Latent Print Examiners Research Articles

Study of the fingerprints of a Spanish sample for the determination of the hand and finger

The individuality and permanence of fingerprints make of them a very useful feature in the identification of individuals. There are now automated computer programmes that allow a quick comparison between a fingermark and a database. However, in order to assess the strength of evidence in fingerprint identification, complementary information on the frequencies of the different morphological features of the dermopapillary ridges is required. This idea is used in this work as a starting point to evaluate the frequencies of the parameters used in the determination of the hand and finger in a large sample of 2600 fingerprints taken from 134 male and 127 female Spanish population. Based on these fingerprints, the frequencies of different categories of the following parameters were obtained: type of pattern, slope of the apex ridge, subtype of two-delta pattern, ridge tracing, major angle, major ridge count, bisector, rotation of the central ridge, assimilation to loops and slant. Moreover, the results have shown that these characters are useful for the determination of the hand in whorls (two-delta pattern) and loops (one-delta pattern), but not for the determination of the finger. The most useful and classificatory parameter when determining the hand of origin of a two-delta fingerprint is the slope of the apex ridge, and for the one-delta pattern, knowing the location of the delta allows the correct estimation of the hand of a fingerprint in more than 93% of the cases. The data presented in this paper are novel and can be used by latent print examiners to improve the statistical basis of their decisions in reaching conclusions.

Reliability of ordinal outcomes in forensic black-box studies

Forensic science disciplines such as latent print examination, bullet and cartridge case comparisons, and shoeprint analysis, involve subjective decisions by forensic experts throughout the examination process. Most of the decisions involve ordinal categories. Examples include a three-category outcome for latent print comparisons (exclusion, inconclusive, identification) and a seven-category outcome for footwear comparisons (exclusion, indications of non-association, inconclusive, limited association of class characteristics, association of class characteristics, high degree of association, identification). As the results of the forensic examinations of evidence can heavily influence the outcomes of court proceedings, it is important to assess the reliability and accuracy of the underlying decisions. “Black box” studies are the most common approach for assessing the reliability and accuracy of subjective decisions. In these studies, researchers produce evidence samples consisting of a sample of questioned source and a sample of known source where the ground truth (same source or different source) is known. Examiners provide assessments for selected samples using the same approach they would use in actual casework. These studies often have two phases; the first phase comprises of decisions on samples of varying complexities by different examiners, and the second phase involves repeated decisions by the same examiner on a (usually) small subset of samples that were encountered by examiners in the first phase. We provide a statistical method to analyze ordinal decisions from black-box trials with the objective of obtaining inferences for the reliability of these decisions and quantifying the variation in decisions attributable to the examiners, the samples, and statistical interaction effects between examiners and samples. We present simulation studies to judge the performance of the model on data with known parameter values and apply the model to data from a handwritten signature complexity study, a latent fingerprint examination black-box study, and a handwriting comparisons black-box study.

Measuring the rarity of core-delta distances in fingerprint patterns in the Dutch population.

In latent print examination, a conclusion on an individualization is primarily based on the presence of corresponding minutiae. Depending on the level of correspondence between the minutiae on the fingermark and on the reference print, a match is concluded. However, a fingermark is analyzed on all three levels: general pattern combined with core-delta distance, minutiae, and third-level detail. In the opinion of the authors, next to the conclusion based on minutiae, all information should be included in the final assessment of the evidence if present. In this study, we present the results of frequency data on the combination of fingerprint patterns and their core-delta distances. The frequency data allow examiners to substantiate their subjective opinions on the strength of corresponding patterns and core-delta distances based on measurements. The frequencies of the core-delta distances in this study were obtained by encoding core-delta distances in a collection of more than 20,000 fingerprints containing either a loop or a whorl pattern. The frequencies for the core-delta distances of loop patterns were subsequently compared with data from the National Institute of Standards and Technology. This study will demonstrate that core-delta distances in loop and whorl patterns contribute significantly to the overall evidential strength of fingerprint evidence. By adding pattern and core-delta distance information to the evaluation of fingerprint evidence, more challenging fingermarks could be added to fingerprint case reports.

What types of information can and do latent print examiners review? A survey of practicing examiners

Understanding typical work practices is important to understanding the decision-making process underlying latent print comparison and improving the reliability of the discipline. Despite efforts to standardize work practices, a growing literature has demonstrated that contextual effects can influence every aspect of the analytic process. However, very little is known about what types of information are available to latent print examiners, and what types of information latent print examiners routinely review. We surveyed practicing latent print examiners (N = 284) regarding what types of information are accessible during routine casework, and what types of information they routinely review during casework. We also explored whether access and inclination to review different types of information vary according to unit size and examiner role. Results indicated that information describing the physical evidence is accessible by almost all examiners (94.4%), and most examiners have access to offense type (90.5%), method of evidence collection (77.8%), and the names of both suspect (76.1%) and victim (73.9%). However, evidence description (86.3%) and method of evidence collection (68.3%) were the only information types consistently reviewed by most examiners. Findings also indicate that examiners in smaller laboratories have access to more information types and often review more information types than examiners from larger laboratories, but both populations choose to not review information at similar rates. Further, examiners in supervisory positions are more likely to choose to not review information than examiners in non-supervisory positions. Although there is some consensus regarding what types of information examiners routinely review, findings suggest that there is little absolute consensus regarding what information examiners can even access, and highlight two sources of variability in examiner work practices: employment setting and examiner role. This is concerning in light of efforts to maximize the reliability of analytic procedures (and ultimately, conclusions) and represents an important area of future study as the field progresses.

A method for quantifying individual decision thresholds of latent print examiners

In recent years, ‘black box’ studies in forensic science have emerged as the preferred way to provide information about the overall validity of forensic disciplines in practice. These studies provide aggregated error rates over many examiners and comparisons, but errors are not equally likely on all comparisons. Furthermore, inconclusive responses are common and vary across examiners and comparisons, but do not fit neatly into the error rate framework. This work introduces Item Response Theory (IRT) and variants for the forensic setting to account for these two issues. In the IRT framework, participant proficiency and item difficulty are estimated directly from the responses, which accounts for the different subsets of items that participants often answer. By incorporating a decision-tree framework into the model, inconclusive responses are treated as a distinct cognitive process, which allows inter-examiner differences to be estimated directly. The IRT-based model achieves superior predictive performance over standard logistic regression techniques, produces item effects that are consistent with common sense and prior work, and demonstrates that most of the variability among fingerprint examiner decisions occurs at the latent print evaluation stage and as a result of differing tendencies to make inconclusive decisions.

Perceptions of blind proficiency testing among latent print examiners

In recent years, scholars have levied multiple criticisms against traditional proficiency testing procedures in forensic laboratories. Consequently, on several occasions, authorities have formally recommended that laboratories implement blind proficiency testing procedures. Implementation has been slow, but laboratory management has increasingly expressed interest in initiating blind testing in at least some forensic disciplines, with some laboratories conducting blind testing in almost all disciplines. However, little is known about how a key population perceives blind proficiency testing, i.e., forensic examiners. We surveyed active latent print examiners (N = 338) to explore perceptions of blind proficiency testing and determine whether beliefs varied between examiners who work for laboratories with and without blind proficiency testing. Results suggest that examiners do not hold particularly strong beliefs about such procedures, but that examiners who work in laboratories with blind proficiency testing procedures view them significantly more positively than those who do not. Further, examiner responses provide insight into potential obstacles to continued implementation.

Chemical composition effect on latent print development using black fingerprint powders

Fingerprint development has been used to visualize latent prints since the 19th century, and several companies produce a variety of commercially available black fingerprint powders. While the method to develop fingerprints has been refined over the years, the composition of fingerprint powders that are used in print development has not been studied extensively. Six different black fingerprint powders were studied using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS) and zeta potential, attenuated total reflectance infrared spectroscopy (ATR-IR), Raman spectroscopy, powder X-ray diffraction (PXRD), and solution-phase nuclear magnetic resonance spectroscopy (NMR) in addition to a quality study involving certified latent print examiners. When comparing all chemical, physical, and morphological results for the fingerprint powder, this study determined that powders ranked best by latent print examiners are fingerprint powders that mainly contain carbon and oxygen with particle sizes around 50 nm and spherical morphology. Powders with large particle sizes, irregular shape, and elemental compositions consisting of many elements ranked poorly in the quality study performed.

Characterizing missed identifications and errors in latent fingerprint comparisons using eye-tracking data.

Latent fingerprint examiners sometimes come to different conclusions when comparing fingerprints, and eye-gaze behavior may help explain these outcomes. missed identifications (missed IDs) are inconclusive, exclusion, or No Value determinations reached when the consensus of other examiners is an identification. To determine the relation between examiner behavior and missed IDs, we collected eye-gaze data from 121 latent print examiners as they completed a total 1444 difficult (latent-exemplar) comparisons. We extracted metrics from the gaze data that serve as proxies for underlying perceptual and cognitive capacities. We used these metrics to characterize potential mechanisms of missed IDs: Cursory Comparison and Mislocalization. We find that missed IDs are associated with shorter comparison times, fewer regions visited, and fewer attempted correspondences between the compared images. Latent print comparisons resulting in erroneous exclusions (a subset of missed IDs) are also more likely to have fixations in different regions and less accurate correspondence attempts than those comparisons resulting in identifications. We also use our derived metrics to describe one atypical examiner who made six erroneous identifications, four of which were on comparisons intended to be straightforward exclusions. The present work helps identify the degree to which missed IDs can be explained using eye-gaze behavior, and the extent to which missed IDs depend on cognitive and decision-making factors outside the domain of eye-tracking methodologies.

Latent print comparison and examiner conclusions: A field analysis of case processing in one crime laboratory

Scholarship on the latent print comparison process has expanded in recent years, responsive to the call for rigorous research by scholarly groups (e.g., National Academy of Sciences, 2009; President’s Council of Advisors on Science and Technology, 2016). Important to the task of ultimately improving accuracy, consistency, and efficiency in the field is understanding different workflows and case outcomes. The current study describes the casework completed by a latent print unit in a large laboratory during one calendar year (2018), including a unique workflow that involves Preliminary AFIS Associations reported out as investigative leads. Approximately 45% of all examined prints were deemed to be of sufficient quality to enter into AFIS, and 22% of AFIS entries resulted in potential identifications. But examiner conclusions and AFIS outcomes (across three AFIS databases) varied according to case details, print source, and AFIS database. Moreover, examiners differed in case processing, sufficiency determinations, and AFIS conclusions. Results are discussed with respect to implications for future research (e.g., comparing these data to case processing data for other laboratories) and ultimately improving the practice of latent print examination.

Why do latent fingerprint examiners differ in their conclusions?

Forensic latent print examiners usually but do not always reproduce each other’s conclusions. Using data from tests of experts conducting fingerprint comparisons, we show the extent to which differing conclusions can be explained in terms of the images, and in terms of the examiners. Some images are particularly prone to disagreements or erroneous conclusions; the highest and lowest quality images generally result in unanimous conclusions. The variability among examiners can be seen as the effect of implicit individual decision thresholds, which we demonstrate are measurable and differ substantially among examiners; this variation may reflect differences in skill, risk tolerance, or bias. Much of the remaining variability relates to inconsistency of the examiners themselves: borderline conclusions (i.e., close to individual decision thresholds) often were not repeated by the examiners themselves, and tended to be completed more slowly and rated difficult. A few examiners have significantly higher error rates than most: aggregate error rates of many examiners are not necessarily representative of individual examiners. The use of a three-level conclusion scale does not precisely represent the underlying agreements and disagreements among examiners. We propose a new method of quantifying examiner skill that would be appropriate for use in proficiency tests. These findings are operationally relevant to staffing, quality assurance, and disagreements among experts in court.

Testing the accuracy and reliability of palmar friction ridge comparisons – A black box study

Critics and commentators have been calling for some time for black box studies in the forensic science disciplines to establish the foundational validity of those fields—that is, to establish a discipline-wide, base-rate estimate of the error rates that may be expected in each field. While the well-known FBI/Noblis black box study has answered that call for fingerprints, no research to establish similar error rates for palmar impressions has been previously undertaken. We report the results of the first large-scale black box study to establish a discipline-wide error rate estimate for palmar comparisons. The 226 latent print examiner participants returned 12,279 decisions over a dataset of 526 known ground-truth pairings. There were 12 false identification decisions made yielding a false positive error rate of 0.7%. There were also 552 false exclusion decisions made yielding a false negative error rate of 9.5%. Given their larger number, false negative error rates were further stratified by size, comparison difficulty, and area of the palm from which the mark originated. The notion of “questionable conclusions,” in which the ground truth response may not be the most appropriate, is introduced and discussed in light of the data obtained in the study. Measures of examiner consistency in analysis and comparison decisions are presented along with statistical analysis of the ability of many variables, such as demographics or image quality, to predict outcomes. Two online apps are introduced that will allow the reader to fully explore the results on their own, or to explore the notions of frequentist confidence intervals and Bayesian credible intervals.

The Utility of Expanded Conclusion Scales During Latent Print Examinations.

During fingerprint comparisons, a latent print examiner visually compares two impressions to determine whether or not they originated from the same source. They consider the amount of perceived detail in agreement or disagreement and accumulate evidence toward same source and different sources propositions. This evidence is then mapped to one of three conclusions: Identification, Inconclusive, or Exclusion. A limitation of this 3-conclusion scale is it can lose information when translating the conclusion from the internal strength-of-evidence value to one of only three possible conclusions. An alternative scale with two additional values, support for different sources and support for common sources, has been proposed by the Friction Ridge Subcommittee of OSAC. The expanded scale could lead to more investigative leads but could produce complex trade-offs in both correct and erroneous identifications. The aim of the present study was to determine the consequences of a shift to expanded conclusion scales in latent print comparisons. Latent print examiners each completed 60 comparisons using one of the two scales, and the resulting data were modeled using signal detection theory to measure whether the expanded scale changed the threshold for an "Identification" conclusion. When using the expanded scale, examiners became more risk-averse when making "Identification" decisions and tended to transition both the weaker Identification and stronger Inconclusive responses to the "Support for Common Source" statement. The results demonstrate the utility of an expanded conclusion scale and also provide guidance for the adoption of these or similar scales.

The Report of the Expert Working Group on Human Factors in Latent Print Analysis -- Latent Print Examination and Human Factors: Improving the Practice through a Systems Approach

The U.S. National Institute of Standards and Technology (NIST) asked 34 forensic scientists, latent print examiners, forensic laboratory directors, psychologists, statisticians, engineers, law professors, and other experts* to prepare a scientific review and offer recommendations regarding human factors in the forensic analysis of latent prints. The findings are presented in the following chapters, which are followed by a list of all recommendations and an extensive bibliography:• Chapter 1 provides an overview of the Analysis, Comparison, Evaluation, and Verification (ACE-V) process for the examination of latent prints.• Chapter 2 outlines the general ideas behind human factors and organizational theory. It also addresses the nature of errors in latent print analysis, the reasons for identifying them or measuring their prevalence, and possible ways to estimate accuracy and error rates.• Chapter 3 describes, defines, and clarifies the interpretative stages of latent print comparisons. In addition, it describes the current state of knowledge, based upon published research, and discusses what this research suggests about potential concerns and pitfalls in the interpretive process.• Chapter 4 surveys new and forthcoming methods, technologies, and techniques. It examines research needs and ways to improve existing technologies for recording and storing exemplars, for utilizing automated searches to locate exemplars for further comparison, and for conducting latent print examinations.• Chapter 5 addresses written reports that summarize and document the results of friction skin impression examinations. Best practices in report writing and documentation increase the likelihood that the evidence is scientifically accurate and will be used appropriately in the administration of criminal justice. The chapter describes the purposes and value of reporting and documenting examinations and makes suggestions regarding the content of these materials. Appendices provide examples of sample reports.• Chapter 6 discusses trial and pretrial communications from the expert to lawyers, judges, and juries. It reviews the more important legal rules and principles that apply to these activities and surveys the types of testimony that might be provided at trial.• Chapter 7 focuses on the conditions under which latent print work is performed that can affect quality in the latent print examination process. It considers issues such as scheduling, lighting, workstations, interruptions, and workplace design.• Chapter 8 reviews the current status of education and training for latent print examiners, requirements and evaluation criteria, and curricula.• Chapter 9 focuses on the role of management in developing and maintaining the system for producing high-quality results. It reviews the components of a quality organization focused on latent print analysis. These include management, personnel, accreditation, certification, proficiency testing, and a systems approach to error identification and mitigation.• Chapter 10 summarizes the most important parts of the preceding chapters. It draws the recommendations from Chapters 3 through 9 into categories that may be helpful for latent print examiners, managers, research funding agencies, researchers, policymakers, and jurists.* The members of the Working Group were David H. Kaye (editor-in-chief), Thomas Busey (editorial committee), Melissa R. Gische (editorial committee), Gerry LaPorte editorial committee), Colin Aitken, Susan Ballou, Leonard Butt, Christophe Champod, David Charlton, Itiel E. Dror, Jules Epstein, Robert J. Garrett, Max M. Houck, Edward J. Imwinkelried, Ralph Keaton, Glenn Langenburg, Deborah A. Leben, Alice Maceo, Kenneth F. Martin, Jennifer L. Mnookin, Cedric Neumann, Joe Polski, Maria Antonia Roberts, Scott A. Shappell, Lyle Shaver, Sargur N. Srihari, Hal S. Stern, David Stoney, Anjali Swienton, Mary Theofanos, Robert M. Thompson, John Vanderkolk, Maria Weir, and Kasey Wertheim.

How do latent print examiners perceive proficiency testing? An analysis of examiner perceptions, performance, and print quality

Proficiency testing has the potential to serve several important purposes for crime laboratories and forensic science disciplines. Scholars and other stakeholders, however, have criticized standard proficiency testing procedures since their implementation in laboratories across the United States. Specifically, many experts label current proficiency tests as non-representative of actual casework, at least in part because they are not sufficiently challenging (e.g., [1–4]. In the current study, we surveyed latent print examiners (n = 322) after they completed a Collaborative Testing Services proficiency test about their perceptions of test items. We also evaluated respondents’ test performance and used a quality metric algorithm (LQMetrics) to obtain objective indicators of print quality on the test. Results were generally consistent with experts’ concerns about proficiency testing. The low observed error rate, examiner perceptions of relative ease, and high objective print quality metrics together suggest that latent print proficiency testing is not especially challenging. Further, examiners indicated that the test items that most closely resembled real-world casework were also the most difficult and contained prints of the lowest quality. Study findings suggest that including prints of lower quality may increase both the difficulty and representativeness of proficiency testing in latent print examination.

Latent Print Proficiency Testing: An Examination of Test Respondents, Test‐Taking Procedures, and Test Characteristics

Proficiency testing is a key component of quality assurance programs within crime laboratories and can help improve laboratory practices. However, current proficiency testing procedures contain significant limitations and can be misinterpreted by examiners and court personnel (Garrett & Mitchell, 2018). To evaluate some of these limitations, we surveyed latent print examiners (n=198) after they completed a Collaborative Testing Services, Inc. proficiency test. Additionally, we evaluated test performance and used a quality metric algorithm to evaluate the quality of test prints. Results do not suggest that respondents are dissimilar to the broader examiner population, although they may engage in different behaviors when completing tests versus casework. Findings show that proficiency testing contains prints of high quality and is perceived as both relatively easy and representative of casework. The test discriminated between inexperienced and experienced respondents, and verification procedures were largely ineffective in reducing errors. Objective quality metrics may provide a path forward to improving proficiency testing in a measurable manner.

Fingerprints and paternity testing: a study of genetics and probability in pre-DNA forensic science

AbstractThis article is a study of forensic science researchers’ attempts to develop paternity tests based on fingerprint patterning, a physical trait that is partially inherited. Pursued in different times and places—ranging from Austria to Japan to China and from the early 20th century to the 1990s—the projects under study represent an ongoing dialogue, carried out through decades of international scientific exchange, about how to extract genetic information from fingerprints and present this data as scientifically-valid evidence in courts of law. Over time, those who engaged in this work increasingly experimented with methods for presenting fingerprint-based evidence of paternity in quantifiable and even probabilistic terms. Fingerprint-based paternity tests remained an obscure area of forensic practice and were eventually overshadowed by advances in serology and DNA profiling. This unfamiliar corner of forensic science, nonetheless, can provide additional perspective on the history of statistical expertise and probabilistic reasoning in modern forensic science, including the application of Bayesian approaches. The larger body of 20th-century ‘dermatoglyphics’ knowledge out of which these tests emerged also continues to influence the foundation of scientific knowledge on which latent print examination is based today.

Gaze behavior and cognitive states during fingerprint target group localization

BackgroundThe comparison of fingerprints by expert latent print examiners generally involves repeating a process in which the examiner selects a small area of distinctive features in one print (a target group), and searches for it in the other print. In order to isolate this key element of fingerprint comparison, we use eye-tracking data to describe the behavior of latent fingerprint examiners on a narrowly defined “find the target” task. Participants were shown a fingerprint image with a target group indicated and asked to find the corresponding area of ridge detail in a second impression of the same finger and state when they found the target location. Target groups were presented on latent and plain exemplar fingerprint images, and as small areas cropped from the plain exemplars, to assess how image quality and the lack of surrounding visual context affected task performance and eye behavior. One hundred and seventeen participants completed a total of 675 trials.ResultsThe presence or absence of context notably affected the areas viewed and time spent in comparison; differences between latent and plain exemplar tasks were much less significant. In virtually all trials, examiners repeatedly looked back and forth between the images, suggesting constraints on the capacity of visual working memory. On most trials where context was provided, examiners looked immediately at the corresponding location: with context, median time to find the corresponding location was less than 0.3 s (second fixation); however, without context, median time was 1.9 s (five fixations). A few trials resulted in errors in which the examiner did not find the correct target location. Basic gaze measures of overt behaviors, such as speed, areas visited, and back-and-forth behavior, were used in conjunction with the known target area to infer the underlying cognitive state of the examiner.ConclusionsVisual context has a significant effect on the eye behavior of latent print examiners. Localization errors suggest how errors may occur in real comparisons: examiners sometimes compare an incorrect but similar target group and do not continue to search for a better candidate target group. The analytic methods and predictive models developed here can be used to describe the more complex behavior involved in actual fingerprint comparisons.

Do evidence submission forms expose latent print examiners to task-irrelevant information?

Emerging research documents the ways in which task-irrelevant contextual information may influence the opinions and decisions that forensic analysts reach regarding evidence (e.g., Dror and Cole, 2010; National Academy of Sciences, 2009; President’s Council of Advisors on Science and Technology, 2016). Consequently, authorities have called for forensic analysts to rely solely on task-relevant information—and to actively avoid task-irrelevant information—when conducting analyses (National Commission on Forensic Science, 2015). In this study, we examined 97 evidence submission forms, used by 148 accredited crime laboratories across the United States, to determine what types of information laboratories solicit when performing latent print analyses. Results indicate that many laboratories request information with no direct relevance to the specific task of latent print comparison. More concerning, approximately one in six forms (16.5%) request information that appears to have a high potential for bias without any discernible relevance to latent print comparison. Solicitations for task-irrelevant information may carry meaningful consequences and current findings inform strategies to reduce the potential for cognitive bias.

Resolving latent conflict: What happens when latent print examiners enter the cage?

Latent print examination traditionally follows the ACE-V process, in which latent prints are first analyzed to determine whether they are suitable for comparison, and then compared to an exemplar and evaluated for similarities and differences. Despite standard operating procedures and quality controls designed, in part, to mitigate differences between examiners, latent print processing and review are inherently subjective. The ACE-V process addresses subjectivity, and the possibility of error, in the verification stage in which a second examiner repeats the analysis, comparison, and evaluation steps in a given case. Other procedures outside the ACE-V framework, such as consultation and conflict resolution, provide further opportunity to understand how differences between latent print examiners emerge. Despite the growing body of research on latent print examination, questions have emerged about how these procedures work in practice. This study reviews case processing data for two years of casework at the Houston Forensic Science Center (HFSC). We describe these data as cases proceed through each step of the ACE-V process, with a particular focus on verification, consultation, and conflict resolution. We discuss trends in these processes regarding modal types of disagreements, modal outcomes, and roles of the examiners involved. Results reveal implications for improving the practice of latent print examination.

Measuring the Rarity of Fingerprint Patterns in the Dutch Population Using an Extended Classification Set.

Latent print examiners often use their experience and knowledge to reach a conclusion on the identity of the source. Their conclusion is primarily based on their personal opinion on the rarity of the matching fingerprint features. Fingerprint patterns, if present, can play a significant role in the final assessment of a match. The authors believe that statistical data on the rarity of fingerprint patterns strengthens the subjective evaluation of the corresponding information. In order to provide fingerprint examiners with additional numerical support, fingerprint patterns were manually classified in a set of 24,104 fingerprints. In this study the frequencies of occurrence of 35 different fingerprint patterns have been obtained. The frequency data presented in this study can be used in the ACE-V process applied in forensic casework, allowing for the assessment of the evidential strength related to a specific fingerprint pattern type.