The four questions from the Lucy Letby case as defence to unveil new evidence

Fresh doubts have been raised about the trial of convicted child serial killer Lucy Letby after claims the jury was misled over key evidence.

Letby’s legal team is to announce this coming week what is claimed to be “new medical evidence” from a panel of 14 international neonatal experts.

The panel, chaired by Conservative MP Sir David Davis, will include retired neonatologist Dr Shoo Lee, who says his research – an academic paper he had co-authored more than 30 years earlier – was misused to convict the nurse.

Police notes, uncovered by news outlet Unherd, also claim the jury was misled over key evidence that Letby was the common link between all the suspicious incidents at the Countess of Chester Hospital’s neonatal unit between June 2015 and June 2016.

Letby, from Hereford, is currently serving 15 whole-life orders after being found guilty of the murder of seven babies and the attempted murders of seven others, with two attempts on one child.

She is only the fourth woman in UK history to be told she will never be released from prison.

Here, The i Paper looks at some of the questions which have arisen from the Letby case ahead of her defence unveiling what they claim to be new evidence.

How was the evidence used and what was the jury told?

A growing number of neonatal specialists have raised concerns over the evidence against Letby and how it was used during her trial.

An appeal over Letby’s conviction was rejected, despite backing from Davies who said he believed it would “clear” the former nurse. Speaking in the Commons, Davies claimed key evidence helpful to Letby’s case is being withheld by the police and the Crown Prosecution Service.

Previously undisclosed police notes, uncovered by Unherd, appear to show disparities between the analysis carried out by retired paediatrician and chief prosecution witness Dr Dewi Evans and what was presented to the court.

One discrepancy, raised by the outlet, involved Letby’s trial being told by one of her colleagues the health of Baby K began to deteriorate after she had deliberately dislodged her breathing tube.

Dr Evans, meanwhile, had told police in 2017 that he believed Baby K died from natural causes or which he had “no suspicions” as she had been born prematurely and “deteriorated”. He told police in an email the health of premature infants was often “unstable”.

Letby was convicted of attempting to murder Baby K in a retrial. The first jury was unable to reach a verdict on the specific case.

Another discrepancy involved Baby B, who collapsed and almost died at 12.20am on 10 June, the trial was told, when Letby was on shift. Dr Evans, examining medical records, told police in 2017 that Baby B was subject to another attack at 10.50pm on 19 June, the outlet reported, when Letby was not working.

Letby was eventually convicted of the murder of Baby B, but the second incident on 19 June was never raised at the trial.

Unherd lists a series of other discrepancies between what was raised as initial evidence and what the jury was told.

The case looked at 28 incidents – Letby was present for 10

Dr Evans also drew up a chart appearing to demonstrate that Letby had been present whenever a baby died or collapsed in suspicious circumstances on the neonatal unit, which was later used at the Manchester Crown Court trial.

The papers, however, show that when doctor originally looked at the 28 cases, Letby was not in the hospital when 10 of the 28 incidents he initially described as “suspicious” took place – more than a third.

The jury was not told this information in court. They were instead told by prosecuting counsel Nick Johnson KC that Letby was “the one common denominator” in unexplained deaths or incidents at the Cheshire hospital.

Dr Evans had initially offered his services to police in May 2017 to examine postmortem photos of a baby that had bleeding over its liver.

He previously said he suspected “foul play” within 10 minutes of reading the medical records. Cheshire Police then supplied him with medical records for all babies who collapsed at the Countess of Chester hospital they were investigating.

Should the babies have been diagnosed with air embolism?

Giving evidence to the trial, Dr Evans referenced a 1989 academic paper by now retired Dr Shoo Lee, formerly a top paediatrician at Mount Sinai Hospital in Canada for more than a decade, and founder of the Canadian Neonatal Network, which includes 27 hospitals and 16 universities.

The study was used to back the prosecution’s case that Letby had killed the babies by injecting them with air – resulting in air embolism.

But after discovering his evidence was used in a trial unknown to him, Dr Lee is now preparing to make a significant intervention, flying 4,000 miles to London to speak at a press conference on behalf of Letby’s legal team.

He told The Sunday Times: “I don’t usually do medical legal cases. I just don’t enjoy them, so I don’t do them. But this one got me interested because they had used my paper … They asked me whether I would look at the evidence for them … and wanted to know if it [the paper] was correctly interpreted.”

After reviewing the court transcripts related to the paper he wrote, the doctor said: “I wasn’t very happy because what they were interpreting wasn’t exactly what I said.”

Dr Lee is expected to outline the details of an independent review carried out by 14 medical experts into the deaths of 17 babies Letby is accused of harming.

He is expected to argue that none of the babies should have been diagnosed with air embolism as none of the descriptions of the babies’ skin discolourations given at the trial matched the kind seen with the “very rare and specific condition”.

It comes weeks after Letby’s barrister Mark McDonald said Dr Evans had altered his views on how three infants had died at the neonatal unit. He said he was immediately seeking permission from the Court of Appeal to relook at her case on the grounds that Evans was “not a reliable expert” and the former nurse’s convictions for murder and attempted murder were unsafe.

Evans said in response to the claims: “Mr Mark McDonald’s observations regarding my evidence is unsubstantiated, unfounded, inaccurate.

“His method of presenting his information reflects clear prejudice and bias. I find his style most unedifying, most unprofessional.

“It’s highly disrespectful to the families of babies murdered and harmed by Lucy Letby.”

Experts argue a different cause of death for some cases

It is understood that in a “large number” of cases, if not all, Lee and his fellow international medical experts – as part of the independent “blue ribbon committee” – have recorded a different cause of death from the one used in Letby’s trial and prosecution, The Sunday Times reported.

Dr Lee told the paper: “This is not fair, because the evidence that was used to convict her, in my opinion, wasn’t quite right. What I can say is that we looked at the cases in great detail and we came to very definite conclusions about what happened in every case.”

He added that he was never called to dispute the prosecution’s claim following Evan’s evidence using the research paper. The Court of Appeal also refused to allow him to clarify how his evidence should have been interpreted.

Evans has maintained that concerns over his evidence were “unsubstantiated, unfounded, inaccurate”. He has repeatedly declined to speak out until the conclusion of Lady Justice Thirlwall’s public inquiry into events at the Cheshire hospital.

Cheshire Police told The Mail On Sunday that they “declined to be involved in much of the ongoing commentary within the media”.

A spokesperson said: “There is a significant public interest in these matters, however, every story that is published, statement made, or comment posted online that refers to the specific details of a live investigation can impede the course of justice and cause further distress to the families concerned.

“It is these families and the ongoing investigations that remain our primary focus.

The force and the CPS were approached for comment by The i Paper.