‘Strong reasonable doubt’ over Lucy Letby insulin convictions, experts say Exclusive: ‘No scientific justification’ to say former nurse definitely poisoned babies with insulin, according to study authors.
The prosecution said test results that showed low blood sugar and “abnormally high” insulin levels, with very low levels of C-peptide, meant it “must be that they have been given or taken” synthetic insulin that had not been prescribed.
The claim that Lucy Letby definitely poisoned babies with insulin has “no scientific justification whatsoever” and there is a “very strong level of reasonable doubt” about the convictions, according to the authors of a 100-page study on the case.
The study adds that insulin poisoning would probably have resulted in far lower levels of potassium and glucose than the babies’ records show, and points out that they showed no symptoms of severe insulin poisoning, such as seizures or heart arrhythmia.
The prosecutor Nick Johnson KC told the jury at Letby’s trial that the nurse “undoubtedly” poisoned the two baby boys known as Baby 6 and Baby 12 eight months apart by spiking their feeding bags with insulin.
