A senior police officer has said that a hospital doctor's vigilance prevented a nurse who murdered four elderly patients from continuing his killing spree.
Staff nurse Colin Norris is set to be jailed for life after he was found to have given lethal doses of insulin to vulnerable pensioners who were receiving treatment at two Leeds hospitals in 2002.
One of Norris's colleagues, Dr Emma Ward, grew suspicious after one of the women fell seriously ill while he was caring for her, and she alerted the authorities.
An investigation was launched and it was eventually discovered that he had already killed three other patients and tried to murder another.
The 32-year-old from Egilsay Terrace, Glasgow, was convicted of four counts of murder and one of attempted murder at Newcastle Crown Court, following a lengthy trial.
Outside court, Detective Chief Superintendent Chris Gregg described Norris as "extremely arrogant", and without remorse for killing Doris Ludlam, 80, Bridget Bourke, 88, Irene Crookes, 79 and Ethel Hall, 86, while he worked at the Leeds General Infirmary (LGI) and the city's St James's Hospital.
He was also convicted of attempting to murder Vera Wilby, 90.
Mr Gregg said: "The Leeds Teaching Hospitals Trust have been extremely supportive during our investigation and were it not for the prompt actions of one doctor, Dr Emma Ward, following the unexplained coma that beset Ethel Hall, then I am convinced that other people would have lost their lives at his hands."