The phone rang before sunrise. It woke Craig Patty, owner of a tiny North Texas trucking company, to vexing news about Truck 793 - a big red semi supposedly getting repairs in Houston. "Your driver was shot in your truck," said the caller, a business colleague. "Your truck was loaded with marijuana. He was shot eight times while sitting in the cab. Do you know anything about your driver hauling marijuana?" "What did you say?" Patty recalled asking. "Could you please repeat that?" The truck, it turned out, had been everywhere but in the repair shop. Commandeered by one of...