CBS News DFW – It was more than a decade in the making, but local and federal officials announce they busted a sports betting ring that handled more than 5-billion dollars. It started with an anonymous letter to Plano police. ‪ A Plano undercover officer spent years peeling back the layers of what turned out to be a sports gambling scheme with international connections — and some bettors placing incredible wagers. “Six or seven figures; and obviously we are in the big time here,” said John Bales, US Attorney for the Eastern District of Texas. How big? Authorities confiscated stacks of…