the southern border empowers the cartels to protect their drug operations and outgun Mexican authorities.

"ATF is committed to stopping as many guns as possible from being illegally trafficked into Mexico ," ATF Director Steven Dettelbach told CBS News in a statement, touting the prosecution of 100 people in the past year . "Investigating straw purchasers is just one tool that we use. Our efforts also include large scale, long term, complex investigations of entire trafficking networks." Neither the Justice Department nor ATF provided evidence to demonstrate that their efforts have meaningfully reduced the flow of American firearms to Mexico . -Adam Yamaguchi and Sarah Metz contributed reporting. for more features..