Fingerprint Comparison and Adversarialism: The Scientific and Historical Evidence
| DOI | http://doi.org/10.1111/1468-2230.12565 |
| Author | Gary Edmond,Emma Cunliffe,David Hamer |
| Published date | 01 November 2020 |
| Date | 01 November 2020 |
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Modern Law Review
DOI:10.1111/1468-2230.12565
Fingerprint Comparison and Adversarialism: The
Scientic and Historical Evidence
Gary Edmond,∗Emma Cunlie†and David Hamer‡
This article suggests that lawyers and courts are largely oblivious to scientic insights regarding
the value and limitations of latent ngerprint evidence. It proceedsthrough a detailed histor ical
analysis of the way ngerprint evidence has been reported and challenged. It compares legal
responses with mainstream scientic research. Our analysis shows that ngerprint evidence is
routinely equated with categorical proof of identity notwithstanding scientic warnings that
such an approach is ‘indefensible’. We nd that legal challenges to latent ngerprint evidence
have been uniformly focused on adjectival issues (e.g. compliance with enabling legislation),
leaving the validity and accuracy of this subjective comparison technique virtually unexamined
since its rst reception at the very beginning of the twentieth century.Lack of legal engagement
with validity, error and scientic research suggest that adversarial procedures have not worked
eectively to secure scientically reliable expert evidence and that legal personnel struggle with
elementary scientic reasoning.
INTRODUCTION: THE CASE OF LATENT FINGERPRINT
COMPARISON
The House of Lords’ Science and Technology Select Committee recently pub-
lished Forensic Science and the Criminal Justice System.1The report identies ‘a
serious decit of high-level leadership and oversight of forensic science from
the Home Oce and Ministry of Justice’ and a lack of funding, regulation
and equitable access to forensic science expertise, leading to declining public
trust and a risk of miscarriages of justice.2Overall, the evidence before the
Select Committee ‘showed a mixed level of understanding of scientic issues
by lawyers and judges’. The Select Committee accepted the Forensic Science
∗Professor, School of Law, UNSW, Sydney, Australia and Research Professor, Northumbria Law
School, University of Northumbria, UK. This research was supported by the ARC (LP16010000
and LP170100086).
†Professor,Allard School of Law,UBC, Vancouver,Canada.
‡Professor,University of Sydney Law School, Sydney,Australia.
[The copyright line for this article was changed on 5 August 2020 after original online publication.]
Email: g.edmond@unsw.edu.au
1 Science and Technology Select Committee, Forensic Science and the Criminal Justice System: A
Blueprint for Change 3rd Report of Session 2017 – 2019 HL 333 (1 May 2019).
2ibid, Summary.
© 2020 The Authors. The Modern Law Review© 2020 The Moder n Law ReviewLimited. (2020) 83(6) MLR 1287–1327
Fingerprint Compar ison and Adversarialism
Regulator’s assessment that ‘[j]udgments have on occasion demonstrated a lack
of understanding of the process of scientic reasoning.’3
This article suggests that the problems identied by the Select Commit-
tee are deeply embedded in the adversarial approach to criminal justice, and
longstanding. Using latent ngerpr int evidence as a case study, we provide an
empirical account of how lawyers and judges have understood this evidence
across more than one hundred years of trials and appeals.4Adding to a growing
body of research on the (in)eectiveness of legal responses to forensic science
evidence in criminal proceedings, the article draws on contemporary main-
stream scientic research and insights to assess the performance of the adversar-
ial legal system.5By referencing scientic knowledge – what we (now) know
about latent ngerprint evidence – we are able to evaluate the eectiveness
of legal mechanisms that are presumed to safeguard the integrity of criminal
proceedings.6
Our study focuses primarily on reported and readily available decisions
that discuss latent ngerprint evidence. We searched Westlaw UK and BAILII
for the word ‘ngerprint’ in the same paragraph as ‘reliability’, ‘admis-
sibility’ or ‘challenge’ (and variations of these terms).7We found almost
300 decisions – mostly appeals – and analysed those cases by the nature of
the challenge, the charged oence, whether ngerprint evidence was the only
evidence of identity, and other questions.8Our focus on reported and read-
ily accessible cases captures how inuential trial and appellate courts treat la-
tent ngerprint evidence and how they respond to challenges in judgments
that are widely accessible to other courts and lawyers. It is possible that more
scientically-informed challenges have been made in trial courts, but remain
undocumented because, for example,such challenges have resulted in acquittals.
However, we have found no evidence of such challenges in our own research
3ibid at [125].
4 Latent ngerprints are traces recovered from a scene or item associated with a specic crime
which are compared with reference ngerprints of a known person to assist with the identica-
tion (or exclusion) of a person as the source.They can also be compared with other (unknown)
prints in an attempt to link oences. See generally D. Ashbaugh,Quantitative–Qualitative Friction
Ridge Analysis: An Introduction to Basic and Advanced Ridgeology (Boca Raton, FL: CRC Press,
1999).
5 Law Commission, Expert Evidence in Criminal Proceedings in England and Wales Report No 325
(21 March 2011); G. Edmond, ‘Is reliability sucient? The Law Commission and exper t evi-
dence in international and interdisciplinary perspective (Part 1)’ (2012) 16 International Journal
of Evidence & Proof 30; T.Ward, ‘A New and More Rigorous Approach to Exper t Evidence in
England and Wales’(2015) 19 Inter national Journal of Evidence & Proof 228; P. Roberts and M.
Stockdale, ‘Forensic Science,Evidential Reliability and Institutional Reform’ in P. Roberts and
M.Stockdale (eds), Forensic Science Evidence and Expert Witness Testimony:Reliability through Reform
(London: Edward Elgar, 2018).
6 P. Roberts et al (eds), Integrity in the Criminal Process (Oxford: Hart, 2015).
7 Westlaw UK and bailii.org databases were searched for any cases with ‘ngerprint/p (reliab!
OR admiss! OR challeng!)’and for ‘nger print OR nger-print OR “nger print”’in any case
before 1980. The last searchwas conducted in January 2019.
8 A full list of cases is on le with the authors. We have not systematically engaged with the
Scottish decisions.
1288 © 2020 The Authors. The Modern Law Review© 2020 The Moder n Law ReviewLimited.
(2020) 83(6) MLR 1287–1327
Gary Edmond et al.
or that of others.9To the contrary,the evidence heard by the Select Committee
and our own experience suggest that the decisions we report are representative
of extant legal strategies and judicial attitudes.10 Thegapswehaveidentiedin
those strategies and attitudes are,we believe,real – as is the structural disconnect
between scientic research and adversarial trial processes.11
The study reveals that latent ngerprint evidence was admitted and relied
upon from its earliest days as conclusive proof of identity,without ever receiving
a serious legal review of its value or limitations. We found no case where a
lawyer had requested or a court required independent evidence of the validity
or reliability of latent ngerprint comparison.12 Despite the conventional legal
valorisation of adversarialism and trial safeguards, there appears to be little, if
any, endogenous legal awareness of systemic limitations with latent ngerprint
evidence.13 Indeed, latent ngerpr int evidence continues to be given in terms
that are, according to research scientists, ‘indefensible’.14
This article’s empirical review of reported (and therefore predominantly ap-
pellate) decisions reveals that while there have been many challenges to the
admissibility and signicance of latent ngerprint evidence, surprisingly few
of these challenges have focused on the epistemological (or epistemic) value of
the evidence.15 The validity and reliability of latent ngerprint comparison
was almost never raised or seriously examined in English criminal proceedings
even when the identity of the defendant was in issue.16 The absence of episte-
mological challenges would not be troubling if latent ngerprint comparisons
had been demonstrated to be both valid and, as has been frequently claimed,
9 See for example A. Cole,Suspect Identities: A History of Fingerprinting and Criminal Identication
(Cambridge MA: Har vard University Press, 2001); Science and TechnologySelect Committee,n
1 above; Lord Campbell, The Fingerpr int Inquiry Report (Edinburgh:APS Group Scotland, 2011)
(Fingerprint Inquiry Report).
10 There was some contestation in early trials, discussed in the monographs below,but few of these
were appealed, legally reported or subsequently cited. See Cole, ibid; C. Seengoopta, Imprint of
the Raj: How Fingerpr inting was Born in Colonial India (London: PanMacMillan, 2003); C. Bea-
van, Fingerprints: The Origins of Crime Detection and the Murder Case that Launched Forensic Science
(London: Hyperion, 2001).
11 We also think it unlikely that trial counsel possesses and applies scientic sophistication that is
not observable across a century of appeals. But,if a reader is aware of UK cases in which the
scientic validity of ngerprint evidence was systematically challenged at trial, the authors would
appreciate hearing from them.
12 Validationrefers to whether a procedure works,in what conditions and how well.It is discussed
below in ‘The scientic status of latent ngerprint evidence: What we know’.
13 This article is not intended to indirectly pr ivilege inquisitor ial processes. For a comparative
analysis of the strengths and weaknesses of inquisitorial processes, see G. Edmond and J. Vuille,
‘Comparing the use of forensic science evidence in Australia, Switzerland and the United States:
Transcending the adversarial/non-adversar ial dichotomy’ (2014) 54 JurimetricsJournal 221.
14 W. Thompson et al, Forensic Science Assessments: A Quality and Gap Analysis – Latent Fingerprint
Examination (Washington,DC:Amer ican Association for the Advancement of Science,2017) 71
(AAAS report).
15 Weaccept that the trial can provide scope for serious challenges and that these might occasionally
take place. In general, however, this study raises questions about the frequency that trials and
appeals facilitate epistemologically sophisticated challenges or encourage appropriate forms of
expression.
16 Contrast the US, where there have been numerous challenges – for example US vMitchell 365
F.3d 215 (3d Cir.2004) and US vLlera Plaza 188 F. Supp.2d 549 (E.D.Pa. 2002) –as Daubert v
Merrell Dow Pharmaceuticals Inc 509 US 579 (1993) was gradually invokedi n criminal proceedings.
© 2020 The Authors. The Modern Law Review© 2020 The Moder n Law ReviewLimited.
(2020) 83(6) MLR 1287–1327 1289
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