Authorities say Lake City child died from abuse

GAINESVILLE, FLORIDA - A couple were charged with first-degree murder in the death of their 6-year-old daughter whose head was crushed from a blow to the back of the skull, officials said. <br> <br> Jessica Miller, who lived with her mother and stepfather in Lake City, died March 29 at Shands Hospital at the University of Florida. <br> <br> Richard Nixon, 30, and Sarah Nixon, 22, were charged with first-degree murder Thursday because of aggravated circumstances involving Jessica&#39;s injury, said Columbia County Lt. Joe Lucas. <br> <br> Child protective services in Georgia, where the Nixons used to live, and in Florida had investigated concerns of abuse against Jessica several times since 1998, according to a Department of Children and Families report. <br> <br> The complaints included numerous bruises over many months, a split lip and a burned mouth. <br> <br> The bruising also happened at least once while Jessica was staying with her father, who lives in Georgia, officials said. <br> <br> The Nixons claimed Jessica had a medical condition that caused her bruises. She was tested several times at Shands but no such condition was found.