3.96 The Court of Appeal has indicated that it favours use of digital images in criminal proceedings, as indicated by Thomas LJ in R v Smith:1
The presentation of the evidence to the jury made no attempt to use modern methods of presentation. The presentation to this court was similar; a large amount of time was wasted because of this. It was incomprehensible to us why digital images were not provided to the jury; the refusal of NAFIS [National Automated Finger Print Identification System] to permit a digital image to be supplied to the court was a further example of the lack of a contemporary approach to the presentation of evidence. The presentation to the jury must be done in such a way that enables the jury to determine the disputed issues.2 1 [2011] EWCA Crim 1296.
2 [2011] EWCA Crim 1296 [61(viii)]; for New Zealand, see R v Garrett [2001] DCR 955 and R v Little [2007] NZCA 491.
3.97 However, due to the critical nature of criminal trials, it is crucial that any computer-generated evidence that is put forward be thoroughly examined.1 The use of a jury in criminal cases is another important reason for assessing the relevance, accuracy, and possible prejudicial effect of computer-generated evidence carefully. For this reason, it is important for defence counsel to be aware of the issues that arise and be suitably prepared to test the evidence. In R v Gardner,2 a person was killed during a fire in a block of flats. One of the experts who gave identification evidence for the prosecution used a new technique that deployed computer software to provide an analysis of video surveillance footage, as described by Waller LJ:
[The expert] had developed a different technique. He had developed equipment to enable the images on a video surveillance film to be presented so as to extract as much information from it as possible. This included enhancing the film by computer to allow frame by frame examination, the ability to zoom in on part of the frame to alter the contrast and brightness to bring out detail and to run the film backwards and forwards. The second purpose of the equipment is to assist in making comparisons between one frame and another. To help in that [the expert]
has developed three techniques. He called the first of them ‘image addition’. By means of his computer he takes an image from one sequence of movements and selects from another sequence an image of a person who displays approximately the same stance and is about the same distance from the camera as the first. The second image is superimposed on the first so the viewer can observe whether the two images are like one another and whether there are any differences. The difference, depending on what it is, may show that the images are of different people. The second technique is referred to as ‘image subtraction’. [The expert]
takes the two images selected because of their comparable poses and distances from the camera and turns the first computerised image into a negative and superimposes the second on it in a positive form. The result is that the features which are common to both images disappear and only what is different remains.
[The expert’s] third technique is a ‘blink comparison’ whereby he can switch from one image to another. When there are differences between the two they generate an illusion of movement so that the eye is able to pick up the differences. That technique also enables the viewer to see that when one image is removed an element which had appeared to belong to the picture which has been removed in fact belongs to the picture which remains.3
1 For an examination of the issues and case law, see Tony Ward, ‘Surveillance cameras, identification and expert evidence’ (2012) 9 Digital Evidence and Electronic Signature Law Review 42.
2 [2004] EWCA Crim 1639.
3 [2004] EWCA Crim 1639, [34]; the admissibility of such evidence was approved in R v Briddick [2001] EWCA Crim 984.
3.98 Even though the defence did not have any material in relation to which they could cross-examine the expert witness and enable the jury to judge the expert’s analysis and assessment that the person identified in the surveillance footage was the defendant, the court guardedly accepted the admissibility of this evidence. In doing so, Waller LJ also sounded a note of caution in relation to new techniques relating to identification. The judge quoted the following statement of Lord Hope in Hopes and Lavery v HM Advocate:
If admitting evidence of this kind seems unfamiliar and an extension of established evidential practice, the answer must be that, as technology develops, evidential practice will need to be evolved to accommodate it. Whilst the courts must be vigilant to ensure that no unfairness results, they should not block steps which enable the jury to gain full assistance from the technology.1
1 [2004] EWCA Crim 1639, [45]
3.99 But even if juries are to be enabled to benefit from the full spectrum of technological evidence, they are particularly vulnerable, often more so than judges and coroners, to any prejudicial effect and inaccuracy of scientific animations. Perhaps this is because juries do not have the same level of cynicism that years of experience with analysing evidence has given judges and, to a lesser degree, coroners. In the case of R v Ore,1 Tucker J stated the defence’s apprehension for the admissibility of a computer- generated animation:
The concern which is expressed by [the defence] … is as to the impact which this evidence will have upon the jury and I understand that concern. [The defence]
fears that the weight which the jury may place upon the graphic animation will be disproportionate to its value in the case. [The defence] fears that they may be distracted from concentrating as they ought to do upon the evidence to be given by the expert witnesses on either side and is concerned, naturally, that the graphic animation reproduces simply one particular side of the coin.
1 (1998, unreported), (Birmingham Crown Court). Stephen Mason tried to obtain a copy of the transcript of the case for the first edition of this text, but the tapes were destroyed, in accordance with the relevant retention and disposal policy (correspondence with Michael Ives of Marten Walsh Cherer Limited). Stephen Mason subsequently corresponded with Sir Richard Tucker, who indicated that he no longer had the notes of this trial, but kindly confirmed the remarks that are attributed to him as quoted in this text.
3.100 The concerns stated above are highly relevant and illustrate real fears about any computer-generated evidence. This is especially true for forensic reconstructions.
Hence, any computer-generated reconstructions should be made as precisely and in
as unbiased a way as possible, and their use has to be shown to be necessary.1 Their probative value should outweigh any potential prejudicial effect.
1 In Maloney v R [2003] EWCA Crim 1373, a reconstruction was developed using computer simulation software in preparation for an appeal against conviction, a technology that was not available at the time of trial. The members of the Court of Appeal decided, in the light that the opinion of the expert that undertook the simulation was not conclusive, that the evidence would have no effect upon the safety of the conviction, and the court did not receive it and dismissed the appeal. It is not clear whether Mr Adrian Redgrave, QC, who appeared for the Crown at trial and on the reference to the Court of Appeal (Criminal Division), explored the technical integrity or the assumptions upon which the program was prepared.
3.101 These lessons may be illustrated by the case of R v Ore, which introduced one of the first forensic computer-generated animations to an English criminal trial. The Crash Investigation and Training Unit of the West Midlands Police Service produced the animation. The case involved a collision between two vehicles at a junction; one of the drivers was killed as he pulled out in front of an oncoming vehicle. The views of both drivers were partially obscured by large hedges and walls around the junction.1 Tucker J, who presided over this case, further stated in his ruling on 25 November 1998:
I am told that this is the first time in which it has been suggested that a jury in a trial such as this should be shown a computer aided animation which pictorially represents a reconstruction of a road traffic accident. It may be that in years to come such displays will be commonplace and that lawyers will marvel that anyone should ever have questioned their admissibility.
… I am satisfied that it would be right to admit this evidence and, indeed, wrong to refuse so to do, provided, as I shall try to do, that I give the jury proper directions as to their approach to this evidence and provided I ensure, so far as I can, that they do not place disproportionate weight upon it. Accordingly, I rule that the evidence is admissible.2
1 M Doyle, ‘Working model: helping the police with their enquiries’ (1997) CAD User 62–63.
2 R v Ore (1998, unreported), (Birmingham Crown Court).
3.102 A well-known example from Northern Ireland is the computer-generated evidence that was extensively used during the Bloody Sunday Inquiry.1 In 1972, 13 people were killed during a peaceful demonstration. The original inquiry produced a report within 11 weeks of the incident, and acquitted the soldiers involved. In 1998, a Tribunal of Inquiry was established to reassess the events.2 Lord Saville, the chair of the tribunal, took full advantage of ensuing improvements in technology, and used a computer software system designed especially for use in the Inquiry to amplify the testimony of witnesses. The Northern Ireland Centre for Learning and Resources produced the computer-generated virtual models, which reconstructed a large area of Londonderry that had been extensively altered since 1972. The user was able to compare the same scene as it appeared at the time of the Inquiry and as it was in 1972.
There were 80 locations stored in the system that could be explored, with specific points of view being recalled when switching between the representations. The system could also store oral evidence about location and movement, and export scenes to a mark-up system so that witnesses could draw on top of images. The computer software system that was admitted was deemed to be unbiased and accurate.
1 See ‘The Bloody Sunday Inquiry’ <www.bloody-sunday-inquiry.org.uk>.
2 Statement by Tony Blair, Prime Minister: HC Deb 29 January 1998, vol 305, col 501.
3.103 The Bloody Sunday Inquiry computer system was not interactive in three- dimensions. Virtual reality or VR, by definition, is an interactive computer-generated simulated environment with which users can interact using a computer monitor or specialized hardware. The computer system used for the Bloody Sunday Inquiry was interactive in the sense that viewers were able to view images of different scenes at varied times. However, the viewer was not able to move around a full three-dimensional virtual environment of Londonderry itself, since the full three-dimensional virtual model of the area did not exist. But over the last few years courts in England and Wales have begun to introduce interactive three-dimensional VR crime scene environments for a number of high profile criminal cases.1 There is little doubt that with the increasing complexity of criminal investigations, we will see more use of virtual environments and immersive virtual environments in legal proceedings.
1 Damian Schofield, ‘Playing with evidence: using video games in the courtroom’ (2011) 2 Journal of Entertainment Computing 47.
3.104 Virtual environments possess the potential to sway juries and decision makers, even more so than computer animations in general. Creating an environment thatt allows viewers to take different perspectives and manipulate objects in that environment do indeed allow for ‘what-if’ scenarios to be played out, and could lead to more robust decisions. But the reconstructions of scenes in these environments are based on various assumptions and premises, not all of which can be elucidated or are transparent, or easily accessible for review by opposing experts and by decision makers. Indeed, analyses of computer-generated displays show that they can be extremely advantageous in the court, provided they are used appropriately. The consequences of a failure to investigate these issues cannot be underestimated, since errors, inaccuracies, misuse, tampering or biases within visualizations are capable of leading to miscarriages of justice.1
1 Marcel Worring and Rita Cucchiara, ‘Multimedia in forensics’, in Proceedings of the 17th ACM International Conference on Multimedia (ACM Press 2009) 1153–1154.