U.S. guns linked to Mexican crime scenes, cartels

The Washington Post's yearlong investigation documenting the way guns move through American society continues with an examination of the role U.S. gun dealers play in supplying Mexican drug cartels. The Post cracked the secrecy of the federal government's gun-trace database and obtained the names of the top U.S. stores with the most guns traced back from Mexican crime scenes. They also uncovered the stores that lead the U.S. in guns linked to crimes nationwide.