(CNN) -- Two bodies dangling from a pedestrian bridge in the border town of Nuevo Laredo, Mexico, created an image as gruesome as any in the four years of the country's offensive against the drug cartels. A man and a woman, both in their early 20s, were left hanging like cuts of meat. The woman was hogtied and disemboweled, her intestines protruding from three deep cuts on her abdomen. She was then hung from the bridge by her feet and hands, topless. The bloodied man was suspended next to her by his hands, his right shoulder severed so deeply you...