Two ICE agents were attacked in Mexico in February. One of the men was killed in the attack. Since that time, federal investigators have been taking a hard look into weapons smuggling on the southern border.
Weapons and drug smuggling have been a major problem on the U.S. border with Mexico for years. Lately, U.S. authorities have become increasingly concerned with Americans who purchase firearms in the U.S. for the purpose of later re-selling those weapons to Mexican drug cartels. This practice of buying and reselling firearms has become known as straw gun purchases. Recently, a federal grand jury indicted three American men on federal weapons charges related to alleged straw gun purchases.
Authorities allege that these men were involved in the sale of a 7.62 mm pistol that was used in the February attack on the ICE agents. Allegedly, one of the men purchased the pistol from a gun dealer and ballistics testing matched that firearm with one of the firearms used in the attack. The men are accused of conspiracy and purchasing firearms by making false statements. Two of the men face the additional charges of owning a firearm that had the serial number removed.
The three defendants initially drew the attention of the Drug Enforcement Administration and the Bureau of Alcohol, Tobacco, Firearms, and Explosives in November as part of a larger investigation of the Zetas cartel's efforts to buy guns in the U.S. and smuggle them to Mexico. Allegedly, ATF agents witnessed the three men delivering firearms to an ATF confidential informant last November.
Source: Reuters, "U.S. indicts three over gun tied to Mexico shooting," Jeremy Pelofsky, 3/24/2011