Under scrutiny, the prosecution’s central evidence against the presumed ‘killer nurse’ may be unreliable.
Under scrutiny, the prosecution’s central evidence against the presumed ‘killer nurse’ may be unreliable.
L ast summer, Lucy Letby, a 33-year-old British nurse, was convicted of murdering seven infants in her care and attempting to murder six more.
Then last week, on July 5, after a retrial of one of the charges, Letby was found guilty of having attempted to murder another “extremely premature” infant by tampering with her breathing tube, taking the total number of attempted murders to seven.
“I’m innocent,” she called out as police led her from the dock.
She may be telling the truth.
From the beginning, a strange aspect of the case was that Letby appears to have been, by all accounts, a normal, well-adjusted young woman.
“We still have no idea why she committed these crimes,” said the senior crown prosecutor, Nicola Wyn Williams. “But the Crown Prosecution Service does not have to prove a motive; we simply need to prove that the defendant committed the crime.”
That’s true, of course. But what if the explanation for why nothing whatever in Letby’s psychological profile points to her being a serial killer is simply that she isn’t one.
On May 13, Rachel Aviv, a star reporter at the New Yorker, published a 13,000-word investigative blockbuster on the case, casting serious doubt on the scientific competency of the prosecution’s key evidence. Reading her account of the Letby trial transformed my nagging doubts into clanging alarm bells. It seems I wasn’t the only one.
Owing to Letby’s retrial this summer, and a British law from the Eighties that limits what can be said publicly during ongoing criminal cases, those skeptical of the prosecution’s case were temporarily censored in the U.K. Upon its publication in May, Aviv’s New Yorker piece was blocked from the U.K. internet.
But now that the recent verdict has been reached, commentators in the U.K. are once again free to make public statements on the trial. In the past week, lengthy investigations questioning the evidence against Letby have appeared in the left-leaning Guardian as well as the right-leaning Telegraph.
The idea that Letby may be a victim of a miscarriage of justice can no longer be dismissed as a fringe conspiracy theory. Those who have expressed skepticism include specialists associated with the University of Edinburgh, Harvard University, and the Royal Statistical Society.
The skeptics’ best defense of Letby is not that the prosecution failed to prove that the nurse murdered the babies (which is the argument Letby’s lawyers made), but that they failed to prove that the babies were murdered, period.
The apparent “cluster” of deaths at which Letby was present was based on flawed statistical reasoning. An alternative statistical reading suggests that the deaths, while tragic, were more likely to have been random.
Consider the visual aid shown to the jury, a chart of every nurse on shift that appeared to show Letby as the common denominator, present during each suspicious infant collapse.
Critically, the chart included only collapses for which Letby was under investigation. Cherry-picking the data skews the results.
The Telegraph reports on Alexander Coward, a former math lecturer at the University of Oxford and the University of California Berkeley, who created a model in which there were 38 fictional nurses, each working 170 shifts. On each shift there’s a 14 percent chance that a baby collapses or dies at random.
Coward demonstrated that by preselecting any of the nurses from the model, a diagram like the one supposedly incriminating Letby could be produced.
Yet the jury never heard this explanation because the defense did not present it to them.
What about the medical evidence the prosecution relied on?
As a jury would presumably be aware, premature infants are an extremely vulnerable patient population. Nevertheless, the prosecution insisted at trial that the babies Letby allegedly killed were “stable” and “doing well.” The facts, however, suggest otherwise.
A retired pediatrician, whose evidence the police relied on in making their case against Letby, said that with the cases in which the babies were thought to have been poisoned by insulin there was “some kind of smoking gun.” But as Aviv reports: “The blood sample for the first baby had been taken ten hours after Letby had left the hospital; any insulin delivered by her would no longer be detectable.”
Or take Baby C (all babies’ names were anonymized in compliance with British law). The Telegraph reports that the infant “had been born at 30 weeks weighing less than 2 lbs after problems with the blood flow to the placenta meant he was only half the size he should have been.” Baby C suffered from pneumonia, respiratory issues, and a potential blockage in his bowel.
“After he collapsed and died, a post-mortem examination at Alder Hey concluded the death was natural, exacerbated by the lack of blood flow in the womb. A coroner supported this finding,” according to the Telegraph. Yet, “despite this, the prosecution claimed his death was caused by Letby pumping air into his stomach.”
Aviv reported that, in response to the allegation that Letby had killed babies by injecting air or fluids into their nasogastric tubes, several doctors she interviewed “were baffled by this proposed method of murder and struggled to understand how it could be physiologically or logistically possible.”
Michael Hall, a neonatologist at a National Health Service hospital in Southampton, was prepared to give evidence for the defense. Hall believed the prosecution’s medical witnesses “exaggerated the degree of wellness of those babies to a significant extent.”
Yet the defense never called on him to testify.
The verdict on Letby in the court of public opinion after her trial ended last summer (a window in which it was legal to offer public comment) was as ferocious as it was absolute. The British press ran with nonstop coverage of the “evil nurse” and “monster” who seemed to have come straight out of “hell.” Excerpts from Letby’s notes written during the hospital’s investigation of her were used to highlight her supposed derangement or even admission of guilt. Aviv reports:
Inside [Letby’s apartment,] [the police] found a note with the heading “NOT GOOD ENOUGH.” There were several phrases scrawled across the page at random angles and without punctuation: “There are no words”; “I can’t breathe”; “Slander Discrimination”; “I’ll never have children or marry I’ll never know what it’s like to have a family”; “WHY ME?”; “I haven’t done anything wrong”; “I killed them on purpose because I’m not good enough to care for them”; “I AM EVIL I DID THIS.”
On another scrap of paper, she had written, three times, “Everything is manageable,” a phrase that a colleague had said to her. At the bottom of the page, she had written, “I just want life to be as it was. I want to be happy in the job that I loved with a team who I felt a part of. Really, I don’t belong anywhere. I’m a problem to those who do know me.” On another piece of paper, found in her handbag, she had written, “I can’t do this any more. I want someone to help me but they can’t.” She also wrote, “We tried our best and it wasn’t enough.”
Isolating the “I AM EVIL” and “I killed them on purpose” fragments, one can easily view these statements as incriminating. But, in context, they can be read another way: as the frantic ramblings of an innocent woman in extreme distress. During a police interrogation, Letby explained that these notes were “just a way of me getting my feelings out onto paper.” When asked whether she thought she had done anything wrong, she answered, “No, not intentionally, but I was worried that they would find that my practice hadn’t been good,” adding, “I thought maybe I had missed something, maybe I hadn’t acted quickly enough.”
Readers interested in the Letby case should also consider that of Lucia de Berk, a Dutch nurse wrongly convicted of murder largely because of the apparent association with her shift patterns and deaths on her ward; she was exonerated in 2010. Another similar case is that of an Italian nurse, Daniela Poggiali, exonerated in 2021.
Aviv reports that in de Berk’s case “a criminologist had calculated that there was a one-in-three-hundred-and-forty-two-million chance that the deaths were coincidental. But his methodology was faulty; when statisticians looked at the data, they found that the chances were closer to one in fifty.”
Letby has been sentenced to life in prison. Her requests to appeal have been denied. Yet, under scrutiny, it appears that the prosecution’s case against her was flawed. It’s disturbing that it has been left to journalists to challenge the evidence that should have been contested in court.