Convicted baby killer Lucy Letby is languishing in prison. There's just one, big problem

Australia Broadcast Center

07-06-2025

The idea of a nurse, ostensibly sweet mannered and competent, coldly killing tiny, frail babies in her care is bone-chilling.
When the young British neonatal nurse Lucy Letby was accused of murdering numerous infants, we gasped in horror and the media fed our incomprehension and appetites by providing colourful, constant coverage of the charges and trial.
It seemed like it was sewn up. Letby had written incriminating entries in her diaries and googled the parents of the babies she had allegedly killed by injecting oxygen into their veins, poisoning them with insulin, and feeding them too much milk. But, most damning of all was the graph which was printed over and over, showing a list of nursing staff against a list of the babies who had died between June 2015 and 2016: Letby had been present, every single time.
She was convicted in August 2023 of seven counts of murder and other attempted murders, and is currently serving multiple life sentences with no chance of release.
Letby was the fourth woman in British history to be sentenced to die in jail. "She has thrown open the door to Hell," the Daily Mail wrote, "and the stench of evil overwhelms us all."
There's only one problem — the cacophony of globally renowned expert voices, some of whose research was heavily relied on by the prosecution, now saying in unison: there is no evidence of wrongdoing.
As David Conn wrote in the Guardian, "It is unprecedented that so large a group of experts with such distinguished reputations have so rapidly, publicly and comprehensively spoken out to dispute convictions for murder."
The whole thing is awful: grieving parents facing the reopening of painful cases and painful discussions again, and yet also, a potentially innocent woman languishing in jail after a miscarriage of justice and poorly run case. And the grim fact that a public who lapped up the stories of the evil nurse has now largely lost interest.
I do not know if Letby is guilty or innocent, but this apparent contradiction between the legal system and medical experts is troubling. The detail is thick and few of us are equipped to deal with the medical and scientific complexities of this case. But this is exactly the problem — the idea of an evil killer, dressed in scrubs, is so spine-tingling that we throw caution.
There are several lessons to be learned from this sorry saga; here are just three.
In May 2024 an extensive, 13,000 word investigative piece in the New Yorker was the first substantial work to tip people off to the fact that "in the rush to judgement, serious questions about the evidence were ignored."
But the man whose slender 1989 academic paper was relied upon by the prosecution to link mottled skin to a pulmonary vascular air embolism (and, they argued, thereby an injection of air into the babies' veins) had been alarmed months before, once he was made aware of the case.
Dr Shoo Lee is a respected Canadian neonatalist who argued before the Court of Appeal that the prosecution's expert witness had fundamentally misinterpreted his work. He said none of the babies in the trial should have been diagnosed with a pulmonary embolism and alternatives should be considered. When the court rejected the appeal request, Lee assembled a 14-strong team of the most respected paediatric and neonatal specialists in the world, including a former president of Britain's Royal College of Pediatrics and a former director of Boston Children's Hospital's neonatal intensive care unit.
Dr Lee promised to release their conclusions whatever they were.
And they were incendiary: finding no medical evidence that Letby had murdered or attempted to murder any baby in her care. The report was 698 pages long.
At a press conference in February this year, Lee said there had been serious errors and failings in medical care, and some of the deaths could have been prevented. One panel member, Dr Neena Modi, neonatology professor at Imperial College London, said: "There was a combination of babies being delivered in the wrong place, delayed diagnosis and inappropriate or absent treatment."
Police shared a graph showing Letby's presence — marked with an X — at the time of each "suspicious incident" involving the deterioration or death of a baby with the media, which reprinted it numerous times. But, as the New Yorker pointed out, "the chart didn't account for any other factors influencing the mortality rate on the unit. It gave an impression of mathematical clarity and coherence, distracting from another possibility: that there had never been any crimes at all."
The neonatal unit Letby worked at, at the Countess of Chester Hospital, run by the National Health Service, in the west of England, was struggling, and a 2016 review by a team from the Royal College of Paediatrics and Child Health found there were inadequate numbers of doctors and nurses. There had been more deaths in the maternal ward as well as neonatal care.
Law Professor Burkhard Schafer from the University of Edinburgh argues this graph shows police are skilled at looking for a responsible human, not "finding a systemic problem in an organisation like the National Health Service, after decades of underfunding, where you have overworked people cutting little corners with very vulnerable babies who are already in a risk category."
When Schafer saw the diagram of suspicious events, an alarm bell rang. To be true, he says, such a diagram should have included all deaths in the unit, not just those in court, and it should have covered more time.
The diagram the police issued has been likened to the "Texas sharpshooter fallacy". Imagine a shooter firing bullets into the side of a barn, then tracing a bulls-eye around the area where most bullets penetrated. In other words, statistical mistakes can be made when analysts ignore a big data set in favour of a small cluster that fits a convenient theory.
This exact mistake had been made in cases about two nurses accused of murder before, in the Netherlands and in Italy, leading to a miscarriage of justice due to the belief that "a coincidence cannot be a coincidence". Both spent time in prison and both were later exonerated.
This "X" diagram was crucial in the Letby case. As David Conn writes:
…there was no evidence against Letby, only the consultants' suspicions due to the statistical coincidence of her having been on shift. Nobody ever saw her harm a baby or commit any of the acts — injecting babies with air, or lacing two feeding bags with insulin — of which she would later be accused and found guilty, and there has never been any tangible or forensic evidence of her doing so. She was well respected as a committed young nurse, who had taken intensive care qualifications, and would volunteer for extra work and overtime when the unit was stretched. Senior staff believed that this explained why she was often on shift for the sickest babies.
Especially if insufficient evidence is given and complexity is skipped over.
Those following the case read about notes written by Letby that police found in her house, which contained these contradictory statements, some of which appeared to show guilt: "WHY ME?"; "I haven't done anything wrong"; "I killed them on purpose because I'm not good enough to care for them"; "I AM EVIL I DID THIS." She wrote, too, "We tried our best and it wasn't enough."
We didn't read of the police video where she said she was processing the guilt of having babies die on her watch: "It was just a way of me getting my feelings out onto paper."
Her self-loathing was wrapped in up feelings of incompetence, and the stress of suspicion. Psychologists have said these notes were "meaningless as evidence."
Then there was the fact that Letby had googled the names of the parents whose babies had died afterwards, 31 times. This confused me when I read it. What I didn't know was that this was somewhat of a compulsive habit of hers — she seemed to google everyone she met — during the year of the investigation, she had conducted 2,287 searches for people online, saying later she was always on her phone.
Her last hope seems to be the Criminal Cases Review Commission, which examines possible miscarriages of justice. Another public inquiry is underway into how murders such as these could have taken place in NHS hospitals, though in August 2024, 24 British experts — doctors, nurses and scientists — sent a letter to the government urging them to postpone or delay such an inquiry due to concern about a failure to learn lessons from "possible negligent deaths that were presumed to be murders".
It is up to the courts to decide if there has been miscarriage of justice. Perhaps, in the interests of public confidence, they will take the chance to do so.
Whatever happens, we must be acutely conscious of the suffering parents who have been through a horrific ordeal, losing a child then enduring a gruelling public trial.
Surely, more than anyone, they deserve to know the truth.
Juila Baird is an author, broadcaster, journalist and co-host of the ABC podcast, Not Stupid.