Colin Norris was a staff nurse in his first year after qualifying when five elderly women on the orthopedic wards where he worked in Leeds fell into deep, unexplained hypoglycemia, a dangerous drop in blood sugar, in 2002. None of the women had diabetes. Four of them died. The last case, that of Ethel Hall, 86, was tested in time: her blood showed about 12 times the normal level of insulin, and the hospital, and later West Yorkshire Police, began looking back through the earlier cases.
In March 2008, after a five-month trial at Newcastle upon Tyne Crown Court, a jury convicted Norris by a majority of 11 to 1 of murdering Ethel Hall, Doris Ludlam, Bridget Bourke and Irene Crookes, and of attempting to murder Vera Wilby. He was sentenced to life imprisonment with a minimum term of 30 years. He has denied the offenses throughout. The case has been fought ever since over medical science: whether severe hypoglycemia in frail, elderly hospital patients is as rare as the experts at his trial said it was. The Court of Appeal rejected his first appeal in 2009. The Criminal Cases Review Commission sent the case back in 2021 on fresh expert evidence, and in June 2025 three appeal judges, having heard that evidence, said they had no doubt that any of the five convictions was safe.
Norris was born in Glasgow, and newspapers covering the trial and the later appeals describe him as a Glasgow man. He was 32 when he was sentenced in March 2008, according to reports of the sentencing. His mother has campaigned for his release for many years and has spoken publicly in support of him.
He trained as a nurse at the University of Dundee. The Courier reported in 2011 that he began a Higher Nursing Diploma there in September 1998 and qualified three years later; the Court of Appeal's 2009 judgment describes his qualification as a nursing degree from Dundee and gives the date he qualified as October 2001. An inquiry commissioned after his conviction by NHS Yorkshire and the Humber, the regional health authority, later found that his training had been extended because of poor attendance at clinical placements and that he "had difficulties dealing with authority," as Times Higher Education reported in 2010. The Courier, describing the same inquiry, said witnesses had described him as aggressive toward lecturers. The university's reference for him called him an average student who was polite and communicated well. The university said that its reference followed standard practice across the sector, that it had included details of his absences, and that no concerns about his care of elderly patients had been raised while he was a student.
In 2002 Norris was working on Ward 36 at Leeds General Infirmary, according to both appeal judgments. In September 2002 he transferred to Ward 23 at St James's University Hospital, also in Leeds. Both wards, the 2009 judgment records, were orthopedic wards that mainly treated elderly women with hip fractures.
The evidence later given about his time there, as summarized by the Court of Appeal, was that he disliked working with elderly patients and could be insensitive and rude to them. Prosecutors told the jury that he had said he disliked caring for "geriatric patients," according to Press Association reports from 2008. Witnesses also described him as arrogant, manipulative and over-confident for a newly qualified nurse. He had shown an interest in diabetes and insulin, had been taught about the effects of insulin, and, according to the 2009 judgment, had attended a lecture about a nurse in the 1970s who injected elderly patients with insulin.
The five women were elderly, frail and recovering from broken hips. None had a history of diabetes, and none had been prescribed any anti-diabetic drug, according to the 2025 judgment. Little about their lives outside the hospital appears in the published record. What does appear comes mainly from their families' statements after the trial.
Vera Wilby was 90, from Rawdon, near Leeds. She was the only one of the five to survive her collapse. She died about eight months later of unrelated natural causes, and the charge relating to her was attempted murder.
Doris Ludlam was 80, from Pudsey in Leeds. She was in Leeds General Infirmary for a heart condition and a broken hip, the hip broken in a fall in the hospital, according to her family's lawyers. She was married, and she left a husband and daughters. One of her daughters said after the family's civil claim was settled in 2009 that the family had been "robbed of our mother and no amount of money can replace her."
Bridget Bourke was 88. She had been admitted with a broken hip and had earlier health problems, including an old stroke, and her recovery after surgery in June 2002 had been complicated, the 2025 judgment records.
Irene Crookes was 79, from Leeds. The 2025 judgment describes her as generally healthy before she broke her hip in October 2002; after surgery she had a series of complications, including a fever.
Ethel Hall was 86, from Calverley, near Leeds. She was admitted in November 2002 after breaking her hip. Her son spoke for the family after the trial and later.
The first case before the jury was Vera Wilby's. On the evening of May 17, 2002, she was given morphine at about 7:30 p.m., and at about 10:30 p.m. she was found hypoglycemic and close to a coma on Ward 36 at Leeds General Infirmary. She survived. The prosecution said at trial that the morphine given to her, and later to Doris Ludlam, had not been needed and had been given on out-of-date prescriptions, according to the 2009 judgment.
Doris Ludlam was given morphine at 2:35 a.m. on June 25, 2002. Norris went off duty at 7:45 a.m., and at about 8:10 a.m. she was found in a coma. She died on June 27. Her death was certified at the time as due to a stroke and heart failure.
Bridget Bourke was found slumped in the early hours of July 21, 2002, while Norris was on duty, according to the 2009 judgment; the 2025 judgment puts the time at about 3 a.m. Glucose treatment raised her blood sugar, but the readings rose and fell repeatedly. She died just after midnight the following night, and her death was certified as a stroke.
By October Norris was working at St James's. On October 19, 2002, during his shift, he reported finding Irene Crookes unresponsive. Her blood sugar reading was 1.6 millimoles per liter, and intravenous glucose raised it, but she was treated for pneumonia and died the next day, October 20. Her death was first thought to be a stroke and was later certified as respiratory failure due to chronic obstructive pulmonary disease, with the hip fracture also listed.
At the time, none of these four collapses was investigated as a poisoning. Blood was not taken at a point that could show whether insulin had come from outside the body, the Court of Appeal noted in 2025; the cases were looked at again only after Ethel Hall's.
Ethel Hall was on Ward 36 at Leeds General Infirmary in November 2002. Pharmacy records showed two vials of Actrapid, a fast-acting insulin, on the ward on the evening of November 18, 2002; they were missing at 6 a.m. on November 20, according to the 2025 judgment. At about 5 a.m. on November 20, during Norris's night shift, she was found in a hypoglycemic coma. Before her collapse, the prosecution said, Norris had told colleagues that she "might go off tonight at about 05:15." The Court of Appeal in 2009 noted that the Crown treated the remark as damning.
A doctor on the ward ordered insulin tests, according to news reports of the trial. The results showed about 12 times the normal level of insulin in Mrs. Hall's blood, and, according to the 2009 judgment, an undetectable level of C-peptide, the substance the body releases when it makes its own insulin. Press Association reports at the trial said she had suffered irreversible brain damage. She died on December 11, 2002. An immunoassay and a full forensic post-mortem examination ruled out natural causes, the 2025 judgment records, and the Criminal Cases Review Commission later wrote that there was no dispute that she had been murdered with insulin.
The test result on Ethel Hall made Norris a suspect, according to Press Association reporting from the trial. Police then examined other cases in which patients without diabetes had gone into hypoglycemic comas while he was working at Leeds General Infirmary and St James's. That review identified the four earlier women. Bridget Bourke had been buried, and 14 months after her death her body was exhumed for a post-mortem examination, the courts record. According to his mother, police first interviewed Norris in 2002, The Justice Gap reported in 2021.
Norris was arrested; the published judgments say only that and do not give the date. In interview, the Court of Appeal noted in 2025, he tried to play down his knowledge of insulin, a point the prosecution relied on at trial. He was charged with four counts of murder and one of attempted murder, and he denied all five charges.
After the verdicts, Detective Chief Superintendent Chris Gregg of West Yorkshire Police expressed the view, according to reports of the case, that Norris would have killed again if a doctor on the ward had not become suspicious.
The trial took place at Newcastle upon Tyne Crown Court before Mr Justice Griffith Williams and a jury. It lasted about five months, with 132 live witnesses, according to the 2025 judgment. Twenty of them were experts: 15 called by the prosecution and five by the defense, the 2009 judgment records.
The Crown's case was that no natural explanation existed for any of the five collapses, that each woman had been given a large dose of insulin or a sulfonylurea from outside her body, and that Norris was the "common denominator." He was the only nurse who had cared for all five women, and he was on duty when three of them were found hypoglycemic. In Vera Wilby's case the Crown said he had intended to kill her. Prosecutors told the jury that the deaths shared "remarkably common facts": each woman was in poor health after a hip fracture and might have been seen as a burden by nursing staff, according to Press Association reports. Police said after the verdicts that he had targeted "frail, elderly women, generally confused and helpless," whom he regarded as difficult.
The medical evidence took up much of the trial. Professor Ferner, for the Crown, told the jury that five natural cases would be "outside the bounds of possibility," according to the 2009 judgment. Dr. Kroker, another Crown expert, said he knew of no syndrome that fitted the cases, and that "the only explanation that I can give is that these ladies were given insulin or possibly sulphonylureas." The Crown also relied on the fact that injected glucose had failed to correct the low blood sugar in any of the cases, which it argued pointed away from a natural cause.
Norris did not accept any of it. He said he had given the women only proper nursing care and had given none of them any harmful substance. His counsel, William Harbage QC, told the jury that no one had ever seen Norris acting suspiciously with a vial or a syringe of insulin, that the evidence was circumstantial, and that the prosecution had offered no motive, according to Press Association reports.
The defense put forward two positive cases. The first concerned another male nurse on the wards, identified in the judgments only by initials, who had diabetes, kept his own supplies of insulin and had mental health problems; according to the 2009 judgment he had no alibi for four of the five critical times. The second concerned a patient, not nursed by Norris, who had suffered unexplained severe hypoglycemia in 2001, when Norris was still a student in Scotland. The defense used her case to argue that such episodes were less rare than the Crown's experts suggested.
The judge left five questions for the jury, among them whether insulin had caused each woman's hypoglycemia and whether Norris had given it. The Court of Appeal later praised his handling of the scientific evidence as "a tour de force."
Near the end of the trial, on February 12, 2008, the jury sent the judge a note. It asked whether there had been further cases of sudden, profound hypoglycemia with coma in patients without diabetes in the Leeds hospitals after 2002, that is, after Norris had stopped working there. Neither side had called evidence on the point, and the judge told the jury to put the question aside, the 2025 judgment records. The question was to return in the later appeal.
On March 3, 2008, the jury convicted Norris by a majority of 11 to 1 on all five counts: the murders of Doris Ludlam, Bridget Bourke, Irene Crookes and Ethel Hall, and the attempted murder of Vera Wilby.
He was sentenced on March 4, 2008. For the murders he received life imprisonment with a minimum term of 30 years, less 166 days he had spent on remand. For the attempted murder he received a concurrent sentence of imprisonment for public protection with a minimum term of 20 years. Passing sentence, Mr Justice Griffith Williams told him: "You are, I have absolutely no doubt, a thoroughly evil and dangerous man."
Ethel Hall's son welcomed the sentence and said he hoped Norris would never leave prison. The women had gone into hospital for help recovering from hip operations, he said, and "did not deserve to die at his hands." He called for an independent inquiry into how the killings had happened.
The inquiry he had asked for was carried out for the Yorkshire and Humber Strategic Health Authority and published in 2010, with 32 recommendations. It examined how Norris had been recruited and how he had been able to obtain insulin on the wards. Linda Smith, a lawyer at Irwin Mitchell who represented several of the victims' families, said the report showed that the four deaths "could have been avoided." She said the hospital trust had not inquired in detail into the backgrounds of nursing staff, and had not followed up gaps in Norris's references, which had come from colleagues rather than from people in authority. Ethel Hall's son said that in some ways he felt more hurt knowing that the trust could have avoided his mother's death.
In December 2009 Doris Ludlam's family settled a civil claim against Leeds Teaching Hospitals NHS Trust at Leeds County Court, receiving a five-figure sum. Their lawyer said the hospital's system for controlling drugs had failed.
Norris appealed on the ground that the judge's directions to the jury had been inadequate. His counsel, William Clegg QC and Jeffrey Samuels QC, argued that the judge had not properly told the jury how evidence about one woman could be used in deciding whether another woman's collapse had been caused by insulin, or who had given it. The Court of Appeal, Lord Justice Aikens, Mr Justice Field and Judge Stephens QC, heard the appeal on November 9, 2009, and dismissed it on December 21, 2009.
The court made a point that would matter later. It said it would be wrong to reason that, because five natural cases would be extraordinary, all five must have been poisonings. The trial judge had not warned the jury against that reasoning, but he had avoided it by making the jury consider natural causes separately for each woman, which the appeal court called wise. Once the jury was sure that someone had given Ethel Hall insulin unlawfully, the court held, that finding could be used in deciding who was responsible in the other cases. The court concluded that "the case against the appellant was very strong indeed" and that all five convictions were safe.
Norris continued to deny the killings, and a campaign to clear his name grew around him. In October 2011 Professor Vincent Marks, a specialist in insulin poisoning, told The Courier that, having reviewed newer research, he saw no proof of insulin poisoning in four of the five cases. "They were all at high risk of developing spontaneous hypoglycemia," he said, and he described the conviction as unsafe. A second expert, Dr. Adel Ismail, said a blood sample from one patient might have been misleading because no later sample had been taken. Norris applied to the Criminal Cases Review Commission on October 21, 2011.
In 2013 supporters said that a review by two medical institutions had concluded that "hypoglycaemia is not uncommon in hospitalised non-diabetic older people," as The Courier reported. His mother appeared on ITV's Daybreak to say she hoped the case would return to the Court of Appeal. By 2016 the justice campaigner Paul May, who chaired the campaign for the Birmingham Six from 1985 until their release in 1991, was representing Norris in his application to the commission and visiting him regularly at HMP Frankland in County Durham. "Back in 2008 it was considered to be very rare, recent research shows it is not at all rare," May told the Yorkshire Evening Post. A West Yorkshire Police spokesman said the force would consider the commission's findings when they were presented.
On February 12, 2021, the commission referred all five convictions to the Court of Appeal. The commission said it had considered new expert evidence submitted by Norris's representatives and had commissioned its own expert reports. It described the case at trial as "wholly circumstantial and heavily reliant on expert opinion evidence," in a complex area "where scientific understanding is still developing."
The experts now agreed, the commission said, that the hypoglycemia in the four women other than Ethel Hall might have had natural causes, and new evidence about how often hypoglycemia occurs in elderly and frail patients undermined the prosecution's expert evidence at trial. There was, it said, a real possibility that the Court of Appeal would find one or more of those four convictions unsafe.
The commission did not question the cause of Ethel Hall's death. But her conviction depended on support from the other four cases and on the prosecution's claim that no one but Norris could have been responsible, and the commission said that claim was "now less secure." There was a real possibility, it said, that the court would quash that conviction too. His mother said: "At long last we have a glimmer of hope."
The appeal was not heard for more than four years after the referral. The Court of Appeal said in 2025 that it had been delayed partly because key expert witnesses had fallen ill or died. Professor Marks, whose evidence had been at the center of the referral, was replaced by another expert, Dr. Hopkins. In March 2024 the court made preliminary rulings: it refused further disclosure of medical records, refused to hear a statistical argument about the clustering of the cases, and allowed limited evidence about a small number of later Leeds patients, the so-called "extra" cases.
By then Norris had changed his name. The 2025 judgment calls him Colin Campbell, "then going by the name of Colin Norris" at the time of his trial. When the appeal opened on May 6, 2025, STV News reported that he was serving his sentence at HMP Frankland. His mother told STV that justice for her son had "constantly been delayed and denied," and said she hoped he would regain "the freedom he should never have lost with his name cleared."
The appeal was heard over 14 days in London, from May 6 to June 6, 2025, before Lady Justice Macur, Sir Stephen Irwin and Mr Justice Picken. Michael Mansfield KC led for Campbell and James Curtis KC for the Crown; neither had appeared at the trial or the first appeal.
The fresh evidence came from two experts for the appellant, Dr. Hopkins and Dr. Simon Croxson. Their hypothesis was that frailty, combined with other illnesses, could bring an elderly patient to a "tipping point" at which the body's control of blood sugar failed, causing sudden and severe hypoglycemia without any insulin being given. The Crown answered with Professor Heller, Professor Semple and three of its trial experts, Dr. Kroker, Professor Ferner and Professor Hall.
Mansfield returned to the jury's 2008 question. Four further cases of "sudden and profound" hypoglycemia had since been identified among patients at the Leeds teaching hospitals after Norris stopped working there, with deaths between January 2003 and August 2005, he told the court. He said the ages of all nine patients, from 78 to 93, were "remarkably similar," a point never discussed at trial. He called it a "straightforward case" and said the judges "must conclude that these convictions are unsafe."
Curtis said that "very little evidence" existed of sudden and severe hypoglycemia arising naturally, that it "remains rare" in the medical literature, and that natural causes had been "fully explored" at the trial, where the jury had heard "a plethora of highly qualified and clinically experienced witnesses" and had the help of "a meticulous, systematic and detailed summing up."
The court gave judgment on June 26, 2025. It admitted the fresh evidence, finding the appellant's experts capable of belief, and then tested it against the clinical records of each woman.
It rejected the natural explanations offered for Vera Wilby, finding no significant organ failure, no heart cause, no evidence of an insulin-producing tumor and no malnutrition, and noting that her hypoglycemia did not return in a severe form after she left hospital. The court accepted the "tipping point" theory for the sake of argument but said it "does not begin to describe or explain" the refractory nature of her hypoglycemia, meaning its resistance to treatment. It found persuasive Professor Ferner's graphs of the women's glucose readings, which showed a repeated rising and falling pattern; the court called them a "potent visual demonstration" of his evidence. Insulin injected under the skin forms a reservoir and is absorbed slowly, the Crown's experts explained, so low blood sugar can persist for hours after a single large dose.
For Doris Ludlam, the court accepted that she had been very unwell but found her heart failure stable, and noted that she had received about 372.5 grams of glucose, "far more" than natural hypoglycemia would be expected to need.
On the "extra" cases the court compared the later patients with the women in the trial. Those patients' hypoglycemia had arisen from identified conditions such as liver failure and cardiogenic shock, a form of heart failure. The index patients, the court said, were "certainly differentiated in the identification of the underlying pathology and particularly so in the refractory nature of the hypoglycaemic episodes recorded." Its conclusion on the point was: "On our own analysis, the 'extra' cases serve to underline rather than undermine this aspect of the phenomena." The court also rejected the argument that the Crown had relied on a forbidden kind of reasoning from rarity, holding, as in 2009, that a jury may legitimately consider whether a set of events is commonplace, rare or vanishingly rare.
The judges found the appellant's expert evidence "inconsistent with, and fails to address the phenomena evidenced" in the patients, and said the Crown's experts had "responsibly interrogated the hypothesis against the facts with an open mind." They concluded: "We have no doubt about the safety of any of the five convictions. The appeals are dismissed."
Campbell's lawyers then asked the Court of Appeal to certify a point of law of general public importance, the step needed before the Supreme Court can be asked to hear a criminal appeal. On September 23, 2025, Lady Justice Macur said the judges had considered the application on the papers and refused it, saying the question "does not arise from judgment handed down."
As of September 2025, Colin Campbell, formerly Colin Norris, remained convicted of four murders and one attempted murder and was serving a life sentence with a minimum term of 30 years. He was reported in May 2025 to be held at HMP Frankland.
The core dispute is medical.
The Crown's position, accepted by the jury in 2008 and by the Court of Appeal in 2009 and 2025, is that the five episodes bore the marks of injected insulin: severe hypoglycemia that resisted glucose treatment, in patients with no diabetes and no condition that explained it, with Norris the only nurse common to all five. Ethel Hall's insulin and C-peptide results were the only laboratory proof of injected insulin; in the other four cases, the 2025 judgment notes, no immunoassay was done.
The appellant's experts and campaigners have argued that severe hypoglycemia in very frail elderly patients is more common than the trial experts believed. Professor Marks said in 2011 that all the women were at high risk of spontaneous hypoglycemia. Dr. Ismail questioned the reliance on a single blood sample. Paul May said in 2016 that later research showed such episodes were "not at all rare." The Criminal Cases Review Commission agreed in 2021 that the new evidence raised a real possibility that the convictions were unsafe. In February 2025 the retired forensic toxicologist Professor Alan Wayne Jones questioned the testing of Ethel Hall's blood sample, noting that the laboratory involved was clinical rather than forensic, the Scottish Daily Express reported, citing the Daily Record.
The Court of Appeal rejected these arguments in 2025 after hearing the experts tested in court. The four later Leeds cases, which the appellant offered as proof that such episodes happen naturally, were in the court's view different in kind, because each had an identified natural cause.
The defense also suggested at trial that another nurse with access to insulin could have been responsible. The jury rejected that suggestion, and the man is identified in the judgments only by initials.
1998, September: Norris begins nurse training at the University of Dundee (The Courier).
2001, October: qualifies as a nurse.
2002: works as a staff nurse on Ward 36, Leeds General Infirmary.
2002, May 17: Vera Wilby, 90, found hypoglycemic and near coma; she survives.
2002, June 25: Doris Ludlam, 80, found in a coma; dies June 27.
2002, July 21: Bridget Bourke, 88, found collapsed; dies the following night.
2002, September: Norris moves to Ward 23, St James's University Hospital.
2002, October 19: Irene Crookes, 79, found unresponsive; dies October 20.
2002, November 20: Ethel Hall, 86, found in a hypoglycemic coma; tests show a very high insulin level.
2002, December 11: Ethel Hall dies.
2008, February 12: the jury asks about later hypoglycemia cases in Leeds.
2008, March 3: convicted by an 11 to 1 majority on all five counts at Newcastle upon Tyne Crown Court.
2008, March 4: sentenced to life with a minimum term of 30 years.
2009, December 21: first appeal dismissed.
2009, December: Doris Ludlam's family settles a civil claim against the Leeds hospital trust.
2010: Yorkshire and Humber Strategic Health Authority inquiry report published, with 32 recommendations.
2011, October 21: application to the Criminal Cases Review Commission.
2021, February 12: the commission refers all five convictions to the Court of Appeal.
2024, March: Court of Appeal preliminary rulings on disclosure, statistics and the "extra" cases.
2025, May 6 to June 6: appeal hearing in London.
2025, June 26: appeals dismissed.
2025, September 23: certification of a point of law for the Supreme Court refused.