The victims' house sits on the same property that was the site of a search by the FBI, SBI and the Rowan County Sheriff's Office last week.
Authorities searched a storage shed at the back of the property and seized multiple items. According to a search warrant filed in the case, only Casey and Sandy Parsons had access to the shed and kept it locked.
Thursday investigators told Eyewitness News despite intense media coverage, a billboard campaign and an appearance on the nationally syndicated talk show "Dr. Phil," they have no leads in the case.
Authorities said, however, they had received hundreds of tip calls.
Family members told Channel 9 the FBI continues to conduct interviews this week and search for new evidence related to the case.
Another vigil is planned Sunday for Erica. The vigil will be held at the Rowan County courthouse at 7 p.m.
Organizers have asked people to bring their own candles to the vigil.