>> you know, broken-up words, and he's crying, and we're crying. that was when he said they think i hurt mom. he was very upset. >> but he didn't sound surprised when he said -- >> no, he was crying. he was crying. he was upset. >> very upset. >> but by the time police investigators were questioning chris, remember, they had heard from lindsay patterson. and at the station, chris's version of events in the spa differed in one crucial detail from what lindsay described seeing that first time she period over the wall and into the hall's backyard. >> that specifically, me holding her down in there, there's >> but investigators were getting a good look at christie's body and saw wounds that to them suggested a struggle and more than one nasty blow to the head. so the police had to choose. which version, chris hall's or lindsay patterson's, was more likely the true story of what happened? tom dove is a senior investigator for the riverside d.a. >> i think they felt this was enough to say this was not an accidental drowning. it was purely much more suspicious than that. >> and so before the night was over, chris hall was arrested and charged with the murder of his wife. the girls could stop waiting. he wasn't coming home. >> it was obviously a tragedy, losing our mother that day. but this is a tragedy on top of a tragedy now. >> because knowing our parents, it's the farthest thing from truth. >> and one that felt infected by some kind of madness, said the girls. cristi was the love of his life. how could he be accused of harming her? she was happy too, they said, as happy as she had ever been, they knew based on that mother/daughter talk they had not long before she died. >> she kept reiterating how happy it was. me and brie will always cherish that. >> that being the last time we actually saw her. >> kind of burned into your memories. >> yeah. >> but right or wrong, the legal trigger had been pulled.