They were shopping in a popular downtown promenade when gunmen chasing a security guard opened fire into the crowd. This wasn't supposed to happen in Monterrey, Mexico's modern northern city with gleaming glass towers that rise against the Sierra Madre, where students flock to world-class universities, including the country's equivalent of MIT.

You can have peaceful, quiet communities (on both sides of the border) or you can have a War on Drugs, but you can't have both ...