. >> 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 her test that day. karen packs holly's lunch and then she's off to teach second grade at scotts hill elementary. >> reporter: did you say goodbye before you left? >> she was sitting at the kitchen table. studying and i kissed her goodbye and told her i loved her. just like every other morning. >> reporter: holly gathers her lunch and homework and walks out to get in her mustang in t