We have something similar going on in our town. A mother and daughter (about 6 years old) disappeared on 11/13/01. They are still missing. There have been some recent developments, however. Apparently, they have suspected the husband/dad all along, but had no proof. But his behavior has been sending red flags throughout the community. One initial report: Hope is Eternal for Man Whose Family is Missing
Recent developments: he's been caught stealing from his employer (after being under surveillance since his family's disappearance) and just tried to commit suicide:
Father Admits Stealing
It really is hard not to look at parents as suspects, sometimes, even though I could never do anything to ever hurt my kids; it's unimagineable.