Probably someone they hired ILLEGALLY.
No wonder they have been keeping this quiet.
My thought, definitely connected somehow someway to hired help. People talk. The perp found out she was a potential target. Elderly, lived alone, multi-millionaire daughter. Could have been a burglary gone bad - Have we heard if the house was "tossed" for valuables by the perps??
Also why Savannah Guthrie her FIRST phone call when she found out her mother was missing was NOT to the cops but to MARK KELLY cause ya, when your family member goes missing you always call your Senator LOL.