Final answer:
JonBenet's official cause of death was 'asphyxia by strangulation associated with craniocerebral trauma', pointing to a combination of factors in her homicide.
Step-by-step explanation:
The official cause of JonBenet's death was 'asphyxia by strangulation associated with craniocerebral trauma'. While her skull was fractured, which is an indicator of craniocerebral trauma, and there was evidence suggesting she may have been sexually assaulted, the coroner's report specifically lists asphyxia, a condition of severely deficient supply of oxygen to the body due to abnormal breathing, as her cause of death. The use of the word 'associated' signifies that the asphyxia occurred in conjunction with craniocerebral trauma, thus indicating a combination of factors leading to her tragic demise.