The law in England and Wales should routinely allow expert opinion evidence regarding the reliability of eyewitness identification evidence. Critically discuss this statement.


In England and Wales identification of the accused as the person who is said to have committed the offence is a crucial element of a criminal trial.1 Frequently, identification will be established through eyewitness testimony. However the reliability of eyewitness evidence has been recognised for many years as being highly questionable.2 Experts in the field of psychology and legal scholars have argued that expert opinion evidence regarding the reliability of eyewitness identification should be routinely allowed at trial.3 The courts remain reluctant to allow expert evidence of this nature and reason that there exists sufficient safeguards both before and during the trial process to ensure eyewitness evidence is treated with caution.4 The ongoing media coverage of the miscarriages of justice that are associated with reliance on eyewitness identification means the issue remains in the public consciousness and incredibly contentious.5

Eyewitness identification evidence in England and Wales

Visual identification is notoriously unreliable.6 There are profound physiological and psychological responses associated with being required to visually identify a person in what is often a highly stressful and certainly out of the ordinary set of circumstances.7 Even for those involved in law enforcement – who one would assume to be more accustomed to the legal processes – eyewitness identification has been shown to be just as unreliable.8 The issue has been subject to scrutiny for many years in England and Wales.9 During the 1970’s two high profile miscarriage of justice cases, that of Mr Laszlo Virag and of Mr Luke Clement Dougherty,10 which had relied upon eyewitness identification resulted in the establishment of a committee to investigate the issue.11 The committee, chaired by Lord Devlin, produced a report which proffered a number of recommendations to combat the conclusively unreliable evidence of eyewitnesses.12 The report noted in particular that judges were already providing a more elaborate summing up when a case relied heavily on eyewitness identification. According to the report this development was one which was to be encouraged.13 However there was no immediate legislative response to ensure the implementation of thorough judicial consideration and direction where eyewitness identification was a significant issue to a case.14

The subsequent case of R v Turnbull (Raymond) drew much from the Devlin Report in providing common law guidance on the treatment of eyewitness identification.15 Foremost the Turnbull guidelines required that where a case hinged either wholly or substantially on eyewitness identification the judge should caution the jury with regards to relying on such evidence to reach a conviction.16Essentially the Turnbull guidelines go on to state that the trial judge should explain to the jury the reason why such a warning is required and that even the most genuine witness may be mistaken.17 In addition the judge should direct the jury to carefully examine the circumstances in which the eyewitness observed the accused and remind the jury of any weaknesses in the identification evidence.18 Finally, the trial judge should emphasise the requirement for a qualitative assessment of the evidence particularly where there are quantitative considerations. Multiple eyewitness evidence is certainly compelling but the notorious miscarriage of justice case of Adolf Beck demonstrates that even numerous eyewitnesses may still be incorrect.19 The case of Adolf Beck, which occurred at the turn of the twentieth century, involved the misidentification by numerous witnesses of Mr Beck as the perpetrator of a large number of frauds.20 Mr Beck was wrongly convicted twice before eventually being acquitted and his case was an instrumental and decisive factor in the creation of the appeal court in 1908.21 Despite the obvious inadequacies of eyewitness identification it should be noted that multiple eyewitness evidence can still act in a mutually corroborative manner.22

The Turnbull guidelines ensure that a jury is made sufficiently aware of both the strengths and weaknesses of eyewitness identification during the trial process.23 However a trial judge may be an expert in law but not necessarily an expert in the complexities of eyewitness identification. It would therefore seem practicable for the court to allow expert opinion evidence to be led regarding the reliability of eyewitness identification evidence. The courts have hitherto rejected this course of action and an understanding of the role of the expert witness in the criminal trial process is essential in determining why this should be the case.

The role of the expert witness in court

The role of the expert witness in court is essentially advisory. The expert witness must ensure that their testimony is reasonably expected to be outwith the knowledge of the judge or jury.24 This follows the principles laid down by Lord Justice Lawton in the case of R v Turner when he stated that “An expert’s opinion is admissible to furnish the court with scientific information which is likely to be outside the experience and knowledge of a judge or jury.”25 Lord Justice Lawton went on to express the view that the opinion of an expert was entirely unnecessary in circumstances where a judge or jury were capable of conclusively forming an opinion based on the facts established.26 The danger is that a judge or jury may defer their own logically reached conclusion if someone with recognised qualifications indicates that they are in possession of expertise on the normal patterns of human nature and behaviour.27

The issue of admissibility of expert evidence regarding eyewitness identification remains unresolved in England and Wales.28 However the Scottish case of Gage v HM Advocate, which was a case referred to the high court by the Scottish Criminal Case Review Commission, may be indicative of how the issue could be resolved in England in Wales.29 In Gage v HM Advocate the accused sought to lead evidence from an expert on eyewitness identification who had reached the conclusion that there was no reliable eyewitness evidence to link the appellant to the scene of the crime.30 However the court found the evidence inadmissible because it was on an issue that was properly within the remit of the jury to decide.31 According to Lord Justice Clerk Gill evidence of this sort was only relevant where it was necessary for “the proper resolution of a dispute.”32 The credibility and reliability of an eyewitness was properly within the remit of the jury to assess and there was no requirement for expert assistance.33

The reluctance of the court to routinely allow expert evidence regarding eyewitness identification must be understood in a practical framework as well as a legal one.34 The fact is that expert testimony is at least partially reliant on fiscal considerations.35 Even without the reluctance of the judiciary to allow expert witnesses to trespass too far into the trial process the legal system simply cannot afford to set any kind of precedent in allowing routine expert evidence of this kind. However it is entirely foreseeable that as further research and advances are made in the field of eyewitness identification the current system of relying on judicial cautions and directions to the jury will be considered entirely unsatisfactory.36 In fact it is not outwith the realms of probability that in time an appeal regarding this matter that has  a foundation in Article 6 of the European Convention of Human Rights will be successful.37

Is there any benefit to allowing expert opinion evidence regarding eyewitness identification?

Two significant arguments in favour of the use of expert opinion evidence relating to eyewitness identification are that jurors are too willing to believe eyewitness testimony and that they are also unable to effectively determine what is an accurate and what is an inaccurate witness identification.38According to leading cognitive psychologist Elizabeth Loftus, who has provided a great deal of research on the issue of eyewitness identification, “jurors rarely regard eyewitness testimony with any scepticism.”39 If this is indeed the case the use of an expert witness to explain the flaws inherent in eyewitness identification would certainly be a beneficial contribution to the trial process.

The fact is that although Loftus represents views of one group of cognitive psychologists that view is not at all definitive. Other research suggests that in fact case specific variables provide tools which jurors also utilise when determining how much weight should be attached to specific eyewitness evidence.40  This research suggests that jurors are, by and large, perfectly capable of assessing any faults in the eyewitness evidence presented to them.41 In addition research that indicates that jurors are unable to discern between accurate and inaccurate eyewitness evidence makes no reference to whether those same jurors approach all evidence presented to them with the same level of belief.42

Conflicting research in this field provides no definitive answer as to whether there is any benefit to allowing expert eyewitness evidence during the trial process. As previously noted, the trial judge is already tasked with advising the jury on the inherent flaws in the reliance on such evidence.43 It would seem that utilising the evidence of expert witnesses regarding this matter could in fact obfuscate the crucial issues under consideration in the trial.

Concluding comments

There is no doubt that the inherent flaws in eyewitness identification provide complex challenges to the criminal trial process. Utilising experts to explain the strengths and weaknesses of eyewitness identification evidence seems to be incredibly practical. However there is a fierce resistance by the judiciary to relinquish control of the trial process and allow it to fall into the hands of the experts. It would seem that there is no benefit in the trial processes becoming one which is controlled by experts. Doing so would take the process away from the “ordinary man” and result in greater fiscal and temporal burdens on the courts. However it should be born in mind that although temporal and fiscal considerations are significant they should remain secondary to the fundamental purpose of the court which is to seek truth on which to determine guilt or innocence. The position in England and Wales of allowing the trial fact finder to weigh the evidence and judge the significance of each piece is an essential element of the criminal trial process but lacks precision and thoroughness.


1Paul Carr and Adrian Turner (Ed.) Stone’s Justices’ Manual 2014, Part II Evidence, Special Rules of Evidence in Criminal Proceedings, Identification (Butterworths, 2014).

2Lord Devlin (Chairman) Report to the Secretary of State for the Home Department of the Departmental Committee on Evidence of Identification in Criminal Cases (Home Office 1976).

3Michael McCloskey and Howard E Hogarth Eyewitness Identification: What Can a Psychologist Tell a Jury? American Psychologist 1983 550-563.

4R v Turnbull [1977] QB 224; R v Turner [1975] QB 834; R v Forbes Independent 21 December 2001; R v Popat [1998] 2 Cr App R 208.

5See for example Finlo Rohrer The Problem with Eyewitnesses BBC News 24/8/2005; Sylvia Rowley Wrongful conviction throws spotlight on unreliability of eyewitness evidence The Guardian 18/8/2009; Yvonne Cooke Cutting down on cases of mistaken identity The Independent 6/4/2011.

6Christopher M Walters Admission of Expert Testimony on Eyewitness Identification (California Law Review (76)(4) 1985).

7Michael McCloskey and Howard E Hogarth (n. 3).

8R v Reid [1990] 1 AC 363.

9The cases of George Edalji in 1903 and of Adolf Beck is distinguished in this regard. Mr Beck was wrongly identified by a large number of witnesses and wrongly convicted twice. The case was instrumental in the creation of the Court of Criminal Appeal in 1908 by the Criminal Appeal Act 1907. The case is discussed in Thomas Garner Identification Evidence (Westlaw Insight, November 2014).

10The cases of Mr Laszlo Virag and of Mr Luke Clement Dougherty were discussed in great detail in the report by Lord Devlin (n. 2).

11Lord Devlin (n.2).



14Although in 1984 Police and Criminal Evidence Act 1984 introduced guidelines for the police in dealing with eyewitness identification evidence.

15[1977] QB 224.

16R v Turnbull [1977] QB 224.



19Lord Devlin (n.2).

20Brian Cathcart The strange case of Adolf Beck, The Independent 17 October 2004.

21Thomas Garner Identification Evidence (Westlaw Insight, November 2014

22R v Weeder (Thomas Henry) (1980) 71 Cr App R 228 and R v Tyler (Patrick John) (1993) 96 Cr App R 332 which were discussed in Thomas Garner Identification Evidence (Westlaw Insight, November 2014).

23R v Turnbull (n. 16).

24R v Turner [1975] QB 834 per Lord Justice Lawton at 841, referencing Folkes v Chadd (1782) 3 Doug KB 157.




28Andrew Roberts Expert Evidence on the reliability of eyewitness identification – some observations on the justification for Exclusion: Gage v HM Advocate E. & P. 2012, 16(1), 93-105.

29Gage v HM Advocate [2011] HJAC 40.



32Ibid per Lord Justice Clerk Gill at 22; Likewise in the Scottish case of HM Advocate v Grimmond (David) 2002 SLT 508.


34Gary Edmond, Simon Cole, Emma Cunliffe, and Andrew Roberts Admissibility compared: The reception of incriminating expert evidence (ie forensic science) in four jurisdictions (University of Denver Law Review 3, 2013).

35Professor Dame Hazel Genn, Manchester Concurrent Evidence Pilot (UCL Judicial Institute, 2012).

36Walker v HM Advocate Case Comment S.C.L. 2011, Sep, 755-775.

37Article 6 of the European Convention of Human Rights as enacted by the Human Rights Act 1998 provides that everyone is entitles to a fair trial.

38Michael McCloskey and Howard E Hogarth (n. 3).

39Elizabeth Loftus Eyewitness Testimony (Harvard University Press 1979) p 197.

40Michael McCloskey and Howard E Hogarth (n. 3).



43Lord Devlin (n. 2).

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