by chanin's killer.eceased and yet someone is using her cell phone to communicate. >> reporter: and to prove it must have been clay who sent those messages, they entered into evidence this seemingly innocuous text message from around 3:00 p.m. that afternoon. >> at 3:06 p.m. chanin starbuck phone to logan starbuck phone, send marsh a note, dad will be there in ten minutes. >> reporter: send marsh a note? who besides his mother might know the nickname marsh? the youngest starbuck marshall came to the stand. >> how often would your dad call you marsh? >> a lot. he also called me son and marshall. >> but he did call you marsh a lot? >> mm-hmm. >> reporter: yes, it had been an intimate act, an angry ex-husband killing the mother of his children, then staging the scene as a humiliating sex crime, premeditated murder said the state. and as evidence of clay starbuck's twisted state of mind, the prosecution offered this final piece to the puzzle. detectives said they found chanin's death certificate on a wall in