The campaign to free Lucy Letby is built on shaky assumptions and falsehoods

It’s wrong to say that she was convicted on statistics alone, but nothing will convince the ‘truthers’

Yet another public inquiry got under way today, the 16th either up and running or about to start. Hardly a day goes by without a demand for an inquiry into a perceived failure of public policy, a scandal, disaster or foul-up. Since 1990, about £1 billion has been spent on scores of them, with the biggest of them all – into Covid – also taking evidence once again. It is looking at how the NHS coped with the pandemic, with the words “not very well” already inked into the conclusions.
Coincidentally, the inquiry which began today is also looking into a part of the NHS, the Countess of Chester Hospital where Lucy Letby was a nurse. 
It will not have escaped your notice that there is a campaign to release Letby from prison, where she is serving a whole life term for the murder of seven newborn infants and attempting to murder several others. She is said to have been the victim of one of the greatest miscarriages of justice imaginable and used as a scapegoat for the appalling state of the hospital and the NHS as a whole.
In 2015/16, there was a sudden increase in deaths on the neonatal ward at the Cheshire hospital and, rather than attributing them to bad practice and poor conditions, it is suggested that Letby was hung out to dry. More than that, say her supporters, she was convicted on the basis of the statistical likelihood that she must be guilty because she was present at all the deaths.
Expert number-crunchers have shown that you can present data in a way that gives a completely misleading picture of what happened. A classic of its type involved the solicitor Sally Clark who, in 1999, was found guilty of the murder of her two infant sons who both died within a few weeks of their birth two years apart. Her defence blamed Sudden Infant Death Syndrome (Sids), but the prosecution relied on statistical evidence presented by a paediatrician called Roy Meadow. He testified that the chance of two children from an affluent family dying in this way was one in 73 million. 
This unquestionably swayed the jury, and why would it not? Such odds are astronomical. Meadow said that the chances were that it would happen only once in 100 years. But if the children shared a common genetic disorder, then the odds of both dying plummet. Clark was released following two appeals after it emerged that evidence the younger child died of natural causes was not disclosed to the court.
The Royal Statistics Society expressed concern about the “misuse of statistics” in trials, something that the campaign to free Letby has seized upon. A former No 10 adviser this week said he had followed the Letby trial and his “instinctive reaction” was to wonder whether the cluster of deaths on the ward could be a statistical coincidence. Sir David Davis, the former Cabinet minister, has also said the jury might have been swayed by statistics, though he also concedes there needs to be alternative explanations for each death, which is the key point. On social media platforms, the cry of “witch hunt” is growing by the day.
If Letby had been convicted on statistics alone, as Sally Clark was, then there would be cause for great concern, but she wasn’t. The prosecution painstakingly looked at every single case to show that the deaths of these babies were not natural but the result of deliberate actions. 
If you accept that the infants were killed, then the only possible culprit is Letby because she was the only one present on every occasion. The statistical arguments are red herrings. This is about opportunity and she was the only one who had it.
The fact there were other deaths and other nurses on different shifts is irrelevant to these specific cases, provided it is accepted that they were murders and not something else. Could it be the case that Letby has been thrown under a bus for a series of clinical failures in order to draw attention away from the hospital, its consultants and the NHS as a whole? If that was the plan, it hardly worked since there is now a public inquiry into what happened.
A number of assertions are being made that are simply not true. It is said that all the children were already seriously ill and their deaths should not be seen as unusual. But there were only three in each of the two years before Letby started working on the ward. Moreover, if you read the ruling of the Court of Appeal in April (which turned down her application for a full hearing), it is striking how many were considered to be relatively healthy and gave no particular cause for concern. Yet they suddenly collapsed and died because, said the prosecution, Letby had injected air through the intravenous drip causing embolisms or in two cases poisoned them with insulin.
Take the case of triplets on the neonatal ward. They were described as “completely normal triplets who were expected to run a healthy course”. But when Letby returned from holiday to nurse them, they suddenly deteriorated. Two died. The third was taken away from the hospital by the parents and survived, effectively ruling out a genetic cause that Letby tried to claim.
This may be circumstantial, but it is deeply troubling. When placed alongside the other evidence, it is hardly surprising the jury found her guilty. Were they misled? Was a crime simply not committed and it was all a great misunderstanding? 
The pro-Letby “truthers” are adamant she was scapegoated, her defence was useless (it wasn’t), and that evidence that would clear her was never properly examined because key witnesses were not called. She was not an obvious oddball like some serial killers, though her behaviour was by no means normal. More than that, jurors who sat through an 10-month trial were apparently unable to handle such difficult cases, unlike clever people who have an “instinctive” understanding of what happened after reading a few tendentious blogs. 
Opening the inquiry, Lady Justice Thirlwall said the “huge outpouring of comment” about the validity of Letby’s convictions had come almost entirely from people who did not attend the trial, causing “enormous additional distress” to the parents of the dead babies. For their sake, it is time the noise abated. But I fear there will be no closure until a full appeal is allowed and everyone can see that justice has been done.