Forensic Science and Technology Commons^™

Internal Validation Of Mastr™ Probabilistic Genotyping Software For The Interpretation Of 2–5 Person Mixed Dna Profiles, Michael S. Adamowicz, Taylor N. Rambo, Jennifer L. Clarke

Forensic Science: Faculty and Staff Publications

Mixed human deoxyribonucleic acid (DNA) samples present one of the most challenging pieces of evidence that a forensic analyst can encounter. When multiple contributors, stochastic amplification, and allele drop-out further complicate the mixture profile, interpretation by hand becomes unreliable and statistical analysis problematic. Probabilistic genotyping software has provided a tool to address complex mixture interpretation and provide likelihood ratios for defined sets of propositions. The MaSTR™ software is a fully continuous probabilistic system that considers a wide range of STR profile data to provide likelihood ratios on DNA mixtures. Mixtures with two to five contributors and a range of component …

Death Scene Insect Succession In Nebraska: A Guidebook, Erin Bauer, Larry Barksdale, Emma Sidel, Justine Laviolette

Department of Entomology: Faculty Publications

Insect behavior can be helpful to law enforcement in determining time of death, manner of death, location, and environment related to human or other animal victims found at a death scene. They may also provide clues about other aspects associated with an investigation (i.e., fly specks, suspect DNA). The study of how insects and related arthropods can aid in legal investigations is known as forensic entomology. Although this includes both civil applications, such as urban (i.e., maggots in mortuaries or insect structural damage) or stored product (i.e., illness from food contamination) entomology, this manual focuses on criminal applications, such as …

Assessment Of Quechers Extraction Protocol For The Lc-Ms/Ms Detection Of Emerging Fentanyl Analogs In Biological Specimens For Clinical And Forensic Purposes, Kylea M. Morris

Graduate Theses, Dissertations, and Problem Reports

Drug abuse within the United States is a dynamic and pervasive issue that affects the quality and life expectancy of our society. One of the major drug classes that are constantly utilized is opioids. Opioids are prescribed for pain management in patients suffering from cancer and other medical illnesses. Long-term use of opioids could lead to tolerance in humans, which poses a risk of reaching fatal overdose levels. Unfortunately, opioids are abused recreationally, and in some instances, individuals are unaware of the presence of dangerous synthetic drugs like fentanyl, hidden in materials such as heroin, cocaine, oxycodone, and methamphetamine. Recent …

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 …

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 …

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 …

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 …

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, …

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 …

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 …

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 …

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 …

Y-Chromosome Dna Extraction From Post-Cranial Skeletal Elements, Mykala D. Ward

Graduate Student Theses, Dissertations, & Professional Papers

The use of DNA in forensic science has become an integral tool for victim and perpetrator identifications, missing person’s cases, paternity testing, etc. A major use of DNA is in the identification of unknown deceased individuals. With a reported number of individuals well over 8,000 in the United States, improved methods to accurately collect and analyze DNA from modern human bone are needed.

This project took the preliminary steps to improve DNA sampling and extraction methods by analyzing the Y-chromosome DNA yield from the two bone types. While both types are composed of the same materials, cortical bone is the …

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, …

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 …

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 …

Evaluating A Test For Shedding Propensity Using Tape Lifts From Different Skin Locations, Xiao M. Chen

Student Theses

The shedding propensity of a person can assist data interpretation in casework when assessing the possibility of passive transfer for DNA analysis. Past studies on shedding propensity evaluated palmar skin (washed and unwashed) deposits. This study compared different skin locations with respect to shedding propensity, and explored the potential of tape-lifts as a skin surface collection method. Eight different skin types and samples were collected with adhesive tape disks from 28 participants over three non-consecutive days; the washed and unwashed fingers from both hands, toe, and arm, neck below ear, and nape. Samples were extracted, quantified, amplified, genotyped, and evaluated …

Reproducibility Of Individual Dna Deposits Detected Through Cellular Fluorescence, Natalee Small-Davidson

Student Theses

Contact traces are an important part of DNA casework, but the probative value of any identified associations depends on the possibility of passive transfer. There is known individual variation in DNA left behind during contact, this DNA shedding propensity has an effect on whose DNA is detected. This study evaluated this variability using a cell staining approach. Volunteers were asked to deposit a fingerprint on a clean glass slide, then wash their hands and deposit a second fingerprint after a 30-minute wait without touching anything. Three sets of samples were collected over three consecutive weeks. Fingerprints were stained with a …

The Understanding Of Digital And Multimedia Evidence (Dme) By Attorneys And Digital Forensic Examiners (Dfe) Within The United States Criminal Justice System, Joseph Levi White

Dissertations

One goal of this research was to determine potential themes that may influence the understanding of Digital and Multimedia Evidence (DME) by attorneys and Digital Forensic Examiners (DFE) within the United States Criminal Justice System. Qualitative semi-structured interviews were conducted to gather information from experienced criminal attorneys and DFEs regarding potential influences on their understanding of DME. The results of these interviews were transcribed, and the data coded to allow for qualitative analysis. Five themes were developed from this data and are thought to play a role in understanding of DME by attorneys and DFEs: motivation for involvement in the …