Introduction
12.1. The trial began before Lord Johnston and a jury at the High Court in Glasgow on Wednesday 21 April 1999 and concluded on Friday 14 May 1999. Mr Murphy Q.C. advocate depute appeared with Mr Dennis, advocate, for the Crown. Mr Findlay Q.C. appeared with Miss Young, advocate, for Ms McKie, instructed by Levy & McRae, solicitors.
12.2. The charge of perjury alleged that Ms McKie had given evidence in the trial in HMA v Asbury that at no time had she gone beyond the porch area of 43 Irvine Road, when in truth she had been beyond the porch and in the vicinity of the bathroom doorway.
12.3. The prosecution case began on 21 April and continued until 7 May. The prosecution led evidence from police officers (including log-keepers), scene of crime officers, a forensic scientist and Mr Dewar, the trial advocate depute in the trial in HMA v Asbury. Three of the four SCRO fingerprint examiners who had signed the joint reports gave evidence at the end of the prosecution case between 4 May and 7 May.
12.4. After the case for the prosecution, the defence led evidence from two police officers, Ms McKie and the two defence fingerprint examiners, Mr Wertheim and Mr Grieve.
12.5. Mr Murphy and Mr Findlay made their speeches to the jury on 13 May. Lord Johnston delivered his charge to the jury on 14 May. The jury then retired to consider its verdict. The jury gave its verdict on the same day, finding Ms McKie not guilty.
12.6. The Inquiry had access to transcripts of the evidence of a limited number of the witnesses, including all the fingerprint examiners and Ms McKie, and also a transcript of Lord Johnston's charge to the jury. The Inquiry also had a detailed contemporaneous record of the trial compiled by Mr Carle, who attended the trial as an observer on behalf of Strathclyde Police.1 The order of witnesses and relevant references to these documents are noted in Appendix 8.
The evidence of Mr Shields, Mr Kerr and Mr Lees
12.7. The Crown case was that the fingerprint evidence could be supported by the evidence of Mr Kerr. By her own admission, Ms McKie had been at the house in the late afternoon of Saturday 11 January 1997, around 17:45 hours, in order to collect the log for photocopying and to return it to Mr Lees.2 Mr Kerr's statements indicated that he had seen Ms McKie at the house (in the porch) that day. The log showed Mr Kerr as having left the house at 13:15 and therefore Mr Murphy inferred that this sighting must have been during the morning, at a time when Ms McKie had no legitimate reason to be there.3
12.8. Mr Kerr's statements were vague so Mr Murphy instructed inquiries.4 He asked Mr Dennis to provide a copy of the log to someone from the procurator fiscal's office so that inquiry could be made of Mr Kerr as to when, precisely, he had seen Ms McKie at the house. The information that came back to Mr Murphy was that Mr Kerr said that he had seen Ms McKie at the house on the Saturday. Mr Murphy understood this to be before lunchtime because he thought that the statement was taken with reference to the log, which recorded Mr Kerr as having left at 13:15.5
12.9. Mr Shields gave evidence at the trial covering the whole of his time with Ms McKie during the investigation. He referred to the attendance of Ms McKie to collect and return the log on the Saturday, which he timed around 5pm and he said that when she collected the log she entered the porch but did not remain long at the house.6
12.10. Mr Kerr's evidence was not as expected. Though he did say that he had seen Ms McKie in the porch that day, his evidence was that he had returned to the house in the afternoon to continue removing door handles, a job that could not be completed in half a day and that it was some time in the afternoon that he saw Ms McKie.7 This removed the basis for any inference that Mr Kerr could place Ms McKie at the house before lunchtime and Mr Murphy told the Inquiry:
"Once this identification evidence was flawed I began to become concerned as I was now relying solely on the fingerprint evidence to place Ms McKie inside the house."8
12.11. The theory that Ms McKie had been in the house on the Saturday placed suspicion on Mr Lees, who was the officer responsible for keeping the log that afternoon. In addition to the log having no record of Mr Kerr being at the house in the afternoon, it had no record of Ms McKie being there at any time that day. His evidence was that Mr Kerr could not have been in the house in the afternoon if his presence was not recorded in the log. As for Ms McKie, Mr Lees confirmed that she had collected the log from him but he said he had not recorded this in the log because he understood that he was to record only those who crossed the threshold of the house and Ms McKie did not do so because she did not enter the porch.9
Scene of crime evidence
12.12. The proposition that Ms McKie had placed her mark on the door-frame on Saturday 11 January was, at least to some extent, understood to be supported by the fact that the mark Y7 was not found when the door-frame was dusted with aluminium powder on 9 January but was found when it was dusted with black powder on 14 January. Mr Kent's conclusion in his report was that it was likely that the fingerprint had been deposited after the application of the aluminium powder10 but it would seem that Mr Murphy did not attach much significance to this evidence because he knew that the mere fact that the mark was not disclosed by aluminium powder was not conclusive proof that it was not on the door-frame at the time.11
12.13. Mr Kent did not give evidence until 6 May and Mr Carle recorded him as saying that he could not give an opinion on when the fingerprint may have been deposited.12 At the time Mr Kent was puzzled that his evidence was uncontested13 and that was probably because it had been overtaken by other evidence, notably by a scene of crime officer, Mr Stewart Wilson, and the focus of the trial had shifted to a battle between the fingerprint experts.
12.14. Mr Wilson gave evidence earlier in the trial.14 He was the scene of crime officer who found mark Y7 when he dusted with black powder on 14 January. His evidence was that it was possible that Y7 was present before the dusting with aluminium powder and, as for the converse, if it had been placed after that dusting he would have expected to have found some evidence of disturbance. Asked if he could exclude the theory that the print had been placed after the aluminium powder he replied: "Yes, I can in my personal opinion."
SCRO fingerprint evidence: overview
12.15. The SCRO fingerprint examiners who gave evidence were Mr Stewart, Ms McBride and Mr MacPherson. Mr Stewart gave evidence on 4, 5 and 6 May, Ms McBride on 6 May and Mr MacPherson on 7 May.
12.16. The basic SCRO position can be summarised as follows:
(i) The four SCRO fingerprint examiners had compared Y7 to Ms McKie's left thumbprint and reached their conclusions independently.
(ii) Each concluded that the bottom half of Y7 was made by Ms McKie's left thumb. The SCRO examiners had found at least 16 points in sequence and agreement in that regard.
(iii) They concluded that the top half of the mark ought to be excluded from consideration. This meant that any apparent differences between the top half of the mark and Ms McKie's thumbprint could be set to one side.
(iv) Y7 was made by Ms McKie's left thumb.
12.17. The defence challenged the substance of SCRO's identification, and, in particular, advanced three broad reasons why it was wrong.
(i) Bar five points that were possibly within tolerance, the differences and the unreliability of the 16 points relied on by the SCRO fingerprint examiners meant that Ms McKie did not make Y7.
(ii) The assumption that the top half of the mark should be discounted was incorrect with the result that clear differences between the top half of the mark and Ms McKie's thumbprint should be taken into account.
(iii) The differences in the top half of the mark Y7 meant that Ms McKie did not make Y7.
SCRO witnesses were cross-examined on this basis.
Mr Foley
12.18. Mr Foley had checked Y7 during the blind trial and had eliminated it to Ms McKie.15 This was not made known to either the prosecution or the defence. Both prosecution and defence had precognosced Mr Foley as a witness included in the Crown List relative to the 1993 incident when Ms McKie's print was found on a production. In the course of the evidence of Mr Stewart on 5 May 1999 the defence successfully objected to any evidence being led about that incident16 and, presumably as a consequence, Mr Foley was not called as a witness at the trial.
SCRO examiners' evidence at the trial
Numbering of characteristics in the charted enlargements
12.19. The evidence at the trial was given primarily by reference to the SCRO charted enlargements in Productions 152 and 189. The two productions featured a combined total of 17 ridge characteristics. Though the majority were common to both productions there were some variations in the numbering of those characteristics. In this Report points are generally referred to by the numbers assigned to them in the SCRO chart produced as part of the comparative exercise.17 Those numbers correspond to the numbering in Production 152 and can be reconciled with the numbering originally in Production 189 by reference to table 1 in Chapter 24. In this chapter, in order to be consistent with the trial transcripts, both the original number and the comparative exercise equivalent will be given. The comparative exercise equivalent is indicated by use of the term "SCRO point [number]".
Mr Stewart
12.20. Mr Stewart was the lead witness, and was the only one of the SCRO officers asked to speak to the full detail of the comparison.
12.21. Using the general (or non-case specific) illustrations in the booklet Production 18118 Mr Stewart gave the jury an introduction to fingerprint identification and the methodology applied by examiners. He told the jury that fingerprint evidence had never been successfully challenged19 and referred to the fact that he was authorised by the Secretary of State for Scotland to give evidence.20 He explained to the jury that as an expert he was happy to identify with 10-12 points but that the convention in the UK was to work to the 16-point standard.21 Though he mentioned that the UK was in the process of moving to the non-numeric standard, his evidence was that the 16-point standard was a very high standard, higher than that applied in some other countries,22 and that the probability that two people would share 16 ridge characteristics was one in 1016 a number grossly in excess of the population of the earth.23 That said, he advised the jury that fingerprint examiners in modern practice no longer cited probabilities because it was felt that fingerprint evidence had been in use for so long that it had been established in its own right as a means of identification.24
12.22. Having given the general introduction he then addressed mark Y7. He mentioned that he had personally checked the comparison three times and also said, without further elaboration, that it had been checked by the quality assurance officer and the deputy head of bureau.25
12.23. In considering his evidence it is necessary for clarity to look separately at (1) his justification for drawing his conclusion from the lower part of the mark and (2) his defence of the proposition that there were at least 16 points in sequence and agreement in the lower part of the mark.
Use of lower part of the mark
12.24. Mr Stewart explained that the identification was made under reference to the lower part of the mark. Three different factors were cited by him in his evidence-in-chief when seeking to explain the reasons for discounting the upper part of the mark:
(i) SCRO were not sure if the top was part of the same or another finger,26 though he contradicted that by saying that his own opinion was that they were more likely to be one print.27
(ii) There was an area of distortion across the mark and the mark appeared as if either (1) the finger had been placed down and rolled away with pressure to the top or side or (2) there had been an impression there already and the thumb had been put down on top of it.28 The second of those possibilities may be summarised as Y7 being the product of superimposition;29 and, as for the first possibility, the added explanation was that pressure can cause distortion round the edges,30 leading to the dissimilarities.31
(iii) The upper part of the mark was very high up to the top of the thumb and the ridge characteristics in that area could not be compared because that section of the thumb was not shown in any of the fingerprint forms available to SCRO.32
12.25. In cross-examination he adhered to the conclusion that the mark as a whole was probably one print33 and also to the explanation that, though the area at the top was not in sequence and agreement with the rest, the explanation lay in the area corresponding to the top of the mark not being shown on the fingerprint form.34
12.26. Defence production 235 was put to him in cross-examination and his evidence relative to that production was clarified in re-examination.36 He accepted that Mr Wertheim's green circles pointed to probably three bifurcations and a ridge ending in the upper section of the mark and in discussing his reasons for excluding the top section of the mark he gave two reasons. Firstly he said that there had been movement with the top part jumping, resulting in the detail in that part being a couple of ridges out. Secondly, he repeated that the top part of the mark was not reproduced in the print forms available to SCRO.
16 points in lower part
12.27. His evidence-in-chief on the finding of 16 points in sequence and agreement was given by reference to the case specific charted enlargements, firstly in Production 152,37 repeating the exercise under reference to Production 189.38
12.28. The account which he gave of the nature of the 16 points in Productions 15239 and 18940 coincided with the description of those points in Table 1 of the SCRO comparative exercise contribution41 but it is fair to say that in his evidence-in-chief he did little more than declare whether the ridge characteristic in question was a bifurcation or a ridge ending. There was little in the way of explanation as to the reasons for inferring how any incomplete detail should properly be interpreted. This was one of the main themes pursued in cross-examination.
12.29. Cross-examination opened by questioning the rationale for the 16-point standard, attributable as it was to the misunderstanding of the Bertillon charts.42 The line being pursued by the defence was that those, like SCRO, who applied the 16-point standard merely counted points, whereas those who applied the non-numeric approach gave closer consideration to the mark as a whole and, in particular, to the quality of the ridge characteristics in it.
12.30. Reflecting Mr Wertheim's opinion, Mr Findlay proceeded on the basis that five points could be within tolerance.43 For the rest, he questioned whether the detail in the mark was of sufficient clarity to admit of any reliable interpretation. He repeatedly asked Mr Stewart to demonstrate characteristics to the jury initially by reference to Production 15244 and latterly by reference to Production 189 and two sub-plots emerged. The first can simply be described as discussion of "blobs" and the second was the issue of "teasing out"45 the points.
12.31. As regards "blobs", when Mr Stewart was demonstrating (under reference to Production 152) what he saw as the two bifurcations SCRO 10 and 11 which met to form a lake, Lord Johnston interjected that even with the benefit of a magnifying glass "it is just a fudge."46 Later Mr Findlay was to use the word "blob" when directing Mr Stewart to any part of the mark that Mr Findlay was suggesting lacked clarity. He first applied this term when asking Mr Stewart to demonstrate his interpretation of point 1 in Production 15247 (i.e. SCRO point 1) as a bifurcation and again Lord Johnston remarked that even with the benefit of a magnifying glass the word "blob" seemed to be appropriate.48 Later Lord Johnston asked Mr Stewart whether he agreed that to the untrained eye points 15 and 16 in Production 152 (i.e. SCRO points 15 and 16) looked like blobs, to which Mr Stewart replied:
"It is a good term that Mr Findlay used earlier. Yes, sir, I would say to someone who has no training and no experience of fingerprints probably a whole lot of that just looks like a black mess you would think, my Lord."49
12.32. Mr Findlay also scrutinised Production 18950 and asked whether he would agree that what he demonstrated (as a bifurcation) at point 6 in that charting (i.e. SCRO point 7)51 could not really be seen, Mr Stewart replied: "I agree again, sir, you would probably call that a blob" and also accepted that he could only claim it to be reliable by appealing to his own experience.52
12.33. As regards "teasing out" points, Mr Findlay used that term specifically later in his examination when he explained what the defence experts would say53 but earlier he had put the same point in lay terms: within any kind of tolerance Mr Stewart was "squeezing too much in to the pot",54 or going looking for something and convincing himself that it existed when in reality it did not.55 When Production 152 was being viewed Mr Findlay questioned SCRO points 7, 10-13 and 15-16 on this basis,56 and when he turned to Production 189 the list was expanded to include the point marked 10 in that chart (SCRO 17 in the comparative exercise).57
12.34. In his evidence-in-chief Mr Stewart had explained that the charted enlargements in Productions 152 and 189 were produced for illustrative purposes only to show the jury how the examiners reached their conclusion and he told the jury that they were not the materials used when the print was first identified.58 In re-examination Mr Murphy sought to diminish the impact of the characterisation of significant parts of the charted enlargements as "blobs" by eliciting from Mr Stewart the explanation that the detail in an image can become distorted as it is enlarged, which is why fingerprint examiners prefer to work with life-size images and not enlargements.59 It is evident from one observation by Mr Murphy that when the life-size image of Y760 itself was displayed on a projector in court and enlarged it was not particularly clear.61 There may have been the added complication that the jury were given reproduction copies of the charted enlargements for their own use which were inferior.62
Ms McBride
12.35. In evidence-in-chief Ms McBride was taken through the joint reports and, with one exception, she was not asked to demonstrate the 16 points in sequence and agreement in each of the charted enlargements. The exception is that she was asked about point 14 in Production 152 (SCRO point 14) and she said that that could be either a bifurcation or a ridge ending but did not like to say which it was by reference to an enlargement because that was not as clear as looking at the original image under glass.63
12.36. The justification for discounting the top of the mark was explored with her.64 She said that she had checked the whole print but did not care for the top part of the mark. It was of no value to her because she could not interpret the ridges properly as it was not clear but she could not give a specific reason for that: it could be distortion, movement or pressure and it may not even have been made by the same author.
12.37. Four points were raised with her in cross-examination.
(i) The depth of her qualification as an 'expert' witness was indirectly questioned by pointing out that she did not attend conferences, deliver papers or write articles.65
(ii) She was asked if she subscribed to the view that her judgment was infallible, and she said that it was not her judgment but rather the system that was infallible: "One person can make a mistake but four people and the quality assurance officer - it is not possible."66
(iii) Her justification for discounting the top part of the mark was addressed. Asked about SCRO point 1 in Production 15267 being a blob, she observed that the top of the mark was a blob,68 and that was why she could not give an opinion on it. However, she did not give a specific reason for discounting the top part. She said that it would be dangerous to venture an opinion on the question whether it was one print or one on top of another because she did not know how the mark was made. She did not have an opinion and discounted the top part because "it is either moved or something else is on top or I say it has been dragged with pressure."69 In the end it came down to the conclusion that her experience told her that that part of the mark could not be properly interpreted.70
(iv) Defence production 2,71 Mr Wertheim's charting, was put to her. Ms McBride told the court that she had not seen Mr Wertheim's production before and had not studied it. She was told that it was a photograph of Y7 but said that she would not comment on it before studying it. She did not want to express an opinion on it without the correct lighting, glasses and a photograph of the correct size.72 Cross-examination ended abruptly at that point.
12.38. After re-examination, Lord Johnston asked one question and Ms McBride agreed that her rejection of the top part of the mark was based on her observation and experience rather than any (specific) reason.73
Mr MacPherson
12.39. Like Ms McBride, Mr MacPherson's evidence was abbreviated and he was not taken through the detail of all 16 points in sequence and agreement in the two principal productions. He was, though, asked to demonstrate the points 3-5 in Production 18974 (SCRO points 3, 4 and 6 in the comparative exercise). He demonstrated those points to the jury by tracing them on screen with a pointer under reference to an image in Production 189 and also an image in Mr Wertheim's defence production 2.75
12.40. In evidence-in-chief he was also asked to explain his reasons for discounting the top section of the mark and, as with Ms McBride, this came down ultimately to a judgment based on his own experience:76
"Because in my opinion the top of the print is either subject to superimposition, one upon itself or upon another print or because of severe twisting and distortion it is not an area which is conducive to a comparison for comparison purposes."77
Asked to explain in layman's terms any features indicative of distortion or superimposition he simply offered: "Well, basically the ridge characteristics do not look genuine."
12.41. In cross-examination Mr Findlay again indirectly questioned the depth of expertise as an 'expert' witness by drawing out that Mr MacPherson had attended few seminars outside the bureau and had not delivered papers or written articles.78 The thrust of the brief cross-examination was to test whether Mr MacPherson would be more specific in his reasons for discounting the top part of the mark but Mr MacPherson was no more specific than he had been in his evidence-in-chief. He accepted that he could see one bifurcation in the upper part of the mark but said that there was uncertainty about a second possible bifurcation, which was why he could not use the top. That prompted this question and answer:
"Does it come to this: we could do this all day, Mr MacPherson, and your response simply is that it is uncertain because 'I say it is uncertain'? - Well from my experience, yes, it is not an area conducive for comparison purposes."79
Ms McKie's evidence
12.42. Ms McKie gave evidence in her own defence on 11 May and was cross-examined. The account that she gave of her movements was consistent with her earliest police statement,80 the statement that she gave to the Mackay team in 200081 and her statement to the Inquiry.82 She denied having been in the house beyond the porch and accordingly denied that the mark Y7 could have been made by her. In particular, she testified that the only time she had been at the house in the course of Saturday 11 January was when she entered the porch to collect the log at about 5.45pm and returned it at about 6.15pm.83
12.43. Evidence that she gave relative to ignorance of Mr Swann's views on Y7 is discussed separately in Chapter 15.
The fingerprint evidence for the defence
12.44. The defence called two fingerprint examiners to give evidence, Mr Wertheim and Mr Grieve. Mr Wertheim gave evidence on 11 and 12 May and Mr Grieve gave evidence on 13 May. Mr Findlay sought to set up their 'expert' status by eliciting evidence from them that they trained others, attended conferences and published papers.84 Only Mr Wertheim gave a detailed critique of the mark, the evidence of Mr Grieve being in more general terms.
Mr Wertheim's evidence
12.45. Mr Wertheim drew a distinction between what he called the "two philosophies" of the threshold approach in the 16-point standard and the evaluative approach in what, at the Inquiry, was referred to as the non-numeric approach.85 He said that under the threshold approach if 16 points were found there was automatically an identification whereas under the evaluative approach there had to be an evaluation of everything that was present. He argued that it was invalid to exclude part of the mark and to focus on only a narrow band; everything must match.86 He also explained that because of the elasticity of the skin ridge detail can vary and it was a necessary part of the analysis phase of a comparison to set a degree of tolerance for minor deviations which could be due to distorting factors.87
12.46. He proceeded through a detailed critique of each of the total of 17 points of similarity in Productions 15288 and 18989 and made reference to a total of eight points of difference, including what later came to be known as the 'Rosetta'.90
12.47. In giving his evidence he used a combination of materials. His principal source materials were in defence production 2,91 the exhibit that he had prepared himself with his own photograph of the mark and a print of Ms McKie's left thumb that he had taken. The exhibit contained layers of acetates to illustrate his various arguments and one of them contained his transposition of the 16 SCRO points as shown in Production 189. When discussing the list of points in Production 189 he was in fact viewing them relative to the images in his own exhibit, but when discussing Production 15292 he looked at the SCRO charting itself.
12.48. Two incidental observations can be made relative to defence production 2.
(i) Mr Stewart had discounted the upper part of the mark in part because he was of the view that that part of the mark came from the top of the thumb, which was not reproduced in the prints available to SCRO. Mr Wertheim had himself taken in excess of 15 or 16 prints from Ms McKie in order to get a print that included the tip of the thumb in order to compare like with like and it was one of those prints that was included in his production.93
(ii) Secondly Mr Stewart was concerned that defence production 2 did not reflect a like for like comparison because it was his opinion that the mark and print were displayed at different angles. Mr Wertheim's evidence was that the two acetates on which he had marked his points of difference also included markings to indicate the location of a target group of five points taken from SCRO Production 189 in order to show that the mark and print were properly orientated.94
12.49. While Mr Wertheim did accept that some people can see things that other people cannot and that there was room for "God given talent", with some detail calling for interpretation by an expert,95 the approach that he adopted in evidence was to seek to demonstrate his viewpoint to the jury using the visual materials. As Mr Findlay put it, Mr Wertheim's thesis was that the jury should not just listen to what the expert's opinion was but should use the evidence of their own eyes and look at the material for themselves:96 "if you cannot see it, you cannot use it."97
12.50. One example of his recurring use of visual demonstrations was that when he was asked to comment on whether Y7 was made by a single touch the transcript records that he made drawings to show the types of ridge structure that he would expect if there was a double touch and from that he proceeded to say that he found that the ridges in Y7 lined up and therefore he found no support for the elimination of the top of the mark from the comparison.98
12.51. In looking at the SCRO points of similarity, Mr Wertheim drew a distinction between:
12.52. The first category comprised a "target group"100 of five points. Using the numbering in Production 189 these were points 3, 4, 5, 8 and 14.101 The corresponding numbers in the comparative exercise are SCRO points 3, 4, 6, 9 and 5, respectively. Even in relation to these points his evidence was sceptical, indicative of the view that he was working to what he regarded as the outer limits of tolerance:
(i) 3, he said, was "well within tolerance".102
(ii) In relation to 4 he said that the ridges had to join in opposite directions in mark and print: "I do not like that but I will accept it as being within tolerance."103
(iii) Point 5 in Production 189 (SCRO 6) was a "splitting ridge" (or bifurcation) in the print but appeared more like a ridge ending in the mark but he was prepared to accept that they matched within tolerance.104
(iv) Point 8 in Production 189 (SCRO 9), was said to be "within tolerance and standing alone and by itself".105 That conclusion had two implicit qualifications. Firstly, when he looked at the corresponding detail in Production 152 (point 9 in that exhibit) he observed that there was a difference in the shape of the bifurcations in mark and print (there was a bump in one and not in the other) and his view was that this point was "on perhaps the outer edge of tolerance".106 Secondly, that concession was made relative to SCRO 9 in isolation, because he said that there was a discrepancy in ridge count relative to SCRO 8 with an intervening ridge being present in the mark but not in the print.107
(v) Point 14 (SCRO 5) he said was a bifurcation in the print and appeared to be a ridge ending in the mark but could be accepted within tolerance.108
12.53. The second category included point 6 in Production 189 (SCRO 7): there was something there in the mark but in the background (because the piece of wood was an uneven surface) he saw other spots and bumps and he would not use it.109 The second point discussed in this manner was point 7 in Production 189 (SCRO 8): in mark and print there were points on the innermost recurving ridge at the core but the appearance of the surrounding detail was different and therefore he could not accept that point as being within tolerance.110
12.54. The examples given of points that did not exist (the third category) were points 9 and 10 in Production 189 (SCRO 10 and 17, respectively)111 and points 12 and 13112 (numbered the same in both Production 189 and the comparative exercise). When Mr Wertheim ran through the points again under reference to Production 152 he accepted the proposition put by Mr Findlay that the jury could ask themselves whether they could see SCRO points 10 and 11;113 but when addressing SCRO 12 and 13 (the incipient ridge) on Production 152 he observed that the image in the SCRO production was an enlargement produced digitally and could be affected by "pixelling".114
12.55. Using the acetates in defence production 2 Mr Wertheim demonstrated to the jury his contention that there were four points in the mark that were not present in the print and a further four points in the print that were not in the mark. The benefit of the acetates was that by lifting them up the jury could see the unmarked image and by placing them down they could see the detail that Mr Wertheim was highlighting and in that way it was suggested that the jury could reach their own view on the matter.115
12.56. Of the four points in the mark that were not in the print, the lowest green circle corresponded to what became known as the Rosetta and it was Mr Wertheim's evidence that if a ridge count were to be done relative to point 14 in Production 189 (i.e. SCRO 5), it could be seen that there was no bifurcation in the same position in the print and his conclusion was that even that difference alone showed that it was "clearly not" Ms McKie's print.116
12.57. Cross-examination did not engage with the detail of Mr Wertheim's views on the points of similarity or the eight points of difference relied upon by him.
(i) Two specific lines were pursued in relation to image quality. The first was that the image of Y7 in defence production 2, which was a photograph taken by Mr Wertheim, showed the mark in a damaged state, with a striation across the centre of it, and Mr Murphy suggested that that damage may have affected some of the points that SCRO had seen when studying images of the undamaged mark. Mr Wertheim replied that the striation had not significantly altered the image because he could still follow the ridges.117 The second related to the quality of the enlargements in Productions 152, 180 and 189. Mr Wertheim accepted that he had had difficulty with those productions because of the magnification process used and that the original photographs in the productions appeared clearer than the enlargements but he did not subscribe to the view that comparison should only be done using one-to-one size images.118
(ii) That apart, the lines of cross-examination were more generalised: fingerprint comparison (including the exclusion of part of a mark as adversely affected by distortion) was a matter of opinion on which the views of experts could differ; though a jury could see for themselves points which were as clear as a pikestaff, on other matters they might require guidance from an expert; expertise was not just a matter of God given talent but included training and experience and the suggestion was made that practitioners, like SCRO, who worked exclusively on fingerprint comparison might have more experience than persons, like Mr Wertheim, who had more mixed careers. It was suggested that SCRO were working to higher standards by subscribing to the 16-point standard and having a verification process that involved a total of four examiners, and Mr Wertheim accepted that there had been cases of misidentification in the USA and none that he was aware of in any country that applied the 16-point standard.
Mr Grieve's evidence
12.58. This was brief. His view was that Y7 came from a different person. He speculated that the mark could been made by a right hand; there was conflicting evidence on the point. The mark formed a single continuous latent and he objected to the charting in Production 152 because it did not show all of the detail. As for the images of mark and print in defence production 2, he said that it was a comparison of like for like and if there were two bifurcations in one and not in the other then they had to come from different people.119
Speeches
12.59. The speeches to the jury by Mr Murphy and Mr Findlay were summarised in Mr Carle's note.120 As presented to the jury by Mr Murphy, the case for the prosecution depended solely on the fingerprint evidence that mark Y7 was made by Ms McKie, resulting in the inference that she must have gone beyond the porch in order to touch the doorway. The prosecution accepted that there was no other evidence placing her there and that, if the prosecution case was correct, not only had Ms McKie lied but somebody else must also have lied by denying either letting her in or being absent from post and giving her an opportunity to enter the house.121
Lord Johnston's charge to the jury
12.60. Lord Johnston began his charge to the jury by making it clear that as he understood it nobody was suggesting, quite correctly in his view, that any of the experts they had heard was deliberately trying to deceive them or even to deceive themselves. The question for the jury was what evidence they found to be reliable.122
12.61. His directions to the jury suggested that they might consider the case in stages.
12.62. Firstly, he said that the jury could decide the case without even needing to consider the fingerprint evidence. If they believed Ms McKie's evidence, or it gave rise to reasonable doubt, they could conclude that she was innocent and acquit her.
12.63. If the jury could not decide the case on that basis, the issue was whether the prosecution had proved her guilt; and in order to do so the prosecution had to overcome each of a number of hurdles beyond reasonable doubt.
12.64. The first hurdle related to the scene of crime evidence. The jury had to consider how and when her print could have got on the bathroom door-frame. The prosecution case was that it was put there some time on the Saturday. He reminded the jury that the scene of crime evidence was that the door-frame was dusted with aluminium powder on the preceding Thursday and that when, on the following Tuesday, Mr Wilson applied the black powder there was no sign that in the intervening period the aluminium powder had been disturbed. The judge said: "One [obvious] conclusion which is open to you is that the print was there when the aluminium powder was put on." He pointed out that that was consistent with Mr Wilson's evidence and that there was no evidence to the contrary and, if that evidence was accepted, the Crown case failed.
12.65. The second hurdle was why Ms McKie should for two years, against pressure and in an isolated and lonely position, deny any involvement with the fingerprint. Lord Johnston asked why should she want to go into the house at all - was it because she was curious and to help with her analysis of the case. This had to be considered bearing in mind that the consistent view of all of the witnesses was that she did not enter the house.
12.66. Beginning from the proposition that the case for the Crown was that the jury could infer that she entered the house from the fingerprint evidence, he then turned to the assessment of that evidence "if you get that far."
12.67. Lord Johnston offered two considerations to be taken into account in addressing the conflicting expert evidence.
12.68. The first was that the jury could take into account the evidence of their own eyes:
"... in assessing the fingerprint evidence, you do not, as it were, count heads, you must look at the evidence on its qualitative basis, albeit there are three led by the Crown and only two by the Defence. But what you have to do... as Mr Findlay properly pointed out to you, is to assess the whole matter against what you were told, but also with your own eyes. You have the photographs, you have the prints, make your own comparisons; you are quite entitled to do so. You can accept expert evidence when they say a blob in fact means something else, because certainly to my mind a blob is a blob. But if somebody says a blob contained something, you can accept that if you believe them. But, on the other hand, where the two comparisons with your own eyes reveal mismatches, then you have to start, I suggest, being seriously concerned about whether this really is Miss McKie's print and certainly seriously concerned to the point of beyond reasonable doubt."123
12.69. The second specific matter that he highlighted was the contrasting performance of the experts when it came to justifying their views in relation to the top of the mark. Lord Johnston observed that if the American evidence was acceptable to the jury and the top third of the mark was genuine and available as a credible piece of evidence then it seemed to him that the Crown case completely collapsed because of the obvious disparities between the tops of the mark and the print that the jury could see with their own eyes. He said that the jury was bound to take into account that the Crown witnesses, particularly Mr Stewart and Ms McBride, offered no reason for dismissing the top part of the mark, other than to say "it is my opinion" and "it is my judgment." Mr Wertheim, on the other hand, drew what he would expect to find as signs of movement and concluded that he found none and therefore that there was a mismatch. Lord Johnston commented: "And he bases that [i.e. the conclusion of mismatch] on reasons, not just judgment."124
The verdict
12.70. After the judge had charged the jury they retired to consider their verdict and after one hour and twenty five minutes returned a unanimous verdict of not guilty.
12.71. The trial concluded with Lord Johnston extending to Ms McKie his respect for "the obvious courage and dignity which you have shown throughout this nightmare, as you have described it. I very much hope you can put it behind you, I wish you all the best."
1. CO_0214
2. CO_0286
3. FI_0070 paras 12-15 Inquiry Witness Statement of Sheriff Murphy
4. FI_0070 para 13 Inquiry Witness Statement of Sheriff Murphy
5. Sheriff Murphy 25 June pages 21-22
6. CO_0214 section 16
7. CO_0214 section 31
8. FI_0070 para 16 Inquiry Witness Statement of Sheriff Murphy
9. CO_0214 section 33
10. CO_3876 para 9
11. FI_0070 para 15 Inquiry Witness Statement of Sheriff Murphy
12. CO_0214 section 74
13. FI_0052 para 29 Inquiry Witness Statement of Mr Kent
14. CO_0214 section 34
15. See Chapter 7 para 120ff
16. SG_0526 pages 114-150
17. FI_0167A
18. CO_0201
19. SG_0526 page 53
20. SG_0526 page 61
21. SG_0526 pages 69-70, 155
22. SG_0526 pages 69-70
23. SG_0526 pages 92-93
24. SG_0526 pages 92,169
25. SG_0526 page 86
26. SG_0526 pages 71, 95
27. SG_0526 pages 97-98
28. SG_0526 pages 71-72
29. See SG_0526 page 99
30. SG_0526 page 73
31. SG_0526 page 97
32. SG_0526 pages 96-100
33. SG_0527 page 233
34. SG_0527 pages 236, 245
35. DB_0172h
36. SG_0527 pages 298-305
37. ST_0006h
38. DB_0012h
39. SG_0526 page 75ff
40. SG_0526 page 105ff
41. FI_0106 SCRO Phase 1 Comparative Exercise
42. SG_0526 page 161ff
43. SG_0526 page 193
44. e.g. SG_0526 page 171
45. See Chapter 28 paras 34-35
46. SG_0526 page 175
47. ST_0006h
48. SG_0526 page 196
49. SG_0526 page 205
50. DB_0012h
51. See table 1 in Chapter 24
52. SG_0526 page 209
53. SG_0526 pages 213-214
54. SG_0526 page 200
55. SG_0526 page 203
56. SG_0526 pages 199-205
57. SG_0526 page 212ff
58. SG_0526 page 67
59. SG_0527 page 269
60. ST_0006h pdf page 6
61. SG_0526 page 70
62. SG_0526 page 85
63. SG_0528 page 20
64. SG_0528 pages 22-26
65. SG_0528 pages 26-27
66. SG_0528 page 30
67. ST_0006h
68. SG_0528 page 34
69. SG_0528 pages 32-33
70. SG_0528 page 34
71. DB_0172h
72. SG_0528 pages 38-41
73. SG_0528 page 45
74. DB_0012h
75. SG_0529 pages 34-38
76. SG_0529 pages 29-31
77. SG_0529 page 29
78. SG_0529 pages 59-60
79. SG_0529 page 59
80. CO_0286
81. CO_2219
82. FI_0071 Inquiry Witness Statement of Ms McKie
83. SG_0531 pages 26-30
84. Mr Wertheim in SG_0531 pages 128-129 and Mr Grieve at SG_0532 page 3ff
85. SG_0531 page 142
86. SG_0531 page 141
87. SG_0531 pages 143-145
88. SG_0530 page 197ff
89. SG_0531 page 162ff
90. See Chapter 25
91. DB_0172h
92. ST_0006h
93. SG_0531 pages 147-150
94. SG_0531 page 178 and SG_0530 page 218
95. SG_0530 page 207
96. SG_0530 page 348
97. SG_0530 page 210
98. SG_0530 pages 210-211
99. SG_0531 pages 163-164 and SG_0530 page 204
100. SG_0531 page 177
101. SG_0531 page 177
102. SG_0531 page 168
103. SG_0531 page 169
104. SG_0531 page 169
105. SG_0531 page 171
106. SG_0530 page 200
107. SG_0531 page 171
108. SG_0531 pages 174-175
109. SG_0531 pages 169-170
110. SG_0531 page 170
111. SG_0531 pages 164, 171-172
112. SG_0531 pages 173-174
113. SG_0530 page 201
114. SG_0530 pages 201-202
115. SG_0531 pages 193-194
116. SG_0531 pages 179-180
117. SG_0530 pages 297-302
118. SG_0530 pages 304-307
119. SG_0532 pages 15-26
120. CO_0214 sections 91 and 92
121. CO_0214 para 91.3
122. CO_1465 page 6
123. CO_1465 pages 16-17
124. CO_1465 pages 18-19 at 19