>> i did. >> reporter: jonathan scharf said he realized his father had likely killed his mother only videotaped interview shows him recalling the dark past for the first time to police. >> she got coffee thrown at her by him. >> reporter: now in court, he had even more to tell about his childhood. like the afternoon he sat cowering in the back seat of a car watching his mother suffer. >> my mom was driving and my dad was hitting her with the bottom of his fist. i was just begging him to stop doing it. >> reporter: he also remembered the last day of his mother's life. he was 10 and said his mother told his father that she didn't want to go out with him alone. >> she said, if i wanted to go out with you, i wouldn't be divorcing you. >> reporter: where was the proof that stephen planned to kill jody that night? well, there was the hammer in the picnic bag. but there was also testimony from this woman -- one of stephen's old girlfriends. >> i even mentioned to my girlfriend that it was a perfect relationship. >> reporter: terry schofield had been dating stephen months before jody's death