TONIGHT's 20/20: After a young couple is murdered, their true identities lead to a shocking twist about their missing baby. @davidmuirabc reports on the case and brings us his exclusive interview with Baby Holly. 20/20 'Baby Holly Found' encore airs tonight (Aug. 21st) at 9/8c on @ABC. Stream on @DisneyPlus and @Hulu (S46, E6). #TrueCrime #Investigation