sealed his fate testifying he confessed to her he had broken rickerson's neck. she said he told her it was an accident. perhaps just as cunning and dangerous was david sweat. at 35, he is supposed to spend the rest of his life behind bars here for killing sheriffs deputy kevin tarcia. after sweat and two with others robbed a fireworks store, the deputy confronted them. his sister spoke by phone to anderson cooper. >> i never put him out of my mind. i always think of what he did and how awful this guy is. >> reporter: it was july 4th, 2002, deputy tarsia pulled in to the parking lot where the men were parked. in court the three suspects shared what happened next. sweat who, was hiding under a truck, said the deputy opened fire first. then sweat got to his feet and started firing. one of sweat's bullets hid