danielle and alexander meitiv , both scientists in maryland , made headlines just before christmas when police found rafi , 10 and dvora , six , wandering the sidewalk on their own .
on sunday , a concerned citizen reportedly called authorities once again after seeing the siblings unaccompanied near a neighborhood park around a third of a mile from their home .
the children were picked up by police , who say they followed protocol by turning them over to cps .