The mother of kidnap victim Hannah Anderson was bound, gagged and beaten to death before the killer set his home ablaze and fled with the teenager to the Northwest, according to the San Diego County medical examiner.
Christina Anderson, 44, a medical assistant, died of blunt force injury to the head with a minimum of 12 blows to her face and head, an autopsy report released Monday said. A crowbar was found near the body.
She also had a broken arm and her throat was slashed, although the latter apparently was done after she was dead, the report said.
Christina Anderson's body was found Aug. 4 in the garage of a burned-out home in the rural San Diego County community of Boulevard owned by family friend James DiMaggio, 40.
Sheriff's investigators have concluded that DiMaggio killed Christina Anderson, her 8-year-old son Ethan and the family dog before fleeing with 16-year-old Hannah.
DiMaggio and the teenager were located six days later, on Aug. 10, in the deep forest of southern Idaho. FBI agents sent to rescue Hannah shot and killed DiMaggio after he fired on them and refused to surrender.
San Diego County Sheriff Bill Gore said Hannah had been held under duress by DiMaggio and was a "total victim" in the incident.
Ethan Anderson's body was so badly burned that the medical examiner was not able to determine a cause of death, according to the report. The family dog had been shot.
"Multiple layers" of duct tape were found around Christina Anderson's mouth and neck. Her ankles were bound with a "large white plastic cable." Her arms and legs had several cuts.
Although there were burn marks on her body, no soot was found in her airway, suggesting she was killed before the fire was set, according to the autopsy report.
Her body was found beneath a green tarp. She was wearing a red tank top with a "Mickey Mouse" and "Minnie Mouse" logo.
The charred remains of Ethan Anderson were found inside the two-story home, which had also been set on fire.
"It is unknown whether the decedent was alive at the time of the fire or already dead," according to the autopsy report. "It is possible that he died of thermal burns without smoke inhalation in the house fire."
Ethan Anderson was identified by DNA examination.
Christina Anderson and her two children lived in Lakeside and had been lured to DiMaggio's home in Boulevard by his assertion that he was moving from the area and wanted to say goodbye, according to interviews given by Hannah Anderson after her rescue.
Investigators have said Hannah did not realize that her mother and brother were dead when DiMaggio forced her into his car and began the drive to Idaho.