Raleigh, N.C. — The grandfather of a 4-year-old boy who died two years ago in the home of his adoptive parents has filed a wrongful death suit against the couple and state and local officials.

Ron Ford Sr., the administrator of Sean Paddock's estate, is using the lawsuit to wrest some answers from the state Department of Health and Human Services, Wake County Human Services and the Children's Home Society of North Carolina, a private adoption agency.

Paddock suffocated in February 2006 after he was tied too tightly in blankets so he would stay in bed, authorities said.

His adoptive mother, Lynn Paddock, has been charged with murder in the case and is scheduled for trial in May. Prosecutors decided not to press charges against Johnny Paddock, Sean's adoptive father.

Lynn Paddock also has been accused of beating Sean's siblings with PVC pipe.