‘Angels of death’: Why do healthcare workers kill those they are meant to protect?

“This was a cruel, calculated and cynical campaign of child murder … There was a deep malevolence bordering on sadism in your actions.”
These were the closing remarks of Justice James Goss as he handed down a whole-life sentence to Lucy Letby, the UK nurse found guilty of killing seven babies and attempting to murder six others.
The 33-year-old is now regarded as one of the country’s worst child killers.
But she is also not the first healthcare worker to kill their patients.