we found a torn up letter that was his words to lottie spencer. >> narrator: daker's torn up letter toottie was hateful. and threatening. prosecutor jesse evans. >> he specifically talked about having plans and backup plans to exact revenge on lottie. and the worst part is that he said i'm going to let you live, i'm going to get revenge on you, but i'm going to let you live. >> narrator: to police and prosecutors, this wasn't just a rant. it looked like a blueprint for murder. now they tried to link daker to the crime skaechb. >> some of the important evidence that we start with is the hair and fiber evidence that we covered off of carmen's body. >> carmen had small puncture wounds on her back, suggesting a ferocious struggle. >> she had been not only tortured and murdered but she had been undressed at some point and redressed. >> narrator: at carmen's bedside she had wanted for peace of mind, never touched as she fought for her life. not far away was the suspected murder weapon, a piece of rope. crime scene technicians dusted for fingerprints and collected blood samples. the evidence