Fingerprints and Other Ridge Skin Impressions
... Una vez localizadas, las huellas latentes se pueden visualizar o se puede mejorar su visualización por medio de reactivos o sustancias reveladoras. Las técnicas -físicas y químicas-que se usan para revelar huellas latentes son muy numerosas (Lee and Gaensslen, 2001;Champod et al., 2016;Bleay et al., 2018), por lo que en este trabajo únicamente se profundiza en la química de un par de ejemplos: uno con un revelador químico gaseoso (vapores de yodo elemental) y otro con un revelador químico líquido (nitrato de plata en disolución). ...
... Estas huellas naturales se pueden imprimir de manera voluntaria o intencional sobre una superficie, por ejemplo, presionando las yemas entintadas de los dedos sobre una hoja de papel (o también se pueden reproducir colocando nuestras yemas sobre un dispositivo que genera una imagen digital de ellas). Este tipo de patrones artificiales que se obtienen mediante una impresión controlada (o ahora también por escaneo), formalmente se denominan impresiones dactilares (Champod et al., 2016) (ver figura 1B). ...
... Aunque a lo largo del tiempo se han utilizado varias formulaciones, una disolución de trabajo muy común es en metanol, con una concentración de nitrato de plata de 2% (peso/volumen). La superficie donde están depositadas las huellas latentes se puede sumergir en -o rociar con-la disolución de nitrato de plata, y luego la superficie se expone a una fuente de luz -ultravioleta o solar-hasta que se logra el mejor contraste entre las huellas reveladas y la superficie (Champod et al., 2016). ...
Las huellas dactilares depositadas sobre las superficies que tocamos o manipulamos, al tener un carácter único para cada persona, son un elemento de identificación individual. Por ello, las huellas dactilares son muy importantes en las investigaciones forenses, ya que permiten demostrar si hay vínculos entre lugares, personas y objetos. En los lugares de investigación, las huellas dactilares por lo común no se ven a simple vista, por lo cual deben encontrarse y revelarse con alguna técnica, ya sea física o química. En este artículo primeramente se proporciona una visión general de las huellas dactilares y su composición, que después será útil para describir y entender la variedad de aspectos químicos de dos técnicas de revelado químico —con yodo elemental y con nitrato de plata—, con el objetivo principal de introducir y despertar el interés por esta área de aplicación y estudio. Además, se tiene la intención de motivar al profesorado para que integre con más frecuencia su enseñanza de conceptos químicos a un contexto forense, como por ejemplo el del revelado de huellas dactilares, ya que la enseñanza contextualizada en situaciones reales —como lo son las aplicaciones forenses— generalmente es motivante y genera interés en el estudiantado.
... It also depends on the composition of the existing fingermark. Although complex and variable, the natural composition of fingermarks includes amino acids, proteins and substances from sebum, such as fatty acids, glycerides, wax esters, squalene, sterols and sterol esters [7][8][9][10]. Since fingermarks are often latent, various development techniques can be used to enhance the contrast between the trace and its substrate. ...
... CA is the method of choice for enhancing fingermarks on glass. However, its application on fingermarks that have been exposed to water can be problematic, as parts of the hydrophilic components of the marks, acting as initiators of CA polymerization, can be washed away [7,10]. Due to its reaction with insoluble components of fingermarks, SPR is described as the technique of choice for improving fingermarks on non-porous surfaces that have been in contact with aqueous solutions [7,11]. ...
... However, its application on fingermarks that have been exposed to water can be problematic, as parts of the hydrophilic components of the marks, acting as initiators of CA polymerization, can be washed away [7,10]. Due to its reaction with insoluble components of fingermarks, SPR is described as the technique of choice for improving fingermarks on non-porous surfaces that have been in contact with aqueous solutions [7,11]. ...
Following a chemical incident involving chemical warfare agents or more broadly, chemical weapons, there are two possible approaches in dealing with the traditional forensic analysis of contaminated exhibits. The first is to analyze the contaminated items under safe conditions (i.e. in laboratories dedicated to the handling of such substances), while the second relies on item decontamination prior to processing them in traditional forensic laboratories. One of the main limitations of the latter is the possible degradation or destruction of traces caused by the decontamination process. Hence, it is crucial to have as much information as possible on the impact of different decontamination agents and procedures on traces. This research presents experimental results on the recovery of fingermarks on glass after the application of decontaminants typically used in case of chemical incidents. The impact of 11 decontaminants on fingermarks deposited on glass and on the subsequent enhancement with cyanoacrylate and Small Particle Reagent (SPR) was evaluated (by visual examination) by four evaluators. The results of the study demonstrated that the persistence of fingermarks on glass is highly dependent on the type of decontaminant used. Decontamination agents based on the principle of nucleophilic substitution to neutralize toxic chemicals allowed good subsequent development of fingermarks with SPR. Powdered decontaminants did not show any indication of alteration of fingermarks, whereas decontamination with oxidants leads to variable results.
... Fingerprint (FP) comparisons are still the most common and credible way to identify individuals when clarifying crimes and other forensically relevant events [1]. Fingerprints on metal surfaces, which can be curved (cartridges) or irregular (coin), can greatly complicate the visualization process, and therefore, new methods are developed to enable high-quality visibility of fingerprints. ...
... Individuals can be identified based on the shape of the papillary lines. The attractiveness of using fingerprints for identification lies in the fact that they are stable throughout life, they are easily restored even after a skin injury [1], and above all, they are unique for each person [1,3]. Therefore, there are no two individuals in the world with the same fingerprints. ...
... Individuals can be identified based on the shape of the papillary lines. The attractiveness of using fingerprints for identification lies in the fact that they are stable throughout life, they are easily restored even after a skin injury [1], and above all, they are unique for each person [1,3]. Therefore, there are no two individuals in the world with the same fingerprints. ...
The characterization of electrochemically visualized latent fingerprints on steel surfaces is demonstrated. Optimization of electrochemical conditions of deposited poly(neutral red) (PNR) films on stainless steel substrates, as well as cyclic voltammetry, electrochemical impedance spectroscopy, and ATR FTIR spectroscopy of PNR-modified substrates, was performed. The parameters of the visualization method (supporting electrolyte, monomer concentration, potential range, number of cycles) were gradually changed until the fingerprint was sufficiently visible. The repeatability of measurements under these conditions was especially important, thanks to which many visible fingerprints on steel substrates were successfully obtained. The electrochemical characterization consisted in comparing the redox properties of the metal surfaces themselves before and after the application of the fingerprints or the polymer film PNR. Experimental findings have shown that the use of latent fingerprint visualization is a simple, fast, efficient, and inexpensive method applicable to forensic evidence.
Graphical abstract
... Despite this, the effectiveness of powders is determined by several factors, among which is the passage of time. The effectiveness of powders has been shown to decrease as the age of the latent fingerprint residue increases [3][4][5][6][7][8]. ...
... Another project sought to increase the effectiveness in the development of aged fingerprints at crime scenes. As has been pointed out previously, the efficacy of using powders on aged prints is highly inconsistent [3][4][5][6][7][8]. ...
The development of fingerprints with powders is one of the techniques most used by forensic teams for latent print detection at crime scenes on objects that cannot be collected and transported to the laboratory. The success of this fingerprint development is conditioned, among other factors, by the age of the latent fingerprint residues. Our study shows that it is possible to increase the effectiveness of the development of aged fingerprints with powders by subsequently applying an iron oxide-based powder suspension. The application of this product resulted in a 26.5% increase in effectiveness in the development of 45-day-old fingerprints on five different nonporous surfaces.
... In recent years, forensic scientists have systematically summarised the most commonly used fluorescent dyes in various countries around the world, such as Ardrox, Basic Yellow 40, MBD, Rhodamine 6 G and RAM [2]. Ardrox is a fluorescent liquid dye, which works well with lasers, forensic light sources and UV lamps [3]. ...
... 3 Fingermark was fully developed and showed more than two-thirds of continuous ridge lines, the ridge detail disclosed being sufficient for identification. 2 Fingermark was partially developed and showed more than one-third of continuous ridge lines, the ridge detail disclosed being just sufficient for identification. 1 ...
Cyanoacrylate fluorescent staining has become a common method for developing latent fingermarks on light-coloured or white objects. The method requires two steps and skilled operation, and the handling process has the risk of damaging the ridge details or even biological samples. To take full advantage of the high-sensitivity fluorescence, recent research efforts on fluorescent cyanoacrylate have aimed to avoid rinsing after staining, add fluorescence to the cyanoacrylate, increase the fluorescence intensity and broaden the fluorescence spectral range. PolyCyano UV is a novel product that can be used to overcome the disadvantages associated with progressing to one-step fuming to directly develop fingermarks. To explore the optimal development conditions and application effects of PolyCyano UV, thermogravimetric differential thermal analysis, fluorescence spectroscopy and control variable analysis are used to determine and analyse the best conditions for using the reagent, including temperature, fluorescence excitation band, relative humidity and fuming concentration. The temperature range of the one-step fuming development method is 212.14 °C–275.16 °C, the wavelength range of the excitation light source is 235–580 nm, the relative humidity is 60%–80%, the concentration of the fume is 1–3 g/m³ and the specific value is related to the surface properties of the object and the aged time of the fingermarks. Additionally, fluorescence spectroscopy shows that the excitation wavelength range of the light source is 235–580 nm. Based on the best fuming condition, many common objects were selected to proceed to the application experiments, which allowed for a comparison with the traditional visualisation method, namely the Cyanobloom reagent + dyeing two-step development method. The comparison showed that latent fingermarks on most non-porous smooth surfaces, especially on light-coloured or white objects, were developed successfully. In addition, a comparative study with the conventional cyanoacrylate glue–fluorescent staining experiments showed that the effect of dyeing afterwards with Rhodamine 6 G is better than the one-step method. The effect of dyeing with BBD is basically the same as that of the one-step method.
• Key points:
• One-step fluorescent cyanoacrylate fuming can be a promising alternative for fingermarks developing based on PolyCyano UV in forensic science.
• The optimum application conditions of PolyCyano UV will provide guidance for fingermark examiners.
• The one-step fuming method based on PolyCyano UV has many advantages over the secondary dyeing method.
... To specify, the main obstacles to the development of fingermarks on the skin surface are, for instance, the fingermark content of the person in contact with the surface, the activities on the skin surface of the contacting person, and the presence of common biochemical substances. These factors show that human skin is not suitable for making latent material in general visible 5 . ...
... Moreover, many studies applied a similar investigation performed with controlled depositing of good quality latent fingermarks on cooled cadaver skin under ideal laboratory conditions. Nonetheless, few success stories have been reported in real cases 5 . ...
Fingermarks used in forensic investigation are biometric elements widely utilized in identification thanks to their unique and classifiable characteristics. Despite numerous studies investigating fingermark development on different surfaces, few studies have addressed the skin surface of deceased individuals, given the challenging nature of this substrate. This study investigated the transfer and development of fingermarks on human skin that had been systematically deposited over the forehead, neck, and wrist. Additionally, gender, age, and the time elapsed since deposition were issued as additional factors impacting fingermark development. Therefore, we prepared a study setting representing a crime scene by modelling the scene and then utilized 400 fingermarks. The marks transferred to thermal paper were developed by applying ThermaNin and magnetic black fingermark powder as fingermark development methods and then photographed. They were then evaluated for their suitability for identification via scoring and statistical analysis. The results indicated that 36% of all marks obtained from the skin of living persons and 66% of those from skin surfaces of dead bodies received the highest score and were assessed as suitable for identification. Despite the negative effect of increased time since deposition, it was revealed that the ThermaNin method yielded better results than magnetic black fingermark powder.
... Natural secretions from the fingers are produced by the eccrine, apocrine, and sebaceous glands. The palms of the hands have a lot of eccrine glands [1][2][3]. Fingerprints are epidermal reliefs found in the phalanges of each of our fingers. They are a unique physical feature that differentiates all humans and are unrepeatable. ...
... In the field of forensic fingerprint detection, powder materials are frequently used. Powder particles cling preferentially to fingerprint remnants in the traditional powdering procedure, providing contrast between the fingerprint features and the background surface [3]. Powder dusting is an old, simple, quick, and successful process for developing latent fingerprints on dry, nonporous surfaces. ...
A person's identity is determined by their fingerprints since they are distinct and one of a kind. Numerous techniques have been developed by experts to find latent fingerprints at crime scenes. With the acquiescence of nanotechnology in different fields of forensic science, the fingerprint development method has also advanced with the use of nanoparticles. In this study, one such nanoparticle has been developed and used as an application for fingerprint development. Zinc oxide (ZnO) is a chemical substance that is made up of inorganic elements. A chemical technique was used to make stable zinc oxide nanoparticles. Zinc oxide nanoparticles were created at 60°C using a modified method that included zinc chloride and sodium hydroxide. We concentrated on the synthesis of ZnO nanoparticles, which entails the production and application of materials with a size of less than 100 nm in one or more dimensions and a cone-shaped morphology. The synthesis of pure phase ZnO nanoparticles was confirmed by SEM and XRD. The developed ZnO nanoparticles were then used in latent fingerprint detection as an application of this study. Developed fingerprints gave excellent results on all kinds of surfaces be they porous, semi-porous, or non-porous. These powders can serve as a replacement for the traditional powders currently in use by forensic scientists.
... The rhizomes of the plant which yield turmeric are short with blunt tubers the merchandise consists essentially of coloring principles 1,7-bis-(4-hydroxy-3methoxy-phenyl)-hepta-1,6-diene-3,5-dione (also referred to as curcumin) and also its desmethoxy and bis-demethoxy-derivatives in varying proportions. Functional use of curcumin as an artificial additive is color (22), (23). The authors during this communication have attempted to develop a replacement technique using turmeric powder, a condiment commonly utilized in Indian food, for the event of latent fingerprints present on different electronic surfaces which has not been reported thus far (24)(25)(26) . ...
... The comparative evaluation of various surfaces with this powder reveals that it gives better results on contrast surfaces than the others examined. The development of latent fingerprints present on surfaces like, laptops, mobile phone,mobile phone charger, power bank, iPad, kettle (22,31) might be successfully done and provides clear ridges as is clear from the figures. The reason for the adherence of turmeric powder to the latent fingermarks are often assigned by the formation of hydrogen bonds between the fatty acids/glycerides of sebum and therefore the carbonyl and hydroxyl of the curcumin component of the turmeric powder. ...
Introduction: Curcuma longa (Turmeric) is a rhizomatous herbaceous perennial plant of the ginger family Zingiberaceae. It has been cultivated in India from very ancient times. The rhizomes which yield turmeric are short and thick with blunt tubers. In this investigation a less expensive, simple and easily available, turmeric powder, a common ingredient in Indian food, has been used to take latent fingerprints on electronic surfaces .It is found that it gives very clear results in the majority of the surfaces.
... Based on the visual analysis of the maps, we already deduced that the generated CAMs showed a strong response around the cores and deltas of the impression. These points are important for the orientation and classification of an impression; however, there is also strong evidence that suggests minutiae points are more densely distributed around those areas in comparison to other areas of the friction ridge structure [48][49][50]. Based on this, we hypothesised that the generated quality maps were related to the minutiae density in the fingermarks. ...
The assessment of fingermark (latent fingerprint) quality is an intrinsic part of a forensic investigation. The fingermark quality indicates the value and utility of the trace evidence recovered from the crime scene in the course of a forensic investigation; it determines how the evidence will be processed, and it correlates with the probability of finding a corresponding fingerprint in the reference dataset. The deposition of fingermarks on random surfaces occurs spontaneously in an uncontrolled fashion, which introduces imperfections to the resulting impression of the friction ridge pattern. In this work, we propose a new probabilistic framework for Automated Fingermark Quality Assessment (AFQA). We used modern deep learning techniques, which have the ability to extract patterns even from noisy data, and combined them with a methodology from the field of eXplainable AI (XAI) to make our models more transparent. Our solution first predicts a quality probability distribution, from which we then calculate the final quality value and, if needed, the uncertainty of the model. Additionally, we complemented the predicted quality value with a corresponding quality map. We used GradCAM to determine which regions of the fingermark had the largest effect on the overall quality prediction. We show that the resulting quality maps are highly correlated with the density of minutiae points in the input image. Our deep learning approach achieved high regression performance, while significantly improving the interpretability and transparency of the predictions.
... Így beszélhetünk fizikai és vegyi módszerekről, másrészt helyszíni és laboratóriumi módszerekről. Sőt, a kriminalisztika fejlődése során egyes eljárások meghaladottá váltak, mert hatékonyabbat, egyszerűbbet, olcsóbbat, kevésbé veszélyeset találtak helyettük (Daluz, 2015;McRoberts, 2011;Champod, Lennard, Margot & Stoilovic, 2004;Lee & Gaennslen, 2001). ...
Cél: A kétrészes tanulmány első fele bemutatja a daktiloszkópiai nyomkutatási módszerek közül a fizikai nyomkutatás eszközeit és eljárásait, azok csoportosítását, rövid történetét, fejlődésének tendenciáit.Módszertan: A dolgozat az utóbbi évtizedben megjelent legjelentősebb külföldi szakkönyvek, illetve több tucat szakcikk feldolgozásával azok szintézisét végzi el. Megjelennek benne korábban publikált saját kutatási eredményeim is.Megállapítások: Az úgynevezett fizikai nyomkutató módszerek mind a mai napig töretlenül fejlődnek. A 19. század vége óta használt porokat is mind a mai napig fejlesztik. A VMD-módszer (fémgőzölés) az utóbbi egy-két évben reneszánszát éli azt követően, hogy a hetvenes évek végére az újabb módszerek egyszer már kiszorították.Érték: A hazai szakirodalomban ilyen alapos áttekintés régóta nem született a témában.
... This method was originally developed to detect fingermarks on the adhesive side of tape, however it has been found to detect marks on non-porous and semi-porous surfaces as well. PS is a safe, inexpensive and simple to use technique that is notably effective in difficult conditions such as marks that have been wet or aged [1,[3][4][5][6]. The Centre for Applied Science and Technology (CAST) recommends the use of different kinds of PS depending on substrate type; pre-mixed carbon-based formulations for adhesive tapes and an iron-oxide formulation that must be made fresh is recommended for other light-coloured, non-porous surfaces. ...
Powder suspensions (PS) are a fingermark development technique made up of a mixture of an insoluble powder and surfactant solution. In the UK, carbon-based PS is used operationally on adhesive surfaces while iron oxide-based PS is used on flexible plastics. In NSW, Australia, only carbon-based suspensions are used due to a lack of research using iron oxide PS in an Australian context. In this research, a range of iron oxide powders and surfactant types were tested to optimise two iron oxide formulations. General observations found that thinner suspensions improved the ease of use in this technique while slightly improving the quality of developed fingermarks. The first optimised formulation involved a magnetic iron-oxide from Fisher Scientific mixed with a dilute Triton X-100 surfactant, and the other an iron-oxide nanopowder from Sigma Aldrich mixed with a 4% Tween 20 solution. The two formulations were then compared with a pre-mixed carbon-based PS, Wet Powder. This comparison showed that the effectiveness of each formulation is heavily dependent on substrate type. Both formulations had issues with heavy background staining on different kinds of surfaces. However, Wet Powder was shown to be the most consistently effective fingermark detection technique overall, especially on adhesive tapes. Despite this, iron-oxide PS were still a highly effective fingermark development technique, notably on plastic surfaces.
... The filing of a "paternity action" is required to ascertain if a man is the father of a kid who was born out of marriage, according to the law. It is possible to prove paternity in such a lawsuit if the claimed father acknowledges being the father [5,6]. Blood-group tests, which are typically performed using the ABO method, cannot prove paternity, but they may definitively rule out a claimed father as a contender for the position. ...
Citation: Abdulaziz Radhi S AL Johni., et al. "DNA Fingerprinting with the Goals of Researching the Charges Made by the Parents, Studying, and Analyzing the Data". Medicon Medical Sciences 3.5 (2022): 11-17. Abstract Forensic DNA analysis is frequently deployed in criminal investigations to discover illicit conduct. On the other hand, forensic DNA analysis is also utilized in civil procedures to determine the paternity of progeny over which there is a dispute. However, in addition to situations of inheritance, guardianship, maintenance, and validity, it may also be necessary to determine paternity in cases of adultery or fornication, as well as in cases of contested paternity arising out of divorce proceedings or questioned legality. Even if the child's validity isn't questioned, this is true. In a scenario in which the mother of the child feels that another person is to blame for her pregnancy, the objective of these investigations is to identify the guy who is the child's biological father.
... It helps in identifying an individual whether the suspect was present at the crime scene . 1 Sweat from the pores on the friction ridge skin of the hands leave finger impressions on objects and surfaces. Pores abound in the ridges of the fingers. ...
Fingerprints are one of the crucial pieces of evidence in criminal investigations.
As fingerprints are majorly found in latent form on the surface, it is necessary
to develop those latent fingerprints appropriately without destroying them or leaving
out any detail. There are plenty of methods for identifying hidden finger impressions.
The powder dusting method, ninhydrin, iodine fuming, cyanoacrylate etc., are traditional
methods. Though these procedures help to develop the latent fingerprints,
they have some drawbacks such as sensitivity, low contrast, and selectivity as well as
high toxicity. To overcome this inadequacy, advanced techniques have been developed
using different chemicals and nanoparticles such as metal nanoparticles, fluorescent
nanoparticles embedded with quantum dots, rare-earth upconversion nanoparticles
etc. The fluorescent nanomaterials enhanced all three levels of fingerprints and provided
the minute details of latent fingerprints. This review paper focuses on the role
of fluorescence-based methods used for the enhancement of the latent fingerprint and
their advantages over traditional methods. As compared to other approaches, fluorescent
nanomaterials can obtain optimal contrast quality, enhancement, better sensitivity,
and selectivity while exhibiting lower toxicity, less autofluorescence interference,
and low background inference.
... The quality of the latent fingerprint is very low due to structured noise (arch, lines, and characters), overlapped print, and low visibility. The latent fingerprints are collected by the latent examiner using some physical or chemical technique [12], [13] and then the Latent examiner marks the fingerprint features (such as minutiae) manually. ...
Latent fingerprints are the fingerprints that are left by the criminal unintentionally on the surface of the crime scene. The qualities of the latent fingerprints are very poor due to the overlapping patterns and structured noises. Latent fingerprint segmentation is a difficult task due to low visibility, structured noise, and complex structure. In this paper, a fusion of morphological and neural network approach is purposed for latent fingerprint segmentation. This method automatically segments the fingerprints and non-fingerprints patterns without human intervention. The morphological method is used for segmentation of the fingerprint region. Fingerprint region then divides into y*y blocks and extracts the features of each block and uses them as an input of NN to classify the blocks into fingerprint and non-fingerprint blocks. We are using the IIIT-D database and the shows that this model batters then the existing model.
... A crime scene or scene of the crime is the particular place where the group of persons or individual persons has committed a crime or where the many pieces of evidence thereof are found and the result is they exchange traces with one another and link them to the crime scene, weapon or object. Fingermarks are formed by sweat released from pores which are present on the friction ridge skin of human hands and the study of sweat pores present on the friction ridges of palmer is known as poroscopy [4,5]. A poroscopy indicate the human finger ridges contain a large number of sweat pores, which is a various shape in male and female finger ridges. ...
... However carefully a criminal is to not leave any traces, yet leaves behind a set or two of latent ingerprints. In general, ingerprints can be classi ied as visible, plastic, and latent ingerprints [1][2][3][4][5]. Visible ingerprints are those prints that are visible to our naked eyes and can be easily collected. ...
Background: Fingerprint development techniques are being used for a long time and are considered one among the oldest methods in forensic science used to identify suspects. Fingerprints are one of the most significant types of physical evidence. There are various types of fingerprint patterns such as visible, plastic and latent. In criminal investigation cases, chance fingerprint impressions are mostly found at the crime scene. These prints are generally invisible and therefore require several development methods. The powder dusting technique of developing fingerprints involves the application of fine powder on the impression of the print with the help of a brush such as glass fiber or a camel hair brush. Main text: This paper rather focuses on various unconventional powder methods than the widely used conventional ones. This will help identify other cheaper, non-toxic powders that are commonly available as an alternative to the expensive, toxic ones. The author’s main aim is to provide a collective review of the work of other scientists in order to identify everyday materials, commonly available that can be used as possible means to develop a fingerprint impression. Conclusion: For a better result, the unconventional powder is used on different surfaces i.e. porous, non-porous, and semi-porous for latent fingerprint impressions. After developing impressions on different surfaces, we conclude our result that unconventional powder is very useful.
... Fingerprints are the most affirmative source of personnel identification and are also one of the most ubiquitous pieces of evidence found at the crime scenes (1). However, successful latent print recovery is not always possible from the crime scenes especially when the prints have been exposed to destructive conditions. ...
Introduction: Fingerprints are a distinctive feature of individuals and are one of the oldest and most widely accepted forensic evidence used to establish personal identity. The most familiar prints encountered at the scene of the crime are the latent prints. These are invisible prints retained on a substrate on account of various secretions from the body. Fingerprints can be deposited on a number of substrates, broadly classified as porous, non-porous, and semi-porous surfaces.
... (7). (8). A short ridge is a single friction ridge beginning, traveling a short distance, and ending. ...
Aim: The study aims to visualize the latent fingerprint using spirulina powder on electronic surfaces. Introduction: A fingerprint is an impression left by the friction ridges of a human finger. The recovery of partial fingerprints from a crime scene is an important method of forensic science. Moisture and grease on a finger result in fingerprints on surfaces such as glass or metal. Latent prints can be found on a variety of surfaces; however, they are not readily visible and detection often requires the use of fingerprint powders, chemical reagents, or alternate light sources. Materials and methods: To develop latent fingerprints with the help of spirulina powder, few grams of pure commercially available spirulina powder was taken in the present study and then further ground in a blender to get a very fine powder to the level of talcum powder but no particle size was measured. Results: The development of latent fingerprints present on electronic surfaces like iPad, mobile, mobile charger, water purification machine, and electronic switch box-surface could be successfully done and gives clear ridges as is evident from the figures. Prints present on the skin could not be developed clearly in comparison to others may be due to lack of contrast. Conclusion: It is concluded that spirulina powder which is easily available, non-toxic and simple can be used successfully on electronic surfaces to develop prints in crime investigations.
... our model can estimate the probabilities of misclassification. Other probabilistic models such as the likelihood ratio and CongruentMatching Cells are used in many forensic applications such as fingerprint identifications and bullet matching[35,57,61,62]. Our focus also is on examining the potential of replicas to transfer all the topological details required for the analysis at the proper magnifications. ...
Silicone casts are widely used by practitioners in the comparative analysis of forensic items. Fractured surfaces carry unique details that can provide accurate quantitative comparisons of forensic fragments. In this study, a statistical analysis comparison protocol was applied to a set of 3D topological images of fractured surface pairs and their replicas to provide confidence in the quantitative statistical comparison between fractured items and their silicone cast replicas. A set of 10 fractured stainless steel samples were fractured from the same metal rod under controlled conditions and were replicated using a standard forensic casting technique. Six 3D topological maps with 50% overlap were acquired for each fractured pair. Spectral analyses were utilized to identify the correlation between topological surface features at different length scales of the surface topology. We selected two frequency bands over the critical wavelength (greater than two‐grain diameters) for statistical comparison. Our statistical model utilized a matrix‐variate t‐distribution that accounts for overlap between images to model match and non‐match population densities. A decision rule identified the probability of matched and unmatched pairs of surfaces. The proposed methodology correctly classified the fractured steel surfaces and their replicas with a posterior probability of match exceeding 99.96%. Moreover, the replication technique shows potential in accurately replicating fracture surface topological details with a wavelength greater than 20 μm, which far exceeds the feature comparison range on most metallic alloy surfaces. Our framework establishes the basis and limits for forensic comparison of fractured articles and their replicas while providing a reliable fracture mechanics‐based quantitative statistical forensic comparison.
... From the past decades, polyfuctional molecules were gain interest to use as organic fluorescent materials in light emitting fields as electroluminescent indicators and forensic science [2]. Now a day's fingerprints are commonly used in personal identifications such as mobile locks, banking sectors and biometric sensors etc., [3]. Fingerprints are considered as primary evidence in the criminal investigation due to their unique identification [4]. ...
Organic dye compounds with luminescent properties are in demand to use in visualizing the latent fingerprints (LFPs) at crime spot investigation. Here, we synthesized some new 4-(4-substitutedphenyl)-6-(4-substitutedphenyl)-2-oxo-1,2-dihydropyridine-3-carbonitrile 4(a-d) and were confirmed using spectroscopic approaches. Optical properties were recorded in solvent media, where peaks were absorbed in ⁓300–400 nm of longer wavelength and emitted at ⁓467–574 nm in the blue region. Dual redox peak current was observed in Cyclic voltammetry at different scan rate and estimated redox onset potential energy molecules have been experimentally calculated. DFT studies have been carried out using Gaussian 09 software at the gaseous phase. From the results of theoretical investigations, compounds 4(a-d) showed higher photostability, chemical reactivity and good reactive sites. Also, synthesized compounds were used to determine the latent fingerprints application with the help of powder dusting method. Level II and III features of LFPs are observed on porous/non-porous surfaces without optical hindrance and images were taken in normal and 365 nm UV light. From the above results, the synthesized compounds are efficient materials for forensic science applications.
... In this research work an offline method of palm print acquisition was employed, in which the palm print data was collected or captured from a non-digital source. Instead, the participants palm print was collected by printing with an ink on to a white paper sheet (Champed et al., 2004). Palm prints were taken with the subjects sitting in a relaxed position with hands washed and dried. ...
Dermatoglypics is the study of dermal ridges on finger balls, palm of the hand and sole of the feet, and provides a myriad of genetic information which are pointer to inherited genetic diseases. The aim of the study was to analyze palm prints (palmer triridii angles) among Hausas of Kano and Zaria. A total of 600 subjects comprising of 300 participants from two original Hausa metropolis (Kano and Zaria) with 1:1 male to female ratio participated. Ink method was used to capture palm prints. Chi-square was used to determine the association between the variables. The result of the study showed that a significant gender differences in the mean value were observed in the atd and dat angles in both cities and Hausas of Kano (t=-2.97, p <0.05 for atd, t= 2.59, P< 0.05 for dat) with no significance in the Hausas of Zaria in right hand. However, a statistical significant difference was present in the atd and adt angles in both cities and Hausas of Kano (t=-4.99, p <0.001 for atd, t= 5.09, p< 0.001 for adt). For the Hausas of Zaria only the atd (t=-3.30, p <0.05 for atd) angle shows significant difference. For comparison based on sex, no significant differences was observed between males from Kano and Zaria, and females from Kano and Zaria with respects to dat and adt angles of right palmer triradii. However, a significant difference was observed between Kano and Zaria males with respects to dat and adt angles of palmer triradii respectively.
... Powder dusting was simple and the most frequently used method for revealing the LFPs (Champod et al., 2004) in which powder of bronze, ferric oxide and rosin was used. These powders were unable to reveal LFPs on some relevant forensic surfaces as it was hazardous and uneven crystallite size. ...
... The suspension of fine titanium dioxide nanoparticles is generally used to develop latent fingermarks on wet, non-porous surfaces. However, the utility of titanium dioxide nanoparticles in developing faint and weak latent fingermarks can be enhanced by coating them with fluorescent dyes (Ramotowski, 2012;Champod, Lennard, Margot, and Stoilovic, 2016). Saunders (1989) used titanium dioxide nanoparticles containing powder suspension to develop latent fingermarks on porous and nonporous surfaces. ...
The term "nanotechnology" was coined by U.S. engineer Eric Drexler in the 1980s. In the past few decades, nanotechnology has found exponential growth in different fields. Nanomaterials are materials that possess at least one, and usually two dimensions with less than 100nm. It can be nanoparticles, nanowires, nanorods, nanosheets, etc. These nanomaterials have gained great attention during recent years due to their unique properties including small size, stability, and low toxicity. Titanium dioxide-based nanomaterials are regularly synthesized and used for different purposes. In this chapter, recent advances in the methods of preparation of titanium dioxide nanomaterials are discussed along with their forensic applications in explosive detection and fingerprint imaging.
... Meanwhile, iodine vapor is used to react with squalene secreted from the sebaceous gland, wax esters, triglycerides, phospholipids, and free fatty acids [7][8][9][10]. Furthermore, the different characteristics of the sample surfaces (porous−nonporous surfaces) necessitate different fingerprint methods, for instance; on porous surfaces (raw wood, paper), iodine vapor, ninhydrin (2,2-dihydroxyindane-1, 3-dione), DFO (1,8-diazflouren-9-one), 1,2-indandione, and 5-MTN (5-(methylthio)ninhydrin) combined with zinc chloride, termanin, and silver nitrate chemicals are used. ...
Although there have been significant advances in fingerprinting techniques, studies on how these techniques affect other criminal evidence are limited. Synthetic cannabinoids (SC), which are illegal substances frequently encountered in crime scenes and are widely used worldwide, are available in various forms in the market (pill, powder, liquid, and herbal product). These synthetic cannabinoid substances have recently been introduced to places such as prisons and rehabilitation centers, primarily via an infused piece of paper. The first seizure of the paper-impregnated form of AB-PINACA and AB-FUBINACA in Turkey was observed in 2014. This study investigates the effects of fingerprint development methods on the concentrations of these SCs impregnated on paper. Therefore, eccrine and sebaceous fingerprints of volunteers were imprinted on the papers before and after they were impregnated with AB-PINACA and AB-FUBINACA. Six different fingerprint development methods were applied. Fingerprint development methods were later checked in 384 fingerprints. AB-PINACA and AB-FUBINACA infused on papers were extracted by the liquid−extraction method, and concentrations were analyzed via LC-MS/MS. After applying Thermanin, 1,2-indandione, iodine vapor, DFO, and 5-MTN fingerprint development methods, the concentration levels of AB-FUBINACA were 26.25, 19.60, 21.43, 17.76, and 17.77 ng/cm², while the concentration levels of AB-PINACA were 1.1, 0.98, 1.31, 1.28, and 1.22 ng/cm², respectively. Finally, although the best fingerprint visualization was obtained on papers that were applied the Ninhydrin method, the method failed to detect SCs on papers.
... For pattern evidence, source-based evaluations have been developed, for example, in the areas of fingermarks [27], facial images [28], and voice recordings [29] (not a pattern per se but an analogue or digital trace). ...
There is an apparent paradox that the likelihood ratio (LR) approach is an appropriate measure of the weight of evidence when forensic findings have to be evaluated in court, while it is typically not used by bloodstain pattern analysis (BPA) experts. This commentary evaluates how the scope and methods of BPA relate to several types of evaluative propositions and methods to which LRs are applicable. As a result of this evaluation, we show how specificities in scope (BPA being about activities rather than source identification), gaps in the underlying science base, and the reliance on a wide range of methods render the use of LRs in BPA more complex than in some other forensic disciplines. Three directions are identified for BPA research and training, which would facilitate and widen the use of LRs: research in the underlying physics; the development of a culture of data sharing; and the development of training material on the required statistical background. An example of how recent fluid dynamics research in BPA can lead to the use of LR is provided. We conclude that an LR framework is fully applicable to BPA, provided methodic efforts and significant developments occur along the three outlined directions.
This article analyses fingerprints identified on a set of backed clay Egyptian funerary figurines, known as ushabtis. The strata in which they were found dates from the late Persian to the early Ptolemaic dynasties (ca. fifth to third centuries BCE), but the objects might have been made some two centuries earlier, during the Twenty-Fifth Dynasty, and then reused for a later burial.
The authors propose that fingerprints preserved on ancient objects can be used to understand the roles that age and sex played in the organization of production systems in ancient societies. The Mean Ridge Breadth (MRB) and Mean Ridge Density (MRD) of each discrete fingerprint was measured. The craftworkers´ ages and heights were calculated from the MRB using specific regression equations, and their probable sex was determined by correlating the MRD with that of the reference population (contemporary Sudan). An age/sex identification matrix was then created to combine the results of MRB and MRD determinations for each piece.
The results show, with high probability, that around 90% of the ushabtis were made by female adolescents between the ages of 11 and 16, and the remainder by children and some adult women. Between four and eight craftworkers manufactured the ushabtis, and due to their age and the relatively low level of skill required, it is proposed that they are likely to have been in the learning phase of their trade.
A facile and high-resolution enhancement of latent fingerprints (LFPs) has been developed by using a wet nitrocellulose (NC) membrane as a matrix under natural light. A clear fingerprint pattern was presented on the membrane after a fingertip touch owing to the difference in light transmittance between the ridge residues and the wet-NC-membrane background. Compared with conventional methods, this protocol can provide a higher resolution fingerprint image to extract level 3 details accurately. It is also compatible with commonly used fingerprint visualization techniques (magnetic ferric oxide powder and AgNO3. The modified membrane could be more general to realize the high-resolution visualization of LFP transferred from various substrates, even independent of light projection. Due to the excellent feasibility and reproducibility of level 3 details extracted by the wet NC membrane, the frequency distribution of the distance between adjacent sweat pores (FDDasp) could be used to effectively distinguish the fragmentary fingerprints. Finally, the level 3 features of LFPs from females and males were conveniently extracted by the wet-NC-membrane method for gender identification. The statistical results indicated that females had a higher average sweat pore density (115/9 mm2) than males (84/9 mm2). Taken together, this approach provided a high-resolution, reproducible, and accurate imaging of LFPs, which shows great promise for forensic information analysis.
Elektronik kartlar beyaz eşya sektöründe yaygın bir biçimde kullanılmaktadır. Bu kartların ürünlere bağlanabilmesi için bir çok bağlantı elemanlarına ihtiyaç duyulmaktadır. Bu bağlantı elemanlarının bir çeşidi de yaylı sabitleme ayaklarıdır. VTC elektrikli ocaklarda kullanılan elektronik kartın bir parçası olan bu yaylı sabitleme ayaklarının ocak taban sacına montajlanması elektrikli ocağın dokunmatiği için önem arz etmektedir. Bu yaylı ayaklar elektronik kartta 4 adet bulunmaktadır. Bu ayakların montajının elektrikli ocağın alt taban sacına düzgün oturtulmaması durumunda dokunmatik algılamamakta veya farklı komutları uygulamaktadır. Bu çalışmada iki farklı ayak tasarımı üzerine analiz yapılmıştır. Bunun sebebi VTC elektrikli ocakta halihazırda kullanılan sabitleme ayaklarının montajlandıktan sonra gereğinden fazla esnemesidir ayrıca elektrikli ocak üzerinde montaj tamamlandıktan sonra cam üzerinde komutların çalışmamasıdır. Bunun üzerine sabitleme ayaklarının esnemesini önlemek amacıyla ek bir tasarım iyileştirmesi yapılmış daha sonra ANSYS Structural ara yüzünde iki tasarımın da tek eksenli ve toplam yer değiştirmeleri incelenmiştir. Mevcut tasarım bu çalışmada tasarım-1 olarak adlandırılmış, tek eksenli yer değiştirmesi 0.45 mm toplam yer değiştirmesi 0.48 mm olarak bulunmuştur. Tasarım iyileştirmesi olarak önerilen ise tasarım-2 olarak adlandırılmış ve tek eksenli yer değiştirmesi 0.4 mm toplam yer değiştirmesi ise 0.42 mm olarak bulunmuştur. Mevcut sonuçlar değerlendirildiğinde yapılan iyileştirmenin fayda sağladığı, endüstriye uygulanabilir olduğu görülmüş, elektronik kartın sabitleme ayaklarının esnemesinin azaltılabileceği tespit edilmiştir.
The tenacity of the fingerprint evidence for the identification of criminals has been well documented, but none of the research work so far focussed on unusual prints. Therefore, in the present study, we attempted to define rarely encountered fingerprints in a human population. Our purpose was to explore unusual pattern types on the finger balls and compare these with commonly occurring and classifiable pattern types. Furthermore, we discuss the occurrence of unusual fingerprints in both the sexes with reference to the finger digits. The study was conducted on 512 participants aged between 18 and 35 years from two ethnic groups of North India. A total of 5120 fingerprints from each digit of the 512 individuals were obtained. The fingerprints were analysed for the pattern types based on Henry’s classification. Patterns that did not fall in the prescribed category as per the definition of the published finger pattern types were identified as unusual fingerprints. We found an incidence of unusual prints of 0.21% and describe these based on a comparison with the general pattern types according to Henry’s classification. We describe eleven unusual fingerprint patterns, formulating categories that may aid in the individualisation process. The proposed new nomenclature of these unusual fingerprints may assist forensic scientists and fingerprint examiners in better understanding and labelling of similar patterns in forensic cases. Our research may also influence the general forensic science community and biological anthropologists in making population standards pertaining to different types of fingerprints in various population groups and their genetic and familial relationships.
It may be asserted that there is no more effective deterrent to crime than the certainty of detection. Equally true is that there is no surer way to establishing identity than by fingerprints. The detection of fingerprints at the scene of crime is therefore one of the most powerful tools available in casework investigations. However, if the crime evidence is deliberately or accidentally exposed to water, the fingerprints get washed out and cannot be detected by conventional techniques. In this communication, we describe a simple experiment that enables the visualization of fingerprints on moist items.
Fingerprints have long been the gold standard for personal identification in forensic science. However, realizing the high-resolution enhancement of eccrine LFPs is difficult using the traditional methods and the label-free detection of fingerprint residue information is also challenging. Herein, we propose two enhancement strategies for LFPs on PVDF membrane (LFPs/PVDF) using blue-black ink staining and scanning electrochemical microscopy (SECM). The blue-black ink staining method was used for the first time to develop three types (sebaceous, natural and eccrine) of LFPs/PVDF based on the difference in wettability between the fingerprint residues and PVDF membrane. The enhanced fingerprints clearly displayed levels 1-3 features with high contrast and low background interference. Furthermore, we achieved chemical imaging of the LFP/PVDF samples, where their possible visualization mechanisms were ascribed to the electrochemical reactivity of squalene and difference in wettability between the LFP and PVDF membrane, which was first proposed and investigated by SECM imaging and water contact angle (WCA) measurements, respectively. Significantly, SECM imaging not only provided fingerprint patterns without any labelling but also revealed the spatial distribution information of squalene in LFPs simultaneously. In addition, it was also demonstrated that LFPs deposited on various surfaces were first successfully transferred to the PVDF membrane, and then further developed with both methods, making them general for personal identity-related applications. Taken together, the blue-black ink staining method can easily and quickly obtain level 3 features of LFPs/PVDF and the SECM approach can non-invasively image the topography and chemical information of LFPs/PVDF, and thus they can be potentially selected according to various requirements in forensic scenarios.
The majority of conventional techniques for latent fingerprint enhancement are based on chemical reactions or interactions between the developer and fin-germark residue components, providing contrast between the surface and the fingerprint ridges. However, these methods might be limited by factors associated with particle size, toxicity of the reagent, selectivity, or sensitivity, that may be circumvented by the synthetic design of innovative materials based on nanoparticles or macromolecular materials, such as conducting polymers, applied as latent fingerprint developers on different surfaces and conditions. Since the structural, optical and electronic properties of the material can be tailored by its molecular scale, the size control of the developer plays an important role to improve the interaction with the latent fingermark residue and/or the surface, enhancing the color contrast and the quality of the developed image (or dactylogram). Hence, creating new reagents and strategies to apply nano-and macromolecular scale materials as latent fingermark developers constitutes an exciting rapidly expanding area, generating a wealth of new materials that lead to forensic methodologies with enhanced performance. Recent progress in the application of such materials for development of latent fingermarks present on different surfaces and subject to complex circumstances will be discussed. This will focus on the main barriers to making nanoparticles and conducting polymers viable-and occasionally preferred-materials routinely used by forensic experts, and the potential advantages over conventional methodologies in the acquisition and analysis of crime scene evidence.
This appendix discusses error types, error rates and case studies of erroneous identifications.
This chapter describes the comparison of details in the mark with those in the print to determine their agreement or disagreement.
This chapter describes the details the examiner may observe in the mark, the support for the use of those details as a means of personal identification, and the way the examiner may document their observations.
This chapter describes some factors that can cause the details in the mark to appear differently to those in a print made by the same area of skin.
This chapter describes how the examiner decides whether the details in the mark are suitable for further analysis and comparison.
This chapter discusses the conclusions the examiner can reach, what those conclusions mean and how the examiner arrives at them.
This appendix discusses the information that can be used to offer an opinion on how or when the mark was left.
Fingermark identification has significance in forensic science, particularly in the processing of crime scene evidence. The majority of literature focused on physical interpretation of fingermarks with limited studies relating to chemical analysis. This systematic review investigated prospective studies dealing with the analysis of latent fingermark constituents. Studies included were those concerned with the analysis of intrinsic organic constituents present in latent fingerprints. Studies with no clear procedure were excluded. Data from the studies were exported into SPSS v22 (IBM, Armonk, NY, USA) where descriptive statistics were applied. The data extraction yielded 19 studies related to identification of lipids ( n = 66) and/or amino acids ( n =27) in latent fingermarks. The primary lipid identified was squalene and the major amino acids included: alanine, glycine, leucine, lysine, and serine. For identification of the aforementioned constituents both chromatographic and spectroscopic techniques of which the main technique was gas chromatography-mass spectrometry. Prior to analysis, the majority of studies involved collection of fingermarks from both hands at room temperature. Deposition was done on different substrates of which the main were glass, Mylar strips, aluminium sheets or paper. In conclusion, chemical analysis of latent fingermarks enabled identifying key biomarkers of individual that could serve as complementary evidence in crime scene investigation.
Specialists have concocted various ways for recognizing inert fingerprints on crime locations. The powder method is an exceptionally basic way of developing fingerprints. Fingerprinting is one of those fields, the modernized scanner displaced ordinary procedures for taking fingerprints. In daily life, individuals regularly apply oils, salves, hand sanitizers, at times on their hands. These restoratives and day by day use items influence the computerized recording of fingerprints, along these lines making it hard for measurable specialists to recognize the genuine wrongdoer in numerous cases. The study was to actually look at the impact of oils, creams, hand sanitizers, and ghee on the fingerprints. For this research, various lubricants were applied on the fingerprint of plain white paper. Lubricants were applied on fingers and were then scanned. 39 fingerprints were taken. These fingerprints were then recorded with the assistance of 20 secugen hamsters. The assessment and examination of finger impression were done. The presence of everyday use items influenced the quality of fingerprints. Different items caused various impacts depending on their properties. Engineered ghee, hand sanitizer, slick balm, and greasy oil ruined the fingerprint quality, resulting in massive differences in the finger impression photographs. Non-slick cream and alcohol-free hand sanitizer had less effect, whereas oil and regular ghee had no influence on the notion of fingerprints. The combination of lubricants added an extra layer to the fingers. This layer caused changes to the fingerprint impressions. As a result, fingerprints should be collected after proper hand washing.
High-efficiency fingerprint imaging agents with turn-on green fluorescence are promising in criminal investigation. Here we design and synthesize an amphipathic green fluorescent probe, PVPOH, which can efficiently light up latent...
Recent advancements in analytical techniques have greatly contributed to the analysis of latent fingermarks’ (LFMs) “touch chemistry” and identification of materials that a suspect might have come into contact with. This type of information about the FM donor is valuable for criminal investigations because it narrows the pool of suspects. It is estimated that at least 30 million people around the world take over-the-counter and prescription nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief, headaches and arthritis every day. The daily use of such drugs can lead to an increased risk of their abuse. In the present study, Raman spectroscopy combined with multivariate statistical analysis was used for the detection and identification of drug traces in LFMs when NSAID tablets of aspirin, ibuprofen, diclofenac, ketoprofen and naproxen have been touched. Partial least squares discriminant analysis of Raman spectra showed an excellent separation between natural FMs and all NSAID-contaminated FMs. The developed classification model was externally validated using FMs deposited by a new donor and showed 100% accuracy on a FM level. This proof-of-concept study demonstrated the great potential of Raman spectroscopy in the chemical analysis of LFMs and the detection and identification of drug traces in particular.
Surface analysis techniques have rapidly evolved in the last decade. Some of these are already routinely used in forensics, such as for the detection of gunshot residue or for glass analysis. Some surface analysis approaches are attractive for their portability to the crime scene. Others can be very helpful in forensic laboratories owing to their high spatial resolution, analyte coverage, speed, and specificity. Despite this, many proposed applications of the techniques have not yet led to operational deployment. Here, we explore the application of these techniques to the most important traces commonly found in forensic casework. We highlight where there is potential to add value and outline the progress that is needed to achieve operational deployment. We consider within the scope of this review surface mass spectrometry, surface spectroscopy, and surface X-ray spectrometry. We show how these tools show great promise for the analysis of fingerprints, hair, drugs, explosives, and microtraces.
Expected final online publication date for the Annual Review of Analytical Chemistry Volume 15 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Latent fingerprint detection and visualization remains a challenge especially where problems of poor contrast, auto-fluorescent surfaces and patterned backgrounds are encountered. As a result there is an increasing interest in the development of simple, cost effective, rapid and yet accurate methods for latent fingerprint detection and recovery. Herein, this paper reports the synthesis of bright blue photoluminescent carbon dots (C-dots) via an eco-friendly and simple one-step microwave-assisted carbonization of potato peels’ biomass. The C-dots were prepared in only 3 min and ground into powder and used without any further treatment. The as-prepared C-dots were characterized using atomic force microscope, Fourier transform infra-red spectroscopy and X-ray diffraction with an average size of 1.0[Formula: see text]nm. The optical properties of the as-prepared C-dots were studied by UV-Vis spectroscopy and spectrofluorometer which established an excitation and emission wavelengths of 390[Formula: see text]nm and 480[Formula: see text]nm, respectively. Owing to their strong solid state fluorescence, the as-prepared C-dots’ powder was successfully used in latent fingerprint detection and imaging on porous and nonporous surfaces. Latent fingerprints were recovered with high resolution and excellent quality providing sufficient details for individual identification. These findings demonstrate that C-dots derived from biomass have a great potential in latent fingerprint analysis for forensic applications.
The long practice of fingerprint science is accompanied by confusing thoughts affecting the interpretation of the fingerprint evidence recovered from a crime scene, and, consequently, prosecutors and judges’ decisions as well. However, despite the tremendous scientific and technological developments relating to fingerprint enhancement, processing, and usage, which clarify precise facts regarding the influence of deposition circumstances, substrate, light, air, temperature, and time factors on fingerprint secretions, misconceptions about fingerprints are still widespread within the law enforcement and judicial system. This problem prevents the proper usage of fingerprints in fighting crimes and supporting the justice system by strong physical evidence. This study aims to highlight some scientific facts about fingerprints as well as a new approach and reconceptualization of fingermarks as a tool for crime scene investigation and training. The article discusses twenty-four myths about fingerprints – part 1 covers ten of them and part 2 discusses the other fourteen.
Identification has always been very vital in forensic casework. Fingerprint patterns are population-specific and individualistic, that makes fingerprinting an important biological trait in human biology and forensics. Fingerprint is an impression of the friction ridges of the finger-ball, where friction ridges are raised portions of the epidermis. Skin on human fingertips contains ridges and valleys which together forms distinctive patterns. These patterns are fully developed in intra-uterine life and remain unaltered until the death of the individual. Injuries such as cuts, burns and bruises can temporarily damage quality of fingerprints but when fully healed, the patterns are restored. The number of ridges present in a unit area on a fingerprint is called the Fingerprint Ridge Density (FPRD). The epidermal ridge density can be determined by examining two parameters - ridge width and distance between the ridges. The thickness of the epidermal ridges varies between individuals and between the sexes. The present review of literature focuses on the sexual dimorphism on the basis of the FPRD and its possible use in forensic examinations. Most of the studies pertaining to the estimation of sex from the FPRD have been conducted in the last two decades when Mark A. Acree in 1999, devised a method of estimation of sex on Caucasian and African-American descent. The present analysis evaluates the studies found in the PubMed database conducted after Acree, 1999. The estimation of sex from the FPRD is based upon the fact that the females have a fine detailing of ridges and consequently more ridges are covered in a unit space in the fingerprints of females as compared to males. The paper also highlights -recent advancements and future perspectives in the area of FPRD. (www.actabiomedica.it).
Level 3 details play essential roles in practical latent fingerprint (LFP) identification. To reliably extract reproducible and identifiable level 3 features, high-resolution images of fingerprints with adequate quality are required. Conventional methods for acquiring level 3 details often involve specific pretreatment, intricate peripheral, leading to time-consuming analysis. Herein, we simply used water to develop the sebaceous LFPs deposited on nitrocellulose (NC) membranes with only one step, and then the high-resolution (2048 pixels per inch) optical micrographs were captured to reflect the live fingertip with high fidelity. From the pictures, level 3 features, including all dimensional attributes of the ridges and pores such as number, size, location, shape, and edge contour can be extracted accurately and reproducibly. Among them, qualitative features (the structures of ridge edges) and several quantitative characteristics (the number and the relative location of sweat pores) exhibit good reproducibility. Remarkably, we proposed a new parameter termed "frequency distribution of the distance between adjacent sweat pores", short form "FDDasp", which was further proved highly identifiable in different individuals, enabling the successful distinguishment between two fragmentary fingerprints with similar level 2 structures. We believe that this methodology provides a fast and quantitative analytical paradigm for latent fingerprint identification at level 3 details.
Evidence law regimes across several contemporary legal orders provide a host of doctrinal devices designed to probe various sorts and sources of information, especially with respect to their accuracy and reliability. These legal provisions, however, are vulnerable to or even tolerant towards uninterpretable evidence, that is evidence whose probative value cannot be assessed. This article critically examines and discusses the «littering paths» of uninterpretable evidence in legal proceedings. We point out the misinformative character of such evidence as well as the potentially misleading impact on criminal adjudication when using scientific evidence for purposes that, strictly speaking, the evidence cannot help with. We identify common causes and possible remedies and argue that to track uninterpretability, it is necessary to understand what exactly it means to say that a piece of evidence is probative in the procedural space of reasons, and how to draw the line between informative and non-informative items of evidence. – To appear in: Quaestio facti (Revista Internacional sobre Razonamiento Probatorio Quaestio facti. International Journal on Evidential Legal Reasoning), 3, 2022.
Low copy number (LCN) DNA profiling is a technique sensitive enough to analyze just a few cells. When this kind of analysis is carried out, special considerations are needed to interpret the results. In particular, it is important to consider the implications of allele dropout and the possibility of contamination from a laboratory source. A rationale for interpreting LCN DNA is described.
Performance in biometric identification is determined by two kinds of variability among the acquired biometric templates:
(1) within-Subject variability, which sets a minimum False Reject rate; and (2) between-Subject variability, whose lower limit
sets a minimum False Match or False Accept rate. Clearly, it is desirable for a biometric to have maximal between-Subject
variability but minimal within-Subject variability. It is also desirable for recognition decisions to be based upon features
which have very little genetic penetrance (so that genetically identical or related individuals would still be distinguishable),
yet high complexity or randomness, and stability over the life of the individual. A phenotypic facial feature with exactly
these properties is the iris pattern within either eye. When imaged at distances up to a meter, the population entropy (information
density) of iris patterns is about 3.4 bits per square millimeter, and their complexity spans about 266 independent degrees-of-freedom.
The resulting decision environment for recognizing persons by their iris patterns has a decidability index of about d’= 11.
Quantitative decision metrics such as these, resulting from 223,000 comparisons between IrisCodes in tests published by British
Telecom, may be used to compare the intrinsic decision-making power of different biometrics.
The statistical variability that is the basis of iris recognition is analysed in this paper using new large databases. The principle underlying the recognition algorithm is the failure of a test of statistical independence on iris phase structure encoded by multi-scale quadrature wavelets. Combinatorial complexity of this phase information across different persons spans about 249 degrees-of-freedom and generates a discrimination entropy of about over the iris, enabling real-time identification decisions with great enough accuracy to support exhaustive searches through very large databases. This paper presents the results of 9.1 million comparisons among several thousand eye images acquired in trials in Britain, the USA, Japan and Korea.
The visualization and endurance of fingerprints on cartridge cases after the firing process have been examined. Cartridges of M16, AK-47 (Kalashnikov) and Parabellum have been tested. Despite difficulties in visualizing these fingerprints, it was found that in some cartridge cases under laboratory conditions--for instance, on M16 brass cartridges--substantial parts of the fingerprints remain intact after shooting. The careful use of illumination after metal vapor deposition enabled visualization. Different possible mechanisms responsible for the partial destruction of the fingerprints are discussed.
We investigated the randomness and uniqueness of human iris patterns by mathematically comparing 2.3 million different pairs of eye images. The phase structure of each iris pattern was extracted by demodulation with quadrature wavelets spanning several scales of analysis. The resulting distribution of phase sequence variation among different eyes was precisely binomial, revealing 244 independent degrees of freedom. This amount of statistical variability corresponds to an entropy (information density) of about 3.2 bits mm(-2) over the iris. It implies that the probability of two different irides agreeing by chance in more than 70% of their phase sequence is about one in 7 billion. We also compared images of genetically identical irides, from the left and right eyes of 324 persons, and from monozygotic twins. Their relative phase sequence variation generated the same statistical distribution as did unrelated eyes. This indicates that apart from overall form and colour, iris patterns are determined epigenetically by random events in the morphogenesis of this tissue. The resulting diversity, and the combinatorial complexity created by so many dimensions of random variation, mean that the failure of a simple test of statistical independence performed on iris patterns can serve as a reliable rapid basis for automatic personal identification.