they quietly told the lawrences their awful news. did your heart just break for mary and dave? >> my heart was slowly breaking the entire time. >> i remember the first thing i felt it was just like a surreal of, i know she's not out there in the cold. >> ronnie gaskins had a confession from rachel and she had led him to a body. but it wasn't enough. why wouldn't you arrest somebody right away who confessed to killing somebody? >> she lied to us a number of times before. so we had so day, who is to say she isn't lying again? so we had to corroborate her statement. >> once more, gaskins needed rachel so he didn't arrest her. instead, he was about to use rachel to get sheila. >> coming up. >> i was devastated. >> i was crying. she was grieving. >> grieving or pretending? >> sheila seemed like she was so upset to have lost her best friend. she even asked me how could