LIVE: FBI Expert Analyzes Juliana's Credibility & Blood Evidence Says Scene Was Staged

The prosecution's entire case rests on one witness: Juliana Peres Magalhães. She's the only person alive who was in that bedroom when Christine Banfield and Joseph Ryan were killed. She testified that she watched Brendan Banfield stab his wife to death. She admitted firing the second shot into Ryan's chest. But for over a year, she lied. She wrote letters from jail promising to "take the blame." She told Banfield's mother she would "give my life for his." She only flipped after his arrest, after hospitalization from stress, and after his family stopped paying her legal bills. Now s...