Vanished Without a Trace (TV)

When 13-year old Cathy disappears, her parents Elisabeth and Jack Porterson, who have two younger sons, Daniel and J.J. who no longer feel safe and protected, mobilize help for the search, and keep going even after the police decides it's no longer worth the resources. In time Jack loses hope and faith in his marriage as Elisabeth focuses exclusively on the search. Just when even Elisabeth's confidence is no longer unshakable, they find the corpse in one of the last places on their map. The police isn't too eager to look for the killer, but she proves just as tenacious there, concentrating on a neighbor... - IMDb