>Yes, no one disputes the family is the first place to look,
The cops still went through the motions in the Susan Smith case even though they knew she did not have any scuffed shoes and that a woman whose children were being driven away would have grabbed a door handle and been dragged. When she changed the location that this all took place in, they knew who was responsible.

One city's police dept. issued fliers and had searches, even though they knew the store's surveillance tape showed the woman entering the store alone and engaging in abolutely no 'searching behavior' prior to suddenly running up to a store clerk and saying she can't find her daughter.