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The Wrong side of the Media: Evaluating the Case Against Lucy Letby

The Lucy Letby case has brought to light significant issues within the English criminal justice system, particularly regarding the use of scientific theories advanced by medical professionals who lack a research science background. This is not to criticize the medical profession for the roles they are trained to carry out but to highlight a persistent myth: thatmedical professionals think and reason like scientists. This topic has already been extensively covered by Science on Trial (SoT). However, in light of the Court of Appeal (CoA) releasing its judgment denying Lucy Letby leave to appeal, there is an opportunity to emphasize how dangerous it is to permit medics to conduct scientific investigations.

Journalistic Response and Public Perception

In the immediate aftermath of Letby being convicted of another case of attempted murder, two prominent journalists, Judith Moritz of the BBC and Liz Hull of the Daily Mail, sought to admonish anyone who questioned the sufficiency of the scientific claims made by expert witnesses in the first trial. The second trial, notably devoid of experts, raised the question: how could harm be ascribed without a baseline suggesting harm had occurred? This question will not be the focus here. Instead, it is noteworthy how Moritz and Hull swiftly labeled anyone who questioned any aspect of the scientific evidence as a "conspiracy theorist."

Both Hull and Moritz appeared overly invested in the Lucy Letby case, boasting of their near-daily attendance. This pattern of attendance was deemed to be in the public interest, with an undercurrent of irritation at the lack of public adulation for their reporting. In reality, journalists served as the primary means by which the general public could access the proceedings, short of taking ten months off work to attend the court in person.

Public Criticism and Media Response

From their journalistic musings emerged a disdain for the general public's criticisms of the scientific evidence and the medical experts responsible for the claims that secured Letby's convictions. Neither journalist seemed to consider that educated and informed professionals might be rightly concerned by the quality of evidence presented. Hull asserted that such individuals were either "ghouls," seeking to support a serial murderer, or pseudoscientists, doubting the scientific findings of credible experts. Both sought to land a hefty punch by branding these critics as conspiracy theorists. For those undeterred by such a label, there was an old-fashioned effort to shame them by citing a personal injury barrister, who claimed that questioning the criminal justice system was a toxic act.

The Silencing Act

Despite their bluster, neither Moritz nor Hull could explain why they were so confident in the scientific evidence used to secure Letby's convictions. They did not blink at the over 3,300 imprisoned individuals in the US who have been exonerated in the last 30 years, with inaccurate forensic evidence and inappropriate testimony of expert witnesses causing over 44% of these wrongful convictions. The fact that the US justice system is derived from the English Common Law system was insufficient for Hull and Moritz to consider that wrongful convictions are directly tied to the adversarial legal process, where defendants must rebut the claims of prosecution witnesses who are convinced they have caught a criminal.

The Court of Appeal Judgment

The Court of Appeal judgment on Letby's application to appeal does not vindicate the medical experts' scientific theories and analysis. If the hope was that the judgment would demonstrate the reliability and validity of the investigative practices employed by the prosecution's star expert witness, Dr. Dewi Evans, the Justices were sorely mistaken.

Medics as Scientists: A Misstep

Hull and Moritz, lacking any basic background in biology, medicine, or research sciences, nonetheless felt supremely equipped to evaluate the scientific evidence because they heard it being delivered in real time. Hull incredulously gasped that critics of the evidence believed:

"The science surrounding air embolism and insulin testing which helped convict her was also flawed."

Her follow-up claim that it was "most laughable" to suggest "that her defense team was poor and had let her down" further illustrates her misunderstanding. In neither the first nor second trial did Letby's legal team present expert witnesses. Letby was left to defend herself against the opinions and claims of some 20 medical doctors, all employed by the NHS, the same employer that reported her to the police. In October 2023, it was revealed that Letby's lawyers had collected £1.5 million from the Legal Aid fund before all the bills were settled. Ben Myers, K.C., admitted on his second day pleading for Letby's appeal that he had no idea that rashes were not associated with air embolism until after Letby was convicted.

In a normal situation, such an omission would be sufficient to argue ineffective assistance of counsel. However, such an argument cannot be advanced by the same legal team responsible for the error. The Court of Appeal opened their judgment by noting that the failure to present expert witnesses to challenge the prosecution's testimony left Letby with essentially no defense.

"More specifically, in the context of this appeal, suggestions made in cross-examination which were not accepted by prosecution witnesses and were not supported by evidence called on behalf of the applicant, are, as the respondent has submitted, irrelevant."

Ultimately, any claims made by Myers regarding his interpretations of the evidence were merely ideas or suggestions. The only opinions that held value were those of expert witnesses, and Myers failed to present any. Much has been made of the fact that Letby's team retained Dr. Michael Hall but did not call him, raising questions about how they managed to secure only one expert when similar cases often involved more than four defense experts.

The Role of Dr. Dewi Evans

Both the media and the Court of Appeal were overly reliant on Dr. Dewi Evans, whose novel scientific theories were pivotal in securing Letby's conviction. Dr. Evans, lacking a clear understanding of basic physiological mechanisms, made several errors in his identification of venous air embolism as a cause of death or harm in the Letby case. His conclusions were not based on robust scientific evidence but on a self-prepared review consisting of only 18 references, which was neither peer-reviewed nor comprehensive. This review failed to include fundamental papers on the diagnosis and determination of air embolism, raising serious questions about its validity.

Dr. Evans' theory that air injected through a nasogastric tube could cause death in neonates is not supported by any substantial body of evidence. The Court of Appeal's judgment does not address the mechanism by which air in a nasogastric tube could cause death, and it is apparent that the mechanism of death or harm in these instances is not air embolism. This oversight is significant, as it underscores the lack of scientific rigor in the evaluation of evidence.

Remarkably, the CoA declared that Dr. Evans' incoherent air embolus theory is admissible and reliable on the basis that there is a sufficient body of evidence to support the inclusion of air embolism. However, Dr. Evans failed to explain that there are different types of air embolism and that the physiological symptoms differ substantially between each case. The different types of air embolism include:

  1. Pulmonary vascular

  2. Arterial

  3. Iatrogenic

  4. Traumatic

  5. Venous

The CoA went on to state that a paper describing pulmonary vascular air embolism is proof that there is a sufficient body of evidence but neglected to realise that the body of evidence did not apply to venous air embolism. Unfortunately, pulmonary vascular air embolism shares none of the symptoms of venous air embolism; they are completely different physiological phenomena with different disease mechanisms and causes. One causes circulatory collapse and blockage of blood flow (pulmonary vascular), while the other causes sudden cardiovascular collapse (venous). Letby is accused of the latter, and no evidence was presented to support that the symptoms described or observed in the infants at CoCH overlapped with venous air embolism.

The media spent nearly two years incorrectly using "air embolus" as a cause of death due to Dr. Evans' apparent failure to distinguish between air embolism and embolus. He did not even provide the correct definition for venous air embolism. The CoA judgment perpetuated this error, describing "air

embolus" as though it were inherently lethal. This error reveals Dr. Evans' limited understanding of the physiological phenomena he claimed to have uncovered and the CoA's failure to recognize that "air embolus" cannot be used as a description of cause of death.

The Lucy Letby case underscores the critical need for scientific rigor and proper expert testimony in criminal trials. The media's quick dismissal of legitimate criticisms as conspiracy theories and the failure of the legal defense to present adequate expert witnesses highlight systemic flaws that can lead to wrongful convictions. The justice system must ensure that scientific evidence is scrutinized by qualified professionals and that defendants receive a fair trial, supported by competent legal representation. The reliance on Dr. Dewi Evans' flawed theories and the media's uncritical acceptance of these theories reveal a dangerous gap in the understanding and application of scientific evidence in the legal process.

The media’s role should be more than that of a cheerleader for the criminal justice system; it should act as a check on the system. They made no effort to scrutinize the claims of Dr. Evans and then wonder why others question their journalistic integrity.


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