Forensic Science and Technology Commons^™

Differentiation Of Cell Populations In Saliva-Skin Mixtures Using Autofluorescence Profiling, Kara Fairfax

Master of Science in Forensic Science Directed Research Projects

While DNA profiling of sexual assault evidence can identify biological contributors, determining the tissue source of recovered profiles remains a significant challenge, particularly in cases of suspected oral assault involving mixtures of epithelial cells. The initial goal of this study was to identify non-genetic signatures for differentiating two types of epithelial cells relevant to oral assaults, saliva epithelial cells and epidermal skin cells. To develop tissue-specific signatures, reference cell populations from saliva and epidermal skin surfaces were collected from 20 donors and analyzed using full spectrum flow cytometry.

Results from single-source reference samples showed that saliva-derived particle populations exhibited higher …

Exploring Variability Of The Cg18562578 Methylquant Assay For The Forensic Discrimination Of Monozygotic Twins, Sydney E. Arnold

Student Theses

Monozygotic (MZ) twins possess identical DNA sequences, posing a problem for forensic scientists, as they are incapable of distinguishing MZ twins from each other using traditional DNA identification methods. However, the epigenomes of MZ twins will differ and might be used for their forensic discrimination. Here, we explored the variability of an assay previously developed by our laboratory that showed high discrimination potential for MZ twins using buccal swab DNA, cg18562578 MethylQuant. We measured precision at each step: bisulfite conversion, nested PCR, and qPCR, reproducibility, and repeatability. DNA methylation ratios were compared between two analysts carrying each step using the …

Comparative Analysis Of Forensic Science Systems: Scotland Vs. America, Alec Noland

Themis: Research Journal of Justice Studies and Forensic Science

Forensic science plays an important role in the justice system of both the United States and Scotland, but the structure, application, and effectiveness differ significantly. This research paper presents a comparative analysis of forensic science in two different legal and institutional contexts, examining differences between the two forensic science systems. This includes forensic laboratories and services, education and training, policing, court procedures, legal framework, and crime scene investigation. The analysis highlights significant differences such as Scotland’s centralized system versus America’s decentralized system, which impacts resource allocation and standardization for forensic science. Despite major differences, both countries emphasize scientific reliability, standardized …

Assessment Of Analytical Workflows Of Gunshot Residue Evidence And Strategies For Implementation Of Advanced Technology In Crime Laboratories., Leah D. Thomas

Graduate Theses, Dissertations, and Problem Reports (ETD)

The rise in gun violence in the United States has increased the demand on forensic agencies to process evidence promptly and accurately. The exchange of imperceptible traces among objects, suspects, and victims can provide critical insights into the interactions and sequence of events during a crime. Gunshot residue (GSR) is a type of trace evidence that holds significant investigative value in shooting reconstructions. GSR can help identify potential shooters, intermediate targets, and bullet trajectories; however, its analysis is often expensive and time-consuming. Consequently, there is an urgent need for more effective solutions.

Methods for on-site screening can significantly streamline forensic …

Child Pornography: A Growing Threat For Forensic Science In The Digital Age, Nadia Palomares

Themis: Research Journal of Justice Studies and Forensic Science

In the United States, child pornography is any visual portrayal of people under the age of eighteen in sexually explicit circumstances. Child pornography can be found in multiple forms. With each advancement in visual technology, there is a new form in which sexual content, including child pornography, can be depicted. Photographs, films, videos, and live streaming are all popular modern forms, while artwork and the written word were popular forms before the invention of the camera in 1816. Unfortunately, the rate of these advancements in technology has far surpassed the rate of those in forensics. The use of outdated techniques …

The Use Of Microbiome Sequencing To Identify Individuals In Forensic Science, Sophia Konieczny

Themis: Research Journal of Justice Studies and Forensic Science

The Human Genome Project's (HGP) completion in 2003 laid the groundwork for further research into the human body. This paved the way for microbiome sequencing, revealing the diverse microbial communities within the human body. These advancements led to the emergence of microbial forensics, leveraging Next Generation Sequencing (NGS) technologies like Amplicon sequencing and shotgun metagenomics for individual identification. Unlike traditional genetic profiling, microbiome analysis provides insights beyond genetic profiling, offering information about an individual's lifestyle and environment. Microbial communities on the skin's surface and objects can serve as trace evidence, aiding in suspect identification and investigative leads. Despite its promise, …

Understandings Of Vulnerability And Social Determinants Of Health In Forensic And Expert Social Anthropology: A Scoping Review, James W. W. Rose, David M. Tran

The Qualitative Report

Forensic and expert social anthropology (FESA) is a branch of social anthropology that specialises in the provision of evidence to legal-administrative processes, which are overseen by courts and other legally empowered bodies, and which give regard to the social cultures of legally and administratively involved individuals and communities (LAIICs). Despite a preoccupation with political advocacy in the broader philosophy of social anthropology, FESA literature does not typically give regard to LAIIC vulnerability defined qualitatively in terms of social determinants of health, including physical, mental, and social well-being. This paper presents findings from a JBI/PRISMA-ScR scoping review of n=1,674 texts, identifying …

Fat And Water Content Effects Of Three Food Substrates (Ground Veal, Ground Beef, And Beef Liver) On Lucilia Sericata (Diptera: Calliphoridae) Development And Mortality, Nicole Dailey

Master of Science in Forensic Science Directed Research Projects

Although temperature has been identified as the most important catalyst affecting blow fly larval development, other variables encountered by these species, such as the fat and moisture content of the food source, may have an impact on accurate estimations of the PMImin in forensic investigations. Thus, body composition differences between human carrion, such as variations in body fat and water percentages between younger and older individuals, or heavier persons, could affect blow fly developmental rates, and in turn cause over or under estimations of the PMImin. In this study, the weight, length, and development times of Lucilia sericata third instar …

The Development And Evaluation Of A Method For Complete Collagenase I Digestion Of Bos Taurus Bone Samples, Reilly Price

Master of Science in Forensic Science Directed Research Projects

Current methods for processing aged forensic bone samples for DNA analysis involve pulverization and organic extraction, which further destroys already degraded DNA and uses large amounts of limited samples. Additionally, the success rates for this type of analysis vary widely as homogenization incorporates PCR inhibitors into the sample. Little research has explored how pulverization results in DNA damage in profiles obtained from skeletal remains. This study proposes an enzymatic digestion method to separate osteocytes from PCR inhibitors in the extracellular bone matrix to improve the quality and quantity of DNA isolated from aged bone samples. The technique described here used …

A Comparative Analysis Of Swabbing Solutions For Sexual Assault Evidence: Direct Impact On Spermatozoa And Dna Recovery, Olivia Q. Kassie

Master of Science in Forensic Science Directed Research Projects

Forensic laboratories struggle with a backlog of sexual assault cases, prompting the need for effective techniques to develop consistent protocols and address scientific gaps. Challenges in recovering optimal DNA from assault evidence stem from factors like collection timing and sampling variables. Variations in lab protocols can lead to differences in DNA yields and profile success. This was observed in a state lab when protocols were developed allowing the use of acetone to swab sexual assault evidence. The use of acetone originated due to their case-routing protocols in multi-section cases involving latent fingerprints. While not necessary for sexual assault and porous …

Cellular Autofluorescence Signatures For Determining Time Since Deposition Of Whole Blood, Hannah Lamer

Master of Science in Forensic Science Directed Research Projects

Knowledge of the relative window of time that evidentiary biological material was deposited at a crime scene, referred to as the time since deposition (TSD), would help investigators determine which evidentiary items are most probative and assist with scene reconstruction. One commonly encountered body fluid at a crime scene is blood. Various methods for estimating TSD of bloodstains have been developed, but none to date have been validated for use in the forensic laboratory. Recently, flow cytometry measurements of cellular autofluorescence and size/structure have been investigated as a signature for TSD of saliva and touch epidermal cells. This study assessed …

The Evaluation Of Semen Extraction Efficiency And Recovery From Reusable Menstrual Underwear, Caitlyn Spencer

Master of Science in Forensic Science Directed Research Projects

A new type of undergarment and feminine product is being submitted to crime laboratories as evidence for sexual assaults: menstrual underwear is underwear that have absorbency and leak-proof abilities and can be washed and re-worn multiple times. The goal of this research was to determine if semen and sufficient DNA could be recovered from reusable menstrual underwear and used to obtain quality DNA profiles. Three menstrual underwear brands of Hanes, Knix, and Thinx were evaluated. Simulated post-coital samples were deposited onto three pairs of each brand of underwear. One pair of each brand was analyzed unwashed, another set was washed …

Quality Management And Oversight Of Texas Forensic Science Service Providers, Sarah P. Chu

Dissertations, Theses, and Capstone Projects

Forensic science oversight in the U.S. largely relies upon voluntary third-party forensic laboratory accreditation programs. Without a national system of regulation and given the highly fragmented local systems of control, few forensic science service providers (FSSPs) are subject to regulatory oversight beyond their third-party accreditors. Texas is unique in its establishment of a robust statewide oversight system and a strong governmental culture of transparency, permitting this study of forensic quality management. This study consisted of two parts. The first part of this dissertation characterized and analyzed quality incident reports (QIRs) published by the Texas Department of Public Safety Crime Laboratory …

Examining The Relationship Between Legal Systems And Forensic Science: Current Issues And Proposed Solutions, Rowan Dunton

Themis: Research Journal of Justice Studies and Forensic Science

Forensics and legal systems are often seen working together, but the relationship between the two disciplines is thornier and more complex than it may appear on the surface. This paper will examine why courtrooms struggle to accommodate forensic fields, how the nature of science can impede its utilization in court, and where legal education may fall short in educating students about the forensic sciences. After the literature is reviewed, solutions will be proposed to address each area of concern. Where possible, these solutions expand on existing infrastructure and ideas to make them easier to incorporate. Since the greater-scope issue is …

The Crisis Of Femicides In Mexico, Alejandra Vela

Themis: Research Journal of Justice Studies and Forensic Science

Femicides are a growing issue in Mexico. These murders are intertwined with the incompetence of authorities, poverty, corruption, and organized crime. Authorities tend to blame victims by not taking missing reports seriously, nor do they conduct searches in these urgent situations. Authorities do not have DNA databases, space in morgues, and have little forensic science training. Ways of identifying remains involve odontology, bitemarks, and saliva. These provide a means of identifying through individual characteristics and DNA. Evidence is usually mishandled and not tested, or purposely lost to stop the investigation, thus, involving corruption. Criminal organizations, known as cartels, bribe authorities …

Horizontal And Vertical Transmission Of Microbes Associated With Blow Flies Of Forensic Importance, Gabrielle Alisa Burton

Master of Science in Forensic Science Directed Research Projects

Entomological and microbiological evidence can be used in the estimation of postmortem intervals (PMI). This study observes the horizontal and vertical transmission of the microbial community associated with blow flies of forensic importance. Variable region four (V4) of the 16S ribosomal DNA (16S rDNA) was amplified and sequenced from various life stages of blow flies (n=72) using dual-index high throughput sequencing strategy on the MiSeq FGx platform. No significant difference in bacterial community structure was observed between blowfly adults with carrion access and blowfly adults with no carrion access. Dysgonomonas, unclassified Proteobacteria, Escherichia, Ignatzschia, Providencia, …

Assessment Of The Acidified Hydrogen Peroxide Method On Uncontrolled Fired Cartridge Case Samples, Kylie S. Richardson

Master of Science in Forensic Science Directed Research Projects

The use of fingerprints to identify individuals in forensic cases has been useful for many years due to the persistence and individuality of the prints. In addition, the presence of firearms in forensic casework is steadily increasing over the years. This study aims to expand upon prior research in the development and recovery of latent prints on fired, brass ammunition using an acidified hydrogen peroxide method. Although latent prints are left on the cartridge casing of ammunition during the handling and loading of ammunition into the firearm, it is hypothesized that the pressure within the barrel of the firearm during …

Optimization Of Microfluidic Device Methodology For Optical Trapping Epithelial Cells In A Mixture, Brittney N. Hackworth

Master of Science in Forensic Science Directed Research Projects

Evidence containing biological mixtures can make DNA interpretation more difficult due to ambiguous allele calls and artifacts that may be present within electropherograms. Separating out these cell mixtures can be advantageous to the analysts’ analysis methods for identifying STR profiles with higher accuracy. A potential cell separation method that could be implemented in the beginning of the forensic DNA workflow is optical trapping.

This research utilized a 5W ytterbium linearly polarized laser split into two optical traps, paired with a microfluidic device to isolate spermatozoa and vaginal epithelial cells from a 1:1 mixture of vaginal fluid and 1:20 diluted seminal …

Comparison Of Cell Counts To Dna Yield In Mock Biological Evidence Samples, Jacob Sewell

Master of Science in Forensic Science Directed Research Projects

The implementation of rapid DNA analysis systems is of interest to forensic DNA casework, as this technology exhibits a sample-to-profile time of approximately two hours with limited handling of samples. This decreases the likelihood of contamination, and can potentially reduce DNA backlogs; however, current rapid DNA analysis systems do not execute one crucial step of the forensic DNA analysis workflow: human DNA quantitation. This step is necessary for DNA profiles to be compliant with the FBI’s Quality Assurance Standard 9.4, allowing DNA profiles to be uploaded and searched within the CODIS database. Coupling traditional qPCR methods with rapid DNA analysis …

Development And Validation Of Microrna Markers For Forensic Body Fluid Identification Using Rt-Qpcr, Jane Goble

Master of Science in Forensic Science Directed Research Projects

Body fluid identification is one of the first and most fundamental steps in the forensic DNA workflow. It allows analysts to determine where a sample might exist on an item of evidence, as well as the type of sample that they are dealing with. However, current serological methods have been documented to produce false or inaccurate results in some cases, and may consume large amounts of sample during processing. Molecular methods, such as the use of microRNA and microbial profiles have been introduced as a means to increase specificity of testing, and have even been combined into a singular assay …

Evaluation Of Direct-To-Amplification Cell Lysis Techniques For Forensically Relevant Non-Sperm Cells, Rhea Arya

Master of Science in Forensic Science Directed Research Projects

While efforts have been made to reduce the pervasive backlog of sexual assault evidence collection kits, the actual laboratory process remains very time-consuming due to the requirement of a differential lysis step before DNA purification, as well as intricate mixture analysis towards the end of the DNA workflow. Previous work in the Dawson Green laboratory at VCU has developed alternative solutions for differential extractions with sexual assault samples using both an in-tube and microdevice assay. Prior work led to the identification of an alternative sperm lysis method – alkaline lysis using 1M NaOH. However, the current lysis method used for …

Evaluation Of Tooth Sample Preparation For Traditional Forensic Dna Vs Rapidhit Id Processing, Morgan E. Eaton

Master of Science in Forensic Science Directed Research Projects

Disaster Victim Identification (DVI) refers to the process of forensic identification of unknown individuals following a mass disaster or fatality incident.¹ In events of mass disaster, human dental structures are often the only viable DNA source remaining, as soft tissues are more easily degraded, contaminated, or otherwise compromised. Due to the protective nature of dental enamel and dentin surrounding the inner pulpal tissue, a labor-intensive sample preparation performed by extensively trained personnel is necessary to expose the nuclear material preceding the traditional forensic DNA workflow.^2,3 In high volume cases, such as those often submitted for DVI, the current …

Dna Transfer And Persistence On Non-Porous Surfaces Submerged In Spring Water [Preliminary Study], Morgan L.. Korzik, Josep De Alcaraz-Fossoul, Michael S. Adamowicz, David San Pietro

Forensic Science: Faculty Publications

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat …

A Comparison Of Methods Used For The Elimination Of Organics From Soil Prior To Analysis By Ftir-Atr And Sem-Eds, Argeliz Pomales

Student Theses

This project suggests improvements to the treatment methods utilized for the sample preparation and evaluation of minerals in soil samples encountered in forensic science casework and research. The evaluation of pre-treated and post-treated soil samples were performed using Fourier-Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR) and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS). Because soil samples contain a significant amount of organic matter and water which interfere with examination of these minerals while using these instruments, pretreatment methods are necessary to isolate the mineral fraction for examination and analysis.

Soil samples were first sieved with various size stainless steel mesh …

Cognitive And Other Types Of Biases Affecting Forensic Evidence: Research Analysis And Expert Conclusions, Sukhmanpreet Kaur

Themis: Research Journal of Justice Studies and Forensic Science

This paper identifies the issue of cognitive bias, with emphasis on confirmation bias, and its implications within the forensic science field. Biased thinking or processing of forensic evidence can have significant effects on an investigation process. The literature analyzed discusses the consequences of providing contextual or irrelevant ancillary information to forensic experts. Following this discussion, the opinions held by forensic professionals with regards to confirmation bias and erroneous conclusions will likewise be evaluated. It is important that the forensic science field continues to listen to its experts in order to develop solutions for dealing with and preventing instances of confirmation …

Leveraging Maching Learning In Financial Fraud Forensics In The Age Of Cybersecurity, Md. Ariful Haque, Sachin Shetty

VMASC Publications

Financial sectors are lucrative cyber-attack targets because of their immediate financial gain. As a result, financial institutions face challenges in developing systems that can automatically identify security breaches and separate fraudulent transactions from legitimate transactions. Today, organizations widely use machine learning techniques to identify any fraudulent behavior in customers' transactions. However, machine learning techniques are often challenging because of financial institutions' confidentiality policy, leading to not sharing the customer transaction data. This chapter discusses some crucial challenges of handling cybersecurity and fraud in the financial industry and building machine learning-based models to address those challenges. The authors utilize an open-source …

Development Of A Loop-Mediated Isothermal Amplification (Lamp) Assay For Detection Of Mirnas, Alisha B. Whelan

Master of Science in Forensic Science Directed Research Projects

Body fluid identification serves a vital role in contextualizing biological evidence received in forensic laboratories. While several fluids can be presumptively detected using immunological or catalytic tests, these tests are susceptible to false results and have limited sensitivity. True confirmatory testing is still somewhat limited in forensic laboratories. With the advancement of DNA typing technologies, laboratories can develop DNA profiles from trace amounts of sample, increasing the demand for sensitive and accurate body fluid detection. This project proposes using loop-mediated isothermal amplification (LAMP) as a method to rapidly detect microRNAs (miRNAs) that are differentially expressed in various body fluids with …

Optimization And Comparison Of Methods For Separation Of Spermatozoa From Superabsorbent Polymer-Containing Forensic Evidence, Hannah Wells

Master of Science in Forensic Science Directed Research Projects

Sexual assault is currently one of the most prevalent crimes that affects victims of all ages. Forensic DNA analysts often confirm proof of contact in sexual assault cases through the identification of spermatozoa and subsequent STR profiling. Diapers and other feminine hygiene products, such as maxi pads and ultrathin pads, are types of superabsorbent polymer-containing evidence that complicate the process of DNA analysis due to the trapping of the spermatozoa in the gel-like matrix. In this study, a comparison of methods was performed to determine which extraction technique produces the highest sperm cell and DNA yield and generates a usable …

Stability And Variation Within Donors Of Mirna Markers For Body Fluid Identification, Kelsey R. Price

Master of Science in Forensic Science Directed Research Projects

Traditional enzymatic tests for body fluid identification are prone to false negatives, false positives, and several body fluids do not have confirmatory or reliable presumptive tests. Therefore, molecular-based tests may be more reliable, such as messenger RNA (mRNA), microbial DNA, or microRNA (miRNA) assays.

miRNAs are small, noncoding RNAs whose main function in-vivo is the regulation of protein expression by selectively suppressing the translation of their corresponding mRNAs. They also lack a poly-A tail, and because of this, their small size, and their association with other molecules such as the RISC protein complex, they are more robust than other RNAs, …

Impact Of 1,4-Dithiothreitol (Dtt) On Microbial Community Structures Associated With Human Semen Samples, Christian R. Blaise

Master of Science in Forensic Science Directed Research Projects

Body fluid identification (BFID) is one of the most important steps in forensic science as it provides important context to how DNA analysis should be performed on biological samples found at the scene of a crime. Many scientific methods on BFID have been developed over the years with respective benefits and flaws. One emerging method in recent years is microbial signature based BFID. This method uses the same DNA extract that is utilized for human DNA profile generation for microbial analysis. Although DNA is extracted from all body fluid samples without any additional steps, extraction of human DNA from semen …