Sexual dimorphism and topological variability in fingerprint ridge density in a north-west Indian population.

The science of fingerprints is very crucial in criminal investigation as it helps identify perpetrators or victims of a crime. Fingerprint ridge density (FPRD), which refers to the number of ridges within a specific area on the epidermal skin layer of the distal phalanges in humans, has been found to differ between males and females. This study attempts to estimate the sex from FPRD and evaluates the diversity in FPRD across several topological areas. The study involves 208 participants (120 males, 88 females) between the ages 18 to 25 years from a North-west Indian population. Fingerprints were collected, and FPRD was accessed in radial, ulnar, and proximal areas as recommended by Gutierrez-Redomero et al. (Forensic Sci Int 180(1):17-22, 2008). FPRD has been quantified using the techniques described by Acree (Forensic Sci Int 102(1):35-44, 1999). When evaluating FPRD in the lateral pocket loops and twin loops, the proximal-side core was considered. The study reveals that males have a mean fingerprint ridge density of 12.82 ridges/25 mm2 while females have 13.01 ridges/25 mm2. Females have higher fingerprint ridge density solely in the proximal area; males have higher fingerprint ridge density in both radial and ulnar areas. In conclusion, this research underscores the potential of fingerprint ridge density as a parameter for investigating population variations and individual identification. Future studies on fingerprint ridge density in India's diverse population will help establish reference ranges, allowing for sex and likely population group estimation, making it a valuable tool for preliminary examinations and exclusion criteria for sex estimation in crime scene investigations.

More than just blood, saliva, or sperm-setup of a workflow for body fluid identification by DNA methylation analysis.

The determination of cellular origin of DNA is a useful method in forensic genetics and complements identification of the DNA donor by STR analysis, since it could provide helpful information for the reconstruction of crime scenes and verify or disprove the descriptions of involved people. There already exist several rapid/pre-tests for several secretions (blood, sperm secretion, saliva, and urine), RNA-based expression analyses (blood, menstrual blood, saliva, vaginal secretion, nasal secretion, and sperm secretion), or specific CpG methylation analyses (nasal blood, blood, saliva, vaginal secretion, nasal secretion, and sperm secretion) for determining the cell type.To identify and to discriminate seven different body fluids and mixtures thereof in a simple workflow from each other, assays based on specific methylation patterns at several CpGs combined with pre-/rapid tests were set up in this study. For each of the seven secretions listed above, we selected the CpG marker achieving the highest possible discrimination (out of 30 markers tested). Validation studies confirmed a definite identification for saliva, vaginal secretion, and semen secretion in 100% of samples as well as discrimination from all other secretions. Moreover, the unambiguously correctly determined proportion of nasal samples, blood and menstrual blood varied between 61% (nasal blood) and 85% (nasal secretion).In summary, our workflow proved to be an easy and useful tool in forensic analysis for the identification and discrimination of seven different body fluids often found at a crime scene.

An avenue to miscarriage: a case report.

Two men were wrongfully convicted of murder in 2017 and sentenced to life imprisonment. After a physical altercation inside a flat, the victim (A) was found dead approximately 60 m away outside a residential address. He had sustained a number of injuries including a stab wound to the left side of his neck which was found to have divided the right carotid artery. The location where A was found was not regarded as a crime scene and not subjected to a specialist forensic examination by scientists as it was assumed that the fatal injury was sustained in the flat. The pathologist, who subsequently carried out the autopsy on A, was not asked to attend the scene. A review of the blood distribution at the scene in conjunction with the pathology findings indicated however that the fatal neck wound had been inflicted outside the flat, near to where the victim was found. An appeal against the convictions for murder was upheld in 2021 and a re-trial ordered. Following this second trial, both accused were acquitted of murder and released from custody. The new pathology and blood pattern evidence introduced at the second trial was a major part of the defense strategy which led to the acquittal of the accused. The case illustrates that a more inclusive and detailed crime scene strategy had been undertaken, including an assessment of the bloodstains present, in conjunction with discussion with the pathologist, then the likelihood is that the two men subsequently charged with murder would have been eliminated as suspects and a miscarriage of justice would have been avoided.

Self-ligature strangulation by multiple cable ties.

This article reports an autopsy of a 39-year-old deceased male who had done suicidal strangulation using multiple self-locking cable ties. The deceased used seven ligatures, constricting at a different level around the neck to accomplish the suicidal strangulation. Each ligature was made up of two cable ties attached to each other. The detailed autopsy examination and crime scene investigation confirm the manner of strangulation as suicidal. Suicidal strangulation is uncommon but not rare. Varying ligature materials and different locking methods were used for this purpose. The present case is remarkable because of the use of multiple self-locking zip cable ties as ligature material.

Crime scene investigation and dynamic reconstruction: importance of synergic collaboration between forensic pathology and digital reconstruction for work-related fatalities.

A crime scene is the result of the dynamic interrelation of various factors. Where a fatality is involved, thorough analysis of the scene by a forensic pathologist produces the first data for verifying consistency between the necropsy results and witness testimonies toward defining the dynamics of injury and death. This step is extremely important in identifying any liability. We present the case of a construction worker who fell through a trapdoor between two floors while holding an iron beam at a building site. This case demonstrates the effectiveness of an integrated approach, using both classic forensic investigation techniques and digital 3-D reconstruction: it allowed verification of the dynamics of the injury and provided important information in assessing the employers liability.

Crime scene investigation and dynamic reconstruction: importance of synergic collaboration between forensic pathology and digital reconstruction for work-related fatalities.

Místo činu je výsledkem dynamického působení vzájemně se ovlivňujících faktorů. Pečlivá analýza místa úmrtí soudním lékařem poskytuje prvotní informace pro ověření souladu mezi pitevním nálezem a výpověďmi svědků a pro stanovení mechanizmu úrazu a úmrtí. Tento krok je nesmírně důležitý pro stanovení odpovědnosti za úraz. Prezentujeme případ stavebního dělníka, který propadl dveřmi mezi dvěma patry na staveništi, zatímco držel železný nosník. Tento případ demonstruje efektivitu komplexního přístupu zahrnujícího jak klasické forenzní vyšetřovací metody, tak metody digitální 3D rekonstrukce. Tento přístup nám umožnil ověřit dynamiku úrazu a poskytnul nám důležité informace pro posuzování odpovědnosti zaměstnavatele.

Rapid separation of post-blast explosive residues on glass electrophoresis microchips.

This study describes the development of an analytical methodology based on the use of microchip electrophoresis (ME) devices integrated with capacitively coupled contactless conductivity detection (C4 D) for the separation and detection of inorganic anions in post-blast explosive residues. The best separation condition was achieved using a running buffer composed of 35 mmol/L lactic acid, 10 mmol/L histidine and 0.070 mmol/L cetyl(trimethyl ammonium) bromide. For C4 D measurements, the highest sensitivity was obtained applying a 700 kHz sinusoidal wave with excitation voltage of 20 Vpp . The separation of Cl- , NO3- , NO2- , SO42- , ClO4- and ClO3- was performed within ca. 150 s with baseline resolution and efficiencies between 4.4 × 104 and 1.7 × 105 plates/m. The found limits of detection ranged between 2.5 and 9.5 µmol/L. Last, real samples of post-blast explosive residues were analyzed on the ME-C4 D devices obtaining successfully the determination of Cl- , NO3- and SO42- . The achieved concentration values varied between 12.8-72.5 mg/L for Cl- , 1.7-293.1 mg/L for NO3- and 1.3-201.3 mg/L for SO42- . The data obtained using ME-C4 D devices were in good agreement with the concentrations found by ion chromatography. The approach reported herein has provided short analysis time, instrumental simplicity, good analytical performance and low cost. Furthermore, the ME-C4 D devices emerge as a powerful and portable analytical platform for on-site analysis demonstrating to be a promising tool for the crime scene investigation.

Gunshot residue on dark materials: a comparison between infrared photography and the use of an alternative light source.

The pattern of gunshot residue (GSR) includes important information about muzzle-target distance since a larger GSR distribution diameter indicates a larger shooting distance. GSR may not be visible to the naked eye when, for example, it is located on dark textiles. In such cases, further procedures need to be performed in order to visualize the pattern of GSR. Besides chemical procedures, an alternative light source or infrared photography can be utilized for non-destructive GSR visualization. In the work presented, these two techniques are compared based on shooting experiments using 26 different dark textiles. Within the range of the alternative light source, the use of a 440-nm light in combination with an orange-colored filter led to the best visualization of GSR in the form of fluorescent particles. Infrared photography, on the other hand, visualized GSR as dark particles, whereas-ideally-the dark textile reflected the infrared light and appeared bright. The comparison of both techniques revealed that the GSR distribution visualized by infrared photography was not identical to the GSR distribution visualized with 440-nm illumination in combination with an orange-colored filter. We concluded that infrared photography visualizes the inner powder soot zone, whereas illumination at 440 nm leads to fluorescence of the outer powder soot zone, which can be visualized using an orange-colored filter. Knowledge of this difference in visualization of the two powder soot zones is important for forensic practitioners assessing firing distances. In the literature, however, this difference is not noted as clearly.

Identification at the crime scene: The sooner, the better? The interpretation of rapid identification information by CSIs at the crime scene.

New technologies will allow Crime Scene Investigators (CSIs) in the near future to analyse traces at the crime scene and receive identification information while still conducting the investigation. These developments could have considerable effects on the way an investigation is conducted. CSIs may start reasoning based on possible database-matches which could influence scenario formation (i.e. the construction of narratives that explain the observed traces) during very early phases of the investigation. The goal of this study is to gain more insight into the influence of the rapid identification information on the reconstruction of the crime and the evaluation of traces by addressing two questions, namely 1) is scenario formation influenced from the moment that ID information is provided and 2) do database matches influence the evaluation of traces and the reconstruction of the crime. We asked 48 CSIs from England to investigate a potential murder crime scene on a computer. Our findings show that the interpretation of the crime scene by CSIs is affected by the moment identification information is provided. This information has a higher influence on scenario formation when provided after an initial scenario has been formed. Also, CSIs seem to attach great value to traces that produce matches with databases and hence yield a name of a known person. Similar traces that did not provide matches were considered less important. We question whether this kind of selective attention is desirable as it may cause ignorance of other relevant information at the crime scene.

Rapid identification information and its influence on the perceived clues at a crime scene: An experimental study.

Crime scenes can always be explained in multiple ways. Traces alone do not provide enough information to infer a whole series of events that has taken place; they only provide clues for these inferences. CSIs need additional information to be able to interpret observed traces. In the near future, a new source of information that could help to interpret a crime scene and testing hypotheses will become available with the advent of rapid identification techniques. A previous study with CSIs demonstrated that this information had an influence on the interpretation of the crime scene, yet it is still unknown what exact information was used for this interpretation and for the construction of their scenario. The present study builds on this study and gains more insight into (1) the exact investigative and forensic information that was used by CSIs to construct their scenario, (2) the inferences drawn from this information, and (3) the kind of evidence that was selected at the crime scene to (dis)prove this scenario. We asked 48 CSIs to investigate a potential murder crime scene on the computer and explicate what information they used to construct a scenario and to select traces for analysis. The results show that the introduction of rapid ID information at the start of an investigation contributes to the recognition of different clues at the crime scene, but also to different interpretations of identical information, depending on the kind of information available and the scenario one has in mind. Furthermore, not all relevant traces were recognized, showing that important information can be missed during the investigation. In this study, accurate crime scenarios where mainly build with forensic information, but we should be aware of the fact that crime scenes are always contaminated with unrelated traces and thus be cautious of the power of rapid ID at the crime scene.

Reconstruction of crimes by infrared photography.

Whenever blunt or sharp forces are used in a crime, analysis of bloodstain pattern distribution may provide important information for the reconstruction of happenings. Thereby, attention should be paid to both the crime scene and the clothes of everyone involved in the crime. On dark textiles, though, it is difficult or even impossible for the human eye to detect bloodstains because of the low contrast to the background. However, in the near infrared wavelength range, contrast is considerably higher. Many textiles reflect light beyond a wavelength of 830 nm and thus appear light-colored, whereas blood absorbs the light and appears dark. In our studies, a D7000 NIKON reflex camera modified for infrared photography produced high-resolution photographs visualizing even very small spatter stains on dark textiles. The equipment can be used at any crime scene or lab and provides immediately available and interpretable images. Thus, important findings can be obtained at an early stage of police investigations, as two examples (homicide and attempted homicide) illustrate.

Identification, Collection, and Preservation of Veterinary Forensic Evidence: On Scene and During the Postmortem Examination.

Although it is the obligation of the veterinary forensic pathologist to be competent in identifying, collecting, and preserving evidence from the body, it is also necessary for them to understand the relevance of conditions on the crime scene. The body is just one piece of the puzzle that needs to be considered when determining the cause of death. The information required for a complete postmortem analysis should also include details of the animal's environment and items of evidence present on the crime scene. These factors will assist the veterinary forensic pathologist in the interpretation of necropsy findings. Therefore, the veterinary forensic pathologist needs to have a basic understanding of how the crime scene is processed, as well as the role of the forensic veterinarian on scene. In addition, the veterinary forensic pathologist must remain unbiased, necessitating an understanding of evidence maintenance and authentication.

Forensic expectations: Investigating a crime scene with prior information.

In a large body of research the influence of contextual information on decisions made in a broad range of disciplines has been studied. To date, the influence of these expectancy effects on the crime scene investigation has not been studied. In the present study we explored the effect of prior information given to crime scene investigators on their perception and interpretation of an ambiguous crime scene. Participants (N=58) were experienced crime scene investigators who were provided with a panoramic photograph of an ambiguous mock crime scene. The victim may have committed suicide or was murdered. Participants either received prior information indicating suicide, prior information indicating a violent death, or they received no prior information. Participants were asked about what they thought had happened at the scene of the crime, both at the initial assessment of the scene and at the end of the investigation when they were asked to describe the most likely scenario. They were also asked which traces they wanted to secure and why. Results showed that participants interpreted the crime scene differently dependent on how it was presented to them. Both the initial assessment of the scene and the most likely scenario that was described after the investigation were influenced by the prior information the participants were provided with, even though roughly the same traces were secured by all, independent of the prior information. Results demonstrate that prior information indeed influences the interpretation of the crime scene, but since the present study was exploratory further research is needed.

Application of augmented reality for crime scene investigation training and education.

The role of the crime scene investigator is complex, and investigators need to be able to conduct multiple frequently performed tasks. Appropriate training and education are critical to impart the crime scene investigator with the necessary capabilities. For a range of reasons, including the COVID-19 pandemic and the need for multi-disciplinary capabilities, training and education requirements have evolved in recent times to be more flexible and accessible. The skills of a crime scene investigator can be broadly categorised into two types of fundamental skills: decision-making and psychomotor skills. Both these skills need to be taught and assessed within training and education programs. The most common approach to impart these skills is by incorporating a crime scene simulation facility; however, not everyone has access to these facilities. Furthermore, crime scene staff often undertake refresher courses and are required to complete proficiency assessments. Conducting these activities in a dedicated crime scene simulation facility is time consuming and costly. Virtual tools have been developed in recent years to address this, but these tools only assess decision-making skills and not psychomotor skills. This paper argues that the implementation of augmented reality (AR) technology should be considered in crime scene investigator training and university education, because it can provide significant advantages when paired with conventional methods of training and education. When appropriately managed, AR can provide an avenue of training where both decision-making and psychomotor skills can be addressed simultaneously, while providing a more flexible and accessible approach. The implementation of AR has the potential to significantly improve the standards of teaching, resulting in better equipped crime scene investigators. The paper will explore how AR has the potential to improve accessibility of training, increase safety, enhance the student experience, enhance collaboration and feedback through connectivity and potentially reduce cost. This paper will also provide an insight into what would need to be considered before implementing AR technology into crime scene investigation training and education alongside current approaches. It is argued that the inclusion of AR into the current training and education arsenal provides significant benefits that are worthy of exploration.

Homicide by drowning: a literature review and analysis of three cases.

Background: Homicide by drowning in adults is rare. Usually, marks of violence are found on both the victim and the perpetrator, unless the victim was under the influence of alcohol, drugs, or was unexpectedly forced or dragged into the water. Indeed, many cases of drowning in adults are believed to be accidental, but they may be the result of drunken fights or attempts to make the death appear ac-cidental. In order to define the manner of death, cooperation between the forensic pathologist and the investigators is mandatory. Indeed, the autopsy is important to distinguish homicide by drowning from other kinds of drowning. The purpose of this study is to highlight the features of homicide by drowning. Materials and Methods: Literature search was conducted using PubMed databases, using the following keywords: "(homicide) and (drowning)". 3 articles were included in the systematic review, in addition to 3 cases observed in our institute. Conclusions: Both external examination and autopsy findings and the results of the investigation are essential to differentiate a homicide by drowning from accidental ones. The low specificity and variability of external and internal findings, the possibility of atypical asphyctic and nonasphyctic pathophysiological mechanisms, whose nature is not detectable at postmortem examinations, makes the diagnosis of cause of death difficult and often based on exclusion criteria only. In complex cases only using a strict forensic method allows to use the essential tools to identify the real manner of death.

CSI-CSI: Comparing several investigative approaches toward crime scene improvement.

Crime scene investigations are highly complex environments that require the CSI to engage in complex decision-making. CSIs must rely on personal experience, context information, and scientific knowledge about the fundamental principles of forensic science to both find and correctly interpret ambiguous traces and accurately reconstruct a scene. Differences in CSI decision making can arise in multiple stages of a crime scene investigation. Given its crucial role in forensic investigation, CSI decision-making must be further studied to understand how differences may arise during the stages of a crime scene investigation. The following exploratory research project is a first step at comparing how crime scene investigations of violent robberies are conducted between 25 crime scene investigators from nine countries across the world. Through a mock crime scene and semi-structured interview, we observed that CSIs have adopted a variety of investigation approaches. The results show that CSIs have different working strategies and make different decisions when it comes to the construction of relevant hypotheses, their search strategy, and the collection of traces. These different decisions may, amongst other factors, be due to the use of prior information, a CSI's knowledge and experience, and the perceived goal of their investigation. We suggest the development of more practical guidelines to aid CSIs through a hypothetico-deductive reasoning process, where (a) CSIs are supported in the correct use of contextual information, (b) outside knowledge and expertise are integrated into this process, and (c) CSIs are guided in the evaluation of the utility of their traces.

Innovations in forensic science: Comprehensive review of hyperspectral imaging for bodily fluid analysis.

Hyperspectral imaging (HSI) has become a crucial innovation in forensic science, particularly for analysing bodily fluids. This advanced technology captures both spectral and spatial data across a wide spectrum of wavelengths, offering comprehensive insights into the composition and distribution of bodily fluids found at crime scenes. In this review, we delve into the forensic applications of HSI, emphasizing its role in detecting, identifying, and distinguishing various bodily fluids such as blood, saliva, urine, vaginal fluid, semen, and menstrual blood. We examine the benefits of HSI compared to traditional methods, noting its non-destructive approach, high sensitivity, and capability to differentiate fluids even in complex mixtures. Additionally, we discuss recent advancements in HSI technology and their potential to enhance forensic investigations. This review highlights the importance of HSI as a valuable tool in forensic science, opening new pathways for improving the accuracy and efficiency of crime scene analyses.

Accidental Cut-Throat Injury by a Broken Glass: Bloodstain Pattern Analyses and Autopsy Findings.

Injuries in the neck region are rarely observed in forensic practice, especially of accidental origin. Primarily, such cases are associated with homicide or suicide. The neck region comprises different and vital anatomical structures, and even minor trauma could be lethal. In the absence of witnesses to the accident, each finding is of utmost importance, from the death/crime scene investigation - bloodstain patterns and trace evidence - to careful examination of the deceased body. The forensic pathologist has the challenging task of analyzing all the findings to make a statement concerning the cause and manner of death and, if there is something suspicious about the current case, to inform the relevant authorities.

Augmented reality in forensics and forensic medicine - Current status and future prospects.

Forensic investigations require a vast variety of knowledge and expertise of each specialist involved. With the increase in digitization and advanced technical possibilities, the traditional use of a computer with a screen for visualization and a mouse and keyboard for interactions has limitations, especially when visualizing the content in relation to the real world. Augmented reality (AR) can be used in such instances to support investigators in various tasks at the scene as well as later in the investigation process. In this article, we present current applications of AR in forensics and forensic medicine, the technological basics of AR, and the advantages that AR brings for forensic investigations. Furthermore, we will have a brief look at other fields of application and at future developments of AR in forensics.

Death by artery injury: two peculiar cases of sharp force fatality.

Background: As sharp force injury accounts for 10-20% of clinical forensic examinations, forensic pathologists are often asked to investigate deceased victims of stab wounds. Moreover, homicide by sharp force (stabbing) is one of the most common in European countries, involving generally domestic or interpersonal conflict. Stabbing as a suicide method constitutes a low percentage of all suicides, 2% to 3%. Accidental death due to sharp force is even rarer (0-3%) and usu-ally caused by an impact or a fall into different type of glass surface. Death due to stabbing is usually caused by exsanguinating incisions to organs or large blood vessels (such as arteries), leading to haemor-rhagic shock. Penetrating artery injuries are well known in clinical settings, and extremities are the most common sites of such injuries. Indeed, 50% to 60% of injuries occur in femoral or popliteal arteries, 30% in brachial artery. Aims: The aim of this paper is to present two rare cases of sharp force fatality, showing how a thorough forensic pathology methodology, including death scene investigation, autopsy examination, and toxicological analyses, are pivotal to detect the manner of death. Case Reports: This paper presents two peculiar cases of sharp force fatalities: the first, a single and accidental stab injury on the right armpit which caused a complete transection of the axillary artery; the second, a single homicidal stab wound on the lower leg causing a full-thickness lesion of the anterior tibial artery.