Federal agents say a Harlingen man is now tied to the murder and kidnappings of the four Americans in Matamoros earlier this month.
According to a criminal complaint filed at the federal court in Brownsville, Mexican authorities recovered one of the weapons used in the fatal shooting of two south Carolina men on March 3.
Two others were kidnapped during the attack.
The federal complaint says the rifle was a Diamondback ar-15 that was originally purchased by Roberto Lugardo-Moreno of Harlingen.
On Friday, he was questioned by Homeland Security and Alcohol, Tobacco, Firearms, and Explosives investigators.
According to the criminal complaint, he told investigators he was paid $100 to purchase the high-caliber rifle and other weapons in 2019 that he knew would eventually be given to someone in the gulf cartel in Mexico.
The complaint say Lugardo-Moreno knew it was illegal to do so and never got a license to export firearms from the united states.
Lugardo-Moreno was taken into federal custody and charged with conspiring to illegally export guns from the U.S. He is being held without bond. He requested an attorney. He will be back in court on Thursday afternoon for a detention hearing.