Breaking NEWz you can UzE...
compiled by Jon Stimac
Finger-tip Convenience Not at Our Fingertips Yet
MUNSTER TIMES, IN - Nov 6, 2005
...asked for a fingerprint as
identification once was sure to have customers seeing red...
Senate Approves Rules to Finger Prints Act –
GOVERNMENT OF JAMAICA - Nov 1, 2005
...various elements of the Rules sought to
protect the rights of persons whose fingerprints were being taken...
Fight Over Defendant's Fingerprints at Double-murder Trial
NEWARK STAR LEDGER, NJ -
Nov 1, 2005 ...attorneys sparred in court
over whether fingerprints found on plastic bags are enough...
Mistaken ID Jailee Plans Suit Against City
JERSEY JOURNAL, NJ - Oct 31, 2005 ...fingerprints sent
through their Livescan came back as a match to the fingerprints
attached to the fugitive...
Recent CLPEX Posting Activity
containing new posts
Bill 05 Nov 2005 10:35 pm
STEAM IRON V. GALLENKAMP
RDODGE 04 Nov 2005 07:48 am
“distortion – dissimilarity”
Wayne 03 Nov 2005 05:59 pm
Guest 03 Nov 2005 02:36 pm
Old Message Board
Shaheen 03 Nov 2005 01:48 pm
g. 02 Nov 2005 06:27 pm
First Time Testifying
Boyd 02 Nov 2005 06:08 pm
Fingerprint Dogma Part III
Guest 31 Oct 2005 10:48 pm
Ninhydrin question revisited
Julie 31 Oct 2005 10:31 pm
Guest 31 Oct 2005 10:27 pm
Fingerprint Dogma, Part II
Guest 31 Oct 2005 06:09 am
UPDATES ON CLPEX.com
No major updates on the website this week
We looked at suggestions for courtroom
We see the paper on a topic presented at the North
East Division, IAI in Vermont last week;
Contextual Information Renders Experts
Vulnerable to Making Erroneous Identifications
In Press, Forensic
Itiel E. Dror, David Charlton, and Ailsa E. Péron
School of Psychology; Faculty of Medicine, Health and Life Sciences,
University of Southampton, Southampton, United Kingdom
We investigated whether
experts can objectively focus on feature information in fingerprints without
being misled by extraneous information, such as context. We took fingerprints
that have previously been used to positively identify suspects. Then we
presented these same fingerprints again, to the same
experts, but gave a context that suggested that they were a no-match, and hence
the suspects could not be identified. Within this new context, most of the
fingerprint experts made different judgements, thus contradicting their
own previous identification decisions. Cognitive aspects involved in biometric
identification can explain why fingerprint experts are vulnerable to make
Being a scientist or
forensic expert is rooted in the ability to examine evidence reliably and
objectively. To do this, these professionals must be able to dissociate
themselves from extraneous contextual and other influences that may interfere
with their ability to examine, evaluate, and judge the relevant information.
Their decisions should be based on the information relevant to the task at hand
and its unbiased interpretation. This involves independent thought that ignores
to a large extent extraneous pressures and influences.
External pressures and influences are many and varied. History of science is
full of examples of extraneous influences, and today too, scientists work
within, and are influenced by, political,
economical and other agendas (e.g., global warming, Genetically Modified crops,
and Measles Mumps Rubella vaccine).
Terrorism has brought about a wave of contextual influences. These include,
among others, heightened suspicion of Muslims, fear, anger, helplessness, as
well as pressure on governments to control (or at least appear to control) such
threats. Such contextual influences provide strong and ample opportunities to
contaminate objectivity, leading to distortions and errors of judgement beyond
the unavoidable. Indeed, within this context we have witnessed major
misevaluations and misjudgements by intelligence experts.
Within a similar extraneous context the United States Federal Bureau of
Investigation (FBI) positively, but erroneously, identified a Muslim as the
Madrid bomber (see Figure 1). This incorrect identification was further verified
by a number of FBI and other fingerprint experts and led to the arrest of an
innocent person. It was only due to rare and exceptional circumstances that this
error was ever revealed and eventually acknowledged by the FBI .
Errors can occur across forensic science evidence, including DNA .
Empirical cognitive research in these areas has been largely neglected (if not
basically ignored), partially because professional expert assessment of evidence
(as in the criminal justice system) is believed to be relatively objective. With
the growing number of anecdotal cases that question this belief and suggest that
forensic assessment is far from being as objective as it can and should be, it
is important to conduct cognitive scientific research in this area. Laboratory
experiments performed by our group have already suggested that emotional context
may bias fingerprint identification. These studies found that university
students were more likely to judge that there was a positive match between pairs
of fingerprints that were presented within an emotional context than those
presented within an emotionally neutral control context [e.g., 3].
However, this vulnerability was apparent only when the prints were ambiguous and
lacked clarity. The emotional context had minimal effect when there was a
clearly matching pair (or a clearly non-matching pair). These studies, however,
were based on non-experts and conducted in a laboratory setting.
The study that we report here presents empirical data on whether actual
fingerprint experts in their normal everyday working routines and environment
are susceptible to extraneous contextual influences. We employed a
within-subject design in which the same experts made judgements on identical
pairs of fingerprints, but in different contexts. Our aim was to focus on and to
examine the contextual influences themselves rather than reveal possible
individual differences between experts. Accordingly, we collected and used pairs
of fingerprints from archives that the same experts had examined and judged
approximately five years earlier as a clear and definite match. These previous
identification matches were taken from real criminal investigations and have
been used in court.
In this study we re-presented these very same pairs of fingerprints to the same
experts who had originally evaluated them as a match, but we now provided them
within an extraneous context that might bias them to evaluate the prints as a
non-match. We wanted to test whether their decisions were independent and
relatively objective, and thus consistent regardless of extraneous influences.
Alternatively, if they contradicted their previous decisions, this would
demonstrate vulnerability to bias.
Figure 1: The FBI’s erroneous
identification of the Madrid bomber. The latent print from the crime scene (left
panel) and the fingerprint of the innocent suspect who was positively identified
by a number of fingerprint experts (right panel).
Participants: Participants were five certified fingerprint experts. Together
they represent over 85 years of experience in examining fingerprints (mean of 17
years). The participants were taken from our international fingerprint expert
pool of volunteers. This pool of participants includes fingerprint experts from
a variety of Fingerprint Bureaus, Agencies, and Laboratories from across the
world (including the USA, UK, Israel, the Netherlands and Australia). We only
used experts that were not familiar with Mayfield’s fingerprint and that we
could covertly access past archival identification matches that they made in the
past (see Procedure, below)
Materials: A different pair of fingerprints was prepared for each of the expert
participants. Each pair of prints had been previously identified as a match by
that same expert in the year 2000, within the normal course of their work.
The latent fingerprints had been
obtained from the crime scenes and were all presented again to the experts in
their original format.
We further established that all of the pairs of
fingerprints were indeed a match by submitting them for verification, ‘context
free’ to two experienced fingerprint experts who were not involved in or aware
of our study (each had over 20 years of experience). Both experts independently
verified that all five pairs of fingerprints were indeed matches.
Procedure: Participants signed a consent form a few months prior to the
experiment. In this form they consented to being tested sometime within the next
12 months without their knowledge. Thus we were able to obtain consent but yet
test the experts within their normal working environment without them knowing
that they were in an experimental situation. We pre-screened our participants
and used only participants that were not familiar with the fingerprint of
Participants were asked by one of their colleagues to examine a set of
fingerprints, composed of a latent print (from the crime scene) and a print
exemplars (a print obtained from a suspect). They were told that the pair of
prints was the one that was erroneously matched by the FBI as the Madrid bomber,
thus creating an extraneous context that the prints were a non-match.
The fingerprint experts were asked to decide whether there was sufficient
information available in the pair of prints to make a definite and sound
decision, and if so, what that judgement was (a match or non-match).
They were allowed to evaluate the prints as they would
do routinely –handling of the prints, magnifying, lighting equipment, and so
forth. The experts were allowed an unlimited amount of time to make their
evaluation. The fingerprint experts were further instructed to ignore the
context and background information, and to just focus solely on the actual print
in their evaluation and decision making.
Only one participant (20%)
judged the prints to be a match, thus making a consistent identification
regardless of the extraneous context. The other four participants (80%) changed
their identification decision from the original decision they themselves had
made five years earlier. Three of these four participants directly contradicted
their previous decision and now judged the fingerprints as definite non-matches,
whereas the fourth participant now judged that there was insufficient
information to make a definite decision (either a match or a non-match).
This study shows that fingerprint identification decisions of experts are
vulnerable to irrelevant and misleading contextual influences. Our study
specifically demonstrates that the extraneous context in which fingerprint
examinations occur can determine the identification decision. When presented
within a different context four out of five experts made different
identification decisions. One of the four decided that there was insufficient
information available in the latent print to make either a ‘match’ or
‘non-match’ decision, whereas the other three fingerprint experts decided that
the fingerprints were a definite ‘non-match’. This is striking given that all
five experts had seen the identical fingerprints previously and all had decided
that the prints were a sound and definite match.
This is the first research study to experimentally examine the possible impacts
of extraneous context in the real world of biometric and forensic science. One
reason for the lack of research in this area is the difficulty in conducting
proper scientific research with experts without their knowledge and in their
real working environment, while obtaining their consent. We could only use
experts for whom we could covertly access and obtain archival files of their own
past judgements and who were not familiar with the Mayfield fingerprint. This
stipulation further decreased the availability of suitable participants, but had
the added advantage of providing a unique opportunity to conduct a
within-subject study. The magnitude of the contextual effect and the fact that
the experts had judged the same fingerprints in the past enabled the sample to
provide clear findings with a high level of confidence. Furthermore, given that
we conducted our experiment within the real world conditions of the criminal
justice system even if only one expert out of five was susceptible to such
effects that in itself would have serious implications.
Even if we were able increase our sample of expert participants ten fold (which
is unrealistic, given all the constraints detailed above) and assuming that none
of the additional participants would have been vulnerable to our manipulation
and changed their judgements (which is statistically highly unlikely), our data
would still demonstrate that approximately ten percent of the experts were
susceptible to misleading extraneous contextual information. Thus, our results
are striking even though we used five expert participants and a strong
The critical question is what do these results reflect and what do they imply.
Are the inconsistent fingerprint identification decisions a reflection of
practitioners’ errors? Do they reveal deeper methodological and procedural
problems in the way that fingerprint experts are trained and identifications are
conducted? Or do the results point out basic flaws in the scientific basis and
assumptions underlying fingerprint identification altogether?
The data presented in this study, along with some of the rare examples where
erroneous identifications are publicly revealed and acknowledged, do not
necessarily indicate basic flaws in the scientific underpinning of fingerprint
identification. The fundamental question as to whether fingerprint
identification is a science is not addressed in this study, since that raises a
different set of issues that pertain to a variety of “sciences” . Our results
also do not reflect or reveal practitioners’ errors whereby experts’ negligence,
carelessness, and personal fault (intentional or not) produce erroneous
identifications. Such causes are often used to deflect deeper scrutiny and
Rather, it seems that our findings of erroneous and inconsistent identification
decisions may reflect cognitive flaws and limitations in conducting objective
and independent processing and evaluation of the information. It is important to
note that such problems arise mainly in the more difficult and challenging
cases, such as with latent fingerprints collected at crime scenes that are
distorted, partially missing, and contaminated. In such cases subjectivity is
more pronounced [3, 5].
As extraneous contextual effects are more pronounced, greater distortions can
arise. The sources of such distortions are many and varied, including emotional
context, pressure, contextual information, group think, biases, hopes and
expectations, self fulfilling prophecies, and peer pressure. In this study we
used a strong misleading extraneous contextual influence, but such influences do
It is important first to establish empirically that experts can be strongly
influenced by extraneous contexts. Now that we have demonstrated such an effect,
further research can and should use different and more subtle manipulations to
examine in greater depth when such factors affect performance and render the
experts vulnerable to misjudgements, and when such factors are unlikely to
affect performance. When vulnerable, these effects can cause a variety of
distortions that arise from ignoring parts of the evident information,
over-emphasising and over-evaluating other parts of the information, and
changing decision criteria, to name but a few.
Vulnerabilities in fingerprint identification can be minimized by better initial
selection and screening of fingerprint experts; appropriate training and
professional development, and the adoption of methodological procedures that
adequately address potential pitfalls. Our results show that even in the face of
strong extraneous contextual information one expert nevertheless did maintain
their original judgement. That expert was indeed able to focus objectively and
consistently on the data, ignoring the extraneous misleading contextual
information. This clearly demonstrates that it is possible to be much more
objective, and that some experts may not be optimizing objectivity in their
The reliability and validity of a scientific method such as fingerprint
identification is maintained only when analysis is relatively objective, and
hence consistent, across individuals, times, and extraneous contexts. For
fingerprint examination to remain a credible forensic science, it must achieve
this level of objectivity of analysis. Our study shows that it is possible to
alter identification decisions on the same fingerprint, solely by presenting it
in a different context. This does not imply that fingerprint and other forensic
identifications are not a science, but it does highlight problems of
subjectivity, interpretation, and other psychological and cognitive elements
that interact and may distort any scientific inquiries.
One of the main sources of weaknesses in biometric and other forensic sciences
is the lack of research, attention, and application of psychological elements
that play a key role in the identification processes. These range from the ways
in which perceptual factors (such as similarity and orientation) affect the
process of pattern recognition  to how we consider decision alternatives and
shift response criteria . With new and future statistical tools
and technologies the face of fingerprint and biometric identification is
changing; however, psychology and cognitive elements continue to play a critical
role in their implementation and success . To highlight and address such
potential pitfalls, cognitive research needs to be applied systematically to the
world of biometrics and forensics. This is all the more necessary in view of our
findings that extraneous contextual information is able to determine experts’
evaluation of fingerprints, a well-established and relatively objective forensic
discipline, then distorting effects are undoubtedly as prevalent, if not more
so, in other biometrics and forensic disciplines .
want to thank all the fingerprint experts who are working together with us and
support our efforts to try and understand the cognitive elements involved in
fingerprint identification, and to thank Arie Zeelenberg, Robert Rosenthal, and
Nick Donnelly for helpful comments on an earlier version of the manuscript.
 Stacey R. B. (2004). Report
on the erroneous fingerprint individualization in the Madrid train bombing case.
Journal of Forensic Identification, 54 (6), 706-718.
 Thompson, W.C. (1995). Subjective interpretation, laboratory error
and the value of DNA evidence: Three case studies, Genetica , 96,
 Dror, I. E., Peron, A., Hind, S., & Charlton, D. (2005). When emotions get
the better of us: The effect of contextual top-down processing on matching
fingerprints. Applied Cognitive Psychology, 19(6), 799-809.
Dror, I. E. & Thomas, R. D. (2005). The cognitive neuroscience laboratory: A
framework for the science of mind. In C. Erneling & D. Johnson (Eds.), The
Mind as a Scientific Object: Between Brain and Culture (pp. 283-292).
Oxford University Press.
Dror, I. E. (2005). Perception is far from perfection: The role of the brain and
mind in constructing realities. Brain and Behavioural Sciences 28 (6).
 Ashworth, A.R.S. & Dror, I.
E. (2000). Object Identification as a Function of Discriminability and Learning
Presentations: The Effect of Stimulus Similarity and Canonical Frame Alignment
on Aircraft Identification. Journal of Experimental Psychology: Applied, 6
 Dror, I. E., Busemeyer, J. R., & Basola, B. (1999). Decision making under
time pressure: An independent test of sequential sampling models. Memory and
Cognition, 27 (4), 713-725.
 Dror, I.E. (2005). Technology and human expertise: Some do’s and don’ts.
Biometric Technology Today, 13 (9), 7-9.
Risinger, D.M., Saks, M.J., Thompson, W.C. & Rosenthal, R. (2002). The Daubert/Kumho
Implications of Observer Effects in Forensic Science: Hidden Problems of
Expectation and Suggestion. California Law Review , 90(1), 1-56.
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