genna? genna? >> one of the last people that she speaks with says that the phone goes dead. genna doesn't call back. her friend pages her a couple of times. genna never calls back. >> police found genna's diary in her bedroom which had an entry from the morning of her murder. >> dear journal, sorry i haven't written you, but i've been pretty busy. things have been going pretty good at school except for the fact that guys don't even know i'm alive half the time. >> the diary expressed a specific interest in two boys. one was considerably older than genna, a boy she met at a local amusement park. >> he was a young man, about 18 to 19 years old, who was preying on children that were not age appropriate. >> he was older than us. not -- not the best kind of person that you'd probably want to -- want to be with. but he -- there was something that she saw in him that attracted her to him. >> investigators needed to start checking alibis and there was one that almost defied belief. ♪ if you want a p

saturday morning in 1995, as cathy mouser was leaving for work, she reminded her 14-year-old daughter, gennaed for the weekend and wasn't allowed to use the telephone, either.