but this program is going to make them very nervous. >> erin moriarty is with us.>> this is a new one formy. the cut and paste letter. this is a copy of it. >> it takes a lot of time. >> it does. all the little letters cut out. i think what's really interesting about that -- when you read it, it sounds like a woman. >> she told me she hated her house. >> here you are claiming response built for it. it's true, she hated her house. but it's true two people were involved. charlie cringed when he heard. her throat was slit. investigators believe it was probably a male who did it, but if a woman wrote this, then there had to be two people. >> so they're asking viewers for help. they want us to do what? >> well, of course, if they remember seeing anyone cutting and pasting but also that sketch. that man who was seen in the neighborhood. >> all right. thnk you. >> thank you, erin. >> thank you so much. >> you can see erin's full report, "solve this case condition who killed kay wenal?" that's at 10:00 p.m. tomorrow, 9:00 p.m. >> how she recreated the iconic opening of the

and now investigators are turning to the public for help. "48 hours" correspondent erin moriarty hasory. >> reporter: why are you talking to me? >> i'm talking to you because i want to find out who murdered my sister. >> reporter: in may 2008, pam sleeper'sleeper's sister, kay ws brutally murdered inside her suburban atlanta home. it's a mystery that has baffled everyone from the local police to a team of private investigators, hired by kay's husband, real estate developer hal wenal. so can this be solved? >> oh, i think it can. >> reporter: investigators believe kay let her killer in and was immediately assaulted. she was able to run to the kitchen, where he caught her. >> and then... cut her neck. >> reporter: it was a violent attack, and yet the killer left little evidence. husband hal had an alibi. what police had was this-- a sketch of a stranger seen in the wenals' neighborhood on the day of kay's murder. and then nearly three months later, police were handed another clue-- an expliative-filled cut-and-paste letter. >> i was in shock. i-- i didn't know what to think. >> reporte