Christina and son Ethan, 8, were found charred Aug. 4 inside a home belonging to James Lee DiMaggio, a family friend, who then kidnapped Christina's 16-year-old daughter Hannah.
Authorities tracked DiMaggio to a remote portion of Idaho and he was killed in a firefight. Hannah Anderson survived the ordeal.
Autopsy reports revealed there were 12 impact sites on Christina's head and a crowbar was found near her body in DiMaggio's garage, U-T San Diego reported Monday. Her ankles were bound by a plastic cable tie, and duct tape was wrapped around her neck and mouth.
She had lacerations on her right arm and left leg, her right arm was fractured, and there was an incision on her neck that was likely inflicted after death, the report said.
Ethan's body was found in the attached two-story house owned by DiMaggio. The autopsy report revealed the boy likely died due to the fire, but he also had fractures likely due to trauma.
A memorial was held for the mother and son Aug. 24 at Guardian Angels Catholic Church in Santee.