Fingerprint Ridge Density as a Potential Forensic Anthropological Tool for Sex Identification

In cases of partial or poor print recovery and lack of database/suspect print, fingerprint evidence is generally neglected. In light of such constraints, this study was designed to examine whether ridge density can aid in narrowing down the investigation for sex identification. The study was conducted on the right‐hand index digit of 245 males and 246 females belonging to the Punjabis of Delhi region. Five ridge density count areas, namely upper radial, radial, ulnar, upper ulnar, and proximal, were selected and designated. Probability of sex origin was calculated, and stepwise discriminant function analysis was performed to determine the discriminating ability of the selected areas. Females were observed with a significantly higher ridge density than males in all the five areas. Discriminant function analysis and logistic regression exhibited 96.8% and 97.4% accuracy, respectively, in sex identification. Hence, fingerprint ridge density is a potential tool for sex identification, even from partial prints.     

An Investigation into the Effects of Force Applied During Deposition on Latent Fingermarks and Inked Fingerprints Using a Variable Force Fingerprint Sampler

Physical factors, including the magnitude of the force applied during fingermark deposition, may affect friction ridge surface area and clarity, and the quantity of residue transferred. Consistency between fingermarks may be required; for example, in research projects, yet differences between marks are likely to exist when physical factors are not controlled. Inked fingerprints and latent fingermarks were deposited at 1–10 N at 1 N increments using a variable force fingerprint sampler to control the force, angle of friction ridge and surface contact, and the duration of friction ridge and surface contact. Statistically significant differences existed between the length and width measurements of the inked prints (p ≤ 0.05), particularly at lower forces. Scanning electron microscopy and surface plot analysis demonstrated how differences in force applied during deposition affected ridge surface area, displacement of latent residue, and differences in the quantity of residue transferred. Consistency between inked prints was demonstrated at equivalent forces.     

Ridge Width Correlations between Inked Prints and Powdered Latent Fingerprints

A methodology to estimate the time of latent fingerprint deposition would be of great value to law enforcement and courts. It has been observed that ridge topography changes as latent prints age, including the widths of ridges that could be measured as a function of time. Crime suspects are commonly identified using fingerprint databases that contain reference inked tenprints (flat and rolled impressions). These can be of interest in aging studies as they provide baseline information relating to the original (nonaged) ridges’ widths. In practice, the age of latent fingerprints could be estimated following a comparison process between the evidentiary aged print and the corresponding reference inked print. The present article explores possible correlations between inked and fresh latent fingerprints deposited on different substrates and visualized with TiO₂. The results indicate that the ridge width of flat inked prints is most similar to fresh latent fingerprints_, and these should be used as the comparison standard for future aging studies.     

A Comparison of Palmar Dermatoglyphics in Two Ethnic Indian Populations of North Bengal,India*

Abstract: Dermatoglyphic print comparisons can be utilized to establish personal identification in forensic cases. The northern part of the state of West Bengal, India, is the home to many ethnic populations. Two such populations are the Rajbanshi and the Mech. Palm prints were collected from 192 adult Rajbanshi (105 men and 87 women) and 100 adult Mech (50 men and 50 women) individuals for print comparison using the standard ink and roll print method. The dermatoglyphic variables studied were mainline formulae, termination of mainline, positional variation of axial triradii, and true pattern of hypothenar and thenar configuration area. There were differences between the Rajbanshi and Mech individuals with respect to these dermatoglyphic variables. The uses of these variables appear to be limited only to ethnic identification, not personal identification. The present investigation further highlights the racial affinity, sex, and bilateral differences among Rajbanshi individuals using dermatoglyphic palmar variables.     

Evaluation of Lip Prints on Different Supports Using a Batch Image Processing Algorithm and Image Superimposition

This study aimed to develop and to assess an algorithm to facilitate lip print visualization, and to digitally analyze lip prints on different supports, by superimposition. It also aimed to classify lip prints according to sex. A batch image processing algorithm was developed, which facilitated the identification and extraction of information about lip grooves. However, it performed better for lip print images with a uniform background. Paper and glass slab allowed more correct identifications than glass and the both sides of compact disks. There was no significant difference between the type of support and the amount of matching structures located in the middle area of the lower lip. There was no evidence of association between types of lip grooves and sex. Lip groove patterns of type III and type I were the most common for both sexes. The development of systems for lip print analysis is necessary, mainly concerning digital methods.     

Distortion in Fingerprints: A Statistical Investigation using Shape Measurement Tools

Friction ridge impression appearance can be affected due to the type of surface touched and pressure exerted during deposition. Understanding the magnitude of alterations, regions affected, and systematic/detectable changes occurring would provide useful information. Geometric morphometric techniques were used to statistically characterize these changes. One hundred and fourteen prints were obtained from a single volunteer and impressed with heavy, normal, and light pressure on computer paper, soft gloss paper, 10‐print card stock, and retabs. Six hundred prints from 10 volunteers were rolled with heavy, normal, and light pressure on soft gloss paper and 10‐print card stock. Results indicate that while different substrates/pressure levels produced small systematic changes in fingerprints, the changes were small in magnitude: roughly the width of one ridge. There were no detectable changes in the degree of random variability of prints associated with either pressure or substrate. In conclusion, the prints transferred reliably regardless of pressure or substrate     

Latent fingermark pore area reproducibility

The study of the reproducibility of friction ridge pore detail in fingermarks is a measure of their usefulness in personal identification. Pore area in latent prints developed using cyanoacrylate and ninhydrin were examined and measured by photomicrography using appropriate software tools. The data were analysed statistically and the results showed that pore area is not reproducible in developed latent prints, using either of the development techniques. The results add further support to the lack of reliability of pore area in personal identification.     

Cheiloscopy: Lip Print Inter‐rater Reliability

Lip print analysis, or cheiloscopy, has the potential to join fingerprints and retinal scans as an additional method to determine human identification. This preliminary study sought to determine agreement among 20 raters, forensic odontologists, using an often referenced system that categorizes lip prints into six classes related to the dominant pattern of vertical, horizontal, and intersecting lines. Lip prints were taken from 13 individuals, and raters categorized eight distinct regions of each print. In addition to ratings made while viewing the actual prints, the raters repeated the exercise using photographs of the lip prints. Multirater kappa, a chance‐corrected measure of agreement, ranged between 0.15 for the actual prints and 0.25 for the photos, indicating only poor to fair levels of inter‐rater reliability. While these results fail to support the use of lip prints for human identification, it is possible that more intensive training may yet produce adequate levels of reliability.     

Enhancing the quality of aged latent fingerprints developed by superglue fuming: loss and replenishment of initiator

The recovery and identification of latent fingerprints from a crime scene are crucial to many investigations. The cyanoacrylate (superglue) fuming method (CFM), which develops fingerprints by growing a polymer coating over the print residue, is a powerful method but encounters severe limitations when prints are aged or exposed to harsh environmental conditions. We examine the aging process and how the changes that occur to a fingerprint residue over time influence the growth of polymer during development. We identify loss of initiator by erosion and degradation that, when coupled with a loss of water from the print residue, result in a decreased ability to polymerize ethylcyanoacrylate. Then, we present a methodology by which the ability of aged latent fingerprints to polymerize ethylcyanoacrylate is recovered. Two print enhancement agents, acetic acid and ammonia, are demonstrated to improve the growth of polymer from the print ridges by over an order of magnitude, while retaining the integrity of the print structure. Comparison between the two enhancement agents indicate that the enhancement occurs due to ridge coating by the ammonia or acetic acid and pH control of the latent print.     

Changes in Fingerprints Depending on Physiological Factors

The aim of the study was to determine the effect of gender, body mass index, and time on the width of friction ridge impressions in fingerprints and the content of sweat and sebum forming the print. The research showed that the friction ridge impressions of women are significantly wider than those of men, and this tendency persists throughout the existence of the print. The differences may result from the anatomical structure of the skin, as well as from the use of protective products such as creams, which are used more often by women. The width of friction ridge impression is similar in underweight and overweight people, but greater than in those with normal body weight, and the amount of sweat and sebum increases with body weight. The passage of time significantly reduces both the width of the friction ridge impression and the content of sweat and sebum secretions in the print.     

Changes in Fingerprints and the Quantity of Material Forming the Print Depending on Hand Cleanliness,Gender, and Ambient Conditions

Impressions of friction ridges left on a surface are important evidence for identifying an individual and can be used to confirm his or her presence at the scene of an incident. Factors influencing the durability of fingerprints include the physiological characteristics and cleanliness of the individual, environmental factors, and time. The aim of the study was to determine the effect of atmospheric factors, gender, hand cleanliness and time on the width of friction ridge impressions and the amount of material forming the print. The research shows that factors such as gender, ambient conditions, and hand cleanliness affect the width of the ridge impressions and the quantity of material forming the print. The passage of time significantly reduces both the width of the ridge impressions and the quantity of the material forming the print.     

Sexual Dimorphism in Finger Ridge Breadth Measurements: A Tool for Sex Estimation from Fingerprints

Previous research has demonstrated significant sexual dimorphism in friction ridge skin characteristics. This study uses a novel method for measuring sexual dimorphism in finger ridge breadths to evaluate its utility as a sex estimation method from an unknown fingerprint. Beginning and ending in a valley, the width of ten parallel ridges with no obstructions or minutia was measured in a sample of 250 males and females (N = 500). The results demonstrate statistically significant differences in ridge breadth between males and females (p < 0.001), with classification accuracy for each digit varying from 83.2% to 89.3%. Classification accuracy for the pooled finger samples was 83.9% for the right hand and 86.2% for the left hand, which is applicable for cases where the digit number cannot be determined. Weight, stature, and to a lesser degree body mass index also significantly correlate with ridge breadth and account for the degree of overlap between males and females.     

Identification of authorship using lateral palm print--a new concept

Identification of individual by signature examination could be improved by the lateral palm print examination. By the use of new technique discussed by the author in this paper, the forensic expert can find out very useful information about the writer of writings even without going into the depth of questioned document/signature examination and without the formal or informal handwriting exemplars. The document expert with little more knowledge of the palm print can identify whether the signature is done by hand/leg/anything else, whether the author is right handed or left handed, the approximate age of the author, whether the signature is genuine or forged. Such information of author would be very much useful in elimination of the list of suspects of anonymous letters. In order to fix the authorship, standard and disputed lateral palm prints can be examined either with photographic superimposition technique or with the statistical study of the outline of the lateral palm print or with the standard method as implied in fingerprint examination. The evidential value of such lateral palm print can be placed at par with the finger prints in the court of law and could be placed right on the top of all other scientific evidences.     

Morphologic patterns of lip prints in a portuguese population: a preliminary analysis

Lip prints are thought to have the ability to distinguish individuals and, hence, have a potential use in human identification purposes. However, questions remain regarding their utility for sex determination. This study aimed to classify lip prints for different individuals in a Portuguese population and to determine whether sex differences exist. Lip prints of 25 females and 25 males were obtained using dark-colored lipstick and cellophane tape. Lip prints were analyzed using a magnifying lens and classified according to the Suzuki and Tsuchihashi classification. A Type II pattern was found to be most common. A comparison of lip-print patterns between males and females showed results with a statistically significant difference: Type III pattern was most common in males, and a Type II pattern in females. This study corroborates the hypothesis that lip prints are able to distinguish individuals and may be useful in sex determination.     

Application of 3D Imaging Technology to Latent Fingermark Aging Studies

In most latent fingermark aging studies, two‐dimensional (2D) features are obtained from photo images, scans, or inked impressions. However, some relevant information is possibly being missed because fingermarks are three‐dimensional (3D) objects that age in all three dimensions. A feature that has not been carefully examined is how the height of ridges changes over time. In this report, a 3D imaging technology—called optical profilometry—is introduced as a tool for the visual examination of the aging process. Optical profilometry is a nondestructive technology that allows the visualization and data acquisition of unprocessed latent fingermarks. Detailed ridge images and spatiotemporal data were successively obtained on the x‐, y‐ and z‐axis, delivering 3D topographical information. OP was able to detect the loss of ridge heights over time. The feasibility of employing this technology to collect data on the aging process of ridges has been proven.     

A Small Population Study on Friction Skin Ridges: Differences in Ridge Widths Between Latent and Inked Fingerprints

Morphological changes in the width of latent fingermark ridges occur naturally over time. This could be used to examine the aging process of latents and eventually estimate time of deposition. In a crime context, it is common practice to compare a questioned (aged) fingermark with a database of known (inked) prints. Therefore, in the absence of fresh fingermarks for aging purposes, it is of interest to reveal correlations between these two categories of fingerprints with regard to the widths of their ridges. The present study explores correlations of ridge widths between flat and rolled inked prints with latent fingermarks visualized with carbon black (CB) and titanium dioxide (TiO₂)-based powders among a small population of ten donors. Results revealed consistent differences between the ridge widths of latent and inked prints as well as flat and rolled impressions. Latent fingermarks visualized with CB and TiO₂ powders showed ridges with comparable widths.     

Chemical Differences Are Observed in Children’s Versus Adults’ Latent Fingerprints as a Function of Time*

Abstract: The identification of aged latent fingerprints is often difficult, especially for those of children. To understand this phenomenon, the chemical composition of children’s versus adults’ latent fingerprints was examined over time using Fourier transform infrared microscopy. Hierarchical cluster analysis revealed that children’s and adults’ prints were distinguishable for up to 4 weeks after deposition, based on differences in sebum composition. Specifically, adults had a higher lipid content than children, but both decreased over time, attributable to the volatility of free fatty acids. The aliphatic CH₃, aliphatic CH₂, and carbonyl ester compositions changed differently in adults versus children over time, consistent with higher cholesterol and cholesteryl esters in children’s prints and wax esters and glycerides in adults’ prints. Thus, fingerprint composition changes with time differently in children versus adults, making it a sensitive metric to estimate the age of an individual, especially when the age of the print is known.     

Integrated DNA and Fingerprint Analyses in the Identification of 60‐Year‐Old Mummified Human Remains Discovered in an Alaskan Glacier

Abstract: This report describes the identification of a merchant mariner who perished in 1948 when Northwest Airlines Flight 4422, a DC‐4 carrying 24 seamen and six crew members crashed into Mount Sanford, Alaska. Fifty‐one years later, a human forearm and hand were found close by the wreckage of the plane, prompting identification efforts using DNA and fingerprints. There were significant challenges to both the fingerprint and DNA analyses. The hand was badly desiccated, making fingerprint friction‐ridge detail almost invisible and the remains had been embalmed upon discovery, making DNA amplification difficult. We present the results of an interdisciplinary approach that successfully addressed these challenges and ultimately led to the identification of the remains. These efforts relied on efficient fingerprint rejuvenation and imaging techniques that improved print resolution, as well as new DNA extraction techniques optimized for aggressively embalmed remains.     

Estimation of stature from hand impression: a nonconventional approach

Stature is used for constructing a biological profile that assists with the identification of an individual. So far, little attention has been paid to the fact that stature can be estimated from hand impressions left at scene of crime. The present study based on practical observations adopted a new methodology of measuring hand length from the depressed area between hypothenar and thenar region on the proximal surface of the palm. Stature and bilateral hand impressions were obtained from 503 men of central India. Seventeen dimensions of hand were measured on the impression. Linear regression equations derived showed hand length followed by palm length are best estimates of stature. Testing the practical utility of the suggested method on latent prints of 137 subjects, a statistically insignificant result was obtained when known and estimated stature derived from latent prints was compared. The suggested approach points to a strong possibility of its usage in crime scene investigation, albeit the fact that validation studies in real-life scenarios are performed.