Examination Of Trace Evidence Research Articles

Application of X‐ray fluorescence in forensic archeology: A review

AbstractForensic Archeology is the application of techniques and principles of archeology in the pursuit of examining a crime or incident with legal interest. A wide range of analytical studies are employed in examining archeological remains. X‐ray fluorescence (XRF) spectroscopy remains to be one of the most used techniques for rapid examination of trace evidence typically found on an archeological crime scene. Studies of interest generally include finding trace elements from various sources, samples, and different environmental conditions and distinguishing whether a skeletal remains under examination is human, animal, or marine species. The present study has been designed to focus on the application of XRF in archeological and anthropological evidences such as the examination of human skeletal and dental remains, determination of species, examination of soil, ceramics, paintings, coins, and so on. The advantage of XRF as derived from the reported literature is that it is a non‐destructive technique making it ideal for forensic analysis and in situ examination. The study also discusses the factors affecting forensic investigations of archeological evidences and the limitations of XRF.

Interpretation and report writing in forensic comparisons of paint evidence: An interlaboratory exercise

This interlaboratory study evaluated a guide for interpreting and reporting trace evidence examinations. The online survey aimed to assess the examiners' interpretation of casework scenarios designed by a subject matter expert panel (SMEP), specifically for paint evidence. A pool of 30 scenarios was created, and 15 were assigned to each participant using multi-factor design to evaluate agreement among examiners on case sets with different conclusion ranges and difficulty levels. Exploratory data analysis and three generalized mixed-effects models were used to assess the data. From the 1267 responses received from 85 participants, approximately 93% of responses were consistent between participants and within the SMEP consensus and the next best category, while 73% agreed with the SMEP consensus that was considered the ground truth. Most disagreements were observed in worst-case scenarios created with intended higher difficulty and complex circumstances.The statistical models showed a strong positive relationship between the reported and expected conclusions, indicating that participants' findings align with the SMEP consensus. On the other hand, the exercise's difficulty level and participant's experience did not have a significant impact on the reported conclusions. However, the credible intervals for the probabilities of the different reported conclusions indicate that more experienced participants achieve greater consensus for a given exercise. The consensus reached among practitioners represents an advance in the trace community’s efforts to standardize reporting of results and opinions when following systematic criteria.

A Regression-Based Approach for Accurate Source Tracking Using Microbial Communities

Microbiome data has emerged as a valuable resource in source tracking studies, owing to its applications in the examination of trace evidence and human identification. In response to the growing importance of microbial information in forensic and environmental investigations, we have developed a novel statistical method called REST (REgression-based Source Tracking). REST offers a robust framework to harness microbiome data for the purpose of linking sample or sink data to a diverse pool of potential sources, identifying missing contributors, and accurately estimating the proportions of each source. Our research findings clearly demonstrate the superiority of the REST method over existing techniques in source tracking. Notably, REST exhibits a remarkable ability to detect and estimate the proportions with a minimal error rate. This advancement holds the potential to significantly enhance the accuracy of identifying individuals in forensic cases and tracking the origins of microbial compositions in environmental samples. By minimizing errors and providing precise estimates, REST opens up new possibilities for improving criminal investigations, mitigating environmental contamination, and addressing public health concerns with greater confidence and precision. The versatility of the REST method extends its applications beyond the scenarios discussed here, making it a valuable tool in various source tracking endeavors.

Editorial | A New Path Forward for Forensic Science Learning

Amazing but true, many criminalists regard forensic microscopy and the light microscope as the single most important instrument in their laboratories for the examination of physical trace evidence. They emphasize proper training as the key to success. McCrone Research Institute began by teaching chemical microscopy courses with the polarized light microscope to chemists and forensic scientists first at Cornell University, then Armour Research Foundation (ARF), Illinois Institute of Technology (IIT), University of Illinois at Chicago (UIC), and in its classrooms and laboratories still located on the South Side of Chicago since 1960. But it hasn’t been an easy path.

Characterization of fracture match associations with automated image processing

During the examination of trace evidence, often a realignment along the edges of known and questioned items are made to determine if a physical fit is present and if those objects were once one continuous piece or object. Duct tape is an evidence type in which the evaluation of physical fits is often conducted and is regarded as conclusive evidence of an association between the items. The examination and conclusion of a physical fit between edges relies heavily on examiner discretion to identify distinctive features across the edges since there are no statistical approaches or objective methodologies for the comparison. This study developed an automated image processing and comparison method to quantify tape end matches using cross-correlation scores and an empirical approach to the assessment. Characterization of 150 hand torn duct tape end pair physical fits were also conducted where matching and non-matching sample distributions were created. This study also evaluated partial duct tape edges and the influence this has on a comparison. Given the strength associated with a physical fit and the presence of stretching or deformation along the fractured edge, an understanding of the value these samples have is paramount. Furthermore, random match probabilities were calculated based on the correlation scores from the inter-comparisons to model the weight of evidence or strength of association between the edges. Finally, the study demonstrated that not every true match holds the same association strength through score distributions, but the approach is able to distinguish matching and non-matching samples at edge widths greater than 27 %.

PROBLEMS OF SOLVING THE QUESTION AS TO DETERMINATION OF THE HEIGHT OF A PERSON BY SHOE BOTTOM TRACES DETECTED AT THE CRIME SCENE

Human footprints and footwear traces were one of the first well-studied forensic objects of examination. This is due to the fact that these traces are most often found at the scene of the incident, as well as by the fact that they contain most valuable and significant information needed for criminal investigation. Forensic examination of footprints and footwear traces of a person are among the most common trace evidence examinations encountered in practice, and defining a human height based on footprints is relevant and important in terms of obtaining primary (up-to-date), and later evidentiary information for a successful investigation and crime detection. The approximate height of a person, as indicated in the current trace evidence literature, can be established by using a certain number of the most common methods, one of which is to establish height by the total length of the trace. However, the existing today methods for calculating human height by foot traces (footprints) have certain disadvantages, which are mentioned in this article.
 The article purpose is to analyze current known methods and techniques for determining human height by footwear (feet) traces, conducting practical research on a given topic, indicating objective defects and the presence of a number of errors that are not taken into account while calculations, formulation of a reasonable conclusion based on the analyzed results of an examination.
 In the course of the analysis of forensic practice, a number of problematic issues was identified that make it difficult to objectively determine a person’s height by footwear traces, namely: non-conformity between the real value of human height and the height value calculated according to the most common formulas given in the forensic literature; non-compliance with standards by manufacturers while the production of shoes; lack of catalogues on shoe production, information on trace formation and the environment when examining a crime scene. All the above factors have a significant impact on the establishment of real human height by foot traces (footprints), and the absence or variability of at least one of these indicators leads to significant differences in the final values. Our research has shown that each individual foot length corresponds to not one, but several height indicators at once. At the same time the limit intervals of the height range are not the same for all foot lengths (3-20 cm for men and 6-20 cm for women). The above-mentioned discrepancies in the data are unacceptable while criminal investigation for the persons involved in crimes commission.
 The methods of establishing a person’s height described in the forensic literature are imperfect and require modification or revision. The conducted analysis indicates the necessity for further research on correlation dependence of the foot length and a person height taking into account all variables of indicators which have been listed above, since the efficiency of the way for establishing a person height by foot and footwear traces will depend on the right adjustment of the given parameter.

FEATURES OF THE PREPARATION AND APPOINTMENT OF FORENSIC EXAMINATION OF VEHICLES AND REGISTRATION DOCUMENTS

The article analyzes the features of the preparation and appointment of forensic examination of vehicles, procedural and tactical requirements for this examination. The vehicle is a special object of forensics, which imposes certain restrictions on its preparation for examination.
 Specific requirements for the tactics of investigative actions with this object are intended to ensure the legality and admissibility of evidence for criminal proceedings. The vehicle is also an object for conducting expert studies of various types. The issue of changing the identification numbers (body, engine), determining the year of manufacture, replacing the data carriers about the car (number and code plates, etc.) are resolved by means of traceability. To solve the issue of replacing the body number by replacing the panel with a number plate, a complex forensic chemical (paintwork research) and trace evidence examination are appointed.
 The issue of re-equipment of the vehicle is solved by complex trace evidence and commodity expertise, etc. The complexity of the study of the vehicle and the accompanying documents requires the appointment of directly comprehensive examinations of various types.
 In the investigation of unlawful acts related to the illegal movement of vehicles across the customs border of Ukraine, auto-merchandising and transport- merchandising examinations can also be carried out to solve the problems associated with determining the market value of wheeled vehicles, their components, as well as the amount of the cost of material losses caused to the owner or to the owner of wheeled vehicles, their components due to damage to the latter. The indicated examinations are quite often appointed in conjunction with the trace evidence examination.
 The fulfillment of certain procedural requirements is designed to ensure the legality and admissibility of evidence obtained in the course of investigative actions and the results of forensic examinations conducted by them.

Importance of Trace Evidence Study in Determining Road Traffic Accident Circumstances in order to Prevent Insurance Fraud

The authors, on the basis of analysis of growing motorization, particularly at the regional level (using the example of Penza region of the Russian Federation) confirm the urgency of the tasks of preserving life and health of road users, note changes in frequency of accidents of various origin, the positive role of insurance instruments in dealing with the consequences of road traffic accidents.At the same time, fraud in the field of compulsory motor third party liability insurance (MTPL) is one of the most important and urgent issues for insurance companies. One of the most common schemes of fictitious accidents is an attempt to get repair or replacement of existing damage at the expense of the insurer. In this regard, the use of transport trace evidence examinations has become widespread.It is this type of transport expertise that reliably and accurately determines conformity of damage to vehicles to the mechanism and circumstances of a road traffic accident. Trace evidence analysis is always assigned when it comes to currently notorious «staged crash». It is impossible to understand the nature of accidents associated with lane change by vehicles moving along the way without study of trace materials. Particularly many problems arise in a situation where both participants in the accident claim that they were moving without changing the direction of movement, and that was the opponent who made a maneuver of lane change not complying with the requirement of the road traffic rules of the Russian Federation on priorities in traffic movement.As an example, the article presents an expert study of a road traffic accident that raised doubts about reliability of circumstances set out by policyholders.

Trace evidence examination using laboratory and synchrotron X-ray diffraction techniques

Abstract In a 2007 homicide in Western Australia, small (<0.5 mm diameter) red brick fragments and soil were identified on the victim's clothing (mainly bra), body (mainly hair) and vehicle. A comparative study of the mineralogy and morphology of the red brick fragments with red bricks from the paved area in front of the victim's house was undertaken by traditional laboratory X-ray diffraction (XRD) using low background Si wafer holders and a 0.5 mm focusing monocapillary attachment. Whilst significant similarities were observed between the two datasets, peak overlaps and poor resolution prevented a specific provenance to be determined. Additional analyses using the superior intensity and resolution of synchrotron XRD that was conducted at the Australian Synchrotron quantified the mineralogy of polycrystalline minerals (cristobalite and mullite) in the small brick fragments. These data established that the brick fragments could not be distinguished from the driveway bricks and were clearly shown to be different to a range of other possible sources. The trial was before a judge only and he concluded that the mineralogy data from the small brick fragments on the victim's clothing and the bricks from her front driveway indicated that she was initially attacked in her front yard and not at Kings Park where her body was buried.

Is MPS always the answer? Use of two PCR-based methods for Y-chromosomal haplotyping in highly and moderately degraded bone material

Forensic and population genetics often rely on Y-chromosomal studies. Whether it is a human identification case, trace evidence examination or phylogenetic analysis, a Y-STR haplotype is an important tool in the hands of law enforcement agencies. A common obstacle in achieving satisfactory results in all of the above mentioned circumstances, is low DNA quantity and quality within samples obtained.In this study we have examined Y-STR haplotypes in 75 bone material samples, coming from different time periods. For this purpose we have chosen YFiler Plus PCR Amplification Kit (ThermoFisher Scientific) and ForenSeq Signature DNA Prep Kit (Verogen Inc.), which use two different allele calling technologies – capillary electrophoresis and Massively Parallel Sequencing respectively. Full profiles were obtained from DNA extracts with as little as 0.1896 ng (Degradation Index 1.3) (ForenSeq) and 0.0591 ng (Degradation Index 26.8) (YFiler Plus) DNA input. The results that we present in this paper show differences in amplification rates between common markers in both kits. The differences strictly reflect mean amplicon length of markers. This, however, does not seem to influence Y-haplogroup estimation results noticeably. In one sample a discordance occurred between haplotypes obtained with both methods, where a 24 allele was called in DYS390 marker by capillary electrophoresis, while for the same sample in this locus a 23 allele was shown with MPS. A reason for this is yet to be investigated. The sequence analysis revealed a significant variation between isometric alleles, especially within repetitive regions of studied Y-STR markers.

METHOD OF NATURAL MODELING WHILE PERFORMING COMPREHENSIVE FORENSIC MEDICAL, TRANSPORT TRACE EVIDENCE AND AUTO-TECHNICAL EXAMINATION

The article points to the importance of applying the method of natural modeling as one of the key methods in carrying out comprehensive forensic medical, transport trace evidence and auto-technical examinations. This method give an opportunity identifying a person who was behind steering wheel of the vehicle during a traffic accident in case of intervention in motor vehicle driving by another person: the driver, determining his location in the cabin; identifying the pedestrian's location regarding traumatic elements of the vehicle; determining person location at the time of the traffic accident: on a bicycle or as a pedestrian, led a bicycle nearby. The mentioned method also allows verifying testimonies of traffic accident participants and excludes farfetched options for its development in future. The importance of the method lies in the ability to accurately simulate (reproduce) the mechanism of a traffic accident regarding reciprocal contact of vehicles, with other objects and a person. Advantage of the method of natural modeling over the method of mental modeling which is more widespread while performing comprehensive forensic medical, transport trace evidence examinations is the opportunity to confirm or disprove versions of previous expert versions and reduce their number to a minimum that means in most cases to one. It allows coming to categorical conclusions about the mechanism of human contact with vehicle elements and is of decisive importance while solving by autotechnician experts issues on the establishment of a causal link between the actions of traffic accident participants and the requirements of Traffic Сode of Ukraine.

USE OF INFORMATION AND REFERENCE COLLECTIONS FOR TRACE EVIDENCE EXAMINATIONS

In most cases while performing trace evidence examinations the research volume depends questions asked an expert. Issues are identifying (sameness determination, group affiliation) and non-identifying (establishing a trace-forming mechanism). Although identifying researches are more important while truth establishing and have some probative value in criminal and other processes, the research of non-identifying nature is also important. However, thanks to them an expert establishes the kind of trace-forming object on general features reflected in traces. Use of information and reference collections is a significant help while performing examinations of a non-identifying nature.
 Using natural objects from collections allows to establish qualitative or quantitative properties of real evidence, to attribute them to certain groups (kind) of objects. This is accomplished by comparing the research object with samples from collections, which results in coincidence or differences in their generic characteristics. Evaluation of these coincidences or differences allows determining that studied object belongs to (or does not belong) a group (kind, class) of the relevant objects in the collection or that it arose as a result of a certain trace-forming mechanism.
 For example if for an expert it is necessary to find out the trace-forming mechanism of dynamic traces, having the collection natural objects; it is possible to perform a number of expert experiments and according to these results to reach a certain conclusion.
 Thus, the use of information and reference collections while performing trace evidence examinations in procedural form (while performing examinations) is a simple and accessible support means for correct and scientifically substantiated answering to questions asked an expert. Effectiveness of using such collections depends on objects number or volume of information contained in, their systematization and classification, as well as expert ability to apply objects of these collections at one or another stage of expert research.

A Generalized Approach to Forensic Dye Identification: Development and Utility of Reference Libraries.

While color is arguably the most important optical property of evidential fibers, the actual dyestuffs responsible for its expression in them are, in forensic trace evidence examinations, rarely analyzed and still less often identified. This is due, primarily, to the exceedingly small quantities of dye present in a single fiber as well as to the fact that dye identification is a challenging analytical problem, even when large quantities are available for analysis. Among the practical reasons for this are the wide range of dyestuffs available (and the even larger number of trade names), the low total concentration of dyes in the finished product, the limited amount of sample typically available for analysis in forensic cases, and the complexity of the dye mixtures that may exist within a single fiber. Literature on the topic of dye analysis is often limited to a specific method, subset of dyestuffs, or an approach that is not applicable given the constraints of a forensic analysis. Here, we present a generalized approach to dye identification that (1) combines several robust analytical methods, (2) is broadly applicable to a wide range of dye chemistries, application classes, and fiber types, and (3) can be scaled down to forensic casework-sized samples. The approach is based on the development of a reference collection of 300 commercially relevant textile dyes that have been characterized by a variety of microanalytical methods (HPTLC, Raman microspectroscopy, infrared microspectroscopy, UV-Vis spectroscopy, and visible microspectrophotometry). Although there is no single approach that is applicable to all dyes on every type of fiber, a combination of these analytical methods has been applied using a reproducible approach that permits the use of reference libraries to constrain the identity of and, in many cases, identify the dye (or dyes) present in a textile fiber sample.

Soil forensics: A spectroscopic examination of trace evidence

Among various trace evidence, the soil is very crucial evidence because it can link the suspect with the crime and crime with its geographical region. Based on this hypothesis, the aim of present research is to characterize, differentiate and classify the soil samples collected from various geological regions of northwestern India via using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometrics. The organic and inorganic parts of surface and depth soil samples are successfully characterized. Sieving and heating of soil in a muffle furnace (650°C) affect the spectral features considerably. The differentiation of soil samples is done by utilizing two approaches i.e. qualitative analysis and multivariate analysis. Both approaches provide a high discriminating power (i.e. qualitative analysis, surface=99.35%, depth=97.38%, and multivariate analysis, surface=100%, depth=100%). A classification model based on canonical discriminant function analysis is also built for grouping of soil to its particular geographical region. The developed model provides 100% correct classification of soil samples after the leave-one-out cross-validation. Therefore, the current study provides useful methods of soil analysis which can further be utilized by soil as well as forensic expert dealing with such cases.

Comparative analysis of Sanger and next generation sequencing methods for 16S rDNA analysis of post-mortem specimens

Forensic microbiology is widely applied to identify people at crime scenes and determine the cause and time of deaths by examination of trace evidence. In particular, identification of bacteria from post-mortem specimens is important because the cause of death could be an infection with clinically significant bacteria that results in a fatal outcome, such as sepsis. The MicroSEQ 500 16S rDNA Bacteria Identification system (MicroSeq ID) from Applied Biosystems is a molecular technique for profiling of bacteria isolated by cultures, based on Sanger sequencing of the bacterial 16S rDNA gene. The MiSeq Illumina platform uses next-generation sequencing (NGS) for metagenomic analysis of 16S rDNA and culture-independent identification of bacteria. In this study, we analysed 65 post-mortem specimens by both methods and compared the workflows involved with regard to methodology, time-efficiency, cost-efficiency, and performance to determine the limitations and benefits of these techniques for forensic application. We found that MiSeq is more time-efficient, and exhibits superior cost-efficiency when more than 30 samples are analysed. In addition, MiSeq has a number of other advantages over MicroSeq ID, including a simpler identification of bacteria that are difficult to culture and use of a larger library of 16S rDNA, allowing more precise identification of bacterial species.

Synthesis of Best Practices in Forensic Trace Evidence Analysis: Towards a Uniform Approach to Complexity Evaluation

The paper addresses the problem of improving the practice of forensic trace evidence examinations with the help of criteria that affect the evaluation of their complexity. It offers a synthesis of data submitted by seven regional centers and four laboratories of the system of forensic science organizations of the Russian Ministry of Justice. It demonstrates that relevant parameters are not always taken into account when assessing the category of analysis complexity, which leads to underestimation of complexity measures in some cases. Recommendations are offered for the optimization of forensic practice to incorporate characteristics reflecting realistic conditions of actual forensic casework.

The Utilization of Microscopy in Developing Investigative Leads from the Examination of Microscopic Trace Evidence in Forensic Investigations

The Utilization of Microscopy in Developing Investigative Leads from the Examination of Microscopic Trace Evidence in Forensic Investigations

Soil examination for a forensic trace evidence laboratory–Part 3: A proposed protocol for the effective triage and management of soil examinations

In the past, forensic soil examination was a routine aspect of forensic trace evidence examinations. The apparent need for soil examinations then went through a period of decline and with it the capability of many forensic laboratories to carry out soil examinations. In more recent years, interest in soil examinations has been renewed due–at least in part–to soil examinations contributing to some high profile investigations. However, much of this renewed interest has been in organisations with a primary interest in soil and geology rather than forensic science.We argue the need to reinstate soil examinations as a trace evidence sub-discipline within forensic science laboratories and present a pathway to support this aim. An examination procedure is proposed that includes: (i) appropriate sample collection and storage by qualified crime scene examiners; (ii) exclusionary soil examinations by trace evidence scientists within a forensic science laboratory; (iii) inclusionary soil examinations by trace evidence scientists within a forensic science laboratory; and (iv) higher-level examination of soils by specialist soil scientists and palynologists. Soil examinations conducted by trace evidence scientists will be facilitated if the examinations are conducted using the instrumentation routinely used by these examiners. Hence, the proposed examination protocol incorporates instrumentation in routine use in a forensic trace evidence laboratory. Finally, we report on an Australian soil scene variability study and a blind trial that demonstrate the utility of the proposed protocol for the effective triage and management of soil samples by forensic laboratories.

Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory.

Soil examination for a forensic trace evidence laboratory—Part 1: Spectroscopic techniques

In the past, forensic soil examination was a routine aspect of trace evidence examination in forensic science. However, in Australia, the apparent need for soil examinations has diminished and with it the capability of forensic science laboratories to carry out soil examination has been eroded. In recent years, due to soil examinations contributing to some high profile investigations, interest in soil examinations has been renewed. Routine soil examinations conducted in a forensic science laboratory by trace evidence scientists can be facilitated if the examinations are conducted using the instrumentation routinely used by these examiners. Spectroscopic techniques such as visible microspectrophotometry (MSP) and Attenuated Total Reflectance (ATR) Fourier Transform Infrared spectroscopy (FTIR) are routinely used by trace evidence analysts for the colour and compositional analysis, respectively, of forensic items, including paints, fibres, inks and toners, tapes, adhesives and other miscellaneous examinations. This article presents an examination of the feasibility of using MSP and ATR-FTIR as a first step in the forensic comparison of soils with particular reference to Australian soil samples. This initial study demonstrates MSP and ATR-FTIR can effectively be used as a screening test for the discrimination of “forensic-sized” soil samples prior to submission for more detailed analyses by a soil expert.