LUCY LETBY CASE TAKES ANOTHER TURN AS NEW REPORT CHALLENGES KEY INSULIN EVIDENCE

LONDON — The Lucy Letby case is once again under intense scrutiny after a new expert analysis raised fresh questions about one of the most important pieces of medical evidence used against the former neonatal nurse.

Letby remains imprisoned after being convicted of murdering seven babies and attempting to murder seven others at the Countess of Chester Hospital.

But her legal team is continuing its fight to have the convictions reconsidered — and a new 100-page analysis has now been submitted to the Criminal Cases Review Commission.

The report focuses on the insulin evidence involving two babies and challenges aspects of testimony given by prosecution expert Professor Peter Hindmarsh.

THE INSULIN QUESTION

At Letby’s trial, prosecutors argued that unusually high insulin readings in two babies were evidence that the infants had been deliberately poisoned.

That evidence became a critical part of the prosecution’s case.

But new analysis submitted by Letby’s legal team argues that there may have been alternative explanations for the laboratory results that were not fully presented to the jury.

The report was prepared by Neil Aiton, a consultant neonatologist at the Royal Sussex County Hospital, and Hilde Wilkinson-Herbots, an associate professor of statistical science at University College London.

According to reporting on the document, the experts allege errors and omissions in the evidence presented by Hindmarsh.

The full report has not been publicly released, so its conclusions cannot yet be independently assessed in full.

A KEY PROSECUTION EXPERT FACES NEW SCRUTINY

The latest development comes months after another controversy involving Hindmarsh.

A Guardian investigation reported that the professor had been subject to a professional fitness-to-practice investigation while Letby’s trial was taking place.

The jury was not told about that investigation.

Cheshire Police and the Crown Prosecution Service said they had not been informed about it before Hindmarsh gave evidence.

The existence of an investigation does not establish that Hindmarsh’s evidence was wrong.

But the revelation has added another question for Letby’s legal team to raise as it challenges the safety of the convictions.

THE CASE IS NOW BEING EXAMINED FROM MULTIPLE ANGLES

The insulin evidence is only one part of the wider legal challenge.

Other experts have questioned the interpretation of statistical evidence used during the original trial, including the controversial chart showing Letby’s presence on shifts when babies became critically ill or died.

An international panel of neonatologists has also disputed aspects of the medical interpretation surrounding the babies’ collapses.

Together, those challenges have created a growing debate over whether the original evidence was as conclusive as prosecutors presented it to jurors.

That does not mean the convictions have been overturned.

They have not.

THE CCRC HAS THE NEXT MOVE

Letby’s legal team submitted a preliminary application to the Criminal Cases Review Commission in February 2025.

Since then, the commission has received expert reports, written submissions and defense materials.

The CCRC confirmed in February 2026 that its review of Letby’s convictions is underway.

Importantly, the commission does not decide whether someone is innocent or guilty.

Its role is to determine whether there is a real possibility that a conviction would not be upheld if the case were sent back to an appellate court.

If the CCRC reaches that threshold, it could refer Letby’s convictions to the Court of Appeal.

BUT LETBY HAS NOT BEEN CLEARED

That distinction is crucial.

Despite the growing criticism of some evidence, Lucy Letby’s convictions currently remain in force.

The new report is an argument for further legal scrutiny — not a court ruling that she was wrongly convicted.

The CCRC has not announced a decision to refer the case back to the Court of Appeal.

THE HOSPITAL’S OWN STORY IS ALSO UNDER REVIEW

At the same time, the Thirlwall Inquiry continues examining what happened at the Countess of Chester Hospital before, during and after the events that led to Letby’s convictions.

The inquiry is separate from the criminal appeal process and cannot overturn her convictions.

However, it is examining the hospital’s practices, responses to concerns and the wider circumstances surrounding the neonatal unit.

The inquiry has continued publishing documents, with its final report not expected until after the summer parliamentary recess.

A CASE THAT REFUSES TO GO AWAY

For years, the Letby case appeared to have a definitive ending: convictions, a whole-life sentence and a former nurse behind bars.

Now, the evidence itself has become the battleground.

The latest report raises questions about insulin.

Earlier investigations have raised questions about expert evidence.

Statisticians have challenged elements of the roster analysis.

And the Thirlwall Inquiry is examining the hospital environment in which the babies became critically ill.

None of those developments, individually or collectively, has yet overturned Letby’s convictions.

But they explain why the case continues to generate intense debate.

For Letby’s supporters, the developments represent evidence that the original trial deserves another look.

For those who stand by the convictions, the new claims remain challenges that must be tested through the proper legal process.

And ultimately, that process now rests largely with one institution:

The Criminal Cases Review Commission.

The question is no longer simply what the original jury believed.

It is whether the new evidence is strong enough to make an appeal court reconsider what happened inside that neonatal unit.

And for now, Britain is still waiting for the answer.