As the search for Nancy Guthrie enters its second week, new security footage and tips have fueled speculation around her son-in-law, Tommaso Cioni, though authorities have not confirmed any suspects.

Authorities have responded to new claims that Savannah Guthrie’s brother-in-law has been made the “prime suspect” in her mother’s disappearance. Nancy Guthrie, mother of TODAY show co-anchor Savannah, ...