is "nightline," may 27th, 2010. >> good evening, i'm terry moran. and we're going to begin tonight with a tragic murder case that today took another twist. this time, toward justice for a little girl named riley fox. she was 3 years old when she was raped and murdered in 2004. her father, kevin fox, was initially jailed after he confessed to the crime. but he said his confession was coerced, and dna helped clear him of the charges. now, nearly six years after that killing, dna has again led to a major breakthrough, as ashleigh banfield reports. >> reporter: today, justice for 3-year-...