The Nature of Expertise in Fingerprint Matching: Experts Can Do a Lot with a Little

Abstract

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.

Perceptual expertise in forensic facial image comparison

“…Differences between groups were most pronounced with 30 s exposure, however, pointing to a more entailed and effective identity examination process by examiners than by less experienced participants. This contrasts with accounts of perceptual expertise in radiographers [28] and fingerprint examiners [29], where expertise appears primarily driven by a shift in perceptual strategy towards fast and global image analysis [30]. Consistent with the training forensic examiners receive [14], our results suggest an opposing trajectory of expertise in forensic facial image comparison characterized by a transition towards controlled and effortful analysis.…”

The emergence of expertise with novel objects

“…Experts show a delay in the N170 EEG component when viewing inverted versus upright fingerprint fragments (a measure of configural processing; Busey & Vanderkolk, 2005), for example, and these examiners are less affected by artificial noise or the spacing of prints in time compared to novices (Busey & Vanderkolk, 2005;Thompson & Tangen, 2014). Fingerprint examiners are also more accurate than novices at discriminating briefly presented prints, although their performance improves even more when given more time (Thompson & Tangen, 2014). Facial recognition experts show a similar advantage when matching briefly presented unfamiliar faces (White et al, 2015).…”

“…The difference in fingerprint matching performance between experts and novices is also more pronounced when given 60 seconds to view the prints versus one second (Thompson & Tangen, 2014), and formal practice guidelines across forensic disciplines encourage a slow, analytic process of marking up and comparing particular features in each case before arriving at a conclusion . These findings and current practices give further reason to suspect that forensic examiners might rely on controlled, effortful, or analytic processes when matching prints that are more dependent on general abilities (Ackerman, 1987).…”

“…The data are now clear, however, that human fingerprint examiners are incredibly accurate compared to novices at comparing fingerprints (e.g., Thompson, Tangen, & McCarthy, 2014). We have also learned that examiners are fallible, and tend to err on the side of caution by preferring to make errors of the sort that would fail to identify a criminal (misses) rather than provide evidence to the court that would incorrectly convict an innocent person (false alarms; Thompson et al, 2014;Ulery, Hicklin, Buscaglia, & Roberts, 2011).…”

“…These professionals also display hallmarks of genuine perceptual expertise. They are impressively accurate compared to novices Ulery, Hicklin, Buscaglia, & Roberts, 2011; but see Ulery, Hicklin, Buscaglia, & Roberts, 2012, Dror & Rosenthal, 2008and Dror & Cole, 2010, for issues of reliability and context effects in fingerprint examinations), and there is evidence to suggest that they rely on configural, holistic, or non-analytic processes when matching fingerprints (Busey & Vanderkolk, 2005;Thompson & Tangen, 2014).…”