As hundreds of federal and local agents scoured the Arizona desert and chased down potential leads in the nearly two weeks since Nancy Guthrie disappeared from her affluent neighborhood, families of other missing people are reminded how elusive answers can be.

Law enforcement agents have been gathering more potential evidence as the search for “Today” show host Savannah Guthrie 's mother heads into its third week.

Fresh surveillance images of a masked person on Nancy Guthrie’s porch the night she went missing, coupled with intense police activity across Arizona and the detention of a man, had raised hopes that ...