LUCY LETBY CASE: NEW EXPERT REPORT PUTS FRESH FOCUS ON INSULIN EVIDENCE AS MAJOR REPORT DATE APPROACHES

The Lucy Letby case is facing renewed scrutiny as new expert analysis continues to challenge aspects of the medical evidence presented during her trial.

The latest development centers on a 100-page report submitted to the Criminal Cases Review Commission (CCRC) in July, examining the insulin evidence involving two babies at the Countess of Chester Hospital.

Letby’s convictions remain in place, but the new material adds another layer to the ongoing review of whether the evidence used against her should be reconsidered.

FRESH QUESTIONS OVER THE INSULIN EVIDENCE

The report, prepared by consultant neonatologist Neil Aiton and statistician Hilde Wilkinson-Herbots, reportedly identifies what its authors describe as errors and omissions in the evidence presented by prosecution expert Professor Peter Hindmarsh.

Among the issues raised are possible alternative explanations for the babies’ insulin readings and questions about whether the alleged poisoning could have occurred during periods when Letby was not working.

The full report has not been publicly released, meaning its claims have not yet been tested through an appeal court.

However, the submission gives the CCRC additional expert material to consider as it reviews Letby’s convictions.

WHY THE INSULIN CASES MATTER

The insulin allegations were among the most significant pieces of evidence presented during Letby’s original trial.

Prosecutors argued that two babies had been deliberately poisoned with insulin and that their medical results provided strong evidence of intentional harm.

Criticism of that interpretation has continued since the convictions.

In 2025, an international group of experts also challenged aspects of the medical evidence, arguing that the scientific basis for some of the conclusions should be reconsidered.

New research published in 2026 has added to the debate, examining how insulin levels can appear abnormal in premature babies and how insulin-binding antibodies may affect measurements.

QUESTIONS ABOUT A KEY PROSECUTION EXPERT

The scrutiny has also expanded beyond the scientific evidence itself.

Earlier this year, reports revealed that Professor Peter Hindmarsh, who provided important prosecution evidence about insulin, had been subject to a fitness-to-practise investigation during the period of Letby’s trial.

The jury was not told about that investigation.

The Crown Prosecution Service and Cheshire Police have said they were not aware of the investigation before Hindmarsh gave evidence.

The significance of that information, if any, will ultimately have to be assessed through the legal review process.

THE CCRC IS STILL REVIEWING THE CONVICTIONS

The CCRC received a preliminary application on Letby’s behalf in February 2025.

Additional expert reports and legal submissions were subsequently provided, with further material continuing to reach the commission.

The CCRC has made clear that its role is not to decide whether Letby is innocent or guilty.

Instead, it must determine whether new evidence or legal arguments create a real possibility that the convictions would not be upheld by an appeal court.

For now, Letby’s convictions remain legally in force.

ANOTHER MAJOR DATE IS APPROACHING

The legal review is unfolding alongside the Thirlwall Inquiry, which has examined what happened at the Countess of Chester Hospital and the wider institutional response surrounding the Letby case.

The inquiry has now confirmed that its final report will be published in Liverpool on September 15, 2026.

The report cannot overturn Letby’s convictions, but it could provide important findings about the hospital, management decisions and how concerns were handled.

THE NEXT CHAPTER

The latest expert report does not mean that Letby has been cleared.

It does, however, ensure that the medical evidence surrounding the insulin cases remains under intense examination.

With the CCRC review continuing and the Thirlwall Inquiry’s final report approaching, the case is entering another significant stage.

Could fresh scientific analysis ultimately change how some of the key evidence is viewed?

For now, that question remains unanswered — but the scrutiny surrounding the Lucy Letby case is far from over.