Lucy Letby murdered seven babies, attempted to murder six others and there are allegations of more.
She was the young nurse nobody would have suspected, working with the most vulnerable of tiny lives in the neonatal unit.
She eclipses Myra Hindley and Beverley Allitt to become the worst child murderer in British modern history.
The families she destroyed remain private but the case raises nationwide issues because of the shocking way NHS managers dismissed the concerns of doctors who were trying to raise the alarm.
Instead of listening and calling the police, managers are reported to have accused them of mistreating the nurse and forced them to apologise.