In light of new expert findings, significant questions regarding the conviction of Lucy Letby for the deaths of seven infants at a British hospital have emerged, highlighting potential flaws in the prosecution's use of insulin test evidence.
Experts Question Reliability of Insulin Testing in Letby Case

Experts Question Reliability of Insulin Testing in Letby Case
New report raises significant doubts about the insulin evidence used to convict nurse Lucy Letby of murder.
Seven pediatric doctors and toxicology specialists submitted a report to Britain’s Criminal Cases Review Commission on Thursday, claiming that the insulin tests used in Lucy Letby’s trial were unreliable. This report was presented by Ms. Letby’s legal team, who seek to appeal her 15-life sentence conviction for the alleged murders of several newborns.
Ms. Letby, who served as a neonatal nurse at a healthcare facility in northern England, was found guilty in 2023 of purposefully causing harm or death to multiple infants. The prosecution's case asserted she injected babies with air, overfed them with milk, and poisoned them with insulin.
In their analysis, the experts—comprising a forensic toxicologist, an esteemed forensic science professor, and an endocrinologist with expertise in medical testing—concluded that the evidence surrounding the insulin and C-peptide tests was flawed. They stated, “Our inescapable conclusion is that this evidence significantly undermines the validity of the assertions made about the insulin and C-peptide testing presented in Court,” as detailed in a summary released to the media by Ms. Letby’s defense team.
Despite maintaining her innocence throughout her trials, Letby's attorneys have faced obstacles in seeking to reopen her case for appeal, even as serious concerns about her conviction continue to circulate in public discourse, amplified by investigative pieces such as a lengthy New Yorker article published last May.
Ms. Letby, who served as a neonatal nurse at a healthcare facility in northern England, was found guilty in 2023 of purposefully causing harm or death to multiple infants. The prosecution's case asserted she injected babies with air, overfed them with milk, and poisoned them with insulin.
In their analysis, the experts—comprising a forensic toxicologist, an esteemed forensic science professor, and an endocrinologist with expertise in medical testing—concluded that the evidence surrounding the insulin and C-peptide tests was flawed. They stated, “Our inescapable conclusion is that this evidence significantly undermines the validity of the assertions made about the insulin and C-peptide testing presented in Court,” as detailed in a summary released to the media by Ms. Letby’s defense team.
Despite maintaining her innocence throughout her trials, Letby's attorneys have faced obstacles in seeking to reopen her case for appeal, even as serious concerns about her conviction continue to circulate in public discourse, amplified by investigative pieces such as a lengthy New Yorker article published last May.