younger sister terri, even though she had suspected mike for years -- >> do you still think of mike lubahnfeel that she would leave you and never come back and never say good-bye? >> no. >> he loved his dad, but also secretly doubted him. something he never revealed until now. >> i was sweating so profusely during that whole trial. he never knew i had these feelings so on the stand publicly i had to basically say, yeah. i'm thinking there are are some weird things about your story, and it was the first time that my father really would have known i felt that way. so i was really, really stressed out about that. >> how hard is it for you to be here today? >> very. >> do you want to believe that your dad is responsible for your mother's disappearance? >> do i want to believe it? >> yes. >> no. >> let's assume that your dad, in fact, did kill your mom. would you want to see him punished for it? >> no. not particularly. >> prosecutor lewin knew the ambivalence of these family members did not help his case. >> but in the end, my job isn't to make sure that the family members get what they want.