Two-month-old J.M. came to the attention of the Los Angeles County Department of Children and Family Services (Department) because she was found to have a medical condition of chronic subdural hematomas. Her parents L.Z. and O.M. had no explanation as to how the injuries occurred. An expert concluded that birth trauma was a possible explanation for the injuries. Others said it was unlikely. At the time of her injuries, she was under the exclusive care of the parents. J.M's 14-month-old sister, L.C., whose father is J.C., had no evidence of injury.