him. reporter: and they sawcentri. certainly not a killer. at last it was time for the state s star witness, rachel mcfarland, the other woman, to show up and tell her story. did you need the jury to like her? we needed the jury to believe her. reporter: rachel testified her relationship with seth started heating up in december, 2011, which was two months after seth got married. it became more sexual, asking me to send pictures or i don t know, just showing off my body i guess. reporter: on may 20th, 2012, seth and rachel met at a nature preserve where they took this selfie to remember their time together. i mean, he kissed me, touched me. he said that we had everything in common and that he had tried working thins out with lisa, and they just weren t work, and i was exactly what he wanted. reporter: she said seth repeatedly told her he was going to divorce his wife.