Former Lucy Letby Supporters Say Barrister Is Damaging Her Chances of Freedom

Two experts who left Lucy Letby’s legal team have claimed her barrister is putting her hopes of release at risk by relying on evidence they believe lacks scientific credibility.

Helen Shannon, a British chemical engineering specialist, and New Zealand-based bioengineering professor Geoff Chase were members of an international group of doctors and scientists who last year supported the argument that Letby may have suffered a miscarriage of justice.

The panel prepared a 100-page report challenging aspects of Letby’s convictions for attempting to murder two babies who were said to have been poisoned with insulin.

However, the pair said on Monday that they had withdrawn their backing for parts of the defence case because of concerns over its “scientific credibility” and what they described as “unresolvable problems” in some of the evidence.

They also accused Mark McDonald, the barrister leading Letby’s bid to overturn her convictions, of exposing her “long-term interests” to “serious, unnecessary and unacceptable risk”.

Letby, 36, continues to deny all wrongdoing. She is appealing convictions for the murder of seven babies and the attempted murder of seven more at the Countess of Chester Hospital.

The Criminal Cases Review Commission (CCRC), which examines possible miscarriages of justice, is assessing a dossier submitted on Letby’s behalf last year by the expert panel. The group was led by Canadian neonatologist Dr Shoo Lee.

At a press conference in February 2025, Dr Lee said the deaths did not amount to murder, arguing that the babies had either died from natural causes or been affected by inadequate medical care.

Speaking to The Guardian, Ms Shannon and Professor Chase said they still stood by their conclusion that it was “very unlikely” Babies F and L, as they were identified during the trial, had been poisoned. However, they said they could not endorse other evidence being advanced by Letby’s defence in relation to the insulin allegations.

The experts said other arguments being presented by the defence did not align with the available evidence, established science or accepted understanding of human physiology.

In a letter to the CCRC, they wrote that while it was legitimate for the defence to put forward several explanations, they could not support some of the arguments currently being made because they considered them scientifically unreliable and fundamentally impossible to resolve.

Letby is serving 15 whole-life orders after being convicted in two trials at Manchester Crown Court. The offences involved seven murders and seven attempted murders, including two attempts against the same child, and took place between June 2015 and June 2016.

Ms Shannon and Professor Chase said the strategy of Mr McDonald was ‘placing the long-term interests of Ms Letby at serious, unnecessary and unacceptable risk’ and that those ‘consequences also extend to the families’ of the babies who died and were injured.

‘We cannot, with integrity, support arguments which are inconsistent with the available evidence, science and established physiology,’ they added.

‘After disclosing these concerns, continued association with arguments we believe are demonstrably inaccurate creates a serious ethical issue under the professional engineering codes governing us in New Zealand and the UK, and exposes us to professional sanction.’

Dr Lee claimed his experts had been assembled without bias to carry out an ‘objective review’ of the medical notes of the 17 babies that Letby was initially accused of murdering or trying to kill at her trial.

But in September their independence was called into question after it emerged he had written to the medics, saying: ‘We might be her (Letby’s) last hope.’

One senior neonatologist told the Mail he declined to take part in the panel for several reasons, including because of the leading nature of the language in Dr Lee’s email.

Then, in April, it emerged Mr McDonald had been reported to the Bar Standards Board for alleged professional misconduct.

Families of the killer nurse’s victims are understood to have made a formal complaint about him to the legal regulator.

The complaint is believed to centre on a letter written by Mr McDonald’s then-instructing solicitors that was leaked to the Sunday Times. 

The correspondence, addressed to Cheshire coroner Jacqueline Devonish, requested that Letby be afforded ‘interested party’ status in upcoming inquests into the deaths of her victims.

But Richard Baker KC, representing the families, said his clients had been ‘extremely distressed’ to learn their babies’ names – which are protected by strict anonymity orders – had been in the letter and ‘recklessly disclosed to a third party’.

In response to the withdrawal of Ms Shannon and Professor Chase, Mr McDonald said the case for Letby’s innocence did not ‘stand or fall on any one expert’.

‘We now have evidence from a number of leading international experts in insulin, endocrinology and laboratory medicine which fundamentally undermines the scientific evidence relied upon at trial,’ he said.

‘The strength of the new evidence lies in its breadth and convergence, with independent experts from different disciplines and jurisdictions identifying fundamental problems with the scientific basis upon which the jury were invited to conclude that babies [F] and [L] had been deliberately poisoned.’

The CCRC, which has been reviewing Letby’s convictions for 18 months, declined to comment.

A public inquiry into the murders will publish its findings on Tuesday. 

The review, led by Lady Justice Kathryn Thirlwall, is expected to highlight a number of missed opportunities for bosses to intervene after doctors raised the alarm about a spike in deaths on the neonatal unit in 2015 and 2016.

A police investigation into potential corporate manslaughter and gross negligence manslaughter at the hospital remains ongoing.