The Expert Working Group on Human Factors in Latent Print Analysis member

Journal of Forensic Identification editorial board member

Consultant for the Office of the Inspector General who published

Article Summaries


Authored a text book:

Vanderkolk, J. Forensic Comparative Science - Qualitative Quantitative Source Determination of Unique Impressions, Images, and Objects. Academic Press/Elsevier, 2009.

-While there is no such thing as a perfect match in the field of forensic comparative science, Forensic Comparative Science: Qualitative Quantitative Source Determination of Unique Impressions, Images, and Objects presents the experience, understanding, and judgment, necessary for concluding whether two unique images share common origin from a unique and persistent source.

Knowing there will be ranges of different levels of details throughout images, the expert must be able to comprehend when a sufficient quality and quantity of details is reached to render a judgment. By utilizing a process of analyzing the first image, analyzing the second image, comparing them to each other, and evaluating the significance of the analyses and comparisons based on expertise, the comparative scientist will be able to recognize the belief and believe the recognition that occurs during comparative examinations.

Forensic Comparative Science presents a philosophical and theoretical approach to explaining the cognitive process of comparative measurements and source determination. Science is about understanding and generalizing nature. This book is about generalizing comparative science.


Authored and co-authored journal articles:

Vanderkolk, J. Ridgeology, Animal Muzzle Prints and Human Fingerprints. Journal of Forensic Identification, 1991, 41(4), 274-284, and correction 1991, 41(5), 317.
-Some animals have muzzle skin similar to friction skin in humans. Studying the skin first and then studying images made by that skin will provide much support for using all the available details in skin impressions. This article supports Ridgeology and Levels of Details as presented by David Ashbaugh by relating the examination of some animal muzzle skin and prints to human friction skin and prints.

Vanderkolk, J. Class Characteristics and ‘Could Be’ Results. Journal of Forensic Identification, 1993, 43(2), 119-125.
- The examination of impressions made by source objects involves first understanding the objects that made the impressions, then understanding the impressions made by those objects. The features on sources can be repeatable or unique. Definitions of class characteristics are presented. Then, the limitations of conclusions based on details of class characteristics are discussed.

Vanderkolk, J. Identifying Consecutively Made Garbage Bags Through Manufactured Characteristics. Journal of Forensic Identification, 1995, 45(1), 38-50.
-Understanding plastic garbage bag manufacturing processes and the variations that can occur in bags is needed to reach meaningful conclusions when examining plastic bags to determine whether a conclusion of common origin can be made. This article includes a description of a manufacturing process and the resulting examination process that might result in the determination that two bags share common origin.

Vanderkolk, J. Forensic Individualization of Images Using Quality and Quantity of Information. Journal of Forensic Identification, 1999, 49(3), 246-256.
- In order to determine the source of the unknown image, an understanding of the source of that image is required. An understanding of the source of the image is required to differentiate between repeatable class characteristics and unique characteristics on the source object. Images or impressions depict the source(s). The images can be produced from a variety of sources, such as friction ridge skin, shoes, tires, guns, or tools. The examination of images consists of visually observing the details in the unknown image, analyzing them, and comparing them to the details in the known image. Then the examination is a mental evaluation of the sufficiency all the information extracted from the details in both images. Visual aids Quality Quantity sufficiency curves are presented.

Vanderkolk, J. Levels of Quality and Quantity in Detail. Journal of Forensic Identification, 2001, 51(5), 461-468.
-David Ashbaugh presented three levels of details for describing impressions, or finger prints. This article expands upon these three levels of details. Within each level of detail is a range of quality and significance of information that be extracted from those details. A visual aid depiction is provided to help understand the information that can be extracted from the ranges of details within each of the three levels. An expansion of the description of the Quality Quantity Curve in a previous article is also made and an updated QQ Curve is presented.

Vanderkolk, J. Forensic Science, Psychology and Philosophy. Journal of Forensic Identification, 2002, 52(3), 252-253.
-This commentary discusses the need to bring more cognitive psychology and philosophy into forensic comparative science. Cognitive psychology and philosophy strive to know how we know and believe. Forensic comparative scientists should also strive to know and believe how we know and believe in forensic comparative science.

Vanderkolk, J. ACE+V: A Model. Journal of Forensic Identification, 2004, 54(1), 45-52.
-Perceiving and judging detail in an examination of physical evidence is the function of a forensic comparative scientist. An explanation or framework of an examination method as a recurring, reversing, and blending application of Analysis, Comparison, Evaluation and Verification or ACE+V is presented. An ACE+V visual aid is provided.

Busey, T.A., and Vanderkolk, J.R. Behavioral and Electrophysiological Evidence for Configural Processing in Fingerprint Experts. Vision Research, 2005, 45, 431-448.
- Visual expertise in fingerprint examiners was addressed in one behavioral and one electrophysiological experiment. Experts demonstrated better overall performance, immunity to longer delays, and evidence of configural processing when fragments were presented in noise. Novices were affected by longer delays and showed no evidence of configural processing. In Experiment 2, upright and inverted faces and fingerprints were shown to experts and novices. The N170 EEG component was reliably delayed over the right parietal/temporal regions when faces were inverted, replicating an effect that in the literature has been interpreted as a signature of configural processing. The inverted fingerprints showed a similar delay of the N170 over the right parietal/temporal region, but only in experts, providing converging evidence for configural processing when experts view fingerprints. Together the results of both experiments point to the role configural processing in the development of visual expertise, possibly supported by idiosyncratic relational information among fingerprint features.

Busey, T., Yu, C., Wyatte, D., Vanderkolk, J., Parada, F.J., Akavipat, R. Consistency and Variability among Latent Print Examiners as Revealed by Eye Tracking Methodologies. Journal of Forensic Identification, 2011, 61(1), 60-91.
-We recorded the eye positions of 18 expert latent print examiners and 18 novice participants across two separate experiments that were designed to represent abbreviated latent print examinations. In the first experiment, participants completed self-paced latent and inked comparisons presented on a computer monitor while their eyes were tracked with a commercial eye tracker. The similarity of eye fixation patterns was computed for each group of subjects. We found greater variability under some conditions among the experts than the novices in terms of the locations visited. However, experts spent approximately 50% longer than novices inspecting the images, which may have led to differences in strategies adopted by the two groups. A second experiment used trials that always lasted 20 seconds and found that under these time-controlled circumstances, experts were more consistent as a group than novices. Experts also had higher accuracy, spent a greater proportion of time inspecting the latent prints, and had shorter saccades than novices. However, the two groups spent an equal time looking at regions that contained minutiae. The results are generally consistent with experts relying on a common set of features that they choose to move their gaze to under time-limited conditions.

Vanderkolk, J. Bodies of Knowledge. Journal of Forensic Identification, 2007, 57(3), 335-337.
-Commentary about there being so much more to knowledge and belief than just “seeing is knowing.”

Vandekolk, J. Examination Process, Chapter 9, of The Fingerprint Sourcebook, 2011, National Institute of Justice.
-The purpose of a forensic comparative examination is to determine or exclude the source of a print. This chapter will discuss a method used by examiners to determine a print’s source by perceiving and comparing the details of general ridge flow in two fingerprints, the sequences and configurations of details of ridge paths, and if needed, the sequences and configurations of details of the morphology of a particular ridge and nearby ridges. This chapter also addresses the philosophies of perception and decision-making that all fingerprint examiners need to understand before turning to the mechanics of a comparison.

Vanderkolk, J. Identical twins don't share fingerprints. Nature, 4 July 2013, 499, 29.
-Correspondence or letter to the editor reference a Nature obituary of Joseph Murray (Nature, 2013, 493, 164) in which it was stated, “…the twins’ fingerprints were identical.” I believe this statement was an error and responded to Nature.

Vanderkolk, J., Homer, C. Letter to the editor reference: Determining the Sequence of Outsole Wear Characteristics During the Forensic Examination of Footwear Impression Evidence. Journal of Forensic Identification, 2013, 63(5), 493-502.
-We struggle with the original Journal of Forensic Identification article, 2012, 62(3), 254-276, and its explanattion of general wear on the surface of a footwear sole and then recorded in impressions as being a class characteristic. Our commentary is a critique of wear, general or otherwise, and defining it as a class characteristic that is shared among other shoes and then within impressions.

Busey, TA, Yu, C., Wyatte, D., Vanderkolk, J. Temporal sequences quantify the contributions of individual fixations in complex perceptual matching tasks. Cognitive Science, 2013, 37(4), 731-756.
- Perceptual tasks such as object matching, mammogram interpretation, mental rotation, and satellite imagery change detection often require the assignment of correspondences to fuse information across views. We apply techniques developed for machine translation to the gaze data recorded from a complex perceptual matching task modeled after fingerprint examinations. The gaze data provide temporal sequences that the machine translation algorithm uses to estimate the subjects' assumptions of corresponding regions. Our results show that experts and novices have similar surface behavior, such as the number of fixations made or the duration of fixations. However, the approach applied to data from experts is able to identify more corresponding areas between two prints. The fixations that are associated with clusters that map with high probability to corresponding locations on the other print are likely to have greater utility in a visual matching task. These techniques address a fundamental problem in eye tracking research with perceptual matching tasks: Given that the eyes always point somewhere, which fixations are the most informative and therefore are likely to be relevant for the comparison task?

Busey, T., Silapiruti, A., Vanderkolk, J. Relation between sensitivity, similar non-matches, and database size in fingerprint database searches. Law, Probability and Risk, 2014, 13(2), 151-168.
- Searching against larger Automated Fingerprint Identification System (AFIS) databases may increase the likelihood of finding a suspect in the database. However, Dror and Mnookin (2010) have argued that this also leads to an increase in the number of similar non-matching prints, which could lead to an erroneous identification. Using simulations, we explore the relation between database size and two outcome factors: close non-matching prints and overall database sensitivity, which is a measure of discriminability between true matches and close non-matches. We find that larger databases tend to increase both the likelihood of finding the suspect in the database as well as the number of close non-matching prints. However, the former tends to asymptote while the latter increases without bound, and this leads to an initial increase and then a decrease in the sensitivity of the database as more prints are added. This suggests the existence of an optimal database size, and that caution should be observed when interpreting results from larger databases. Quantitative evidentiary techniques such as likelihood ratios have the potential to address some of these concerns, although they too must consider the database size when calculating the likelihood ratio. Implications for practitioners are discussed.

Busey, T., Swofford, H.J., Vanderkolk, J., Emerick, B. The impact of fatigue on latent print examinations as revealed by behavioral and eye gaze testing. Forensic Science International, 2015, Vol 251, p202-208.
- Eye tracking and behavioral methods were used to assess the effects of fatigue on performance in latent print examiners. Eye gaze was measured both before and after a fatiguing exercise involving fine-grained examination decisions. The eye tracking tasks used similar images, often laterally reversed versions of previously viewed prints, which holds image detail constant while minimizing prior recognition. These methods, as well as a within-subject design with fine grained analyses of the eye gaze data, allow fairly strong conclusions despite a relatively small subject population. Consistent with the effects of fatigue on practitioners in other fields such as radiology, behavioral performance declined with fatigue, and the eye gaze statistics suggested a smaller working memory capacity. Participants also terminated the search/examination process sooner when fatigued. However, fatigue did not produce changes in inter-examiner consistency as measured by the Earth Mover Metric. Implications for practice are discussed.

Busey, T., Nikolov, D., Yu, C., Emerick, B., Vanderkolk, J. Characterizing human expertise using computational metrics of feature diagnosticity in a pattern matching task. Cognitive Science, November 10, 2016,
-Forensic evidence often involves an evaluation of whether two impressions were made by the same source, such as whether a fingerprint from a crime scene has detail in agreement with an impression taken from a suspect. Human experts currently outperform computer‐based comparison systems, but the strength of the evidence exemplified by the observed detail in agreement must be evaluated against the possibility that some other individual may have created the crime scene impression. Therefore, the strongest evidence comes from features in agreement that are also not shared with other impressions from other individuals. We characterize the nature of human expertise by applying two extant metrics to the images used in a fingerprint recognition task and use eye gaze data from experts to both tune and validate the models. The Attention via Information Maximization (AIM) model (Bruce & Tsotsos, 2009) quantifies the rarity of regions in the fingerprints to determine diagnosticity for purposes of excluding alternative sources. The CoVar model (Karklin & Lewicki, 2009) captures relationships between low‐level features, mimicking properties of the early visual system. Both models produced classification and generalization performance in the 75%–80% range when classifying where experts tend to look. A validation study using regions identified by the AIM model as diagnostic demonstrates that human experts perform better when given regions of high diagnosticity. The computational nature of the metrics may help guard against wrongful convictions, as well as provide a quantitative measure of the strength of evidence in casework.


Member of and contributor to their documents:

Scientific Working Group of Friction Ridge Analysis, Study and Technology (SWGFAST) documents: and

-SWGFAST Objectives:
1. To establish guidelines and standards for the development and enhancement of friction ridge examiners’ knowledge, skills, and abilities.
2. To discuss and share friction ridge examination methods and protocols.
3. To encourage and evaluate research and innovative technology related to friction ridge examination.
4. To establish and disseminate guidelines and standards for quality assurance and quality control.
5. To cooperate with other national and international organizations in developing standards.
6. To disseminate SWGFAST studies, guidelines, standards, and findings.

Consultant for the Office of the Inspector General, resulting in the publication: A Review of the FBI’s Handling of the Brandon Mayfield Case, Office of the Inspector General, Oversight and Review Division, March, 2006.
- In May 2004, the Federal Bureau of Investigation (FBI) arrested Brandon Mayfield, an Oregon attorney, as a material witness in an investigation of the terrorist attacks on commuter trains in Madrid, Spain, in March 2004. Mayfield had been identified by the FBI Laboratory as the source of a fingerprint found on a bag of detonators in Madrid that was connected to the attacks. Approximately two weeks after Mayfield was arrested, the Spanish National Police (SNP) informed the FBI that it had identified an Algerian national as the source of the fingerprint on the bag. After the FBI Laboratory examined the fingerprints of the Algerian, it withdrew its identification of Mayfield and he was released from custody. As a result of these events, the Office of the Inspector General (OIG) initiated an investigation into the misidentification, investigation, and detention of Mayfield. We sought to determine the causes of the misidentification and to assess the FBI Laboratory's responses to the error. We also examined whether the FBI used the USA PATRIOT Act (Patriot Act) in connection with the investigation of Mayfield, whether the FBI targeted Mayfield because of his Muslim religion, and whether the FBI's representations to the United States District Court in support of the requests for a material witness warrant and search warrants were accurate. In addition, we examined Mayfield's conditions of confinement and whether they were consistent with the material witness statute.

National Institute of Standards and Technology (NIST), Organization of Scientific Area Committees for forensic science (OSAC) documents:
-The mission of the Organization of Scientific Area Committees (OSAC) for Forensic Science is to strengthen the nation’s use of forensic science by facilitating the development of scientifically sound forensic science standards, and by promoting the adoption of those standards by the forensic science community.
- All standards approved for inclusion on the OSAC Registry must be developed by a process that follows the core OSAC principles of openness, balance, consensus and harmonization.

National Institute of Justice (NIJ) and the National Institute of Standards and Technology (NIST) The Expert Working Group on Human Factors in Latent Print Analysis’ document Latent Print Examination and Human Factors: Improving the Practice through a Systems Approach. 2012.
-The National Institute of Justice (NIJ) Office of Investigative and Forensic Sciences (OFIS) within the U.S. Department of Justice and the National Institute of Standards and Technology’s (NIST’s) Law Enforcement Standards Office (OLES) sponsored the work of this expert panel to examine human factors in latent print analysis and to develop recommendations to reduce the risk of error and improve the practice of latent print analysis.