Forensics without uniqueness, conclusions without individualization: the new epistemology of forensic identification

Little is known about the nature and development of fingerprint expertise and, therefore, the best way to turn novices into experts. Little is known about the factors that affect matching accuracy and, therefore, what experts can legitimately testify to in court. This thesis explores the factors that affect matching accuracy and the development of expertise in fingerprint identification, in order to inform training, and to provide an empirical basis for expert testimony in the courtroom. The investigation is grounded in exemplar, signal detection, and dual-process theories, and draws from literature on expertise and skill acquisition, and familiar and unfamiliar face recognition.The thesis comprises four parts. In Part 1-Establishing Expertise-I attempt to find evidence for expert-novice differences in fingerprint matching, and explore where performance differences might lie. In Part 2-Depicting Expertise-I explore alternate methods for presenting signal detection results by depicting the data in a contingency space. In Part 3-Nature of Expertise-I explore the cognitive processes that might account for the superior performance of expert fingerprint examiners, and I explore the limits of rapid expert decision making. In Part 4-Expression of Expertise-I propose a framework for the expression of expert opinion in the courtroom, in order to integrate extra-legal recommendations and emerging research.Taken together, I find that qualified, court-practicing fingerprint examiners are more accurate and more conservative than novices, and that errors are more likely to occur on prints from large databases, which are highly similar but nonmatching. I find that performance, both in terms of accuracy and response bias, changes as people move from novice, to trainee, to expert. I find that experts can discriminate matching and nonmatching prints that are iii artificially noisy, spaced by a short time, briefly flashed on screen, and even when presented in the blink of an eye. These findings indicate that experts make use of non-analytic processing when identifying prints, and they perform accurately when information is sparse-experts can do a lot with a little. Further programs of research, like this one, on the factors that affect fingerprint matching accuracy and performance, will create a foundation for evidence-based training, and serve to increase confidence in the legitimacy of claims made by expert witnesses in the courtroom.iv

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“…Despite considerable acrimony, examiners continue to make claims of individualization or similar (Cole, 2009(Cole, , 2010.…”

Section: The Current Modelmentioning

confidence: 99%

Expertise in Fingerprint Identification

Thompson

Tangen

McCarthy

2013

Journal of Forensic Sciences

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“…34 (Pretty & Sweet, 2001;Kieser, 2005;Bowers, 2006). 35 See in this connection (McLachlan, 1995;Saks & Koehler, 2008;Champod, 2009;Cole, 2009;Kaye, 2009a;Kaye, 2010). forensic science. These conclusions were eventually incorporated into the latest NRC report (2009).…”

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confidence: 99%

Scientific Evidence in Europe -- Admissibility, Evaluation and Equality of Arms

Champod

Vuille

2011

International Commentary on Evidence

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This study was commissioned by the European Committee on Crime Problems at the Council of Europe to describe and discuss the standards used to asses the admissibility and appraisal of scientific evidence in various member countries. After documenting cases in which faulty forensic evidence seems to have played a critical role, the authors describe the legal foundations of the issues of admissibility and assessment of the probative value in the field of scientific evidence, contrasting criminal justice systems of accusatorial and inquisitorial tradition and the various risks that they pose in terms of equality of arms. Special attention is given to communication issues between lawyers and scientific experts. The authors eventually investigate possible ways of improving the system. Among these mechanisms, emphasis is put on the adoption of a common terminology for expressing the weight of evidence. It is also proposed to adopt an harmonized interpretation framework among forensic experts rooted in good practices of logical inference.

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“…B 370: 20140259 (a) Clarifying the inference process My position regarding reported conclusions in fingerprint matters was expressed in 2008 already [70]: experts shall abandon the identification/individualization conclusion altogether. Cole followed with the same recommendation in 2009 [71] and some fingerprint experts start to come to the same conclusion [72]. A proper evaluation of the findings calls for an assignment of two probabilities.…”

Section: A Way Forward?mentioning

confidence: 99%

Fingerprint identification: advances since the 2009 National Research Council report

Champod

2015

Phil. Trans. R. Soc. B

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This paper will discuss the major developments in the area of fingerprint identification that followed the publication of the National Research Council (NRC, of the US National Academies of Sciences) report in 2009 entitled: Strengthening Forensic Science in the United States: A Path Forward. The report portrayed an image of a field of expertise used for decades without the necessary scientific research-based underpinning. The advances since the report and the needs in selected areas of fingerprinting will be detailed. It includes the measurement of the accuracy, reliability, repeatability and reproducibility of the conclusions offered by fingerprint experts. The paper will also pay attention to the development of statistical models allowing assessment of fingerprint comparisons. As a corollary of these developments, the next challenge is to reconcile a traditional practice dominated by deterministic conclusions with the probabilistic logic of any statistical model. There is a call for greater candour and fingerprint experts will need to communicate differently on the strengths and limitations of their findings. Their testimony will have to go beyond the blunt assertion of the uniqueness of fingerprints or the opinion delivered ispe dixit.

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Forensics without uniqueness, conclusions without individualization: the new epistemology of forensic identification

Cited by 110 publications

References 9 publications

Expertise in Fingerprint Identification

Expertise in Fingerprint Identification

Scientific Evidence in Europe -- Admissibility, Evaluation and Equality of Arms

Fingerprint identification: advances since the 2009 National Research Council report

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