Accuracy and expertise in human fingerprint identification

Psychonomic Bulletin & Review, 2010

Latent print examiners face a daunting task. Fingerprints are often the only physical evidence left at a crime scene, but these are typically invisible until developed and lifted. Even after they are dusted with lifting pow-

PLoS ONE, 2014

Expert decision making often seems impressive, even miraculous. People with genuine expertise in a particular domain can perform quickly and accurately, and with little information. In the series of experiments presented here, we manipulate the amount of “information” available to a group of experts whose job it is to identify the source of crime scene fingerprints. In Experiment 1, we reduced the amount of information available to experts by inverting fingerprint pairs and adding visual noise. There was no evidence for an inversion effect—experts were just as accurate for inverted prints as they were for upright prints—but expert performance with artificially noisy prints was impressive. In Experiment 2, we separated matching and nonmatching print pairs in time. Experts were conservative, but they were still able to discriminate pairs of fingerprints that were separated by five-seconds, even though the task was quite different from their everyday experience. In Experiment 3, we separated the print pairs further in time to test the long-term memory of experts compared to novices. Long-term recognition memory for experts and novices was the same, with both performing around chance. In Experiment 4, we presented pairs of fingerprints quickly to experts and novices in a matching task. Experts were more accurate than novices, particularly for similar nonmatching pairs, and experts were generally more accurate when they had more time. It is clear that experts can match prints accurately when there is reduced visual information, reduced opportunity for direct comparison, and reduced time to engage in deliberate reasoning. These findings suggest that non-analytic processing accounts for a substantial portion of the variance in expert fingerprint matching accuracy. Our conclusion is at odds with general wisdom in fingerprint identification practice and formal training, and at odds with the claims and explanations that are offered in court during expert testimony.

2002

In United States v. Llera Plaza, 188 F. Supp. 2d 549 (E.D. Pa. 2002), a federal district initially limited expert opinion testimony on fingerprint identifications because the government was unable to show that such identifications were sufficiently valid and reliable under Federal Rule of Evidence 702. Then, the court withdrew the opinion. This article reproduces an exchange of notes on the initial opinion submitted by five law professors.

Nowa Kodyfikacja Prawa Karnego, 2021

The long practice of fingerprint science is accompanied by confusing thoughts affecting the interpretation of the fingerprint evidence recovered from a crime scene, and, consequently, prosecutors and judges’ decisions as well. However, despite the tremendous scientific and technological developments relating to fingerprint enhancement, processing, and usage, which clarify precise facts regarding the influence of deposition circumstances, substrate, light, air, temperature, and time factors on fingerprint secretions, misconceptions about fingerprints are still widespread within the law enforcement and judicial system. This problem prevents the proper usage of fingerprints in fighting crimes and supporting the justice system by strong physical evidence. This study aims to highlight some scientific facts about fingerprints as well as a new approach and reconceptualization of fingermarks as a tool for crime scene investigation and training. The article discusses twenty-four myths about ...

Journal of Forensic Sciences, 2012

Although fingerprint experts have presented evidence in criminal courts for more than a century, there have been few scientific investigations of the human capacity to discriminate these patterns. A recent latent print matching experiment shows that qualified, court-practicing fingerprint experts are exceedingly accurate (and more conservative) compared with novices, but they do make errors. Here, a rationale for the design of this experiment is provided.

Applied Cognitive Psychology, 2020

Forensic examiners routinely compare a crime-relevant mark of unknown origin against a single suspect's sample, which may create an expectation that the two will match. We tested how embedding the suspect's sample among known-innocent fillers (i.e., an evidence lineup) affects expert decision-making. Experienced fingerprint examiners (N = 43) compared crime-relevant marks against either individual suspect fingerprints (i.e., the standard procedure) or arrays of fingerprints (i.e., evidence lineups), with a matching fingerprint either present or absent. Evidence lineups promoted conservative decision-making, as evidenced by fewer correct IDs and a higher rate of inconclusive judgments. Though errors were rare, evidence lineups also occasionally revealed errors that would have otherwise gone undetected. Our findings thus support arguments that evidence lineups can expose fraud, identify flawed methodologies, and curb overconfidence. The potential benefits and challenges of implementing evidence lineups in forensic laboratories are discussed.

Law and Human Behavior, 2014

There has been very little research into the nature and development of fingerprint matching expertise. Here we present the results of an experiment testing the claimed matching expertise of fingerprint examiners. Expert (n = 37), intermediate trainee (n = 8), new trainee (n = 9), and novice (n = 37) participants performed a fingerprint discrimination task involving genuine crime scene latent fingerprints, their matches, and highly similar distractors, in a signal detection paradigm. Results show that qualified, court-practicing fingerprint experts were exceedingly accurate compared with novices. Experts showed a conservative response bias, tending to err on the side of caution by making more errors of the sort that could allow a guilty person to escape detection than errors of the sort that could falsely incriminate an innocent person. The superior performance of experts was not simply a function of their ability to match prints, per se, but a result of their ability to identify the highly similar, but nonmatching fingerprints as such. Comparing these results with previous experiments, experts were even more conservative in their decision making when dealing with these genuine crime scene prints than when dealing with simulated crime scene prints, and this conservatism made them relatively less accurate overall. Intermediate trainees-despite their lack of qualification and average 3.5 years experience-performed about as accurately as qualified experts who had an average 17.5 years experience. New trainees-despite their 5-week, full-time training course or their 6 months experience-were not any better than novices at discriminating matching and similar nonmatching prints, they were just more conservative. Further research is required to determine the precise nature of fingerprint matching expertise and the factors that influence performance. The findings of this representative, lab-based experiment may have implications for the way fingerprint examiners testify in court, but what the findings mean for reasoning about expert performance in the wild is an open, empirical, and epistemological question.

Most fingerprint comparisons are still done by human examiners, who examine two impressions to determine the amount of perceived detail in agreement. Examiners must rely on their training and experience to determine whether the quality and quantity of detail in agreement is sufficient to warrant an identification decision, which makes their perceptual and decision-making abilities central to our understanding of the strength of fingerprint evidence. Research on latent print examiners has documented the influence of configural processing, greater working memory, and greater consistency of eye gaze among experts relative to novices. All of these lead to universally higher accuracy relative to novices. However, examiners must contend with fatigue and the problem of non-mated prints that are somewhat similar in appearance. Surprisingly, this problem only gets worse as databases increase in size. Currently, the field contends with a relatively high number of erroneous exclusions and inconclusive decisions, which may allow a potentially guilty suspect to remain free from charges. We discuss policy implications that follow directly from the research and suggest future research directions that address unresolved issues.

Nowa Kodyfikacja Prawa Karnego

This is the second part of the study that aims at highlighting twenty-four myths about fingerprint evidence. In this paper, the authors are going to explicate and clarify the difference between the scientific facts and the wrongful concepts that negatively affect the justice system and the effective usage of fingerprint evidence starting from the initial investigation at the crime scene until the final trial at the courtroom.