Criminal Cases Review Commission

Baby Harry Clark was found dead at eight weeks of age. Dr Williams commissioned lab tests on Harry immediately after his death, which found lethal levels of bacterial infection in his body, which were present during his life, showing that the baby died of natural causes. Examinations by experts have shown that the cause of death was 5 staphylococcal infection, or a 6disseminated staphylococcal infection.

This is an infection which progresses quickly and without any obvious pre-existing illness. It is a recognised cause of S. I. D. S and is a natural disease; no other conclusion could be sustained. There is clear medical evidence that both babies died from natural causes, albeit different ones and not at their mother's hand, yet eighteen months later at the trial, the jury asked TWICE whether any blood tests had been carried out on Harry to show whether he had died from natural causes, once during the evidence given by Professor Tim David, and again during cross examination. But Dr Williams said there had not been. This is a contravention of 7 The Human Rights Act Art 6.

Dr Williams told the jury that there was no evidence of infection and also no evidence that the child died as a result of natural disease. However he was not disclosing the results of the tests he had commissioned which showed a natural cause of death. The jury were aware that Dr. Williams findings were the subject of much criticism, but how would the knowledge of failure to disclose vital evidence have affected their view of his competence, honesty and reliability to give evidence as an expert? The 8other flawed expert evidence involved the testimony of Professor Green, another pathologist employed by the Crown.

Dr. Williams and Professor Green came to the conclusion that the deaths of the children were due to their being smothered, even though initially they had suggested shaking as the cause of death. The retraction and revision of their opinion concerning the cause of death came after being challenged by a pathologist for the defence regarding flaws in their evidence. Expert witnesses occupy a special position in court 9in that they may give evidence of opinion as well as fact. Danger can arise when the jury is unclear as to which is which, as their evidence is regarded as somehow infallible and the pristine truth.

So-called experts are a mixed bag,10 a worrying number are ready to advance opinions in fields of expertise well outside their own. This leads to advise which is at best 'unhelpful' and at worst 'misleading'. The pivotal evidence which has persuaded the Criminal Cases Review Commission to refer Sally's case back to the Court of Appeal turns on the reliability of Dr Williams, as the medical evidence contained in his report which was not disclosed at the original trial shows that Harry, the second baby to die had suffered from a natural disease which had almost certainly killed him.

During the trial there were numerous other flaws identified in the Crown's pathological evidence and, although attempts were made to counter them, the evidence was deemed sufficient to be 'beyond reasonable doubt' by the jury and, later, passed muster with the Court of Appeal which held the medical evidence incriminating Mrs Clark to be 'overwhelming'. The prosecution also painted a sinister picture of family life in the Clark household, they said Sally was tired, depressed and had resented the interruption that the children had made to her career.

Nothing could have been further from the truth but the defence were never given the chance to respond to the character assassination. There is no doubt that with days of conflicting forensic evidence at the initial trial, the Crowns case was very much bolstered by the testimony of such an eminent paediatrician. However, I would like to point out that throughout this case the prosecution did not believe that the deaths of the two babies were from S. I. D. S. they thought it was murder.

Also, the defence agree that the two deaths were not S. I. D. S. They say that Christopher's death was recorded by the doctor, as lung infection, which would mean it was not SIDS; and Harry's death was caused by bacterial infection, which would mean it was not SIDS. So since neither prosecution nor defence thinks a double-S. I. D. S. is the explanation, the probability of double-SIDS is completely irrelevant to the case.

The jury should have been directed most strongly to disregard any statistics relating to double-SIDS. During the trial the jury clung onto two things – Professor Meadow's flawed statistical evidence and Williams flawed medical evidence. The statistic was subsequently rebutted, and has been rubbished by the professional body for statisticians, and the judge directed the jury to discount it, but it ran constantly through the trial, and we know that for the 10 of the 12 jurors who found Sally guilty, it was hugely influential.

At the Appeal hearing, the defence realised that the incorrect use of the statistics in the original trial had had a large part to play in the guilty verdict. They countered this with the statement that the jury should have been warned about the 'prosecutors fallacy' 11The mathematical community give the label 'prosecutors fallacy' because it is a trap into which highly intelligent people often fall, and it is easy to see how the jurors fell into such a trap.

The jury were faced with deciding between two events, a natural double-death or a double murder. It is given that the prosecution was saying that the odds against the natural explanation are impossibly highso, the murder explanation must be true. The appeal court judges concluded that "In the context of the trial as a whole, the point on statistics was of minimal significance and there is no possibility of the jury having been misled so as to reach verdicts that they might not otherwise have reached.

" They also chose to second guess the statistical comprehension of the jury and said regarding the prosecutors fallacy:12 "It is stating the obvious to say that the statement 'in families with two infants, the chance that both will suffer true SIDS deaths is 1 in 73 million 'IS NOT THE SAME AS' if in a family where there have been two infant deaths, then the chance that they were both unexplained is 1 in 73 million. It is clear that the second statement does no follow on from the first. You do not need a label 'The Prosecutor's Fallacy' for that to be clear to the jury.