Forensic Science and Technology Commons^™

Validating Machine And Human Decision-Making In Forensic Fire Debris Analysis, Frances A. Whitehead

Graduate Thesis and Dissertation 2023-2024

This work presents a background on the chemical complexity of fire debris analysis, including an ever-present matrix of pyrolysis products as the catalyst that led to the creation of the National Center for Forensic Science's Fire Debris Database. A selection of these 1,000+ casework-relevant ground truth samples was used to create two newly proposed analyst workflows to connect the current method of categorical reporting with evaluative reporting practices reflective of the strength of the evidence. Both workflows use linear sequential unmasking to help mitigate bias, a discrete scoring system for quantification of the analysis, and receiver operating characteristic (ROC) curves …

U.S. Online Romance Scams: A Mixed Methods Analysis Of Factors Associated With Victimization And Exploration Of Lived Experiences Of Victimization, Rebecca A. Cole

Social Work Dissertations - Archive

The objective of this dissertation is to understand develop an understanding of experiences of online romance scam¹(ORS) victimization and to examine factors associated with ORS victimization. The dissertation samples ORS victims and uses purposive sampling strategies to recruit participants. The research used a mixed methods explanatory design approach. Inclusion criteria included ORS victims 18 and older who lived in the U.S., lost any amount of money in ORS scam, and met the scammer on any Internet platform. Three research manuscripts complete this dissertation. The first manuscript is a scoping review to understand the mental and physical health outcomes …

Forensic Archaeology Protocols For Wildfires And Fire Related Scenes, Erik Schulz

Nebraska Anthropologist

Forensic Archaeology Protocols for Wildfires and Fire-Related Scenes

Forensic archaeology is a relatively new area of study and focuses on the medical legal aspects of archaeology. This paper will focus on how forensic archaeology should be used for wildfire and other fire-related fatalities or investigations, what happens to bone when exposed to heat, what protocols should be in place and how an excavation should look, and finally the challenges of fire-related investigations. This report will focus on the larger scale of the investigation and will be using several sources from different wildfire and fire fatality reports.

Inter- And Intra-Observer Error In Forensic Anthropology: Based Upon Langley Et Al. 2016 Data Collection Procedures For Forensic Skeletal Material 2.0 For The Cranium And Femur, Maggie M. Klemm, Dakota L. Taylor

Nebraska Anthropologist

Following the Daubert v. Merrell Dow Pharmaceuticals (1993) ruling three decades ago, guidelines were established for determining the reliability and validity of expert testimony in court. These guidelines include considerations of whether the theory and methodologies employed have been tested, the establishment of potential or known error rates, and the existence and maintenance of the standards (Christensen, 2004). Testifying in court as an expert witness has become a critical role as a forensic anthropologist. As such, the methodologies, techniques, and standards utilized by forensic anthropologists must be carefully considered and adhere to the Daubert guidelines within the court system. One …

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 …

Evaluation Of Charcoal Strip Extraction Efficiency Under Varying Substrate Conditions, Abby Wester

Master of Science in Forensic Science Directed Research Projects

The ability of a forensic examiner to identify the presence of ignitable liquids (ILs) in fire debris collected from the area of origin of a fire is an essential component for determining intent in fire investigations. However, this relies on an effective extraction method that provides a complete picture of what is present in the debris. In this study, eight substrate materials underwent three different treatments: a low-volume of substrate that was unburned, a low-volume of substrate that was burned, and a high-volume of substrate that was unburned. Each sample was spiked with a 1:1 mixture of gasoline and diesel …

Discrimination Of Blue Denim Fibers Utilizing Physical Characteristics, Optical Properties, Fluorescence Microscopy, Ultraviolet-Visible Microspectrophotometry, And Microchemical Testing, Elkin Howard

Master of Science in Forensic Science Directed Research Projects

Cotton, the most common natural fiber, has numerous uses in the textile industry. This fiber type is ubiquitous in forensic casework due to its prevalence, particularly in blue jeans. The abundance of blue cotton in society and its limited variations in features can diminish the probative value of its presence on items of evidence. While a pair of blue jeans may be constructed with a combination of natural and manufactured fibers, the most likely fiber type to be transferred between sources is cotton. In this study, a comprehensive analytical approach to blue jean fiber analysis was explored to determine if …

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 …

Overcoming The Effects Of Oily Contaminants On Dna Extraction Efficiency Using Dna Iq™ System, Elizabeth G. Gillece

Master of Science in Forensic Science Directed Research Projects

In forensic science DNA extraction and purification are crucial to DNA analysis as evidentiary items vary in DNA quantity and quality. In casework the goal to is maximize DNA yield, remove PCR inhibitors, and develop a full profile while preserving evidence. Extraction methods are developed to target the DNA for optimal isolation. Solid-phase extraction is advantageous as it can extract DNA from a variety of tissue types, it is amenable to automation, and it provides quick and efficient purification of DNA. Solid-phase extraction methods may have complications with contaminants that hinder the quantity and quality of the DNA recovered. In …

A Novel Dual Configuration Dart/Uhplc-Ms/Ms System For The Rapid Analysis Of Psilocybin-Containing Mushrooms And Other Seized-Drug Submissions, Aron R. Jaffe

Master of Science in Forensic Science Directed Research Projects

The use and availability of controlled substances is highly dynamic. When a classical or novel psychoactive substance becomes popular, an influx of seized-drug evidence submissions closely follows, contributing to an ever-growing backlog of exhibits awaiting identification. The need for inclusive, rapid, and robust analytical methods is apparent, as demonstrated by recent growth in hallucinogen use. Psilocybin and psilocin, among other entheogens, have become increasingly popular and an increase of psilocybin mushroom seizures by law enforcement has followed. The structural similarity and thermal lability of many entheogens preclude their identification using many conventional analysis techniques. A DART and UHPLC were interchangeably …

Using The Microbiome To Assess The Health Status Of The Individuals Recovered From The East Marshall Street Well, Arian Karim

Master of Science in Forensic Science Directed Research Projects

In 1994, during the construction of the Kontos Building on the Medical College of Virginia Campus, a well on East Marshall Street was discovered to contain artifacts and human remains of African descent. Upon archaeological analysis by the Smithsonian, the ancestral remains can be dated back to the mid-19th century, when grave robbing and the use of cadavers for anatomical purposes [BS1] in medical schools were common. The human oral microbiome is the second largest human microbiota, containing over 600 species of organisms. Dysbiosis of the oral microbiome can lead to the overgrowth of pathogenic species, resulting in illness and …

Temporal Discrimination Of Lucilia Sericata Pupae Using Dart- Tof-Ms And Statistical Analysis, Nguyen-Khoa N. Pham

Master of Science in Forensic Science Directed Research Projects

Lucilia sericata (Diptera: Calliphoridae) is a forensically important blow fly species. These flies have been extensively studied as they are one of the earliest colonizers of corpses. Adult females blow flies lay approximately 200-2,300 eggs, which upon hatching will feed off the body as they metamorphosize from first to second, and third instars. The third instar larvae then migrate away from the body in a stage known as pre-pupa, and develop into the puparial stage. The adults emerge from the pupa stage, leaving behind their empty puparium. These developmental stages are used by forensic entomologists to determine a minimum postmortem …

Quantitation And Visualization Of Epithelial Cells On Cartridge Cases, Paige Kibler, Christopher Ehrhardt, Katherine M. Philpott, Jody H. West, Stephanie Walcott

Master of Science in Forensic Science Directed Research Projects

Fired cartridge cases are a common type of evidence submitted to forensic DNA profiling but are challenging to analyze because they usually contain only trace amounts of biological material. As such, there is a significant need in caseworking units for new screening techniques to determine if biological material is present and is in high enough quantity to attempt DNA profiling. The goal of this study was to test a new method for quickly visualizing biological material on cartridge cases. Biological deposits were created by handling fired and unfired cartridge cases through a series of conditions. The biological material was collected …

Further Optimization Of A Simplified Protocol For Tooth Sample Preparation For Analysis Using The Applied Biosystems™ Rapidhit™ Id Instrument, Yen H. Dang

Master of Science in Forensic Science Directed Research Projects

Due to the destructive nature of mass casualty incidents (MCIs) or mass fatality events (MFEs), tooth samples are often one of the only viable sources for Disaster Victim Identification (DVI) because of the incredible integrity of the enamel layer surrounding the tooth. However, the resilient structure of the tooth requires harsh chemicals and a labor-intensive sample preparation protocol to ensure successful STR profile development. Considering this difficulty, one of the promising resolutions is the Applied Biosystems RapidHIT™ ID ID platform, which is a fully automated system that is designed to perform cell lysis, DNA isolation, polymerase chain reaction (PCR) amplification, …

Judging Firearms Evidence, Brandon L. Garrett, Eric Tucker, Nicholas Scurich

Faculty Scholarship

Firearms violence results in hundreds of thousands of criminal investigations each year. To try to identify a culprit, firearms examiners seek to link fired shell casings or bullets from crime scene evidence to a particular firearm. The underlying assumption is that firearms impart unique marks on bullets and cartridge cases, and that trained examiners can identify these marks to determine which were fired by the same gun. For over a hundred years, firearms examiners have testified that they can conclusively identify the source of a bullet or cartridge case. In recent years, however, research scientists have called into question the …

Program And Proceedings: Nebraska Academy Of Sciences 1880–2024, 144th Anniversary Year, One Hundred-Thirty-Fourth Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Aeronautics and Space Science Poster Session

Anthropology: Humans Past and Present

Maiben Lecture: "Platte Basin Timelapse: A Watershed in Motion," Grant Reiner

Applied Science and Technology

Biological Sciences

Biomedical Sciences

Chemistry

Earh Sciences

Environmental Sciences

Physics

Science Education

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 …

The Determination Of Ethanol And Phosphatidylethanol (Peth) In Donated Packed Red Blood Cells, Jordan E. Keller

Master of Science in Forensic Science Directed Research Projects

This research investigates the safety and reliability of blood donations by examining the presence of ethanol and phosphatidylethanol (PEth) in packed red blood cells (pRBCs). As blood donation is integral to healthcare, ensuring the safety of blood products is paramount. Current protocols focus on screening for infectious diseases, such as hepatitis C and human immunodeficiency virus (HIV), but do not routinely asses alcohol consumption, which can significantly impact patient outcomes. As a direct indicator of alcohol consumption, ethanol can affect blood quality, interfere with medical treatments, and present legal issues, such as false conclusions or assumptions. Ethanol detection methods include …