Is Lucy Letby Innocent? The Challenge to Her Convictions

Lucy Letby has been convicted twice, by two separate juries, of murdering seven babies and attempting to murder seven others. Both sets of convictions have survived an application for permission to appeal. As a matter of law, she is guilty of these crimes, and remains so unless and until a court rules otherwise.

At the same time, the case is now the subject of one of the most substantial post-conviction challenges seen in England and Wales in decades: a formal review by the Criminal Cases Review Commission, a public statement from fourteen international neonatal specialists that they found no medical evidence of deliberate harm, and an ongoing statistical dispute among professional statisticians about how one of the trial's central pieces of evidence should be interpreted. This piece sets out what that challenge actually consists of, and what serious voices on the other side of the argument have said in response — because, unusually for this kind of case, there is a genuine, technical argument happening on both sides, not simply a prosecution case versus a fringe conspiracy theory.

What "Convicted" Actually Means Here — and What It Doesn't

Letby's original 14 convictions were upheld when the Court of Appeal refused her leave to appeal in May 2024; a fifteenth conviction, from her 2024 retrial, was upheld when a further appeal application was refused that October. Those are the only two occasions since her original trial on which a court has formally reconsidered the safety of her convictions, and on both occasions the court found no basis to interfere with the jury's verdicts.

The CCRC review now under way is a different kind of process. It exists specifically to catch cases where new evidence or argument might justify sending a case back to the Court of Appeal, and the commission has been careful, in every public statement it has made, to stress that reviewing a case is not the same as finding someone innocent. "The CCRC is looking at this case" is not itself evidence of anything about Letby's guilt or innocence — it reflects the fact that her legal team has submitted a formal application, which the commission is obliged to consider on its merits.

The Medical Challenge: Dr Shoo Lee's Panel

In February 2025, a panel of fourteen international neonatologists and paediatricians, convened by Canadian physician Dr Shoo Lee and including Professor Neena Modi, a former president of the Royal College of Paediatrics and Child Health, held a press conference to say they had found no medical evidence of deliberate harm in any of the seventeen cases they reviewed. Dr Lee, whose own 1989 research on air embolism had been cited at trial, said his work had been misapplied to the case. This challenge, examined in full in our piece on the alleged methods, remains the single most significant medical intervention in the case since conviction, and forms a central part of the material now before the CCRC.

The Statistical Challenge: Was the Rota Chart Misleading?

Separately from the medical evidence, a number of professional statisticians have raised concerns about a specific piece of trial evidence: a chart showing Letby was on duty for every incident she was charged with, while other nurses were not. Professor Peter Green, a statistician and former president of the Royal Statistical Society, has publicly argued the chart was potentially misleading, since it only displayed the 25 incidents that led to charges, excluded further deaths and collapses that occurred when Letby was not on shift, and didn't account for the fact she was working more shifts than average during the period in question. "It's a natural human thing," Green said. "We all see patterns that are not there."

Critics have connected this to a recognised statistical error sometimes called the "Texas sharpshooter fallacy" — identifying a cluster of events after the fact and treating it as significant, without accounting for how the cluster was originally selected. The Royal Statistical Society published a report in 2022, before Letby's trial concluded, addressing statistical pitfalls in investigations of suspected healthcare-related harm clusters, drawing on earlier miscarriage-of-justice cases involving healthcare workers elsewhere, including the Dutch nurse Lucia de Berk, whose own wrongful conviction was eventually overturned after statisticians successfully challenged the reasoning used against her.

The Pushback: "She Wasn't Convicted on Statistics Alone"

This is where the debate becomes genuinely two-sided rather than one-directional. A number of commentators, including the writer Christopher Snowdon, have pushed back hard against what they describe as a popular myth that Letby was convicted primarily on the strength of the rota chart. Their argument is that the chart established opportunity and presence, not guilt on its own, and that the jury heard extensive additional evidence — falsified or altered medical records, the handwritten notes, digital search history and the specific medical findings for each individual charge — that did the actual evidential work of persuading them beyond reasonable doubt. They also point to the jury's mixed verdict, acquitting on some counts and failing to reach agreement on others, as evidence jurors were weighing each charge individually rather than simply inferring guilt from a striking chart.

The Insulin Evidence: Still the Hardest Question

The insulin poisoning charges relating to Child F and Child L remain, by most accounts on both sides of the debate, the hardest element of the case to explain away as coincidence or natural causes, because they rest on a specific, objective laboratory finding — an insulin-to-C-peptide ratio in each baby's blood consistent with externally administered insulin rather than the body's own production — rather than on clinical interpretation of symptoms after the fact. Even some commentators broadly sympathetic to Letby's legal team have acknowledged this is the part of the case that requires the most convincing alternative explanation, and it remains a specific focus of ongoing expert submissions to the CCRC.

Public and Political Voices — and Why They're Not Expert Verdicts

Beyond the medical and statistical experts, a number of public figures have added their voices to the debate, including Conservative MP Sir David Davis, who has said publicly he believes there is a high probability Letby is innocent, and journalist Peter Hitchens, who has written extensively questioning the safety of her convictions. These interventions have raised the case's public profile considerably. It's worth being clear, though, that political and journalistic advocacy, however sincerely held, is a different category of evidence from a peer-reviewed medical panel or a formal CCRC submission, and neither carries legal weight in determining the safety of a conviction.

What Would Actually Need to Happen

For any of this challenge to change Letby's legal position, the CCRC would first need to conclude there is a "real possibility" the Court of Appeal would now find the convictions unsafe, and refer the case back on that basis. The Court of Appeal would then need to hear the fresh evidence and actually agree the convictions are unsafe — a referral does not guarantee that outcome, and the Court of Appeal has already declined to hear some of this material once, on narrower procedural grounds, at Letby's original appeal. Both steps remain genuinely open questions, and neither has happened as of August 2026.

Where the Balance of Opinion Stands

There is no single, settled expert consensus on this case as things stand. A substantial and credentialled body of medical and statistical opinion has publicly challenged specific elements of the evidence base underpinning Letby's convictions. An equally credentialled, if less publicly organised, body of opinion maintains that the trial evidence, taken as a whole rather than any single chart or test result, supported the jury's verdicts. The honest position, this website included, is that the question posed in this article's title doesn't currently have a definitive answer — and won't, until either the CCRC declines to refer the case, or the Court of Appeal rules on a referral it does make.

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