In December 2002 nurses at a Leeds hospital found Ethel Hall, an eighty-six-year-old woman recovering from a broken hip, in a hypoglycemic collapse, with a blood sugar reading of 1.5 millimoles per liter. She was not diabetic. A doctor wondered aloud whether she had been given insulin by mistake, and a consultant had a sample of her blood sent for specialist analysis. It came back with a very high level of insulin and a suppressed C-peptide, the chemical signature of insulin injected from outside rather than made by the body. Ethel Hall died. The staff nurse assigned to her was Colin Norris, a twenty-six-year-old from Glasgow, and the result sent West Yorkshire Police back through every ward he had worked that year.
Four other elderly women on the same orthopedic wards had collapsed the same way in 2002, sinking into sudden, deep hypoglycemia that no one could explain. Doris Ludlam was eighty, Bridget Bourke eighty-eight and Irene Crookes seventy-nine, and all three died. Vera Wilby, ninety, survived. Norris, born in 1976 and trained at the University of Dundee, had come to Leeds that year to work at the Leeds General Infirmary and St James's University Hospital, and in each case he was the nurse caring for the patient. He was arrested on October 12, 2005, and charged with four murders and one attempted murder.
The trial ran five months at Newcastle Crown Court, and it was fought over medicine. No one had seen him inject anyone. The Crown's experts said that spontaneous hypoglycemia in an elderly patient without diabetes was vanishingly rare, and the experts retained by the defense agreed. The one natural explanation raised, a rare condition called insulin autoimmune syndrome, was dismissed by a consultant geriatrician as less likely for a single patient than winning the lottery. That left the defense arguing that some other person could have come onto the wards and injected the women unseen. Prosecutors called Norris the common denominator. On March 3, 2008, the jury convicted him by majority on all five counts, and he was sentenced to life with a minimum term of thirty years. He has denied the killings from the start.
He lost his first appeal in 2009. The question that would keep the case alive had been asked by the jury itself: near the end of the trial it wanted to know whether any patients in the Leeds teaching hospitals had suffered sudden and profound hypoglycemia after Norris stopped working there. Four such cases were later identified, deaths recorded between January 2003 and August 2005, and no one suggests they were anything but natural. Researchers meanwhile reported that unexplained low blood sugar in frail elderly inpatients was more common than the experts of 2008 had believed. A BBC Panorama film made that argument in 2014. After a review that began with submissions in 2011, the Criminal Cases Review Commission referred all five convictions to the Court of Appeal on February 12, 2021, describing the prosecution case as wholly circumstantial and saying there was a real possibility the verdicts were unsafe. Ethel Hall's conviction went with the rest, because the jury had been entitled to treat each case as support for the others.
By the time the appeal opened on May 6, 2025, he had changed his name and came before the court as Colin Campbell. His counsel, Michael Mansfield KC, told Lady Justice Macur, Sir Stephen Irwin and Mr. Justice Picken that an evolution in medical knowledge had made the verdicts unsafe, and pointed to the four later Leeds deaths. On June 26, 2025, the court dismissed the appeal. The judges held that the later cases underlined rather than undermined the features that marked the 2002 episodes as injected insulin, and said they had no doubt about the safety of any of the five convictions.
The convictions stand, and he remains in prison on the life sentence. His lawyers have applied to the European Court of Human Rights, a process his solicitor, Rory Hearty, has said will take many years. In 2026 a BBC podcast went back through the medical records and the police interviews, and some members of Ethel Hall's family, who for two decades had believed he murdered her, have said they are no longer sure.