Audrey Manuel presented with dangerously low blood sugar.(Supplied)
Dr Tuan Quach sent for blood tests to see if his patients had been injected with insulin (ABC News: Brendan Esposito )
Dr Tuan Quach is an endocrinologist, meaning his speciality is blood sugar levels and insulin (ABC News: Brendan Espositio )
Dr Tuan Quach was the first person to realise a killer was on the loose at SummitCare Wallsend. (ABC News: Brendan Esposito )
Gwen Fowler was murdered by Garry Davis at the SummitCare aged care facility.(Supplied)
Without Dr Tuan Quach, it's possible no-one would have noticed a pattern in patients turning up from SummitCare.(ABC News: Brendan Esposito )
Police found syringes and needles in a container under Garry's bed at the home where he lived with his grandmother.(Supplied)Loading...
Ryan Kelly celebrates his 80th birthday, the same year he was murdered by Garry Davis.(Supplied)
SummitCare Wallsend is where Garry Davis worked for three years before he was charged with two murders and one attempted murder.
(ABC News: Brendan Esposito )
Mark Ramsland arriving for the day at his Newcastle office. (ABC news: Brendan Esposito )
Lawyer Mark Ramsland regrets the outcome of Garry Davis's case.(ABC News: Brendan Esposito )
SummitCare Wallsend is where Garry Davis worked for three years before he was charged with two murders and one attempted murder.
(ABC News: Brendan Espostio )
Dr Tuan Quach thought multiple cases of hypoglycaemia in one night was strange and decided to investigate
(ABC News: Brendan Espositio )
Police found a black bag containing medical paraphernalia under Garry Davis's bed.(Supplied)
Dr Michael Diamond analysed Garry Davis for police.(ABC News: Sissy Reyes)Loading...
Dr Diamond does not believe that the murders Garry Davis was convicted for were his first instances of harming patients.(ABC News: Sissy Reyes)
Elizabeth Eifler was a resident at SummitCare Wallsend in the ward where Garry Davis worked.(ABC News: Brendan Esposito )
Elizabeth Eifler with her husband.(Supplied: Eifler family)
Elizabeth Eifler as a young woman.
Peter Eifler believes police "overlooked things" following his mother's death.(ABC News: Brendan Esposito)Loading...
Kathleen Lowe is still impacted by what happened to her grandfather at SummitCare Wallsend.(ABC News: Jack Fisher )