Night was his anger was building, building and perhaps fuel bide alcohol. reporter: prosecutors tried to show that clayton whittemore already established a pattern of violence. called ex-girlfriend to testify about a scary episode. we were arguing in a parking lot, he choked me. i locked him out of his car to cool down and he did. reporter: but that one was serious? yeah, it was scary. reporter: hunter played hockey on the college prep team in florida. hunter, too, had a scary experience. it happened after clayton drank half dozen beers. the one team he saw his teammate drink. he walks in the kitchen and grab as knife and looked like he was possessed. he took a step towards us and our host mom saw what was happening and said, clayton put the knife down. reporter: the defense attorneys didn t deny he killed