The Lucy Letby case expert witness was under fitness to practise investigation during trial
A doctor who provided crucial expert testimony about insulin poisoning in the prosecution of nurse Lucy Letby was under investigation by the medical regulator at the time due to serious concerns about his fitness to practise. The General Medical Council (GMC) opened an investigation into Professor Peter Hindmarsh, including allegations of patient harm, on the first day he testified at Letby's trial in late 2022.
The GMC investigation was ongoing when Hindmarsh testified for a second time at the Letby trial three months later. Great Ormond Street Hospital reported Hindmarsh to the GMC after a formal investigation led by his main employer, University College London hospitals trust (UCLH).
The jury in the trial of the nurse, who was convicted of murdering babies in the Countess of Chester hospital's neonatal unit, was never informed about any investigation into Hindmarsh, one of the prosecution's key witnesses. While the GMC conducted its investigation, and during some of the period when Hindmarsh testified, a medical tribunal ordered severe restrictions on his work, stating that he "may pose a real risk" to members of the public. The tribunal also considered the allegations about Hindmarsh "may have the potential to impact on his ability to act as an expert witness".
Nevertheless, the tribunal permitted him to continue giving expert evidence for the prosecution of Letby. The Crown Prosecution Service told the defense it would oppose any attempt to inform the jury of the GMC investigation, on the basis that the allegations had not reached a final adjudication. Ultimately, the GMC investigation was never concluded, because Hindmarsh removed himself from the GMC register, a process known as "voluntary erasure". That effectively ended the investigation, and there was no regulatory finding against him.
Details of the allegations against Hindmarsh at the time of his evidence have been uncovered in an investigation by the Guardian. Letby was convicted of murdering seven babies and attempting to murder seven others, over two trials in 2023 and 2024. She was sentenced to 15 whole-life terms in prison. Court of appeal judges turned down her applications to appeal. She has always maintained she is innocent, and many of her supporters believe she was scapegoated for medical failings on the unit.
Since the convictions, dozens of leading UK and international medical and scientific experts have argued that the prosecution's medical case, including Hindmarsh's evidence, was wrong. Dr. Shoo Lee, a renowned Canadian neonatologist who argues that the prosecution misrepresented his own research, last year delivered findings of a 14-member expert panel. They found unanimously that the babies died or collapsed due to natural causes and poor care on the unit, that there had been no evidence of murders, nor insulin poisoning or any other deliberate harm.
In February last year, Letby's lawyer, Mark McDonald, applied to the Criminal Cases Review Commission (CCRC), which examines possible miscarriages of justice, to have her case sent back to the court of appeal. The CCRC is reviewing the application, which is supported by the reports of 27 leading experts, including Lee's panel.
'Multiple and wide-ranging concerns'
Hindmarsh appeared twice as a key witness for the prosecution during Letby's first trial, which took place between October 2022 and August 2023, thought to have been Britain's longest-ever murder trial.
A professor and consultant paediatric endocrinologist with extensive clinical experience working with children, Hindmarsh had practiced at UCLH hospitals for decades and was also an honorary consultant at Great Ormond Street. He first testified on November 25, 2022, as an expert witness for the prosecution's case that Letby attempted to murder two babies, referred to as F and L. Hindmarsh's evidence supported the case that both babies had been poisoned with insulin injected into their fluid feed bags.
However, the jury was never told that in the months leading up to the trial, Hindmarsh had been facing allegations at the two hospitals that threatened to tarnish his reputation and undermine his credibility. He was still at UCLH but no longer working at Great Ormond Street, as his contract had been terminated four months earlier, in July 2022.
When contacted by the Guardian, the children's hospital declined to say whether the termination of the contract was related to the allegations of clinical failings that were ultimately referred to the GMC. A representative for Hindmarsh said he had no comment to make in response to questions from the Guardian.
Insulin evidence contested
Hindmarsh first formally told the police that he was subject to a GMC investigation on December 14, 2022, two weeks after Great Ormond Street told him it had referred him to the GMC. The CPS then waited a further two months before informing Letby's then barrister, Ben Myers KC, about the investigation into one of its key witnesses. It was formally disclosed just four days before Hindmarsh was due to give his second day of evidence.
The prosecuting barrister, Johnson, told the defense he would oppose the jury being told anything about the GMC investigation, on the grounds that it had not reached a final adjudication. The Guardian asked Johnson about that position. He replied via a representative: "We do not conduct cases through journalists." In response to similar questions, a CPS spokesperson said: "We do not accept that the jury was misled about the qualifications or experience of the expert witness in this case."
It is unclear why, after it was informed about the GMC investigation into Hindmarsh, Letby's defense did not make an application to the judge, James Goss, for the jury to be informed. Myers, her lead barrister at the time, told the Guardian he could not answer any questions due to continuing client confidentiality.
The GMC did not directly respond to questions about whether it should have prevented Hindmarsh from giving further evidence.
