The Caballeros Templarios -- or Knights Templar - is a Mexican drug cartel specializing in the very modern crystal meth trade.

The Knights take their name from a medieval order of Christian Crusaders, and claim to live by a strict moral code. But they're believed responsible for hundreds of drug-related murders in Mexico.

Ioan Grillo is a journalist and author of the book "El Narco", which chronicles the rise of Mexico's drug cartels.

Reuters Photo