PHOENIX (AP) — “Today” show host Savannah Guthrie and her siblings have posted a series of videos online since their mother, 84-year-old Nancy Guthrie, went missing earlier this month in a mysterious case that has gripped the nation. In the Instagram videos, Savannah, Camron and Annie Guthrie acknowledged media reports of a ransom letter. The family has pleaded for their mother's return and requested proof of life and contact with whoever took their mother.