The Presentation and Examination of DNA Evidence Adduced During Adversarial Trials

316 Pages·2016·1.44 MB·English

The Presentation and Examination of DNA Evidence
Adduced During Adversarial Trials

Richard Abbey Graham

Submitted in accordance with the requirements for the degree of
Doctor of Philosophy

The University of Leeds
School of Law

March 2016
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The candidate confirms that the work submitted is his own and that
appropriate credit has been given where reference has been made to the
work of others.
This copy has been supplied on the understanding that it is copyright
material and that no quotation from the thesis may be published without
proper acknowledgement.

Assertion of moral rights:
The right of Richard Abbey Graham to be identified as Author of this work
has been asserted by him in accordance with the Copyright, Designs and
Patents Act 1988.
© 2016 The University of Leeds and Richard Abbey Graham
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Acknowledgements
I would like to thank my supervisor, Professor Louise Ellison, for her
continuing enthusiastic support and firm hand in the face of my deviations
from the straight path, and downright procrastination. I would also like to
thank my erstwhile co-supervisor, Dr Carole McCartney for all her help and
support before she departed for academic pastures anew.
My family, Dr Amanda Graham, and lawyer-to-be Hazel Beddows have,
equally, supported me with patience and support. I couldn’t have done it
without them.
Not least, I would like to thank all the interviewees, who went out of their way
to be helpful during this research.
The hopeful refrain of ‘We’re almost there’ seems, at last, to have become
‘We’re finally there’.
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Abstract
This study examines the presentation and examination of DNA evidence in
the English Criminal Courts, from the perspective of forensic experts. The
methodology involved qualitative analysis of expert perception and opinion,
through interview.
Much activity has concerned the contribution of faulty expert evidence to
miscarriages of justice, however forensic experts have been largely ignored
as sources of valuable data. This study is original in specifically examining
their experience.
Criticisms of expert evidence in the English courts are commonly described
as having their origins in detrimental effects of the adversarial trial system,
however the position supported by this study is that many claimed
detrimental effects are based on misunderstanding of the workings of
adversarial procedure.
The study examined experts’ perceptions of challenges they faced in the
presentation and examination of DNA evidence, including their duty to offer
objective and unbiased opinion. The study determined that whilst experts
may give ‘unbiased’ opinion, ‘impartiality’ was practically difficult to achieve
because of the different roles played by prosecution and defence experts.
Furthermore, a lack of clarity regarding the responsibilities implied by the
requirement of remaining ‘unbiased’ meant that experts put different
interpretations on their duties in this regard. This study concludes that the
policy objectives underlying the concept of ‘unbiased’ should be examined,
with a view to better defining appropriate expert responsibilities.
The study investigated experience within court. Interviewees reported similar
experiences to those faced by forensic experts reported in previous studies.
However, evidence in this study supports the proposition that DNA evidence
is qualitatively different from older forensic identification techniques. First,
the complexity of DNA evidence magnifies many known trial ‘pathologies’ in
terms of presentation and examination. Second, it is fundamentally different
in that its probabilistic nature means that experts are forced to present it in a
rigorously scientific manner. In this way, not only does DNA represent a new
paradigm in forensic identification, but it must inevitably force existing
tensions between the law and scientific evidence into the open.
This study found experts to be generally passive in supplying the demands
of the judicial process. This has included passivity in the face of legal rulings
on how complex DNA evidence should be presented. From an evidential
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perspective, this is indubitably a judicial responsibility. This study supports
the proposal, however, that steps must be taken to engage scientific experts
in the scientific aspects of these determinations, if the ‘new paradigm’ of
DNA evidence is not to be diluted.
The Government must take a lead in co-ordinating expert bodies towards an
integrated approach to complex evidence such as DNA, in the inevitable
anticipation that future forensic technologies can only be more complex still.
It may do this without infringing the over-riding interests of the adversarial
system of justice.
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Table of Contents
Acknowledgements ..................................................................................... 3
Abstract ........................................................................................................ 4
Table of Contents ........................................................................................ 6
Table of Cases ........................................................................................... 10
Table of Legislation ................................................................................... 11
List of Figures ............................................................................................ 12
Chapter 1 Introduction .............................................................................. 13
1.1 Objectives and Summary of Study ................................................ 13
1.2 Study Context ................................................................................ 19
1.3 Importance of the Study ................................................................ 27
1.4 What we do not know and Originality ............................................ 28
1.5 Methodology .................................................................................. 29
1.6 Study Outline ................................................................................. 34
Chapter 2 Literature Review ..................................................................... 37
2.1 Introduction .................................................................................... 37
2.2 Forensic Expert Experience .......................................................... 39
2.3 Medical Expert Experience ............................................................ 44
2.4 DNA Expert Experience................................................................. 47
2.5 Lay Witnesses ............................................................................... 49
2.6 Forensic Evidence in the Adversarial System ............................... 53
2.7 Is DNA Evidence Different? ........................................................... 54
2.8 Accusations of ‘Trial Pathology’ in the Adversarial Trial ................ 56
2.9 The Expert, Unbiased, Impartial, Objective or Independent? ........ 58
2.10 Examination-In-Chief and the ‘Crucible’ of Cross-
Examination................................................................................. 62
2.11 Are Judge and Jury Competent? ................................................. 64
2.12 Cognitive Bias and the Expert Witness........................................ 70
2.13 Equality of Arms in the Crucible? ................................................ 72
2.14 Law and Science: Incompatible or Competing Cultures? ............ 75
2.15 Law and Science: Engagement of Forensic Science .................. 77
2.16 Conclusions ................................................................................. 81
Chapter 3 The Criminal Trial and DNA Evidence .................................... 83
3.1 Introduction .................................................................................... 83
3.2 The Adversarial Trial ..................................................................... 84
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3.3 The Objectives of the Trial ............................................................ 88
3.4 Trial Procedure in the Crown Court ............................................... 92
3.5 The Creation of Competing Cases ................................................ 93
3.6 Case Construction ......................................................................... 95
3.7 Role of Evidence ........................................................................... 97
3.8 Expert Evidence in the English Court ............................................ 98
3.9 DNA Profiling ............................................................................... 104
3.9.1 A Paradigm Shift .............................................................. 104
3.9.2 The Structure and Location of DNA ................................. 104
3.9.3 DNA Markers .................................................................... 105
3.9.4 DNA Profiling .................................................................... 106
3.9.5 Complex DNA Samples .................................................... 109
3.9.6 DNA Profiles and the National DNA Database ................. 109
3.10 DNA Profiling in Evidence ......................................................... 111
3.11 Ensuring DNA Evidence Addresses the Right Question ........... 112
3.12 Probabilistic Expression of DNA Evidence ................................ 113
3.13 Development of DNA Evidence in the English Court ................. 115
3.14 Doheny and Adams ................................................................... 116
3.15 Complex DNA Evidence ............................................................ 122
3.16 Conclusions ............................................................................... 127
Chapter 4 Methodology .......................................................................... 129
4.1 Introduction ................................................................................. 129
4.2 Qualitative Methods ..................................................................... 130
4.3 Research Design ......................................................................... 135
4.4 Validity and Reliability ................................................................. 137
4.5 Interview Structure and Design ................................................... 139
4.6 Sample Design and Implementation............................................ 140
4.7 Interview Schedule Design .......................................................... 149
4.8 Pilot Interview .............................................................................. 155
4.9 The Interview Process ................................................................. 157
4.10 Data Analysis ............................................................................ 160
4.11 Ethical Issues ............................................................................ 166
4.12 Informed Consent ...................................................................... 169
4.13 Conclusions ............................................................................... 170
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Chapter 5 The Unbiased Expert ............................................................. 171
5.1 Introduction .................................................................................. 171
5.2 Prosecution and Defence Expert Roles ....................................... 172
5.3 Changing Role of Prosecution Expert ......................................... 174
5.4 Pressures for Bias towards Prosecution ...................................... 175
5.5 Adversarial Experts ..................................................................... 178
5.6 Evidence of Bias towards the Prosecution .................................. 179
5.7 The Defence Experts’ View ......................................................... 182
5.8 A Cultural Gap between Two Schools ......................................... 183
5.9 What Experts Understand by ‘Unbiased’ ..................................... 185
5.10 Conclusions ............................................................................... 188
Chapter 6 The Experts’ Experiences in Court ....................................... 195
6.1 Introduction .................................................................................. 195
6.2 Appearances in Court .................................................................. 196
6.3 Pre-trial Discussions .................................................................... 200
6.4 Engagement with Counsel and Others ........................................ 206
6.5 The Expert’s Role ........................................................................ 209
6.6 The Expert’s Responsibility ......................................................... 211
6.7 Experience in the Witness Box .................................................... 212
6.8 Interviewees’ Compensatory Behaviour ...................................... 227
6.9 Conclusions ................................................................................. 231
Chapter 7 Science and Law – Incompatible Discourses? .................... 243
7.1 Introduction .................................................................................. 243
7.2 Flawed Presentation of DNA Evidence?...................................... 244
7.3 Rationalising Conflicts between Science and Law in the Court
Room ......................................................................................... 253
7.4 Experience versus Experiment or Prosecution versus
Defence? ................................................................................... 256
7.5 Engagement of the Forensic Expert and the Court ..................... 261
7.6 Conclusions ................................................................................. 267
Chapter 8 Concluding Remarks ............................................................. 271
8.1 Introduction .................................................................................. 271
8.2 Importance and Originality of the Research ................................ 273
8.3 The Unbiased Expert ................................................................... 276
8.4 Experience in Court ..................................................................... 281
8.5 Science and Law ......................................................................... 284
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8.6 Theoretical Implications ............................................................... 288
8.7 Policy Implications and Future Direction ..................................... 290
8.8 Final Reflections .......................................................................... 293
Bibliography ............................................................................................ 294
Appendix A Information Sheet and Consent Form .............................. 309
Appendix B Interview Schedule ............................................................. 312
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Table of Cases
United Kingdom
Adams [1996] 2 Cr App R 467.
Bates [2006] EWCA Crim 1395.
Bowman [2006] EWCA Crim 417; [2006] 2 Cr App R 3.
Broughton [2010] EWCA Crim 549.
C [2010] EWCA Crim 2578, [2011] 3 All ER 509.
C [2011] EWCA Crim 1607.
Cannings [2004] 1 WLR 2607.
Clark [2003] EWCA Crim 1020.
Clarke [1995] 2 Cr App R 425, CA.
Deen (1994) The Times, 10 January.
Derby Magistrates’ Court, ex parte B [1996] 1 AC 487, HL.
Doheny [1997] Cr App R 369.
Dlugosz [2013] EWCA Crim 2, [2013] 1 Cr App R 32.
FNC [2015] EWCA Crim 1732.
General Medical Council v Meadow [2006] EWCA 1390, [2007] QB 462.
Grant [2008] EWCA Crim 1890.
Hill (1989) The Times, 20 October.
Hoey [2007] NICC 49 (20 December 2007).
Lashley [2000] CA 9903890 Y3 (8 February 2000).
Maguire (1992) 94 Cr App R 133.
McIlkenny (1991) 93 Cr App R 287.
Ogden [2013] EWCA Crim 1294.
Preddie [2007] EWCA Crim 2044.
Reed [2009] EWCA Crim 2698, [2010] 1 Cr App R 23.
Sampson (Albert) [2014] EWCA Crim 1968.
Summers [1952] 1 All ER 1059.
T [2010] EWCA Crim 2439, [2011] 1 Cr App R 9.
Toth v Jarman [2006] EWCA Civ 1028, [2006] 4 All ER 1276.
Turner [1975] 1 QB 834, CA.
Ward (1993) 96 Cr App R1.
Weller [2010] EWCA Crim 1085.
Woolmington v The Director of Public Prosecutions [1935] AC 462 HL.

European Court of Human Rights
S and Marper v The United Kingdom - 30562/04 [2008] ECHR 1581 (4
December 2008).
Salov v Ukraine (app.no.65518/01), ECtHR Judgment 6 September 2005.
United States
Daubert v Merrell Dow Pharmaceuticals, Inc. 113 S Ct 2786 (1993).
Frye v US 293 F. 1013 (1923).

South Africa
R v Bonython (1984) 38 SASR 45.