Evidence presented in the first trial of Lucy Letby showing which staff came in and out of the baby unit she worked on was incorrect, the Crown Prosecution Service (CPS) has acknowledged.
The nurse was convicted last year of murdering seven babies and attempting to kill six others at the Countess of Chester hospital in north-west England. Letby, the worst child serial killer in modern British history, is serving 14 whole-life sentences, meaning she will never be released from prison.
A retrial at Manchester crown court last month found the 34-year-old from Hereford guilty of the attempted murder of another child, known as Baby K.
During the retrial, Nick Johnson KC, prosecuting, told the court that door-swipe data, showing which nurses and doctors were entering and exiting the intensive care ward, had been “mislabelled”.
The Crown Prosecution Service told the Telegraph that the discrepancy discovered was related to one door in the neonatal intensive care unit and that it had been corrected for the retrial.
A spokesperson for the Mersey-Cheshire Crown Prosecution Service said: “The CPS can confirm that accurate door-swipe data was presented in the retrial.”
David Davis, the Conservative MP, has written to Sarah Hammond, chief crown prosecutor of Mersey-Cheshire CPS, asking her to “urgently make clear” what timing errors were made during the first trial and how they related to the prosecution’s case.
Davis, who is planning to bring a parliamentary debate after the summer recess, said: “The door-swipe data is clearly vital to knowing which nurse was where at one point in time, and this in turn was vital to the prosecution’s case in the first trial.
“It is therefore essential that the CPS makes it plain whether those errors occurred throughout any of the evidence of the first trial.”
In the initial trial, the prosecution said Dr Ravi Jayaram, a consultant, had discovered Letby standing over Baby K at 3.50am on 17 February 2016. The baby was deteriorating and its breathing tube had been dislodged.
The prosecution said door-swipe data showed that the baby’s designated nurse had left the intensive care unit at 3.47am. But the data was amended in the retrial to show the nurse had returned at that time, meaning Letby was not alone.
During the retrial, the prosecution and the defence accepted that it was a genuine mistake, and the nurse was convicted of the attempted murder of Baby K.
Letby faced a three-week retrial on the single count of attempted murder, which she denied, after the jury in her original trial last year was unable to reach a verdict.
A public inquiry led by Lady Justice Kathryn Thirlwall will begin in September into how Letby was able to continue working with babies despite the concerns of senior doctors who connected her to a number of suspicious incidents.
On Saturday, a CPS spokesperson said: “Two juries and three appeal court judges have reviewed a multitude of different evidence against Lucy Letby, and she has been convicted on 15 separate counts following two separate jury trials.
“We confirm that accurate door-swipe-data was presented in the retrial.
“We have been transparent in clarifying this issue and rectified it for the retrial. We are confident that this issue did not have a meaningful impact on the prosecution, which included multiple strands of evidence.”
• This article was amended on 19 August 2024 to clarify that Lucy Letby is the worst child serial killer in modern British history, not all of British history.
