because the home belonged to earl mann and his common-law wife. >> it was like a lightbulb that wentking, wow, is this too unreal or not? what would be a normal person's reaction to a child showing up at your door saying your grandmother has been killed and you're bloody and a mess. what would your reaction be? it wasn't what her reaction was, definitely. >> we ended up getting a rap sheet on her old man, which was pages and pages long. and most of the things started off with the word "aggravated" beforehand. a lot of violent-type offenses. >> melinda now had a pretty good idea who committed this crime. but she needed to find some way to prove it. using tricks she learned from "forensic files," melinda first tried to get his saliva. >> i started writing earl mann some letters. i gave him a brief description of what i look like, which is totally different than what i normally -- what i really look like. and just that i was kind of a lonely person, and i was searching the web for pen pals. >> and what her objective there was to see if she could get saliva on the envelope flap, if he we