>> i dialed angie's number at work. and a lady answered, and i said, this is carol dodge, angie's mom. and she said, angie's been found dead. >> just over the phone? >> and i remember saying, god, no. please no. this can't be real. >> reporter: it happened, it turned out, the night before in the tiny ni second floor walkup where the independent 18-year-old had just started to build her life, stabbed to death, her throat cut. and carol was haunted by a conversation she'd had with angie that very week. >> that's what she said to me, you know, mom, i've done something really stupid. >> did you say to her, what did you do?ou >> no, i didn't want to pry. >> reporter: what could that have been, that something stupid? did it lead to murder? idaho falls, idaho, big blue heaven above, dazzling white mormon temple below to anchor the town, and signal like a