Fingerprint Deposits Research Articles

Transfer and recovery of DNA and metal particles: A proof-of-concept application of a parallel strategy by DNA and environmental scanning electron microscopy analysis

According to the principle of Locard “Every contact leaves a trace", when touching a surface, a bi-directional transfer of self and non-self-DNA residing on the hands and touched objects can occur. Metals are commonly encountered in forensic evidence and, during hand contact with these surfaces, a transfer of metal particles could occur together with the transfer of human DNA. This study proposes a proof-concept approach for the original detection of metal particles and touch DNA to track the activity performed by a donor and particularly to assess the metallic substrate touched before the contact with a subsequent surface. To this scope, a scenario of contact events was simulated by three volunteers, who participated in fingerprint deposition firstly on copper and then on plastic and glass surfaces. Twenty-four stubs were collected on the hands of volunteers and the secondary surfaces and then analyzed by environmental scanning electron microscopy (ESEM). DNA was quantified only from copper and plastic surfaces. Ten additional volunteers followed the same protocol of deposition on copper and then on plastic surfaces to evaluate DNA transfer only. On 20 touch DNA samples, the copper surface yielded significantly lower DNA amounts, ranging from 0.001 to 0.129 ng/μl, compared to the secondary touched plastic surface, ranging from 0.007 to 0.362 ng/μl. ESEM-EDS analysis showed that copper particles could be abundantly detected on the hands of the volunteers after contact with the copper surface. Particles containing silicates with copper were shown on plastic, while they were only found in 1/3 of samples on glass. Our proof-of-concept study has shown that ESEM-EDS analysis has the potential to detect copper particles transferred to the hands of volunteers during contact with a copper metallic surface and deposited on secondarily touched items. The results suggest that this original ESEM-DNA parallel approach could potentially allow the tracking of DNA transfer and metal particles at a crime scene, although this represents only a first step and further research on a wider casuistry could help to address the interpretation of results given activity level propositions.

#2984 SLE associated fibrillary glomerulonephritis vs SLE nephritis with fibrils: can a straightforward distinction always be made?

Abstract Background and Aims Fibrillary glomerulonephritis (FGN) is an uncommon but serious kidney disease with unclear aetiology, variable prognosis, and a not well-established treatment. FGN has been associated with autoimmune diseases including SLE. Other aetiologies comprise diabetes, malignancies, HCV and chronic infections. Our goal is to discuss the pathologic and clinical differential diagnosis conundrums that a patient with a suspected SLE presented. Method We present the case of a 53-year-old woman evaluated for proteinuria (1 g/24 h), and glomerular haematuria. Renal function was normal. She referred mild arthralgias for the past two years. Her medical history was unremarkable for diabetes and hypertension. ANA and anti-dsDNA were positive. The rest of the immunological work-up was normal as well as protein immunofixation/free light chains. HCV, HBV, and HIV serology was negative. A thorough evaluation for malignancy was negative. A renal biopsy was performed. Results The renal biopsy showed enlarged glomeruli with mesangial matrix expansion (Congo-red negative), mild mesangial hypercellularity and focal endocapillary hypercellularity without hyaline deposits, fibrinoid necrosis or crescents, without significant chronic lesions (Fig. 1). A probable diagnosis based on light microscope could be that of a lupus nephritis class III with low activity and low chronicity indices. Immunofluorescence demonstrated weak or moderate immunofixation of IgG (2+), IgA(1+), C3(2+), C1q(1+), κ(1+) and λ(1+) in the mesangium and segmentally in the capillary walls with a smudgy appearance. IgM, C4, fibrinogen and albumin were negative. The lack of a full-house pattern and, more significantly, the low C1q intensity raised some questions about the validity of a lupus nephritis diagnosis. Ultrastructural evaluation revealed abundant fibrils that occupied the mesangium and permeated the glomerular basement membranes (GBMs). Fibrils were non branching and randomly oriented with a mean diameter of ∼15 nm (range: 11,87 nm -18,84 nm) (Fig. 2). No electron dense deposits, fingerprint deposits or tubuloreticular inclusions were detected. Immunohistochemical staining for DNA-J heat-shock protein family member B9 (DNAJB9) was then performed showing strong positivity in the mesangial matrix and GBMs. Interestingly, C4d was also strongly positive with the same pattern as DNAJB9. The diagnosis of fibrillary glomerulonephritis was suggested, mostly based on ultrastructural evaluation and immunohistochemical findings. Conclusion It is well known that the characteristic features of lupus nephritis (intense C1q staining, full-house staining, extraglomerular deposits, tubuloreticular inclusions, and combined subendothelial and subepithelial deposits) are, in some cases, neither universally present nor specific for lupus nephritis. Of special interest is the identification of fibrils in the renal biopsy of an SLE patient. The crucial importance of distinguishing between SLE associated FGN and SLE nephritis with fibrils is based on the generally poor renal prognosis of FGN as well as the unsatisfactory performance of immunosuppression. The differential diagnosis can be very challenging especially when DNAJB9 is not available.

Alkaline Phosphatase for Estimating the Time since Deposition of Blood Fingerprints by Scanning Electrochemical Microscopy.

Blood is one of the most frequent and valuable traces encountered at crime scenes, where knowing the time since deposition (TSD) of bloodstains tremendously assists forensic experts to screen out crime-related evidence and aids in the reconstruction of the event sequence. Although increasing proof-of-concept methodologies for investigating the TSD of bloodstains have been reported, there is still no accepted strategy in forensic practice as the aging mechanism involves complex components, leading to the inaccuracy of the estimation results. Herein, an endogenous biomarker of alkaline phosphatase (ALP) was chosen to investigate the TSD by scanning electrochemical microscopy (SECM). Results demonstrate that the ALP activity acquired via SECM lateral scan assay exhibited a clear decrease over time, and a similar trend was observed on both poly(vinylidene fluoride) (PVDF) membrane and glass, with the aging kinetics on PVDF membrane being faster than glass. By means of quantitatively calculating the flux of generated p-aminophenol (PAP), we established the aging curve and realized the TSD estimation of blood fingerprints (BFPs) that was unable to be distinguished via optical measurements. Intriguingly, the as-obtained estimation accuracy ranged from 74.6 to 93.7%, proving the possibility of using an ALP biomarker and SECM. More appealingly, the predicted TSDs were capable of accurately differentiating the deposition sequence of overlapping BFPs, which was hardly achieved by optical means. Therefore, this proof-of-concept strategy demonstrates the value of SECM as a forensic tool and opens possibilities for revealing multidimensional information about crime.

Predicting Fingerprint Age Based on Ozonolysis Kinetics of Unsaturated Triacylglycerol Degradation.

Answering the question, "How old is a fingerprint?", is a highly sought-after aim in forensic science. Despite several decades of studies to find an empirical correlation in fingerprint aging, there has been no reliable method so far. In this study, we attempt to determine the time since deposition (TSD) of aged fingerprints from the chemical profile captured within a matrix-assisted laser desorption/ionization mass spectrometry data set. Our approach is based on the chemical kinetics associated with the ambient ozonolysis of unsaturated triacylglycerols (TGs), a major component in fingerprint lipids. First, ozone concentration and ambient temperature were determined to be the major factors in the degradation of unsaturated TGs. A simple kinetics model is then developed to describe the decay of unsaturated TGs, dictated only by the temperature and ozone concentration. This model is then applied to the degradation of TGs in a mixture of TG standards and multiple individuals' fingerprints. The overall decay of unsaturated TGs follows the pseudo-first-order reaction kinetics, validating our hypothesis; however, there are significant person-to-person variations in the initial abundance of unsaturated TGs and the decay rate, hampering the accurate prediction of TSD unless they are corrected for each individual. Nevertheless, the model's applicability for ambient fingerprint aging data was successfully demonstrated.

The use of liquid latex as a pre‐treatment to recover debris‐covered latent fingerprints from exterior surfaces of vehicles

This study evaluated the effectiveness of using liquid latex as a pre-treatment for fingerprint recovery from the exterior surfaces of vehicles in summer. The sample of this study was 540 sebaceous latent fingerprints deposited on the lower body of three vehicles. Thirty control and thirty experimental fingerprints were deposited on each vehicle, and the experiment was repeated three times. The three vehicles were driven daily for either 2, 3, or 4 weeks after the deposition of fingerprints. After the vehicles reached their designated debris accumulation duration, the latent fingerprints in the control groups were developed with black fingerprint powder. Liquid latex was applied onto the fingerprints in the experimental groups, and they were subsequently developed with black fingerprint powder. A chi-sure test indicated that there was a significant difference in fingerprints recovery performance between two methods (X2 =4.903, d.f. = 1, p=0.027). An odds ratio test indicated the control method increases the probability of fingerprint recovery by 1.54 times. A Fisher's exact test was used to evaluate the quality of fingerprints recovered from both methods and it indicated that there is no significant difference in quality using the two methods (p=0.058). This study indicated that the traditional fingerprint powder method performed better for fingerprint recovery from exterior surfaces of vehicles in summer.

Molecular docking study on europium nanoparticles and mussel adhesive protein for effective detection of latent fingerprints

Background: Reflecting on the difficulty of finding the evidence of latent fingerprints on wet and rough surfaces, scientists need to visualise those fingermarks without any background interference and stable adhesion of visualising material over the fingermark residues. Objective: To stabilize the interaction with the fingermarks, the synthesized nanoparticles were conjugated with a highly adhesive biopolymer, Mussel Adhesive Protein (MAP) which can effectively interact with fingerprint deposits. Material and Methods: Rare earth metal, europium oxide and nanoparticles were used as a visualisation material to get high contrast and reduced background interference-based fingerprints. To stabilise the interaction with the fingermarks, the synthesised nanoparticles were conjugated with highly adhesive biopolymer, Mussel Adhesive Protein (MAP) which can effectively interacts with fingerprint deposits. A molecular docking study was done using Auto-Dock to find the binding affinity between the metal nanoparticle and the protein. Further, the stability of the bioconjugated with fingerprint residues was analysed by protein-protein interaction study through patch dock and PDB Sum. Results: The docking analysis between europium and nanoparticles with MAP was found to be −8.77 kcal/mol and −47.49 kcal/mol respectively. Protein-protein interaction studies showed a highest affinity for dermcidin and keratin with a binding affinity of −16.76 kcal/mol and −24.76 kcal/mol respectively. Conclusions: The docking studies showed an efficient interaction between the synthesised molecules and the fingermark residues. Results of these interaction studies proved that this bio-conjugated complex can be explored for efficient visualisation of low intensified fingermarks.

Novel Ambient Oxidation Trends in Fingerprint Aging Discovered by Kendrick Mass Defect Analysis.

A Kendrick mass defect (KMD) plot is an efficient way to disperse complex high-resolution mass spectral data in a visually informative two-dimensional format which allows for the rapid assignment of compound classes that differ by heteroatom content and/or unsaturation. Fingerprint lipid oxidation has the potential to be used to estimate the time since deposition of a fingerprint, but the mass spectra become extremely complex as the lipids degrade. We apply KMD plot analysis for the first time to sebaceous fingerprints aged for 0–7 days to characterize lipid degradation processes analyzed by MALDI-MS. In addition to the ambient ozonolysis of fingerprint lipids previously reported, we observed unique spectral features associated with epoxides and medium chain fatty acid degradation products that are correlated with fingerprint age. We propose an ambient epoxidation mechanism via a peroxyl radical intermediate and the prevalence of omega-10 fatty acyl chains in fingerprint lipids to explain the features observed by the KMD plot analysis. Our hypotheses are supported by an aging experiment performed in a sparse ozone condition and on-surface Paternò–Büchi reaction. A comprehensive understanding of fingerprint degradation processes, afforded by the KMD plots, provides crucial insights for considering which ions to monitor and which to avoid, when creating a robust model for time since deposition of fingerprints.

Heterogeneously-wetting glass with enhanced anti-fingerprint properties

The rapid development of user interface products (such as touch-operated smartphones, panels, and computers) has tremendously changed how we interact with technology. Inevitably, undesirable fingerprint oil contamination is often left on touchscreen glass, significantly impairing the users' visual experience. To date, attempts based on oil-repellent or oleophilic coatings have been utilized to prevent the deposition of fingerprints on glass. However, these methods exhibited limited performance, particularly under real-world conditions. Inspired by the heterogeneous wettability of Stenocara beetles, we designed a novel heterogeneous glass surface, made up of nanopillars consisting of oleophilic top surfaces with oleophobic sidewalls and bases. This configuration combines the anti-fingerprint properties of both oleophobicity and oleophilicity. The beetle-like heterogeneous structures with remarkable wettability contrast enable excellent optical and wetting properties, including high transparency, low haze, hydrophobicity, and oleophobicity. The synergistic integration of oleophobic and oleophilic characteristics contributes to the non-uniform distribution of adhesion force, leading to a 74.6 % increase in fingerprint resistance and a 59.2 % increase in the ease of fingerprint removal over conventional oleophobic glass. The heterogeneous glass also maintained stable anti-fingerprint properties after ten standard cycles of finger touch and wiping, and even up to 1000 cycles of continuous wiping, illustrating good mechanical robustness. Thus, our findings provide a new route for the future design of anti-fingerprint glass.

Analysis of after effects of using hand sanitizers and hand cream on latent fingerprint's development with time gap

Many skin formulations, such as hand sanitizers and hand creams, are often utilised. When applied to the skin, the ingredients of such formulations can remain on the superficial level. This is extremely persuasive in fingerprint detection field since the components in hand sanitizer and hand cream can survive upon friction ridge skin and transported to the surface after deposition. The present study is aimed to determine whether or not the application of these, prior to fingerprint deposition, influences the subsequent chemical detection of fingerprints.

Impact on development techniques by the application of hand sanitizer prior to the fingerprint deposition

The general public's interest in hand sanitizers has soared after the covid-19 pandemic pestilence. This gave rise to the notion that the use of such hand sanitizers may hinder or enhance the visibility of developed fingerprints. Based on this hypothesis, a hand sanitizer was tested to see how it affected the detection of fingerprints left behind after use. Fingerprint detection techniques used included: ninhydrin, silver nitrate, iodine fuming and cyanoacrylate method.

Determination of Time since Deposition of Fingerprints via Colorimetric Assays.

Past investigations involving fingerprints have revolved heavily around the image of the fingerprint—including the minutiae, scarring, and other distinguishing features—to visually find a match to its originator. Recently, it has been proven that the biochemical composition can be used to determine originator attributes, such as sex, via chemical and enzymatic cascades. While this provides pertinent information about the originator’s identity, it is not the only piece of information that can be provided. This research was designed with three goals in mind: (1) identify how long it would take before an aged female fingerprint could no longer be differentiated from a male fingerprint, (2) identify a correlation between the data collected and a specific time since deposition (TSD) time point, and (3) identify if a specific amino acid could be contributing to the decreasing response seen for the aging fingerprints. Using ultraviolet–visible (UV–vis) spectroscopy, aged fingerprints were evaluated over the course of 12 weeks via three chemical assays previously used for fingerprint analysis—the ninhydrin assay, the Bradford assay, and the Sakaguchi assay. As fingerprints age, the conditions they are exposed to cause the biochemical composition to decompose. As this occurs, there is less available to be detected by analytical means. This results in a less intense color production and, thus, a lower measured absorbance. The results displayed here afforded the ability to conclude that all three goals set forth for this research were accomplished—a female fingerprint can be differentiated from a male fingerprint for at least 12 weeks, UV–vis data collected from aged fingerprints can be correlated to a TSD range but not necessarily a specific time point, and the decomposition of at least a single amino acid can afford the ability to estimate the TSD of the fingerprint.

Impact of hand sanitizer on the fingerprints developmental techniques

BackgroundThe general public's interest in hand sanitizers has soared after the covid-19 pandemic pestilence. This gave rise to the notion that the use of such hand sanitizers may hinder the visibility of developed fingerprints.MethodologyBased on this hypothesis, a hand sanitizer was tested to see how it affected the detection of fingerprints left behind after use. Fingerprint detection techniques used included: ninhydrin, silver nitrate, iodine fuming and cyanoacrylate method.Result and conclusionWhen hand sanitizedfingerprints were compared to non-hand sanitized fingerprints, the alcohol-based hand sanitizers improved the visibility of fingerprints developed with ninhydrin and iodine fuming, and marginally improved those developed with silver nitrate and cyanoacrylate method. To determine the longevity of improved developed quality, various parameters such as time since hand sanitizer application prior to fingerprint deposition was tested.

Determining Fingerprint Age with Mass Spectrometry Imaging via Ozonolysis of Triacylglycerols.

Despite the common use of fingerprints as a trusted means of identification, no method currently exists to reliably establish the time since deposition of latent fingerprints. A reproducible method of establishing latent fingerprint age would allow forensic personnel to determine if a latent fingerprint was relevant to a crime. This work investigates the ambient aging of triacylglycerols (TGs) and other lipids in latent fingerprint residue utilizing matrix-assisted laser desorption/ionization mass spectrometry imaging. Unsaturated TGs were found to undergo ambient ozonolysis resulting in a decrease over time. At the same time, two series of compounds related to the degradation of unsaturated TGs due to ambient ozonolysis emerged with time and were detectable within a single day of aging. Tracking the degradation of unsaturated TGs over time proved to be relatively reproducible in multiple individuals and is suggested as a means of establishing latent fingerprint age.

New insights into the rapid deposition and visualization of latent fingerprints: Cyan light emitting GdAlO3:Ce3+ nano fluorescent probe

The marvelous blend of nanoscience and nanotechnology evoke much interest due to their prospective applications in many fields. They can bridge gap between the nanoscale and microscale world and afford favourable functions. Among various fields, forensic science especially latent fingerprints are the substantial evidences due to their characteristic details and special chemical compositions; hence they serve as identity tool for forensic enquiries as well as medical diagnosis. Therefore, considerable attention was paid by the researchers to visualize latent fingerprints. During visualization, background hindrance from the underlying surface diminishes the visualization sensitivity. Hence, many efforts were attempted to overcome from the background hindrance, but still need to improve. This exciting objective stimulating to fabricate novel GdAlO3:Ce3+ (1–9 mol %) nanophosphors by a facile solution combustion method. The diffraction patterns confirm the orthorhombic phase of the prepared nanophosphors. The photoluminescence emission spectra exhibit a broad peak centered at ˜ 466 nm, which attributed to 5D3/2→7FJ transitions (J = 7/2 and 5/2) of Ce3+ ions. The photometric properties confirm that the prepared samples emit cyan blue color with high color purity. The optimized sample can be used to visualize latent fingerprints with high resolution, sensitivity and less background hindrance. Furthermore, type 1–3 details of latent fingerprints were clearly revealed on various hydrophilic and hydrophobic substrates. These results indicate that the optimized GdAlO3:Ce3+ (5 mol %) nanophosphors were considered as a potential material for latent fingerprints visualization for forensic investigations and anti-counterfeiting applications.

Evaluation of Antifingerprint Properties of Plastic Surfaces Used in Automotive Components

The antifingerprint properties of a range of surfaces produced with different technologies (in-mould decoration, in-mould labeling, and painted) were objectively evaluated by depositing on them in standard conditions an artificial fingerprint for direct determination of its visibility. The artificial fingerprint behaves similarly to the real human fingerprints. A classification method is then proposed to classify surfaces on the base of antifingerprint properties by measuring the roughness profile (Ra) and calculating the % variation of gloss (GU 20 and 60°), haze, luminance (L), and diffuse reflectance (R) values after fingerprint deposition. This approach provides an objective and quantitative test method to determine visual antifingerprint properties of coated surfaces, instead of the “easy-to-clean” properties commonly evaluated. The data acquired provides a design guideline for fabricating visually fingerprint-free surfaces by controlling roughness, texture, color, and transparency of surfaces, with the aim of optically masking fingerprints.

DNA Identification from Sebaceous Sweat Fingerprint Deposits on Corpse Integuments

The paper presents the results of a pilot molecular genetic study of sweat and oil residue left by the fingertips and hand palms of male volunteers (donors) on various regions of the skin surface of dead bodies (recipients) of both sexes. In cases of contact with female recipients donor-specific allele combinations were obtained for only 11.6% of autosomal loci and 12.9% of Y-chromosomal loci. Donor-specific traits were absent in 68.4% of autosomal loci and 87.1% of Y-chromosomal loci. In cases of contact with male recipients the full genetic profile was obtained for 18.6% of autosomal loci, and 64.2% of loci showed a lack of donor-specific alleles. Meanwhile, allelic combinations specific to female recipients were encountered in 40.5% of autosomal loci, and to male recipients – in 34.2% of autosomal loci. Results demonstrate poor adhesion of sweat and oil compounds from donors’ hands to the corpses’ skin, probably due to significant temperature differences between contact surfaces.

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.

The Effect of Varying the Composition of Fingerprint Sweat Deposits on the Corrosion of Brass and Fingerprint Visibility.

Corrosion of α-phase brass by sebaceous sweat fingerprint deposits produced identifiable impressions in a majority of samples (n = 40) 4 days after deposition. Combining sebaceous with eccrine sweat yielded a greater percentage of identifiable fingerprint deposits, although this increase was not statistically significant. Production of identifiable fingerprints from eccrine sweat deposits was dependent on the sampling time of year with deposits taken during summer months giving similar percentages of identifiable fingerprints to sebaceous deposits. A statistically significant positive correlation was found between elapsed days after deposition and identifiable eccrine (ρ = 0.787, p < 0.05), sebaceous (ρ = 0.724, p < 0.05), and eccrine/sebaceous mixture (ρ = 0.908, p < 0.01) fingerprints deposited during summer months. The summer increase in the percentage of identifiable eccrine sweat deposits was statistically significant compared to winter eccrine deposits (p < 0.0001). Observations were consistent with results obtained from artificial sebaceous and eccrine sweat.

A Modified Electrostatic Adsorption Apparatus for Latent Fingerprint Development on Unfired Cartridge Cases.

Visualization of latent fingerprints on metallic surfaces by the method of applying electrostatic charging and adsorption is considered as a promising chemical-free method, which has the merit of nondestruction, and is considered to be effective for some difficult situations such as aged fingerprint deposits or those exposed to environmental extremes. In fact, a portable electrostatic generator can be easily accessible in a local forensic technology laboratory, which is already widely used in the visualization of footwear impressions. In this study, a modified version of this electrostatic apparatus is proposed for latent fingerprint development and has shown great potential in visualizing fingerprints on metallic surfaces such as cartridge cases. Results indicate that this experimental arrangement can successfully develop aged latent fingerprints on metal surfaces, and we demonstrate its effectiveness compared with existing conventional fingerprint recovery methods.

Unusual Nature of Fingerprints and the Implications for Easy-to-Clean Coatings.

Irrespective of the technology, we now rely on touch to interact with devices such as smart phones, tablet computers, and control panels. As a result, touch screen technologies are frequently in contact with body grease. Hence, surface deposition arises from localized inhomogeneous finger-derived contaminants adhering to a surface, impairing the visual/optical experience of the user. In this study, we examined the contamination itself in order to understand its static and dynamic behavior with respect to deposition and cleaning. A process for standardized deposition of fingerprints was developed. Artificial sebum was used in this process to enable reproducibility for quantitative analysis. Fingerprint contamination was shown to be hygroscopic and to possess temperature- and shear-dependent properties. These results have implications for the design of easily cleanable surfaces.