here's keith morrison with the con kru conclusion of dark valley. >> how did a friend like john creech? well, said defense attorney, it was all very simple. creech never intended to kill gavin smith. this was a case of self-defense. >> had to defend himself against this intruder, an intruder into his marriage. >> and she said only one person could tell that story. >> who is the first witness that you want to call on behalf of the defense? >> my client, john creech. >> his attorney began by asking him about that meeting with gavin's sons. >> at any point did you tell them that you were going to kill their father? >> no. that's absurd. >> and two years later when it all happened, he and chandy were separated, he said, though they still lived in the same house. and he still worried about her, thought she might be drinking and driving. so he and installed an app on his phone that allowed him to