Alissa Turney: What occurred to her, and has she been discovered?
‘Dateline NBC,’ the longest-running primetime sequence in NBC’s historical past, is now in its thirty third season. Anchored by Lester Holt and that includes correspondents Blayne Alexander, Andrea Canning, Josh Mankiewicz, Keith Morrison, and Dennis Murphy, the present returned Friday evening with one other haunting case: the 2001 disappearance of 17-year-old Alissa Turney. Lacking since…