Guns from the United States are flooding Latin America

LIKE A CRIMINAL and his fingerprints, every gun leaves its mark on the ammunition it uses. Such traces are what Sergio Sandoval de la Peña pores over daily in Mexico City’s ballistics lab. A series of dark-green circles, like the sub-woofer of a speaker, appear on his computer screen. It is a digitised three-dimensional model of a cartridge, found at the scene of a robbery this year and placed under a microscope. Checking the marks against hundreds of thousands of potential matches, Mr de la Peña concludes that the gun that ejected it was also used in a murder last year.

The ballistics technology employed to work such wonders comes courtesy of the United States. Alas, so does the gun, according to Mr de la Peña’s database. A study of weapons found at crime scenes suggests that 70% of gun crimes in Mexico involve American-bought weapons. The share of homicides in Mexico involving a firearm grew from 16% in 1997 to 66% in 2017. That suggests around half of Mexico’s 33,000 murder victims last year were killed by a gun manufactured in the United States, which had 14,542 gun homicides in 2017. An American-made gun is more likely to be used in a murder in Mexico than at home.