The case of care home worker Karen Pedley, who was given 14 life sentences in 2016 and found guilty of killing a 96-year-old resident by setting fire to her room.

The case of New York paramedic Paul Novak, who boasted of committing the perfect murder after the dust had settled on the death of his first wife Catherine.

The case of carer Thomas Dunkley, who aided boxer Shaun 'The Guv'nor' Cummins after he became paralysed, and later killed and dismembered his patient.

The story of debt-ridden mother-of-three and night-time sex worker Beverley James. By day, she was meant to care for Harriet Davison, a frail woman she beat to death.

Care worker Thelma Purchase plotted with her son and a friend to murder disabled Greg Baker who Purchase once worked for. She knew he couldn't defend himself and she stood to be a beneficiary in his will.

The murder of politician Kathy Augustine, who died after being given paralysing drug succinylcholine by her husband Chaz Higgs, a professional nurse.

The case of care worker Bunthawee Rimmer, who enjoyed a comfortable lifestyle as a live-in carer to Paul Norfolk. When she was made the main beneficiary in Paul's will, Rimmer stood to inherit almost £350,000 and resorted to a hammer attack to ensure he would not change his mind.

When an autopsy revealed high levels of insulin in Eric Lloyd's body, police realised his widow, nurse Marie Whiston, had been using her medical skills not to care but to kill.

When Alice Grant died it was sad, but not unexpected. The 84-year-old needed round-the-clock care from her nurse Alison Firth. What nobody expected was how much Firth would resent the extra care her vulnerable patient required, or what lengths the lazy nurse would go to in order to avoid the work.