Forensic Science and Technology Commons^™

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 The Age Of Evidence In Mock Biological Touch Evidence Samples, Emma P. Hirst

Master of Science in Forensic Science Directed Research Projects

As more sensitive DNA profiling techniques have been developed, questions about how and when the DNA was deposited have become a driving issue in forensic casework. Image flow cytometry (IFC) offers a way to estimate the time since deposition (TSD) of trace DNA samples based on individual cells' morphological and autofluorescence properties. Previous work has shown that a TSD can be determined from a single contributor in touch samples. To determine if TSD could be correctly estimated for mixtures containing a fresh deposit (less than a week old) and an older deposit, this project characterized a series of samples that …

Analysis Of Forensic Relevant Cell Mixtures Using Cellular Autofluorescence And Fluorescence Activated Cell Sorting (Facs), Shayla Smith

Master of Science in Forensic Science Directed Research Projects

Biological mixtures containing DNA from more than one contributor can make DNA profile interpretation challenging, especially for ‘touch’ or trace biological evidence. One approach to improve this is by differentiating cell populations from separate individuals prior to DNA profiling by utilizing intrinsic features of cells such as size, shape, and biochemical profiles. The goal of this study was to develop a new method for detecting and separating contributor populations in biological mixture samples using flow cytometry, a rapid and non-destructive approach with an unexplored potential for forensic casework. To accomplish this, two different mixture systems were investigated (1) mixtures containing …

Determination Of The Trace Elemental Signature Of Drywall Dust And Its Implication As Forensic Evidence, Emilee Holmes

Master of Science in Forensic Science Directed Research Projects

Drywall is found in most homes built in the United States of America because it is cost effective, light weight, and easy to install. Its brittle nature makes it less resistant to impact which can cause dust to form if a force is exerted on it. Airborne dust can settle on anything or anyone around it and can be considered trace evidence for its ability to connect suspects, victims, and scenes; however, this type of dust is not emphasized as trace evidence and is not always collected due to a lack of understanding of their forensic signatures.The seven producers of …

Utilizing Gc-Ms To Determine The Effect Of Solvent Extraction Parameters On Forensic Smokeless Powder Analysis, Leighann R. Weber

Master of Science in Forensic Science Directed Research Projects

Since its invention in 1884, smokeless powder has been of scientific interest. During World War II, research initially focused on developing methods to evaluate powders' stability. However, today, the focus has shifted to developing instrumental techniques sufficient for forensic classification and comparison work. Smokeless powder is typically encountered in forensic science casework involving firearms and explosives. In forensic investigations, determining the exact formulation of smokeless powders is challenging due to their complex chemistry and the proprietary nature of production. LC-MS and GC-MS techniques have been used to analyze intact and post-blast smokeless powders. Despite the vast amount of research that …

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 …

Morphological And Autofluorescence Signatures For The Identification Of Vaginal Cells In Mixture Samples Containing Saliva And/Or Epidermal Cells, Hannah L. Burden

Master of Science in Forensic Science Directed Research Projects

In forensic casework the identification of body fluids at a crime scene can frequently play an important role in reconstructing the events that occurred. There are several bodily fluid identification methods to characterize unknown stains recovered as evidence. However, there has not been a reliable method for detecting the presence vaginal cells and/or differentiate it from other forensically relevant tissue types that may be recovered from a crime scene. The detection of vaginal fluid is important for forensic casework due to the abundance of sexual assault kits that are not only backlogged but continue to be submitted to the lab …

Analysis Of Fiber Uv Degradation Through An Environmental Chamber, Davis A. Eames

Undergraduate Research Posters

Environmentally degraded fibers could impact multiple aspects of a fiber comparison, considering that collected weathered fabrics/fibers may express an altered chemical structure and/or colorimetric property compared to their unexposed counterparts. Depending on the amount of degradation the evidence has suffered, it could be challenging for forensic scientists to make conclusions from their comparative analyses. Observations presented in this study were orchestrated to test the possible outcomes that sunlight has on fabric-based materials. Photodegradation of fabrics was investigated through the use of an environmental chamber for a duration of six weeks, which would be equivalent to three months of real-world UV …

Identification Of The New Synthetic Opioid Bucinnazine And Its Metabolites Using Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Karissa N. Resnik

Master of Science in Forensic Science Directed Research Projects

In the past 20 years, the rate of opioid use increased drastically in the United States. The country has experienced an enormous number of deaths caused by opioid overdose, opioid use disorder (OUD), as well as other harms as a consequence of the high numbers of opioid prescriptions. Fentanyl, a well-known synthetic opioid, has been a contributor to the opioid crisis since 2013 due to its popularity in clinical and illicit use. It has a high potency, which makes it an effective analgesic but a dangerous illicit substance. A new synthetic opioid, bucinnazine, has recently become a new black-market opioid …

The Analysis Of Commercially Available Kratom Products In Richmond, Virginia, James H. Fleming Jr

Master of Science in Forensic Science Directed Research Projects

Kratom is a novel psychoactive substance that has gained popularity within the past ten years. Originating from Southeast Asia, the leaves of the Mitragyna speciosa tree contain two principal alkaloids, mitragynine and 7-hydroxymitragynine, that play a key role in opioid-like effects. Twenty-nine kratom products were obtained from tobacco shops in the Richmond, Virginia area, including powders, teas, capsules, extracts, and a carbonated beverage. Samples were analyzed using Direct Analysis in Real Time-Mass Spectrometry (DART-MS) for kratom alkaloids, labeled ingredients, and other possible organic compounds. Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) was used to quantitate aluminum, arsenic, copper, iron, magnesium, nickel, …

Using A Non-Destructive Method To Estimate The Number Of Contributors And Predict Dna Yield In Touch Dna Mixtures, Christin Lee

Master of Science in Forensic Science Directed Research Projects

Touch DNA samples are low templates and often are mixtures, making them typically one of the most difficult types of evidence to interpret. Short tandem repeat analysis is a standard method to estimate the number of contributors and DNA yield for each contributor; however, there are some limitations. Applying a non-destructive pre-DNA analysis technique that provides information about the touch DNA may improve the casework process. Antibody probes to hormones such as testosterone and dihydrotestosterone (DHT), and proteins including cytokeratins (CK) inside epidermal cells, have been demonstrated to produce a personalized signature for human touch cell populations. Testosterone, DHT, and …

A Comparison Of Cyanoacrylate Fuming Followed By Mbd Dye Staining And Gun Bluing For Development Of Latent Fingerprints On Cartridge Cases, Jamie Zaleta

Master of Science in Forensic Science Directed Research Projects

The development of latent fingerprints on cartridge cases is a desirable ability for the forensic laboratory, offering the potential to provide probative evidence as to the handler of whole ammunition or fired cartridge cases discovered at the crime scene. Previous studies have focused primarily on intentionally-laid fingerprints on cartridge case surfaces, which do not represent samples likely to come across the desk of a forensic analyst. This study focuses on naturally-handled ammunition and the success rates associated with latent fingerprints produced in a more realistic set of circumstances. A comparison was performed of two fingerprint development methods—gun bluing and MBD …

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, …

Optimization Of A Microfluidic Device For Cell Capture Using Optical Trapping, Samantha C. Pagel

Master of Science in Forensic Science Directed Research Projects

Biological mixtures which result from evidence produced in sexual assault cases are one of the most common types of mixtures observed in forensic biology casework and have contributed to evidence backlogs across the country. In the forensic community, this has highlighted the need for a more efficient cell separation method at the beginning of the DNA analysis workflow than the currently accepted method. One promising novel front-end cell separation technique is optical trapping. In heterogeneous mixtures, optical tweezers have been demonstrated to manipulate and isolate cells of interest from other cell types.

For this research, a range of 5 to …

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 …

A Quantifiler Trio-Based Hrm Mixture Screening Assay For The Quantstudio 6 Flex Qpcr Platform, Dayanara A. Torres

Master of Science in Forensic Science Directed Research Projects

At present, the forensic DNA workflow is not capable of providing information about the contributor status (single source vs. mixtures) of evidentiary samples prior to end-point analysis. This shortcoming can exacerbate the challenges inherent to mixtures and low-template DNA samples. Provided additional sample information earlier in the workflow, protocols could be implemented to mitigate these challenges. High-resolution melt (HRM) curve analysis is a technique used to detect genetic variation in DNA fragments and in the last decade has been evaluated for use in differentiation of samples by genotype and/or contributor status. To this end, a proof-of-concept HRM assay using the …

Classification And Differentiation Of Forensically Relevant Cell Populations Using Imaging Flow Cytometry, Arianna D. Decorte

Master of Science in Forensic Science Directed Research Projects

Forensic casework relies heavily on DNA profiles which may be time-consuming to generate and difficult to interpret when biological mixtures are present. Additionally, there are significant challenges in using sub-source data alone to answer the activity-level questions often most pertinent in criminal cases. Source level information can add critical probative value, however, methods that can provide information as to the source tissue of evidentiary cell populations are limited. There remains a need for new methods that can differentiate between and classify various cell populations, particularly for vaginal and epidermal tissue, since there are no conventional serological techniques specific to these …

Determination Of Cotinine Concentration In Urine By Liquid Chromatography Tandem Mass Spectrometry, Allison Beckett

Master of Science in Forensic Science Directed Research Projects

Tobacco use can cause lasting health conditions which can lead to death. Tobacco exposure comes from obvious sources like smoking or chewing tobacco, however these are not the only administration methods. Secondhand smoke exposure can affect even those who choose not to expose themselves to tobacco, which also opens them to the health issues that come along with tobacco use. Tobacco contains many different compounds, one of which is nicotine (Kataoka, 2009). Although nicotine is the most abundant compound in tobacco, it does not stay in the body for long periods of time. Nicotine metabolizes into cotinine which is more …

Assessing The Detectability Of Cannabinoid Analogs (Delta-8 Thc, Delta-10 Thc And Cbd) And Their Major Metabolites In Six Commercial Cannabinoid Urine Screening Kits, Ashley A. Pokhai

Master of Science in Forensic Science Directed Research Projects

Background:

There has been an exponential surge in the presence and use of cannabinoids since the federal legalization of hemp (Agricultural Improvement Act of 2018), which involves the legalization of medical use, adult recreational use, and decriminalization of cannabis in several states. This growth is not only attributed to ∆9-tetrahydrocannabinol (∆9-THC) and cannabidiol (CBD), the most abundant phytocannabinoid components of cannabis and hemp, respectively, but with many other emerging THC analogs. Structurally, these analogs are similar to ∆9-THC, yet very little information is available about their potency and even less information is available regarding their detectability using commercially available cannabinoid …

Method Validation Of Headspace Gas Chromatography With Dual Flame Ionization Detection For Analysis Of Blood Alcohol Concentration And Other Volatile Organic Compounds, Caroline A. Fudala

Master of Science in Forensic Science Directed Research Projects

Ethanol is one of the most commonly encountered substances in toxicology analysis and is the most misused substance. Blood alcohol concentration (BAC) analysis is performed for a variety of scenarios, including cases of driving under the influence, drug facilitated crimes, intoxication deaths, workplace drug testing, substance use treatment centers, probation/parole, and other clinical settings. Due to the high prevalence of ethanol in forensic and clinical casework a fast, accurate, and cost effective method for BAC analysis is critical. Headspace gas chromatography with flame ionization detection (HS-GC-FID) is the standard for BAC analysis. This is due to its ease of use, …

Creation And Optimization Of An Optical Trapping Microfluidic Device For The Separation Of Mock Forensic Sexual Assault Samples, Mackenzie Lally

Master of Science in Forensic Science Directed Research Projects

Cell mixtures are often seen in forensic samples and commonly involve sexual assault cases where mixtures of sperm cells and vaginal epithelial cells are frequently encountered. This produces challenges in downstream analysis in the form of STR mixture profiles. The only method currently in use in crime laboratories for front-end sperm and epithelial cell separation is differential extraction. This method often results in STR mixture profiles due to carryover into both the male and female fractions and suffers from a wide range of efficiency depending on the laboratory or individual processing the sample. Optical trapping offers an alternative method for …

The Impact Of Latent Print Processing On Firing Pin And Breechface Impressions During Firearm Examination, Brittany B. Harrington

Master of Science in Forensic Science Directed Research Projects

Latent prints can be a valuable source of forensic evidence when solving a crime. They can verify if a person was at a specific scene, identify unknown individuals to connect them to a scene, and help to corroborate eyewitness accounts. Latent prints, however, are not always visible until they have undergone enhancement or visualization techniques. When fired cartridge cases are suspected of containing latent prints, they are brought in for latent print processing before any firearm analysis is performed. As a result, these cartridges are often coated in various residues or dyes when they arrive for firearm examination. In response, …

Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan

Master of Science in Forensic Science Directed Research Projects

Following the FBI mandated expansion of the CODIS core loci from 13 to 20, several manufacturers developed short tandem repeat (STR) typing kits in response to the new criteria. One such manufacturer was the Promega Corporation, which released the PowerPlex® Fusion 5C megaplex STR typing kit (Fusion 5C) in 2012. Currently, the Virginia Department of Forensic Science (VDFS) utilizes this amplification kit for both casework and database applications. In 2015, Promega released the PowerPlex® Fusion 6C STR typing kit (Fusion 6C), which contains three additional loci beyond those included in PowerPlex® Fusion 5C, and a sixth color channel. The power …

The Efficacy Of Recovering Latent Fingerprints From Fired Cartridge Cases By Way Of Cyanoacrylate Fuming Combined With Basic Yellow Dye Staining, Lily Mantz

Master of Science in Forensic Science Directed Research Projects

This experiment attempted to tackle the long-standing struggle to consistently recover latent fingerprints from fired cartridges. With an emphasis on realistic handling of high volume of samples combined with Cyanoacrylate fuming followed by Basic Yellow dye staining, a total of 740 cartridges were examined. These included fired and unfired brass and nickel case 9mm Luger and 40 S&W cartridges. The cartridges were divided into five different groups; each were treated differently prior to cyanoacrylate fuming and dye staining, which was conducted in the same manner for the groups. The groups included the positive and negative controls, loaded, cycled, and fired. …

Differentiation Between Peripheral Blood And Menstrual Blood Using Mirna Markers, Anaya Valentine

Master of Science in Forensic Science Directed Research Projects

Abstract

In forensic investigations, body fluids can provide crucial information and is helpful for corroborating the circumstance of the case. For cases of sexual assaults or homicides, being able to differentiate if the blood is peripheral blood or menstrual blood is important. Peripheral blood can be indicative of a traumatic event, while menstrual blood is of a natural cause. Currently, serology based methods are used for body fluid identification, however, their lack of sensitivity and specificity remains an issue. MicroRNAs (miRNAs) are a class of non-protein coding nucleic acids that are able to be co-extracted with DNA, and their small …

Evaluation Of Dna Extraction Efficiencies Of Promega’S Dna Iq™ Methods And Casework Extraction Kit For Low Template Samples, Emily M. Anderson

Master of Science in Forensic Science Directed Research Projects

Biological evidence from crime scene samples frequently contain low levels of DNA, such as the most predominant form of evidence, which is DNA deposited by handling objects or “touch evidence”. To maximize the DNA yield recovered from theses challenging samples, forensic laboratories must optimize the extraction methods utilized to isolate and purify DNA for downstream short tandem repeat (STR) amplifications. Currently, the Virginia Department of Forensic Science (VADFS) uses a DNA IQ™ System (DNA IQ) extraction method for isolation of DNA from most forensic samples. This extraction procedure, which combines DNA IQ™ lysis buffer and Dithiothreitol (DTT), has been validated …