A Lewisville police affidavit alleges that Bobbie J. and Fred Mitchell’s grandson may have premeditated the attack on the county commissioner and her husband and broke into their house, even though he lived with them.

A county commissioner in Denton County, Texas, is in the hospital and her husband is dead after a stabbing attack by the victims' grandson, local police said Monday. Police in Lewisville — a suburban city north of Dallas — said officers responded to a home just before 4 a.