Fingerprints are unique patterns used as biometric keys because they allow an individual to be unambiguously identified, making their application in the forensic field a common practice. The design of a system that can match the details of different images is still an open problem, especially when applied to large databases or, to real-time applications in forensic scenarios using mobile devices. Fingerprints collected at a crime scene are often manually processed to find those that are relevant to solving the crime. This work proposes an efficient methodology that can be applied in real time to reduce the manual work in crime scene investigations that consumes time and human resources. The proposed methodology includes four steps: (i) image pre-processing using oriented Gabor filters; (ii) the extraction of minutiae using a variant of the Crossing Numbers method which include a novel ROI definition through convex hull and erosion followed by replacing two or more very close minutiae with an average minutiae; (iii) the creation of a model that represents each minutia through the characteristics of a set of polygons including neighboring minutiae; (iv) the individual search of a match for each minutia in different images using metrics on the absolute and relative errors. While in the literature most methodologies look to validate the entire fingerprint model, connecting the minutiae or using minutiae triplets, we validate each minutia individually using n-vertex polygons whose vertices are neighbor minutiae that surround the reference. Our method also reveals robustness against false minutiae since several polygons are used to represent the same minutia, there is a possibility that even if there are false minutia, the true polygon is present and identified; in addition, our method is immune to rotations and translations. The results show that the proposed methodology can be applied in real time in standard hardware implementation, with images of arbitrary orientations.

UNASSIGNED: The present study is an attempt to study the sex differences in minutiae frequencies of thumbprint with respect to dermatoglyphic patterns. A sample of 100 subjects (50 males and 50 females) were gathered from Shimla, Himachal Pradesh (North India). In regards to pattern type, maximum number of minutiae was present in loop pat-tern followed by whorls and least minutiae were in the arches in the right hand of both the sexes and left hand of females only, whereas in left hand of the males highest frequency of minutiae were noticed in whorls followed by loops and lowest in the arches, thereby indicating the lessened bimanual symmetry in males. It can be inferred from the present study that the simple pattern (arch) has less discontinuance in the regular flow of the ridges, while the complex patterns (loops and whorls) exhibited more interruptions in the dermal ridges.

A variety of suspended silica and metal nanoparticles have been used over the last 20 years to enhance latent fingermarks. This study quantitatively evaluates enhancement of natural and sebum-enriched fingermarks from three adult subjects acquired with a consistent applied force on glass with a fingermark press using suspended commercially available polystyrene (PS) particles. Images of the enhanced fingermarks acquired with total internal reflection (TIR), or standard overhead white light (WL), illumination are compared with fingermarks enhanced with conventional methods including cyanoacrylate fuming. The different enhancement and illumination methods are quantified based on the brightness and contrast of the fingermark images, as well as the number of minutiae that can be identified and matched to those on an inked manually acquired \"template\" fingermark using automatic fingerprint identification system (AFIS) software. Enhanced fingermarks acquired with the press are shown to be more consistent than manually acquired fingermarks based on these metrics. The results demonstrate that TIR illumination from a large-area illuminator built in house gives enhanced fingermark images with more matched minutiae and contrast superior to that for WL illumination for all types of enhancement. \"Wet-powdering\" with PS particles gives fingermark images that are for the most part comparable in terms of the number of matched minutiae to fingermarks enhanced with more conventional methods, suggesting that this novel enhancement method has a performance comparable to conventional enhancement methods. Interestingly, the age of the fingermark appears to have almost no effect on this new type of enhancement; sebum-enriched fingermarks ranging in age from 12 h to 435 days appear to have statistically identical numbers of matched minutiae.

Palmprints have been systematically less studied than fingerprints, despite being of great use in the identification process. In Spain, they were not included in Automated Fingerprint Identification Systems (AFIS) until 2009. Very few investigations performed within the field of palmprints have assessed the sexual and population variability of the number and distribution of minutiae on its surface, despite the fact that these particularities are the basis for personal identification in forensic science. That is why a study was conducted to assess total, bimanual, and sexual density per morphological regions (superior or distal, thenar, and hypothenar) and per counting areas of 1 cm2 on 120 palmprints obtained from 30 male and 30 female individuals of Spanish nationality. Also, the frequency in the location of each type of delta or triradius (a, b, c, d, and t) per count area was calculated. Results have shown a topological variability in the distribution of the density of minutiae, which is similar between sexes and a specular effect between both hands. The most frequent locations of the deltas coincide with areas of high minutiae density. It has also been shown that there are sexual differences in the total number of minutiae, which cannot be due to sexual dimorphism in adult hand size, since minutiae are established at an early stage of fetal development and their number will not change during later postnatal growth. These differences can only be attributed to genetic factors related to sexual determination.

The selection of minutiae is a critical part of the analysis phase within the fingerprint identification methodology, known as analysis-comparison-evaluation-verification. This study assessed the accuracy and reliability of the minutiae selections of 92 Chinese fingerprint examiners during the analysis phase, absent an exemplar print, of the fingerprint identification process. Specifically, we measured the accuracy (trueness) of their annotation of minutiae, and we measured their reliability which is the reproducibility and repeatability in their annotations in one complex mark by using R software. We observed significant variation within inter- and intra-examiner annotations of the minutiae. We saw no statistically significant differences for the variability of minutiae annotations based on the participant\'s sex or years of experience.

Fingerprint Recognition System is widely deployed in variety of application domain, ranging from forensic to mobile phones. Its widespread deployment in various applications were person authentication are required, has caused concern that a leaked fingerprint template may be used to reconstruct the original fingerprint and the reconstructed fingerprint can be used to circumvent all the applications the person is enrolled. In this paper, a non-invertible fingerprint template that stores only the relative geometric information about the minutiae points is proposed. The spatial location of the minutiae points in original fingerprint and its orientations are not available in the proposed template which makes it impossible to estimate the orientation of fingerprint from the template. The proposed template is invariant to rotation, translation and distortion and immune to reconstruction algorithm. The proposed system is experimented using standard FVC2000 database and yields better results in terms of EER and FMR as compared with latest techniques.

BACKGROUND: We know that teeth trouble us a lot when we are alive, but they last longer for thousands of years even after we are dead. Teeth being the strongest and resistant structure are the most significant tool in forensic investigations. Patterns of enamel rod end on the tooth surface are known as tooth prints.
OBJECTIVE: This study is aimed to know whether these tooth prints can become a forensic tool in personal identification such as finger prints. A study has been targeted toward the same.
METHODS: In the present in-vivo study, acetate peel technique has been used to obtain the replica of enamel rod end patterns.
METHODS: Tooth prints of upper first premolars were recorded from 80 individuals after acid etching using cellulose acetate strips. Then, digital images of the tooth prints obtained at two different intervals were subjected to biometric conversion using Verifinger standard software development kit version 6.5 software followed by the use of Automated Fingerprint Identification System (AFIS) software for comparison of the tooth prints. Similarly, each individual\'s finger prints were also recorded and were subjected to the same software.
METHODS: Further, recordings of AFIS scores obtained from images were statistically analyzed using Cronbach\'s test.
RESULTS: We observed that comparing two tooth prints taken from an individual at two intervals exhibited similarity in many cases, with wavy pattern tooth print being the predominant type. However, the same prints showed dissimilarity when compared with other individuals. We also found that most of the individuals with whorl pattern finger print showed wavy pattern tooth print and few loop type fingerprints showed linear pattern of tooth prints.
CONCLUSIONS: Further more experiments on both tooth prints and finger prints are required in establishing an individual\'s identity.

The fingerprints of the Buenos Aires and Chubut provinces in Argentina have been studied, with the aim of knowing and quantifying the variability of these features, which are used in the identification process. The data studied for this research was obtained from 330 individuals, of both sexes, from two Argentinian population samples (170 individuals from Buenos Aires and 160 from Chubut), which amounts to a total of 3300 fingerprints. The different types of minutiae were located, identified, and visually quantified in four areas on the fingerprint. Two perpendicular axes were drawn whose intersection was located in the center of fingerprint. In addition, a circle was defined on these quadrants whose radius cut fifteen ridges. This method divides the fingerprints into four quadrants with two sectors apiece. The results obtained for both populations were compared statistically with those published previously for an Argentinian population sample, which had been collected using the same methodology. Therefore, Argentina becomes the country with the most information in this matter. For both populations, the highest frequencies were of ridge endings, followed by bifurcations and convergences. In this study of minutiae, statistically significant differences were found between the area of the fingerprint (inside and outside the circle), males and females, and types of main pattern for both samples. However, although the results show common patterns in the distribution of minutiae, there are also significant differences between populations. This reveals a significant ancestral and frequency effect of the minutiae, which would indicate that the minutiae are more genetically dependent than has been suspected so far. Furthermore, the non-equiprobability found for the frequency of the types of minutiae indicates that the weight provided by these characteristics is not the same when applied in identification processes, whether used quantitatively (numerical standard) or qualitatively (holistic method).

To support fingerprint expert opinion, this research proposes an approach that combines subjective human analysis (as currently applied by fingerprint practitioners) with a statistical test of the result. This approach relies on the hypothesis that there are limits to the distortion caused by skin stretch. Such limits can be modelled by applying a multivariate normal probability density function to the distances and angle formed by a marked ridge characteristic and the two closest neighbouring minutiae. This study presents a model tested on 5 donors in total. The \"expected range\" of distortion in a within-source comparison using 10 minutiae was determined and compared to between-source comparisons. The expected range of log probability densities for within-source comparisons marked with 10 minutiae was determined to be from -33.4 to -60.0, with all between-source data falling outside this range, between -83 and -305. These results suggest that the proposed generated metric could be a powerful tool for the assessment of fingerprint expert opinion in operational casework.

The authors are exploring degradation patterns of latent fingermarks over time which can be quantitatively determined in a predictable manner by visual means. Several physical degradation parameters for assessing this hypothesis are evaluated. This article analyzes the parameter \"minutiae count\" as a function of time. Experiment variables included were secretion type (sebaceous-rich and eccrine-rich), substrate (glass and plastic), and exposure to light (dark, shade, and direct light). Depositions were sequentially visualized with Titanium Dioxide powder over a period of 6 months, photographed, and number of minutiae recorded. Results revealed a significant decrease of minutiae for eccrine-rich marks on glass but insignificant for sebaceous-rich marks on the same surface. However, significant degradation was observed for both types of secretions on plastic. The authors conclude that the distinctive prevalence of minutiae changes over time indicates with a high degree of certainty the hypothesis is valid and deserves additional exploration.