A MOTHER’S CRUSADE AIRING ON “20/20,” MAY 13, 10 P.M. EDT ON ABC

— -- What happened to Kelsie Schelling? Twenty-one year old Kelsie mysteriously vanished into thin air in Pueblo, Colorado over three years ago. The family says surveillance video, text messages, and other evidence point to her boyfriend’s involvement, yet to their outrage, police have not yet classified the case as a homicide and have not charged him with a crime. But then a series of Facebook messages to Kelsie’s mother raise new theories – is the missing girl’s disappearance prompting someone to attempt extortion? “20/20” investigates and confronts those behind the mysterious plot and uncovers developments about what really happened to Kelsie. Ryan Smith’s reports airs on “20/20” on FRIDAY, MAY 13 (10:00 – 11:00 pm EDT) on the ABC Television Network.