I've always followed the Etan Patz story (a NYC 6 year old who disappeared 31 years ago walking to school). I recently read "After Etan", a book about his family's life in the aftermath of Etan's disappearance, including their victory in a civil case against the #1 suspect, who is currently serving time for molesting two other boys.
As part of his recent campaign promises, the new DA for NYC has reopened the case.