danielle candidly described it as troubled. >> we had been not getting along for many months. >> danielle also explained that she knew sam was having an affair despite sam's best efforts to conceal it. >> dull know where he went today? >> today? i'm sure he went to his girlfriend's, yeah. but he always goes to her house. i'm not surprised by that. >> danielle then admitted she too was unfaithful. >> she was pretty straightforward, told me about the affair. >> it was wrong. i shouldn't have done it. nobody should cheat. >> little by little, the detectives led danielle to believe they were focusing their investigation on her lover michael. >> so it would kind of shock you if michael went and confronted him? >> yeah. >> that's what happened. >> really? >> and we have michael. >> do you? >> it wasn't the reaction the detective was expecting. he found her tone to be strangely flat and unemotional. >> that was troubling to me. that was disturbing to me. >> i cannot believe he did this.