U.S. guns arm Mexican drug cartels

SIERRA VISTA, ARIZ. -- High-powered automatic weapons and ammunition are flowing virtually unchecked from border states into Mexico, fueling a war among drug traffickers, the army and police that has left thousands dead, according to U.S. and Mexican officials.

The munitions are hidden under trucks and stashed in the trunks of cars, or concealed under the clothing of people who brazenly walk across the international bridges. They are showing up in seizures and in the aftermath of shootouts between the cartels and police in Mexico.

More than 90% of guns seized at the border or after raids and shootings in Mexico have been traced to the United States, according to the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives. Last year, 2,455 weapons traces requested by Mexico showed that guns had been purchased in the United States, according to the ATF. Texas, Arizona and California accounted for 1,805 of those traced weapons. ....