>> i was so happy. i mean, i was walking on cloud nine. >> defense lawyer billy richardson was driving through mississippi when he heard the news. >> i said stop the car. it was just like somebody had taken a 2x4 and hit me upside of the head with it. >> i was convinced that if anybody could ever run an actual dna on that sample, they would find someone other than tim hennis, and i believed it with every fiber of my being. >> but the shocking dna results led to a pragmatic question. >> what do you do now? timothy hennis had been ajudeicated not guilty, and therefore, the south carolina was not going to try him again. >> we fought a revolutionary war because somebody could be tried over and over again for the same offense. and the founders put it in the constitution that there is no