"You were told, quite correctly, that what you must not do is to conclude that if the defendant killed one baby she must have killed the other. That would be quite wrong. It was suggested that the only safe approach was to look at the death of each child independently and only if you reach the conclusion that the defendant killed one child should you ask yourselves whether that helps you in relation to the other child."
"Professor Meadow's evidence of the statistical probability of two SIDS deaths in one family undermined the safety of the convictions for the following reasons: a) the figures cited were erroneous (application to call fresh evidence); b) Professor Meadow's opinion as to the deaths being unnatural was founded in part on the statistical evidence cited in breach of the guidelines in R -v- Doheny & Adams [1997] 1 CAR 369; c) the learned judge failed to warn the jury against the "prosecutor's fallacy" as referred to in R -v- Deen Times,10th January 1994 CA. To the contrary, the learned judge appeared to endorse the prosecution's erroneous approach."
"... the sudden death of a baby that is unexpected by history and in whom a thorough necropsy examination fails to demonstrate an adequate cause of death."
"* deaths that were unexpected, and unexplained at autopsy (ie those meeting the criteria for SIDS); * deaths occurring in the course of an acute illness that was not recognised by carers and/or by health professionals as potentially life threatening; * deaths occurring in the course of a sudden acute illness of less than 24 hours duration in a previously healthy infant, or a death that occurred after this if intensive care had been instituted within 24 hours of the onset of illness; * deaths arising from a pre-existing condition that had not been previously recognised by health professionals; * deaths resulting from any form of accident, trauma or poisoning."
"The broader category of SUDI rather than SIDS was chosen because it is often not possible to distinguish between SIDS and other unexpected deaths until the first autopsy results become available, which may not be for some weeks after the death, and even then the distinction may not be clear-cut. In addition, it was expected that health professionals would more often have been involved in the care of babies whose deaths were explained, so that enquiry into those would be more likely to yield lessons in professional audit and consequent improvements in service." 107. The Study was a major work, covering 470,000 live births, of which 456 SUDIs were identified. Of these 93 were later fully explained leaving 363 finally classified as true SIDS. 108. The Crown took the view that neither Christopher's nor Harry's death was a SIDS death because both were attended by unusual/suspicious circumstances suggesting death caused by a parent because of (inter alia) the existence in the case of each boy of unexplained recent and old injuries found after death. But until cross-examination of the defence medical witnesses, the Crown believed that the defence experts at trial would be mounting a case that the deaths were SIDS deaths, ie unexplained natural deaths. 109. The trial started on Monday12th October 1999 , there were 13 days of evidence in all, and it was not until the defence expert medical evidence was called (ninth to twelfth days of evidence - 26th to 28th October) that it became clear that the medical experts called by the defence accepted that neither death was a true SIDS death. But though the precise measure of rarity was not a significant issue by the end of the trial, the principle of rarity was. The appellant and her husband had not abandoned her defence that both the deaths were natural and true SIDS. 110. The Crown had sought to meet the issue - true SIDS or not - by evidence of the rarity of true SIDS deaths - death by unexplained natural causes. On5th June 1998 a witness statement by Professor Sir Roy Meadow was served. In paragraph 7 he stated: "
"(7) The possibility of two babies dying from SIDS is, according to the evidence of Professor Meadow, extremely remote and estimated at 1 in a million. Mr Bevan [leading counsel for the defence] submitted that that evidence cannot assist the jury in deciding which death may have been natural and which may have been unnatural. He said if one was unnatural, the chances of there being one SIDS in the family remained at 1000:1. Mr Spencer [leading counsel for the Crown] did not press that aspect of the matter any further." 114. The judge, in making his order of mutual admissibility relied on the first six similarities. But it is clear that the Crown had not abandoned the seventh. 115. When the defence expert evidence was delivered a week before trial, it contained two statements relevant to the rarity of two unexplained sudden deaths in infancy (SIDS) in one family. First, Dr Rushton said: "
"The occurrence of repeat unexpected deaths is a topic on which I have been doing research over the last few years and have been able to do a confidential study involving approximately 100 such deaths. These have all been families who have presented as having two `cot deaths'. My findings have been that approximately a third of the deaths have been due to a whole series of rare natural causes which had been missed by those doing the necropsy [ie, not true SIDS - see paragraphs 104 - 105]. A third of the deaths were associated with different forms of child abuse and having a whole number of features which indicated that they were unnatural deaths [ie, not true SIDS]. In the final third no suspicion of unnatural death was found and no natural cause was found and these children constitute what may be termed at the moment as `true idiopathic unexpected child deaths' [ie, true SIDS]. The occurrence of two unexpected deaths in a family thus raises a definite suspicion of unnatural death which in my experience is confirmed only in a third of such cases". ie that over the "... last few years ..." he has examined approximately 33 cases which he concluded were two genuine SIDS in one family. He was not called to give evidence at trial, but his report had been put to Professor Meadow in cross-examination at the old style commital proceedings and, as we shall see, Professor Meadow dealt with Professor Emery's report in his evidence at trial. 117. The Crown tell us and we accept that it was on the basis of that material that they concluded that the rarity of multiple true SIDS deaths in the same family was to be an issue which both prosecution and defence would explore at trial. 118. At this time counsel for the Crown learnt that Professor Meadow was writing the preface to the CESDI Study, and that Study included a table entitled "
"Further to my original statement, I have read the reports of the other medical experts. Apart from non-accidental injury, no likely specific medical cause of death has been proposed. Thus it is suggested that the deaths of both children should be considered as examples of SIDS [that was how he understood the defence case]. The likelihood of SIDS varies with social circumstances. The most recent estimation of the incidence in England is that for a family in which the parents do not smoke, in which at least one has a waged income and in which the mother is over the age of 26 years, the risk is 1:8,543 live births. [the three prenatal factors referred to in paragraph 112 above] Thus the chances of two infant deaths within such a family being SIDS is 1:73,000,000."
" Infants and families at risk Overall, in the population included in this Study the SIDS rate was 0.768 per 1,000 live births, ie approximately one baby in 1,300 died as SIDS. From our data, it is possible to identify within the population a number of factors which are associated with an increased risk of SIDS. The identification of families at higher risk of SIDS is of importance in allowing the appropriate deployment of scarce health care resources, and in attempting to achieve changes in life style or patterns of child care that might reduce this risk. For families already at low risk, knowledge of the factors influencing risk may help to provide reassurance and encouragement in continuing appropriate patterns of care. Table 3.58 shows the three prenatal factors with the highest predictive value (based on the Wald Score) of an increased risk of SIDS, and the likely effect of the presence or absence of each factor on the incidence of SIDS, along with the effect of combing those factors. [NB: we reproduce this paragraph in the final form in the Report, which the appellant's statisticians had, and not as originally delivered (in draft) to the defence, for which see Prosecution Appeal Bundle, p130.] Thus, an infant living in a household in which nobody smoked had a risk of SIDS of around one in 5,000, whilst if anyone in the household smoked this risk rose to around one in 700. Similarly for an infant in a household in which there was no waged income, the risk was around one in 500, compared with one in 2,000 if there was a waged income. The correlation between the factors was taken into account when more than one factor was used to calculate the rate, but because all three factors are independently significant in the multivariate analyses, the presence of more than one will have an increased effect. Thus, it can be seen that for infants in families in which all three factors [ie, someone smokes in the household, there is waged income in the household, and the mother is 26 or under] are present the risk of SIDS was one in 214, compared with a risk of one in 8,543 for infants in families with none of the factors, ie a 40-fold difference in risk. Since the factors will generally remain the same (with the possible exception of maternal age below 27 years) the risk of SIDS to a subsequent child in a family in which one infant has already died will range from one in 214 to one on 8,543. this does not take account of possible familial incidence of factors other than those included in Table 3.58. For a family with none of these three factors, the risk of two infants dying as SIDS by chance alone will thus be one in (8,543 x 8,543), ie approximately one in 73 million. For a family with all three factors, the risk will be one in (214 x 214), ie approximately one in 46,000. Thus, for families with several known risk factors for SIDS, a second SIDS death, whilst uncommon, is 1,600 times more likely than for families with no such factors. Where additional adverse factors are present, the recurrence risk would correspondingly be greater still."
"One must always approach statistics with caution, but Professor Meadow has worked out the probability of there being two genuine unexplained natural deaths (SIDS) in a family such as this where material standards are high, the mother is over 26 years old and neither parent smokes. The chances of one genuine unexplained natural death in such a family are about 1 in 8,500. The chances of two genuine unexplained natural deaths in such a family are about 1 in 73 million."
"Q Just before we look at the figures, does this leave out of the equation deaths which showed suspicious features in any event? A Yes, ... they did not include babies whose deaths were being investigated by the police or were the subject of a coroner's `not ascertained', or it was thought to be ... murder or harm to the child. So these are babies that died suddenly and unexpectedly. The starting position was that these deaths were thought to be natural deaths."
"Q Later on in the paper does it go on to work out the risk of two infants dying of SIDS in that family by chance alone? A Yes, you have to multiply one in 8,543 times 1 in 8,543 and I think it gives that in the penultimate paragraph, its points out that it's approximately a chance of 1 in 73 million .... It gives a chance of 1 in 73 million live births and in England, Wales and Scotland there are about, say, 700,000 live births a year, so it is saying by chance that happening will occur once every hundred years."
"They'd only be included if the pathologist had described them under the label Sudden Infant Death Syndrome, and I think with their findings at autopsy, fractures, bruises and things, they would not have described them as Sudden Infant Death Syndrome so they wouldn't have been .... I think these two cases would probably have been likely to have been excluded from the Study."
"Q Until this study was done and these figures were calculated was there a much lesser figure which didn't take account of these particular household features, smoking, age, wage earning and so on? A Well in general if someone asks me what the risks of two babies within a family dying and being labelled as SIDS I would just say one in a thousand or 1,300 times 1 in 1,300. I'd just give the global rate but you then ... have to take into account as this paper has done and you have to in all individual cases of the circumstances. In other words, in a family where there's no wage earner, where they smoke, where it's a young mother, the chance of a sudden natural death is very, very much greater than the chance in a professional family, non-smokers and of a mature age."
"In England and Wales an estimated 50 families a year experience a second unexpected infant death."
"It was addressing a different issue. The research workers investigating families in which two or more children had died suddenly and unexpectedly, and they went back over all the records and had multi-disciplinary meetings and researched them very carefully to see if they could elucidate better the reasons for those deaths. They had in all 57 deaths to investigate in 24 families, most of families with two deaths. They couldn't get material on all of them but they were mainly two death families. Of those 57 deaths they, on more detailed and modern investigation were able to find a natural cause, that's a disease cause or a genuine accident for 30% of the cases, so their point there was saying nearly a third of those cases should never have been labelled as SIDS, they should have been identified as either a natural accident or a natural disease. Fifty-five percent of the cases they ended up by saying this child had been killed by the parents, and that was not observed first time around. In five percent of the cases they came to no conclusion, and in nine percent, that was in five children they ended up saying: `I don't know what the matter is, we too would use the label SIDS'. So they ended up with five children where they couldn't decide upon a likely cause. They point out in their article that of all the families involved, 24 families, it was only in one family where there were two children who had died and in their opinion were completely unexplained ... in other words SIDS."
"Q Finally, coming back to these two babies, in your opinion, Professor, could either of these two deaths be classified as SIDS, Christopher and Harry. A No. Q Can you think of a natural explanation for either death? A No. Q In your opinion did Christopher die a natural death? A No. Q In your opinion did Harry die a natural death? A No."
"Q It's a bit like a coin isn't it? If you flip a coin heads or tails, yes? A Yes. Q It's the same odds each time isn't it, one to one? A Yes ... This is why you take what's happened to all the children into account, and that is why you end up saying the chance of two children dying naturally in these circumstances is very, very long odds indeed, one in 73 million. You know I mean ... Q That's a double death every hundred years? A I know, but I mean ... you have to say two unlikely events have happened and together it's very, very, very unlikely."
"There may be familial diseases which we are not clever enough to recognise but there may be other familial factors that predispose that family, for reasons we don't understand, to a second death. So this Study, this is a theoretical calculation. It is not the result of observation ... [but of] multiplying those figures together ... when you go out and look for families who have had ... second SIDS .... they are commoner than you would expect from this type of calculation."
"Well that, members of the jury, leads me to the conclusions of the various medical experts. I start with Sir Roy Meadow and I start with him on purpose because there was an aspect of his evidence which is not strictly speaking a conclusion but which is most conveniently dealt with at this stage. What I refer to is his statistical evidence because you may remember he dealt with statistics relating to two SIDS death occurring in one family. His figures were derived from a recent and very thorough research study, Government funded report, call CESDI. You have, members of the jury, a table containing those statistics in section 8 of the folder. In short, in a case were nobody smokes in the household and there is at least one waged income in the household and the mother is more than 26 years old, the probability of one SIDS death in the family is 1 in 8,543 and the probability of two SIDS in the same family is 1 in 73 million live births. That means there is a chance of two SIDS in the same family happening one every hundred years. In addition to that, in these two cases, there are features which are suspicious in any event. So that was the evidence that he gave in evidence in chief about those statistics. In cross-examination figures from a report by CONI - Care of the Next Infant programme - which was published in October 1998 were put to Sir Roy Meadow. In that report, 8 [deaths] out of [5,000] babies in their programme were treated as true cot deaths after confidential enquiries. ... It was suggested that using the three high risk factors in the table from the CESDI Study, the risk of a SIDS death would be 1 in 214 which would be a risk of a double death of 1 in 46,000, and applying that correlating it to the figure of 5,000 babies, the risk it was put at that time would be 72 in every 46,000. I think Mr Bevan in his final submissions referred to a figure of 54 rather than 72 but the point still remains the same. Sir Roy Meadow's response to this was that that was not a valid way of assessing the evidence. The CONI report was nothing like the same standard of the CESDI report, he said, and the research was not scientifically valid. He said that it does not have any value statistically and cannot be compared to the CESDI Study."
"I should I think members of the jury just sound a note of caution about the statistics. However compelling you may find those statistics to be, we do not convict people in these courts on statistics. It would be a terrible day if that were so. If there is one SIDS death in a family it does not mean that there cannot be another one in the same family. That part of the evidence relating to statistics is nothing more than that. It is a part of the evidence for you to consider. Although it may be part of the evidence to which you attach some significance, it is of course necessary for you to have regard to the individual circumstances relating to each of these two deaths before you reach your conclusion on the two counts on this indictment. Having said that, members of the jury, I turn then to what truly were the conclusions of the relevant experts relating to Harry. The first one is Sir Roy Meadow and his conclusion was that Harry's death could not be classified as a SIDS death and in his opinion Harry did not die a natural death. He also said that the further information that he had received since he made his witness statement in June 1998 sadly increased the strength with which he felt that these two deaths were not natural."
"He said that he would not classify either of these deaths at SIDS deaths because they have features which are not typical of SIDS deaths. Both deaths, he said, gave him considerable concern. He thought the timing of the deaths was unusual but not very unusual for a SIDS death. So far as the statistics are concerned relating to the likelihood of there being two SIDS deaths in one family, that figure of 1 in 73 million, he thought it was wrong to multiply the two figures of 1 in 8,543 together because if there was one SIDS in the family, then there maybe other factors present in the family which might make it more likely that another death would occur."
"It was therefore submitted by the prosecution all of those finding on their own were ... too powerful to amount to anything else but a deliberate killing of Christopher. All Professor Meadow's features for an unnatural death rather than a SIDS death were applicable in the case of these two babies, it was submitted by the prosecution, namely previous unusual episodes, inconsistent accounts between parents, both events had happened in the evening, both babies had just taken a feed, and there was, say the prosecution, smothering combined with some other form of abuse. Professor Meadow's opinion you were reminded was that neither death was natural. Reliance was also placed by the prosecution on the statistics mentioned by Professor Meadow for the probability of two SIDS deaths within the family, namely one in 73 million and even longer odds, it was said, if you take into account the existence of the old and fresh injuries, and reliance was also placed on the seven similarities between the two deaths which I mentioned to you early in my summing up, and which the prosecution suggest make it beyond coincidence that these two deaths were natural deaths."
"So far as the statistics are concerned relating to the possibility of 2 SIDS deaths in one family, reliance was placed on the CONI figures, those were the figures which Professor Meadow had dismissed in his evidence, and reliance was also placed on Professor Berry's point that the risks were inherently greater in any event in a family which had already had a SIDS death. You were told, quite correctly, that what you must not do is to conclude that if the defendant killed one baby she must have killed the other. That would be quite wrong. It was suggested that the only safe approach was to look at the death of each child independently and only if you reach the conclusion that the defendant killed one child should you ask yourselves whether that helps you in relation to the other child. It was submitted that you cannot say with any degree of certainty that the defendant deliberately killed either of these children. She had done nothing untoward to either child and whilst there may be suspicious features, the prosecution have not proved this case so that you can be sure that she had killed either of them. Well, members of the jury, that is I hope a reasonably fair summary of the way in which both sides put their cases to you."
"without prejudice to any matter which the subsequent Court may decide."
"Whereas such methods may be appropriate for suggesting broad general hypotheses about the relationship between the outcome studied (here SIDS) and possible explanatory factors, it can be very misleading to use them to construct precise numerical formulae for predictive or explanatory purposes."
"The scientist should not be asked his opinion on the likelihood that it was the defendant who left the crime stain, nor when giving evidence should he use terminology which may lead the jury to believe that he is expressing such an opinion."
"The learned judge failed to warn the jury against the `prosecutor's fallacy' as referred to in R -v- Deen , The Times,10th January 1994 . To the contrary, the learned trial judge appeared to endorse the prosecutor's erroneous approach."
"... you take what's happened to all the children into account, and that is why you end up saying the chance of two children dying naturally in the circumstances is very, very long odds indeed, one in 73 million"
"You have to say two unlikely things have happened, and together it is very, very, very unlikely."
"The `logic' implicitly applied at the trial was as follows: a certain event (the deaths of two babies in one family) has occurred. We are unsure of the cause. One possible cause is that both babies died of SIDS. However, the probability of two babies in the same family both dying of SIDS is extremely tiny. Therefore we can exclude that possibility and, in consequence, accept that the babies were murdered - if that is the only alternative."
"... the prosecution said that it was beyond coincidence that both children could have died naturally. The probability was one in 73 million"
"The fresh evidence of Dr Evett and Professor Dawid demonstrates that the prosecution invited the jury to adopt the figure of 73 million as having a significance in itself when in truth, without reference to the likelihood of a competing possibility, the figure has no relevance or significance at all"
"I should I think members of the jury just sound a note of caution about the statistics. However compelling you may find those statistics to be, we do not convict people in these courts on statistics. It would be a terrible day if that were so. If there is one SIDS death in a family it does not mean that there cannot be another one in the same family. That part of the evidence relating to statistics is nothing more than that. It is a part of the evidence for you to consider. Although it may be part of the evidence to which you attach some significance, it is of course necessary for you to have regard to the individual circumstances relating to each of these two deaths before you reach your conclusion on the two counts on this indictment. Having said that, members of the jury, I turn then to what truly were the conclusions of the relevant experts relating to Harry. The first one is Sir Roy Meadow and his conclusion was that Harry's death could not be classified as a SIDS death and in his opinion Harry did not die a natural death. He also said that the further information that he had received since he made his witness statement in June 1998 sadly increased the strength with which he felt that these two deaths were not natural."
"If there is one SIDS death in a family, it does not mean there cannot be another one"
"Q You expressed an opinion when I asked you questions yesterday based upon recent experiences you said. A I've seen these haemorrhages again more recently in some cases where there's undoubtedly been smothering or overlaying, but I mean they are not always present and they are not invariable, they are just an observation one has made on a couple of occasions. Q This is in children of what age? A Similar sorts of ages to these, but whether they are just there by chance, because it's well recognised that in asphyxia mechanisms of death, whatever the cause, that you get quite large haemorrhages at the front of the eyes, but in addition you not only get the petechial, small pin point haemorrhages but in the whites of the eye you see quite large haemorrhages on occasions. Now in discussing it, or thinking about it with colleagues one wonders whether its just a reflection, what one sees in the front of the eye occurring in the back of the eye, but its not been reported. Q But in the cases you are describing have you seen it on the back of the eyes or the front of the eyes? A In these cases it's again been on the back of the eye, but can I just say that it's not a normal practice in strangulations in older people, even older children, one does not routinely examine the backs of the eyes, one does not take the roof of the orbit off, and as a result it may be that we have not been looking rather than it's not there."
"... because as you are removing the eyes from the orbit, you have to cut through the various muscles that make them move from side to side and up and down. You also have to cut through the optic nerve and you will cut through the optic nerve and you will cut through the blood vessels which are supplying the eye, and the tissues around them. And veins, even though after death there is no pressure in them, can ooze a little blood."
"I can only speculate, and as I say I have never seen anything like this in my personal experience: had a vein of any size been cut I would have thought that there would have been more diffuse bleeding in the fat covering the eye as well as on the surface of the eye itself."
"The blood was between the membrane covering the hard white globe of the eye"
"Secondly, so far as the eyes are concerned, on internal examination, Doctor Williams found an area of haemorrhage about 7 millimetres across on the upper surface of the right eye and also a small area of haemorrhage on the upper surface of the right eye. Indeed, he said he saw it immediately the eyes were exposed. Doctor Williams said that he had only seen such features in cases of death caused by over-laying or smothering."
"Next Professor Luthert dealt with the blood that had been found on the surface of the backs of both Harry's eyes. He and Professor Green agreed that it was not a classic sign of shaking and that it was not a finding associated with any particular disease. Professor Luthert speculated that the blood might have dropped down on to the eyes during dissection. He said that the blood appeared to be beneath the access points for dissection to both of the eyes. That was challenged in cross-examination but he said that the de-roofing of the orbit was quite extensive so there did not have to be a precise alignment. He described it in cross-examination as total speculation that the blood had dropped down in that way but he said it was a workable hypothesis in the absence of any other explanation. He also agreed that he could not exclude the possibility that it resulted from suffocation. He considered, however, that it was most likely that the blood had accumulated post mortem and was not indicative of any pathology before death. He said that he saw no significant pathology in Harry's eyes. It was suggested to Professor Luthert that if the blood at the back of the eyes had dropped down during dissection it would be a common occurrence but Professor Luthert said that pathologists do not necessarily focus in on every aspect of what they are looking for and that routinely they factor out the presence of blood. By that he meant that they would tend to assume that haemorrhaging is due to blood loss at the time of post mortem, unless it is something out of the ordinary. He agreed, however, that pathologists would be on the look out for this kind of blood during a general examination of the eyes."
"Fourthly, the haemorrhages to the backs of the eyes which Professor Luthert thought were artefactual but which he said could possibly be consistent with asphyxia. You were reminded that Dr Spillman who had been at the post mortem had immediately noticed the 7mm area of haemorrhage."
"[Professor Green] was also wrong, it was submitted, in saying that if the blood on the backs of the eyes had been artefactual, it would have been washed away because Professor Luthert had shown that the material above the eyes was absorbent."
"With reference to your letter of 14 th March 2000 detailing specific requests of Dr Alan Williams he has responded as follows: Dr Williams confirms that he has identified one baby death which has recorded haemorrhages in the orbit and on the surface of the back of the eye, and also an adult case with the same findings seen recently. He has not extended his search further. If required he can produce these reports with the permission of the appropriate coroner."
"The officer, you may remember, put to [the appellant] the similarities between the deaths of the two babies, their age, the time of death, both in the bedroom when she was on her own and both in a bouncy chair and the fact that three medical experts were saying that both deaths were unnatural. Her solicitor advised her not to comment on that in the absence of disclosure of the reports and she accepted her solicitor's advice. Some criticism is made by the prosecution of the defendant's failure at that time to dispute that both children were in the bouncy chair in view of her subsequent evidence that Christopher was not in a bouncy chair at the relevant time. You will obviously want to consider the whole of pages 29 to 31 of that summary that you have when you are considering that point and in particular the last question and answer on page 31 but you may think that, looking at the matter overall, she was in effect following her solicitor's advice to make no comment, which I should tell you was something she was quite entitled to do."
"Solicitor: Can I just say to you this highlights the difficulty of seeking to advise you in the absence of disclosure of reports, I suggest that you make no comment whatsoever about the observations that the Officer just put to you, none whatsoever. Question: Okay, right do you have any comment to make on any of those similarities? Answer: 'No comment'."
"(1) Subject to the provisions of this Act, the Court of Appeal - shall allow an appeal against conviction if they think that the conviction is unsafe; and shall dismiss such an appeal in any other case."
"Although the court may choose to test its views by asking itself what the original jury might have concluded, the question which in the end we have to decide is whether in our judgment, in all the circumstances of the case including both the verdict of the jury at trial upon the evidence they heard and the fresh evidence before this court that we have heard, the convictions were safe and satisfactory. If so the convictions must stand. If not the convictions must be quashed."
"It seems plain on the language of the statute and on authority that the court is obliged to exercise its own judgment in deciding whether, in the light of the new evidence, the conviction is unsafe."