Coahuila state prosecutor Homero Ramos (L), accompanied by member of his staff Gerardo Villareal (R), speaks during a press conference regarding the death of the founder of the Zetas drug cartel on October 9, 2012. - 

This week Mexican marines took out the leader of one of Mexico's most powerful -- and certainly its most violent -- drug gangs. The Zetas are dominant along much of the U.S. border, and there's some hope this might disrupt their reign of terror there.

As Mexico is one of our primary trading partners, close behind Canada and China, having the Zetas turn the border into a war zone hasn't done any favors for cross-border trade.

Ray Grawunder owns La Mariposa in Dallas -- it's one of the largest and oldest retailers of Mexican imports in the U.S. He says the gang tensions have disrupted his business significantly. "I've had to work out systems to get my merchandise up here. One of my vendors was held up twice, on his way to come see me, another one of my vendors was pulled out of his van in a border town and beaten up and got his merchandise stolen."

The result? Grawunder says its a "double edged sword." His in-store sales have gone up because customers are reluctant to go to Mexico and instead buy from La Mariposa. On the flip side, supply risks have caused product and vendor prices to rise.

"I don't know what the solution is," says Grawunder, "I've been doing this for 35 years, and I still don't know how we help [Mexico] come to a peaceful resolution and get rid of the violence."

Follow Jeff Horwich at @jeffhorwich