it's where karen and dana bobo live. in a home they built with own hands, with their 25-year-old son clint, and his younger sister, 20-year-old holly. >> holly was pretty much a mother's girl. we shared a bond that she would sometimes look at me and say that it's scary, because we could finish each other's sentences. >> reporter: whitney duncan, a country music singer, is holly's cousin. >> she had a beautiful voice, so i would kinda help coach her a little bit on that. ♪ will will be peace in the valley for me ♪ >> reporter: and it was a special time for holly, she had recently received a promise ring, from her boyfriend, drew scott. >> and i remember her showing me and just being so excited about the future. she really was planning their life together. >> reporter: the last day of her life was a wednesday. a perfectly ordinary april morning in 2011. too early for trouble. the sun climbing the trees, chasing off the mist. the bobo family is rising too. holly, a nursing student is up by 4:30 that morning, studying for he