S08:E04 - The Stepping Hill Poisonings

Usually it is immediately obvious when there has been a murder. But for some time after Victorino Chua embarked on his killing spree at Stepping Hill hospital during the summer of 2011, no one really noticed. His victims were mostly, but not exclusively, elderly. All were unwell. Each was already in hospital when he secretly loaded their drips with insulin to cause a hypoglycaemic attack.