A neuropathologist has told a jury a Northland toddler died of a "catastrophic" head injury so severe the young girl could never have survived it.
Two-year-old Ariah Roberts died in her home at Mangawhai Heads last August.
She had been left in the care of her mother's former boyfriend Aaron Archer - who is now on trial in the High Court at Auckland accused of murdering her.
RNZ court reporter Anneke Smith filed this story.
