Hennepin county is being sued over a l990 child protection case where two children were returned to their biological mother who abused them. The youngsters, now nine and ten years old, have been adopted and no longer live with the biological mother. The adoptive parents are suing saying county social workers disregarded and even concealed evidence of the abuse. The county says it concealed nothing and argues the children were not in its custody when the abuse occurred. Minnesota public radio's Dan Olson reports, the federal civil suit may clarify the liability counties face when child protection cases go awry.