Cheshire police arrest three senior staff from Countess of Chester hospital, where Letby worked before her conviction for murder of babies

A slight mishap while on a trip to the northwest of England during a political campaign some time back required that I attend hospital for a routine test. It was nothing in the end, a brief interlude to my day and of no consequence at all.

But as I arrived at the hospital entrance, I craned to read the big sign as we drove past: the Countess of Chester hospital. Its notoriety immediately registered.

“This is the Lucy Letby hospital,” I thought, recalling the 2023 conviction of a neonatal nurse from the hospital. She was found guilty of the murder of seven babies and the attempted murder of six more between June 2015 and June 2016. She was later convicted of a seventh attempted murder in a second trial.

The Letby verdict was billed at the time as her country’s worst ever case of the mass killing of children, a horror show that roiled the British nation. How could this seemingly unremarkable woman carry out such a campaign of death under the noses of hospital bosses? Why would anybody do such things?

Two years on, the story around Letby is morphing into a horror show of a potentially different variety for Britain’s medical and legal establishments. The 35-year-old languishes in prison serving a whole-life order. As it stands, she will never be released.

Yet after four court cases – two trials and two failed appeals – almost two years into a public inquiry and deep into a fresh police investigation of events at the hospital, the sense is that Britain is even less certain now of what happened than it was before.

Letby’s case is now being examined by the Criminal Cases Review Commission. Political pressure is growing on it to speed up its examination and, if it finds it warranted, to refer the case back to the courts as a potential miscarriage of justice

There were murmurings about Letby’s conviction soon after the verdicts. There was no direct physical evidence linking her to any incident. Nobody had seen her harm a baby. One doctor had given evidence that he walked in on Letby as she stood by while a baby, its breathing tube apparently dislodged, was in distress.

Almost all of the prosecution case against Letby hinged on a statistical argument that it could only have been her who could have perpetrated the incidents. She was the common denominator, always on shift when things went wrong, and so always in some way involved. There was also a note of Letby’s, written after she fell under suspicion, where she scrawled “I killed them … I did this”.

Another doctor gave expert medical evidence that, it was argued, showed the babies had been attacked. Sometimes it was by having air injected into their bloodstream, while others were apparently poisoned with insulin.

The sense that a rethink might be needed gathered pace at the beginning of this year when David Davis MP, a respected former Tory minister, stood up in the House of Commons and said there was “no hard evidence” that Letby did anything wrong. Davis is known for campaigning on alleged miscarriage-of-justice cases.

Letby had changed legal team. They contacted Davis, who said he had seen a dossier of medical evidence that suggested Letby’s conviction was potentially unsafe. Soon, we all saw it. In February, I was among a group of journalists who gathered in a grand, oak-panelled room near the Palace of Westminster to hear from representatives of a global independent panel of 14 medical experts assembled for Letby’s legal team.

The chair of that panel of experts, retired Canadian neonatal expert Shoo Lee, said the panel “did not find any murder”. Instead, he argued, all of the cases could be explained by hospital neglect or natural causes.

Davis later revealed he had seen leaked emails that contradicted the evidence of the doctor who apparently had walked in on Letby, the only testimony from a medical professional that directly linked her to any alleged incident. In the emails Davis saw, a paediatrician wrote that Letby had called the doctor into the room that day. Davis said the doctor who had given evidence should be investigated by police.

Letby’s case is now being examined by the Criminal Cases Review Commission (CCRC). Political pressure is growing on it to speed up its examination and, if it finds it warranted, to refer the case back to the courts as a potential miscarriage of justice.

On Tuesday, it emerged that Cheshire police had arrested three managers who worked at the hospital between 2015 and 2016, as part of an investigation into possible gross negligence manslaughter. Police said it did not “impact on the convictions of Letby”. That is a truism. Only a court decision can have an impact on her conviction.

All the while, a public inquiry chaired by appeal court judge Kathryn Thirlwall trundles along. It was established with its starting point the assumption that Letby is a remorseless mass murderer. Yet in the background swirls a growing campaign that maintains her conviction is unsafe. The inquiry’s report has been delayed until next year.

Where might Letby be by then? That might depend on the CCRC and the courts.

In the meantime, the distraught parents of 13 babies (Letby was convicted of trying to kill one of them twice) will be in a hell of somebody else’s making, their grip possibly loosened on answers they had believed were settled.