Fingerprint Examiners Research Articles

An expert–novice comparison of feature choice

SummaryPerceptual experts have learned to rapidly and accurately perceive the structural regularities that define categories and identities within a domain. They extract important features and their relations more efficiently than novices. We used fingerprint examination to investigate expert–novice differences in feature choice. On each fingerprint within our set, experts and novices selected one feature they thought was most useful for distinguishing a particular print and one feature they thought was least useful. We found that experts and novices often differed in the features they chose, and experts tended to agree more with each other. However, any such expert–novice difference appeared to depend on the image at hand typically emerging when salient or more conspicuous features of a fingerprint were unclear. We suggest that perceptual training ought to direct attention to useful features with the understanding that what is useful may change depending on the clarity of the stimuli.

Switchgrass Rhizosphere Metabolite Chemistry Driven by Nitrogen Availability

Plants and soil microorganisms interact closely in the rhizosphere where plants may exchange carbon (C) for functional benefits from the microbial community. For example, the bioenergy crop, switchgrass (Panicum virgatum) is thought to exchange root-exuded C for nitrogen (N) fixed by diazotrophs (free-living N-fixers). However, this interaction is not well characterized and it is not known how or if switchgrass responds to diazotrophs or their activity. To explore this question, we assessed rhizosphere metabolite chemistry of switchgrass grown in a hydroponic system under two N levels and under inoculated or uninoculated conditions. Plants were grown with the inoculum Azotobacter vinelandii DJ for 3 days before harvest. We found switchgrass root exudate chemistry to be driven by N availability. Total metabolite concentrations were generally greater under high N versus low N and unaffected by inoculation. Examination of rhizosphere chemical fingerprints indicates metabolite chemistry was also driven strongly by N availability with a greater relative abundance of carbohydrates under high N and greater relative abundance of organic acids under low N. We also found evidence of changes in rhizosphere chemical fingerprints by inoculation treatment. However, we found little evidence of N treatment and inoculation interaction effects that suggests this response is not directly mediated by N availability. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Defence against the modern arts: the curse of statistics: Part I—FRStat

Abstract For several decades, legal and scientific scholars have argued that conclusions from forensic examinations should be supported by statistical data and reported within a probabilistic framework. Multiple models have been proposed to quantify and express the probative value of forensic evidence. Unfortunately, the use of statistics to perform inferences in forensic science adds a layer of complexity that most forensic scientists, court offices and lay individuals are not armed to handle. Many applications of statistics to forensic science rely on ad hoc strategies and are not scientifically sound. The opacity of the technical jargon that is used to describe these probabilistic models and their results, and the complexity of the techniques involved make it very difficult for the untrained user to separate the wheat from the chaff. This series of article is intended to help forensic scientists and lawyers recognize limitations and issues in tools proposed to interpret the results of forensic examinations. This article focuses on the tool proposed by the Latent Print Branch of the U.S. Defense Forensic Science Center (DFSC) and called FRStat. In this article, I explore the compatibility of the results outputted by FRStat with the language used by the DFCS to report the conclusions of their fingerprint examinations, as well as the appropriateness of the statistical modelling underpinning the tool and the validation of its performance.

On perceptual expertise

Expertise is a cognitive achievement that involves experience and learning and that requires explicit, time‐consuming training specific to the relevant domain. It is intuitive that many such experts—radiologists, bird watchers, fingerprint examiners, and so forth—are better perceivers in the domain(s) of their expertise. The goal of this paper is to motivate three related claims. Perceptual expertise is genuinely perceptual and genuinely cognitive, and this phenomenon reveals how we can become epistemically better perceivers. These claims are defended against opponents that deny significant cognitive effects on perception, and opponents who maintain that any such effects on perception are epistemically pernicious.

Wpływ wybranych cech osobowości na przebieg i wyniki porównywania śladów daktyloskopijnych

Forensic experts in the field of fingerprint examination are prone to cognitive errors that can affect the opinion issuing process. A study was conducted to determine if students exhibiting certain intensities of two personality traits: the need for cognitive closure and controllability, have a predisposition to be better fingerprint examination experts compared to others. The study consisted of three stages: completion of personality questionnaires, training in fingerprint examination, and finally a fingerprint examination – related task. The task was appropriately staged to introduce cognitive illusions, led by which, the subjects were more likely to give incorrect answers. No significant correlation was found between the studied characteristics and correctness, biases, caution, and decisiveness in the task performed. The subjects were significantly more likely to give incorrect answers. There was a positive correlation of time with the number of correct answers. A significant positive correlation was also observed between the preference of order and caution in task performance. The results obtained can be used in typing individuals who will perform better at comparing fingerprints.

Metalizacja próżniowa (VMD) – charakterystyka metody

Vacuum metal deposition was introduced in the process of visualization of latent fingermarks already in the 20th century. However, due to the requirement of using specialist equipment to ensure appropriate conditions for the development process, which would have generated significant costs, the method was not available in Poland. Technological developments, however, made it possible to create compact devices with smaller dimensions and lower parameters, which, nowadays, can be used in virtually every forensic fingerprint identification laboratory. The article describes the theoretical basis of the process of developing fingerprints by means of the vacuum metal deposition method with the use of sequential deposition of gold, zinc and silver on the tested surfaces. The device used for the VMD method is also presented along with sample effects of treating fingerprints on various surfaces, including registration in the range of reflected infrared light and with recovering marks on lifting foils. The final part deals with the issue of accrediting forensic service providers performing fingerprint examinations, including problems related to the implementation of vacuum metal deposition in the range of accredited fingerprint visualization techniques.

Opracowanie zaawansowanego technologicznie systemu informatycznego umożliwiającego zautomatyzowane przetwarzanie informacji zgromadzonych w kryminalistycznych biometrycznych bazach danych w celu zwalczania przestępstw lub identyfikacji osób

Forensic biometric databases are an out of court tool to support the work of law enforcement agencies. They are used to detect the perpetrators of crimes, indicate the connections of a person with previously committed crimes, and allow the identification of living persons and corpses with unknown identity or individuals trying to hide their identity. In police practice, among the methods of identification of living persons and corpses, fingerprint and DNA tests are mainly used. These two forensic areas are supported by such tools such as AFIS (Automatic Fingerprint Identification System) and CODIS (Combined DNA Index System). These are the main police systems operating within two datasets, namely the dactyloscopic dataset and the DNA dataset. The systems are operating in two different locations of the Central Forensic Laboratory of the Police (CFLP). This results in the processing of individual biometric data independently of each other at different times and locations (Fingerprint Examination Department and Biology Department). Currently, there is no comprehensive approach to the collection and processing of biometric data such as fingerprints, DNA or facial images. To improve the exchange of information between police authorities, in July 2019, the Central Forensic Laboratory of the Police submitted a project application, and on 25 November 2019 signed with the National Center for Research and Development the grant agreement no. DOB – BIO10/09/01/2019 for the implementation and financing of the project in the area of state defense and security (competition no. 10/2019) entitled “Development of a technologically advanced information system enabling automated processing of information collected in forensic biometric databases for the purpose of combating crime or identifying people – acronym “BIOMETRIA”.

Substancja potowo-tłuszczowa a wiek człowieka

The article presents results of the relationship between the quantity of sweat and sebaceous secretions and the age of a person. The study was carried out in a group of 70 persons of various ages and both sexes. Basing on the results it may be concluded that the age and sex have a significant influence on the quantity of sweat and sebaceous secretions. This can be used during preparation of various test samples, for example competence tests for fingerprint examiners.

Airborne dust traffic from Australia in modern and Late Quaternary times

Abstract A review is provided of first-documented occurrences of dust transport within Australia for the last century, but which later on were considerably improved as a result of access to satellite observations and extensive ground observations. This was followed by the use of the HYSPLIT tracking models that enabled people to determine the major sources of dust in Australia. As a result of several important studies, the Lake Eyre Basin in central Australia is now considered to be the main source of dust entrainment, although other regions do contribute to dust production. This is followed by examination of the occurrence over the last few decades of dust transport and deposition within Australia and across the Tasman Sea, with dust being deposited even as far as New Zealand. After that, consideration is given to the deposition of dust not only at sea around Australia but also in New Zealand during the Holocene and Late Quaternary. As a consequence of these observations, a shift in the direction of dust plumes exiting Australia is noted. For example, during the Last Glacial Maximum (LGM), a substantial northerly shift of the Trans-Tasman dust plume is recorded and this coincides with stronger westerlies and an equatorward shift of oceanic fronts such as the Intertropical Convergence and Subpolar and Antarctic Fronts that were located closer to Australia compared to today. Strengthening of the winds during the LGM may have prevented dust plumes from travelling over the southern part of the Tasman Sea, even perhaps reaching Antarctica. Examination of the dust components in cores in the western Pacific Ocean would address this question. The second part of the paper examines the geochemical fingerprints of dusts from Australia, South America and those recovered from Antarctic ice cores. Examination of atmospheric conditions that prevailed in the Southern Ocean around Antarctica during a major dust storm event that occurred in Australia in October 2002 helps identify how dust can be entrained around cold fronts and eventually reach the Antarctic mainland. Once again, it appears that Australian dust did travel as far as Antarctica more frequently during the Holocene, than prior to that time. New Zealand as a dust source to some Antarctic sites is also discussed. Examination of the isotopic fingerprints in Antarctic ice cores point to South America being the main source of dust during the Last Glacial Maximum and previous glacial periods, with intermittent occurrences likely to have come from Australia and New Zealand as well. It is postulated that Australian dust plumes did travel mostly over the Tasman Sea, and eventually over the western Pacific Ocean during the LGM, and frequently less so towards Tasmania and the Southern Ocean as a result of the strengthening of the westerlies and their northward shift. It transpires that the dust flux from Australia was much higher during the glacial periods. It appears also that the dust plumes that traverse the eastern Indian Ocean remained unchanged during the LGM. Finally, this paper concludes by identifying that there is a need to either obtain larger dust samples from ice cores, or use more elaborate analytical techniques to combine more than two isotopes to fingerprint the origin of dusts recovered in ice cores. Perhaps a combination of not only isotopes, but also rare earth elements and major elements would eventually provide a better definition of atmospheric circulation in the Southern Hemisphere for comparison between glacial and interglacial periods.

Forensic examination of handwriting and thumb impression-A case study

Handwriting Science and Finger Print examination both are significant branches of Forensic Science. This article illustrates one of the important cases related to cheating by impersonation in constable recruitment examination. The case was submitted in Central Forensic Science Laboratory CBI, New Delhi for examination and opinion on handwritings as well as finger thumb impressions with detailed questionnaires. Inter see examination and comparison of questioned document with standard document reveals that both the sets were consistent in detailed characteristic features and execution of strokes in construction of letter and their combination in words. The authorship of questioned documents was matched with the supplied specimen documents. Also, the questioned thumb impressions were compared with the standard thumb impression and were found consistent between both the sets. The case was examined thoroughly by applying the principle of handwriting science and finger thumb impression. The case was successfully solved on the basis of forensic analysis of handwritings and finger thumb impressions. The scientific evidence was produced during court testimony by the experts and opinion was accepted in the court of law and finally the suspected person was convicted. Keywords: Questioned document examination, Thumb impression, Forensic examination.

ABOUT METHODS OF FALSIFICATION OF TRACKS OF PAPILLARY PATTERNS OF HUMAN HANDS AND THE POSSIBILITIES OF THEIR DETECTION DURING DACTYLOSCOPIC (FINGERPRINT) EXAMINATIONS

In the article, based on the generalization of expert practice of fingerprinting studies, the methods of falsifying traces of human papillary patterns are described. The signs displayed in the traces when using one or another method of fraud are made. The stage of the diagnostic study of fingerprint objects is described based on the examples of several expert studies from practice. As examples, the signs characterizing the transfer of traces of papillary patterns of human hands from one object to another are given. The importance of the diagnostic study during repeated fingerprint examinations is indicated. Descriptions and illustrations of comparison of signs of falsification (transfer) identified in the traces are given. An algorithm for conducting such studies and an approach to integrated assessment is described. It justifies the need for a stage of diagnostic research with the involvement of experts from other specialties (biologists, chemists, physicists, etc.) to establish the origin of the traces. According to the results of the analysis, recommendations were given regarding an integrated expert approach to the assessment of signs which were reflected in the traces identified at the research sites, and on a comprehensive assessment of the signs of the trace-receiving surface from which the traces of human papillary patterns were examined. The article also substantiates the need to develop guidelines for the diagnostic study of traces of papillary patterns of human hands to determine the method of their origin. Key words: fingerprinting, papillary patterns, falsification, artificial traces.

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.

The impact of proficiency testing information and error aversions on the weight given to fingerprint evidence.

Fingerprint examiners regularly participate in tests designed to assess their proficiency. These tests provide information relevant to the weight of fingerprint evidence, but no prior research has directly examined how jurors react to proficiency testing information. Using a nationally representative sample of American adults, we examined the impact of proficiency testing information on the weight given to the opinions of fingerprint examiners by mock jurors considering a hypothetical criminal case. The fingerprint examiner's level of performance on a proficiency test (high, medium, low, or very low), but not the type of error committed on the test (false positive identifications, false negative identifications, or a mix of both types of error), affected the weight that jury-eligible adults gave to an examiner's opinion that latent fingerprints recovered from a crime scene matched the defendant's fingerprints, which in turn affected judgments about the defendant's guilt. Jurors who had no information about proficiency gave similar weight to the testimony as jurors exposed to highly proficient examiners, suggesting that jurors assume fingerprint examiners perform at high levels of proficiency unless informed otherwise. We also found that a plurality of Americans deems false acquittals just as aversive as false convictions and a significant minority deems false acquittals more serious. These differences in error aversions predicted differences in evidentiary assessments, suggesting that error aversions of jurors may play an important role in criminal trials.

The permanence of friction ridge skin and persistence of friction ridge skin and impressions: A comprehensive review and new results

This study addresses the permanence and persistence of friction ridges and the persistence of impressions made from these friction ridges over months and years. Permanence is the unchanging presence and appearance of friction ridge arrangements and their attributes between recurring observations of the skin. Permanence was evaluated from direct photographs of fingers collected over a period of 30–45 days (covering one or more skin regeneration cycles) as well as after 8 or more years had elapsed. Persistence embodies the operational concept of whether or not a pair of images displays sufficient similarity upon which to base an informed decision that they were made by the same finger, while acknowledging certain dissimilarities or distortions due to friction ridge physiology, image capture, matrix, substrate, and applied pressure. Persistence applies to both friction ridge skin and impressions made from these friction ridges. Permanence and persistence of skin were assessed from direct photographs of fingers taken two months apart and from finger photographs separated by an interval of at least 8 years. Permanence and persistence were also assessed from impressions taken over 4 months, as well as those separated by 8–53 years. Variability due to capture method was assessed by using four image capture methods over a four month period: direct photography of fingers, impressions captured by ink, holographic imaging, and live scan. Qualified latent fingerprint examiners assessed all changes observed over time, as well as any limitations imposed by capture method.The practice of comparison and identification of fingerprint impressions was upheld, as was the prevailing use of the word persistence to describe stability of friction ridges. All photographs and impressions of the same finger were identifiable as originating from the same source. Within all the periods of observation, level 1 detail was permanent and persistent. Persistence, but not permanence, was supported for level 2 detail. Notably, the small changes observed were only in appearance; there were no changes in the presence of new, or absence of existing, minutiae. Level 3 details of ridge edge shape and pore presence were neither permanent nor persistent. Ridge width was permanent and persistent. Incipient ridges were neither permanent nor persistent.

FORENSIC-FINGERPRINT EXAMINATION IN CRIMINAL PROCEEDINGS

The article in Based on the use of the norms of the current legislation and the practice of its implementation, experts have characterized the stages of conducting examination of fingerprints, as well as factors that affect its effectiveness. Indicates the need for further development of scientific and legal foundations of experts’ activities, improvement of means, methods, methods of their work with fingerprint information.

Projekt "Mapowanie odbitek linii papilarnych" (część I) - geneza

Since the publication of the National Research Council Report titled: Strengthening Forensic Science in the United States: A Path Forward for the United States Department of Justice, there has been an international discussion on scientific character of fingerprint examination, and Poland has not been excluded from it. The approaches to fingerprint identification in the United States of America and Poland are completely different. In the first case, the holistic standard is used basing exclusively on the experience and conviction of the expert, and in the other one, numerical standard precisely determining the minimum number of consistent individual characteristics (minutiae) required for identification. Both standards have both advantages and significant drawbacks. A good way out of this situation would be finding a solution combing the holistic and numerical approaches and the project “Mapping of friction skin ridges impressions” implemented by the forensic experts of Fingerprint Examination Department in the Central Forensic Laboratory of the Police makes constitutes contribution to that.

The Effects of High Dynamic Range on Fingerprint Images Processed by Photoshop.

High dynamic range (HDR) imaging is a function that combines five images with different exposures into a single image. This technique may provide fine ridge details of fingerprint images for forensic latent fingerprint examination. Therefore, viewing fingerprints under optimal conditions is of paramount importance. This paper analyzes HDR and non-HDR photos by using the Michelson contrast formula. The Michelson formula will provide a measurement to determine whether better contrast between the background and print can be achieved using the HDR function and if the background color affects the quality of the images. Two hypothesis were tested: (i) the HDR image provides more details of fingerprints with a better tone, greater clarity, and contrast than a normally exposed image regardless of the background color; (ii) the background color does not affect the quality of HDR fingerprint images overall, but the multi-color background may increase the contrast of HDR fingerprint images in some cases.

Touch DNA: The effect of the deposition pressure on the quality of latent fingermarks and STR profiles

Latent fingermarks (FMs) present unique, and sometimes the only, evidence found at a crime scene. Several factors affect their quality, including deposition pressure (DP). Its effect on FM size and quality, and on STR amplification success rate, is an emerging area of interest in forensic science. This study examined 540 FM samples, each consisting of index, middle and ring fingers, deposited by 30 donors on glass, polythene (PE) and paper under a range of weights from 0.1 to 10 kg. Both length and width of FMs increased with the increasing DP. FMs deposited under lower (≤0.5 kg) DPs varied in size (p < 0.01), while those deposited at higher (≥3 kg) DPs were more consistent. FM quality on glass and PE, as determined by the AFIS minutiae count and by a fingerprint examiner on a scale from 0 to 4, improved with the increasing DP, but it deteriorated on PE at DP of 10 kg. FM quality on paper continued to improve from DP of 1 kg up to the maximum DP of 10 kg. The effect DP has on the efficacy of DNA profiling from latent FMs was significant as shown by an increase in the DNA amount recovered, the number of amplified loci per FM sample, and the number of forensically useful DNA profiles (defined here as those with ≥8 full STR loci detected) as DP increased. This effect was most pronounced with PE (R = 0.98) and paper (R = 0.96). Altogether, the success rate of DNA profiling varied from 16.3% in FMs deposited on paper to 21.2% and 22.5% of those on PE and glass. The highest number of useful DNA profiles was obtained from glass under DP of 10 kg. Forensically useful FMs obtained at low (≤1 kg) DP from all three substrates significantly outnumbered that of STR profiles, while an opposite, though less pronounced trend, was observed at high (≥3 kg) DP on PE and paper. Application of the simple device for collecting of FMs under controlled pressure designed for this study, and the palm-up mode of FM deposition as described, allowed us to eliminate the undesirable effect of the hand self-weight and to objectively assess the actual effect of increasing DP on FM size and quality, as well as on the efficacy of DNA profiling.

Certainty &amp; Uncertainty in Reporting Fingerprint Evidence

Everyone knows that fingerprint evidence can be extremely incriminating. What is less clear is whether the way that a fingerprint examiner describes that evidence influences the weight lay jurors assign to it. This essay describes an experiment testing how lay people respond to different presentations of fingerprint evidence in a hypothetical criminal case. We find that people attach more weight to the evidence when the fingerprint examiner indicates that he believes or knows that the defendant is the source of the print. When the examiner offers a weaker, but more scientifically justifiable, conclusion, the evidence is given less weight. However, people do not value the evidence any more or less when the examiner uses very strong language to indicate that the defendant is the source of the print versus weaker source identification language. We also find that cross-examination designed to highlight weaknesses in the fingerprint evidence has no impact regardless of which type of conclusion the examiner offers. We conclude by considering implications for ongoing reform efforts.

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.