The evidence seemed damning. Her senior colleagues demanded her removal from their neonatal unit after a spate of unexpected deaths. The court was told she stalked the families of her victims, stole confidential medical papers, and wrote a confession on pieces of paper in her room.

But experts were not so certain. A new review conducted by 14 of the most renowned neonatal and paediatric specialists in the world says that there was "no medical evidence" that Letby had murdered or attempted to murder a single infant in her care.

Letby was never witnessed harming or killing a single baby and her conviction hinged on the medical evidence that these experts claim has been debunkedDisproved..

Leading the panel was Dr Shoo Lee, a Canadian neonatologistA medical professional who specialises in caring for newborn babies, particularly those who are ill or born prematurely. whose research paper was originally used by prosecutors to convict Letby. Lee says that his paper, written almost 40 years ago, was misrepresented and offered no evidence of Letby's guilt.

Throughout the trial, the prosecution alleged several lurid and gruesome methods for the murders. They said Letby poisoned babies with insulinA hormone which controls blood sugar levels and helps your body to turn food into energy., injected air into their bodies to prompt an embolismA block in an artery caused by blood clots or other substances, such as fat globules, infected tissue, or cancer cells., overfed them with milk, among other things.

But many feel the prosecution failed to meet the burden of proof that these methods were used, let alone that they were used by Letby.

Post-mortemsA medical examination of a body after death, to establish why a person died. of the infants were nowhere close to conclusive. In general, a large proportion of infant deaths are unexplained.

For months now, new evidence revealed to the public has led some to question the integrity of the guilty verdict against Letby.

Notes scrawled by Letby which prosecutors claimed amounted to a confession - she had written "I AM EVIL I DID THIS" - were revealed to have been written on the advice of counsellors to relieve her feelings of guilt and stress.¹

Prosecutors also used a chart listing 25 deaths with dates to prove that Letby had been present for each infant death. But they failed to tell the jury about six other unexpected deaths in the same period, when Letby was not present.

If the convictions against Letby were overturned, she would not be the first nurse wrongfully convicted as a serial killer. Her case has drawn comparisons to that of Lucia de Berk, a paediatric nurse in the Netherlands charged with killing 13 patients and trying to kill five others.

De Berk was accused of being an "angel of death" and sentenced to life in prison. In 2010, the prosecutors' case against her was found to be based on statistical misrepresentation, and she was exoneratedTo show or state that someone or something is not guilty of something..²

Could she be innocent?

Yes: There is no proof that the methods she was convicted of were used. There are no witnesses to her harming or killing a single infant. Medical experts across the world have voiced their unease with the verdict. And there is precedence in other cases of wrongfully convicted "killer nurses."

No: There is still no explanation for why Letby repeatedly searched the victims' families online, why so many babies on the ward became so suddenly critically or fatally ill, or why one witness walked in on Letby seeming to do nothing as a baby rapidly declined.

Or... We might never know if Letby is responsible for these deaths. Her presence at so many deaths might be normal statistical variance, or it could be no coincidence at all. But it is a baseline of a healthy society that people are offered a fair trial, and it is clear that Letby's trial was far from fair.

Debunked - Disproved.

Neonatologist - A medical professional who specialises in caring for newborn babies, particularly those who are ill or born prematurely.

Insulin - A hormone which controls blood sugar levels and helps your body to turn food into energy.

Embolism - A block in an artery caused by blood clots or other substances, such as fat globules, infected tissue, or cancer cells.

Post-mortems - A medical examination of a body after death, to establish why a person died.

Exonerated - To show or state that someone or something is not guilty of something.