6 years ago,
Violence is running out of control in Mexico as rival drug cartels battle over the smuggling routes to America. Mexico's president declared war on the gangsters but the only result has been an escalation of murder.
BBC's Katya Adler journeys into the midst of this shocking conflict, uncovering human stories behind the violence. What does the continuing freedom of the world's most powerful drug runner, Joaquin "Chapo" Guzman, say about the War on Drugs?