Crime - Mexico's Drug Cartel War

Violence is running out of control in Mexico as rival drug cartels battle over the smuggling routes to America. Mexicos president has declared war on the gangsters but the only result appears to be an escalation of the killings. Katya Adler journeys deep into the heart of a shocking conflict, uncovering the human stories behind the seemingly random and disturbing violence. She asks whether the continuing freedom of the worlds most powerful drug runner, Joaquin Chapo Guzman, is evidence that the Governments war is toothless.