Forensic Science and Technology Commons^™

Effect Of Food Resource, Preservation Method, And Preservation Duration On Larval Size Of Forensically Important Fly Species (Order: Diptera), John Zukowski

Student Theses

Forensic entomology is a vital discipline that can aid in the proceedings of criminal cases. Larval age and development are important aspects to consider when utilizing blow flies (Family: Calliphoridae) for estimates pertaining to the initial time of colonization (TOC), which contributes to postmortem interval (PMI) estimations. Thus, it is important to understand the factors that influence larval size and development, since larval size is commonly used as a proxy for age. Larvae of three species of flies, Lucilia sericata (Meigen), Calliphora vicina (Robineau-Desvoidy), and Phormia regina (Meigen), were reared on five different food resources. Specimens of L. sericata and …

From Prairie To Practice: Forensic Taphonomy, Ethics, And Regional Ecology In Southeastern Nebraska, Jessica F. L. Gammage

Department of Anthropology: Theses and Student Research

Forensic taphonomy examines the postmortem processes that affect human remains within specific environmental contexts and plays a critical role in medicolegal death investigation. Despite significant advances in decomposition research, experimental studies remain geographically and environmentally uneven, limiting the transferability of postmortem interval (PMI) estimation methods across regions. The Central Great Plains are underrepresented in forensic taphonomic research despite its distinct ecological and geomorphological characteristics.

This thesis evaluates southeastern Nebraska as a specific regional setting for forensic taphonomic research by integrating ecological, pedological, and geomorphological data with current forensic literature. Tallgrass prairie vegetation, loess-derived soils, seasonal moisture variability, and dynamic fluvial …

Understanding Roma Oppression In Europe Through Humantarian Forensic Analysis, Christal L. Quinn

Department of Anthropology: Theses and Student Research

This thesis examines the marginalization of Roma people in Europe, and how humanitarian forensic practices may help Roma communities in their quest for justice and recognition. The study draws exclusively on secondary information to examine the social, political, and legal issues affecting the Roma communities, who have endured centuries of institutional discrimination, marginalization, and violence. This thesis identifies ways in which systematic oppression continues to limit Roma communities’ access to education, housing, healthcare, and legal protection through a review of relevant literature and applicable theoretical frameworks. The study also examines the relevance of forensic science, particularly its humanitarian applications, in …

Rehumanizing Anatomized Individuals: Using Osteobiographies As A Step Towards Reparative Justice, Lillie C. Turpin

Department of Anthropology: Theses and Student Research

In 1985, India banned the export of human remains. This ended the major trade route for primarily US and European anatomical supply companies. Until this point, companies like Carolina Biological Supply exploited and erased vulnerable people's identities, molding them into anonymous anatomical specimens. This study investigates the life and postmortem history of twenty-five individuals, previously used as anatomical specimens, housed at the University of Nebraska–Lincoln. Using an osteobiographical approach, this research reconstructs aspects of these individuals' lived experiences and examines how anatomical preparation practices reflect structural violence and apathy.

Skeletal analysis of twenty-five individuals revealed a range of biological profiles, …

Non-Destructive Automated Classification Of Human And Large Mammal Long Bone Fragments: A Deep Learning Approach Using Micro-Ct Histomorphology And Grad-Cam Interpretation, Kathleen Marie Kelley

Department of Anthropology: Theses and Student Research

This study explores the development and validation of an automated, deep learning system designed to differentiate human from large mammal long bone fragments using micro-CT imagery. A comprehensive dataset of cross-sectional µCT images was assembled from human and animal skeletal material processed at the DPAA, Nebraska. A convolutional neural network (CNN) based on a ResNet-18 architecture, utilizing transfer learning from ImageNet weights, was trained to classify µCT images as human or animal. The model achieved a mean classification accuracy of 89.85% (± 8.27%) across five sample-level cross-validation folds, with a sensitivity of 96.21% and a 95% bootstrap confidence interval of …

Decomposition Study Using Pigs In Southeastern Nebraska During The Fall And Winter Seasons, Ryan Bodine

Department of Anthropology: Theses and Student Research

When an individual is found deceased, one of the tools used in the identification process is estimating the post-mortem interval (PMI). This estimate is used to determine how long an individual has been deceased once their remains are found. To estimate an accurate PMI, knowing how decomposition is affected by external factors is key. The transition period from fall to winter in southeastern Nebraska consists of fluctuating temperatures as the seasons transfer from fall to winter. This thesis investigates how decomposition is affected during this transition period while also looking at two different environments that are common in Nebraska, prairies …

Exploring The Biocultural Profile Of The Undocumented Populations Of The Sonoran Corridor: A Skeletal Assessment Of The Prevention Through Deterrence Strategy, Mary A. Vaughn

Department of Anthropology: Theses and Student Research

Over the last thirty years the mortality rate of the undocumented population at the US-Mexico border has risen, requiring methods distinguishing US-born individuals from immigrants to improve the likelihood of identification and repatriation through foreign consulates. Forensic anthropologists with the Pima County Office of the Medical Examiner (PCOME) have advocated for the use of the biocultural profile, combining the biological profile with factors including oral health, osteological stress, and personal effects. The biocultural profile serves two purposes, functioning both as a tool for identification and with which to document structural inequality within communities of origin.

This study examines changes in …

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 …

Oviposition And Immature Development Of Blowflies In Forensic Investigations, Amalia Herrera-Benitez

Themis: Research Journal of Justice Studies and Forensic Science

Forensic entomology is a subspecialty within the field of forensic science where insect evidence is analyzed to solve criminal cases. Insects begin to colonize the body, with blowflies being the first insects to arrive. Within minutes, blowflies can lay eggs on a decomposing body, and the larvae will feed once they hatch. The life cycles of blowflies are analyzed to help determine an estimated post-mortem interval (PMI), which is crucial in investigations, as it can help establish a timeline. Various factors, such as temperature and access to the body, can cause delays in the oviposition of blowflies. A delay in …

Accurate Body Weight Class Prediction From Mirna And Gene Expression In Blood And Saliva Samples, Kimberly Lettner

Master of Science in Forensic Science Directed Research Projects

miRNA interference on protein abundance related to glucose uptake and lipid production has been evaluated in biomedical research and linked to metabolic disorders like severe obesity. The direct regulation of protein abundance caused by miRNAs on a person’s metabolism can lead to an increased weight and overall size. Body size, measured by BMI, provides additional physical descriptions that can be combined with hair color, eye color, age, and skin pigment to aid investigations of unidentified remains or unknown suspects not found in a database. The purpose of this project was to evaluate the miRNA expression of target biomarkers in dried …

Extraction Of Challenging Forensic Samples Using The Microgem Dna Extraction Kit, Falyn R. Vega

Student Theses

In forensic science, DNA extraction can be a tedious and resource-intensive process. Extraction with Proteinase K is an industry standard but has its drawbacks, such as requiring multiple ionic detergents and washing steps. MicroGEM has developed a new enzyme called forensicGEM that is temperature-dependent and compatible with mesophilic enzymes, offering complete DNA extraction in about 20 minutes in a single tube, limiting contamination, loss of sample, and working time. ForensicGEM can extract DNA from highly degraded samples, potentially leading to more complete STR profiles. Highly degraded tissue and bone samples were collected and extracted with the forensicGEM …

Analyzing The Viability Of Direct Pcr For Use In Conjunction With Cyanoacrylate Enhanced Fingerprints, Coral M. Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Efficient methods for DNA analysis are desperately needed in laboratories due to the influx in DNA analysis requests. The current DNA processing methods are costly, time consuming, and involve multiple tube changes, increasing the risk of contamination. However, the use of direct PCR can simplify the DNA analysis process by eliminating the extraction, purification and quantitation steps. Presently, the FBI Quality Assurance Standard 9.4 requires all evidence samples to be quantitated. As a result, the direct PCR method of DNA processing cannot be implemented on evidence samples at this time. Direct PCR presents the opportunity to provide efficient DNA analysis, …

Mtdna Heteroplasmy In Hair Shafts Versus Buccal Swabs For Forensic Applications, Sara R. Bodnar

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mitochondrial DNA (mtDNA) analysis has several forensic applications such as criminal investigations, identification of human remains, and missing person investigations. It is also the only type of DNA that is available from certain sample types such as hair shafts. The presence of mtDNA heteroplasmy within and between tissue types can lead to mtDNA sequence differences when comparing samples originating from the same individual. Studies on mtDNA heteroplasmy are increasingly being carried out for their implications in forensic interpretation of mtDNA sequences. Specifically, mtDNA in buccal swabs compared to hair samples from one individual may show differences in sequence due to …

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 …

Evaluation Of The Effect Of The Humic Acid Inhibitor On Forensic Genetic Investigations Of Human Skeletal Remains, Madeline King

Honors Theses

Postmortem survival of DNA in human skeletal remains occurs due to the compact microstructure of the skeleton and its ability to provide a strong, protective physical barrier to environmental insults. On a molecular level, DNA preservation in bones/teeth involves electrostatic interactions between the negatively-charged DNA backbone and positively charged calcium residues in hydroxyapatite, the latter of which is one of the main components of bone microstructure. Despite these protections, over time endogenous DNA becomes damaged, limiting our ability to detect it and affecting its utility in making a positive identification. Hence, forensic genetic investigations of unidentified human remains (UHRs) are …

How To Get Away With Murder: The Effectiveness Of Blood Detectors On Surfaces Cleaned Of Blood, Grace Cavanaugh

Undergraduate Theses and Capstone Projects

The purpose of this experiment was to test blood detectors against household cleaners. Similar experiments have been run before, but not on the selected surfaces. It is important to understand what one is looking for at a crime scene, and what a cleaned surface may look like. Four surfaces were chosen for this experiment: ceramic tile as a control, concrete, laminated wood flooring, and drywall. For each surface, 0.5mL of pig’s blood was allowed to dry before being cleaned off with either Clorox bleach, Dawn soap and hot water, a Mr. Clean Magic Eraser, or Mrs. Meyer’s Multi-Purpose Concentrate. Bluestar …

Further Evaluation Of A Dry Vacuuming Technique For Recovery Of Dna From Handwritten Documents, Christian Hopkins

Student Theses

A previously developed, non-destructive, homemade vacuum method for collecting biological material from handwritten documents had promising DNA results for white copy paper, preserved indented writing, and latent prints. Prior to casework implementation, additional validation experiments are warranted and here the method was tested for different paper substrates. This work describes testing of notebook paper, bank deposit slips, magazine pages, and manila envelopes. The quantity of recovered DNA varied from donor to donor, but the mean quantities showed a trend that can be explained by the different sizes and surface properties of the tested paper types. The rougher paper type, like …

Investigating The Efficacy Of Dna Damage With Bleach In Forensic Laboratories And At Crime Scenes, Alyssa Tuccinardi

Honors Theses

Household/commercial bleach (6% NaOCl, sodium hypochlorite) degrades DNA through oxidative damage, production of chlorinated base products, and cleavage of DNA strands (breaking it into smaller and smaller fragments). The presence of these lesions significantly impacts the ability to generate a full genetic profile from an evidentiary sample. In fact, knowledge of the damaging effect of bleach on DNA is the basis for its use in forensic laboratories to clean workbenches and prevent cross-contamination of samples between cases. Additionally, bleach is used intentionally by criminals to clean up crime scenes and destroy DNA evidence. A previous study demonstrated that bleach has …

The Utilization Of Sex Hormone Antibodies For Screening And Separation Of Trace Biological Mixtures, Kristin N. Jones

Master of Science in Forensic Science Directed Research Projects

Touch or trace evidence consists of epidermal cells deposited by contact with items such as handled objects, touched surfaces, or worn clothes. This type of evidence has surpassed most other sample types submitted to forensic labs and typically consists of low quantities of DNA and multiple contributors. In this study epithelial skin cells, i.e., “touch/trace evidence,” were used as they are estimated to constitute approximately half of the casework evidence items submitted for DNA analysis. For the optimization of antibody staining, male and female skin epithelial samples from donors were incubated and hybridized with antibodies of various concentrations of Alexa …

Development Of A Quantitative Pcr (Qpcr) Based Method For Studying Temporal Dna Degradation In Waterlogged Bone, Isis Thornton

Master of Science in Forensic Science Directed Research Projects

Human activities are often centered around the presence of water, thus it is not surprising that there are many water-related human deaths. Accumulated degree days (ADD), and other aquatic variables may affect DNA retrieval from waterlogged bone. Calcium and collagen in bone can inhibit the PCR necessary to produce an STR profile; the current solution is a time-consuming organic extraction. While there are examples of research on DNA degradation in terrestrial bone over time, there has been little work done on submerged bone samples and they are usually limited to case studies. The major aim of this study was to …

Correcting Forensic Dna Errors, Greg Hampikian

Biology Faculty Publications and Presentations

DNA mixture interpretation can produce opposing conclusions by qualified forensic analysts, even within the same laboratory. The long-delayed publication of the National Institutes of Standards and Technology (NIST) study of 109 North American crime laboratories in this journal demonstrates this most clearly. This latest study supports earlier work that shows common methods such as the Combined Probability of Inclusion (CPI) have wrongly included innocent people as contributors to DNA mixtures.The 2016 President’s Council of Advisors on Science and Technology report concluded,“In summary, the interpretation of complex DNA mixtures with the CPI statistic has been an inadequately specified—and thus inappropriately subjective—method. …

Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this work we demonstrate the power of compound-specific isotope analysis (CSIA) to analyze proteinaceous biological materials in three distinct forensic applications, including: 1) linking necrophagous blow flies in different life stages to their primary carrion diet; 2) identifying the harvesting area of oysters for food authentication purposes; and 3) the ability to predict biometric traits about humans from their hair.

In the first application, we measured the amino-acid-level fractionation that occurs at each major life stage of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) blow flies. Adult blow flies oviposited on raw pork muscle, beef muscle, or chicken liver. Larvae, pupae …

A Novel On‐Chip Method For Differential Extraction Of Sperm In Forensic Cases, Fatih Inci, Mehmet O. Ozen, Yeseren Saylan, Morteza Miansari, Duygu Cimen, Raghu Dhara, Thiruppathiraja Chinnasamy, Mehmet Yuksekkaya, Chiara Filippini, Deepan Kishore Kumar, Semih Calamak, Yusuf Yesil, Naside Gozde Durmus, George Duncan, Leonard Klevan, Utkan Demirci

Biology Faculty Articles

One out of every six American women has been the victim of a sexual assault in their lifetime. However, the DNA casework backlog continues to increase outpacing the nation's capacity since DNA evidence processing in sexual assault casework remains a bottleneck due to laborious and time‐consuming differential extraction of victim's and perpetrator's cells. Additionally, a significant amount (60–90%) of male DNA evidence may be lost with existing procedures. Here, a microfluidic method is developed that selectively captures sperm using a unique oligosaccharide sequence (Sialyl‐LewisX), a major carbohydrate ligand for sperm‐egg binding. This method is validated with forensic mock samples dating …

The Y-Screen Assay: Validation And Evaluation Of Subsequent Str Success, Kassandra Luyando

Student Theses

There are hundreds of untested sexual assault kits in police custody. As of 2017, New York State passed a law stating that all untested kits must be turned over to forensic laboratories to be tested, causing backlogs at laboratories to increase. The Y-Screen assay is a DNA extraction protocol which utilizes NaOH to rapidly lyse epithelial and sperm cells, and the Quantifiler Trio DNA quantification kit to detect the presence or absence of male DNA prior to standard sample processing. The Y-Screen assay is a commercial product used in this research to test a defined set of validation samples with …

Forensic Markers Of Lampricide Toxicity In Oncorhynchsus Mykiss, Chris White

Theses and Dissertations (Comprehensive)

The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used for decades to control invasive sea lamprey (Petromyzon marinus) populations in the Great Lakes, normally with little harm to other fish populations. However, due to the nature of lampricide treatments and the chemical properties of TFM, adverse effects to non-target fishes and non-target mortality occasionally occur. However, investigations of non-target mortality can be complex, particularly if fish deaths are not noticed immediately, due to decomposition of the carcasses. The objectives of this thesis were to expose rainbow trout (Oncorhynchsus mykiss) to TFM in order to: (i) identify forensic markers …

Optimizing A Method For Simultaneous Recovery Of Proteins And Dna From Fingerprints, Steven Kranes

Student Theses

DNA testing on touched objects is a valuable tool in forensic investigations, but DNA is usually present in low amounts, causing poor STR typing results. For touch DNA evidence, there is a clear need for additional individualization, especially for highly probative samples. This could be achieved by testing genetically variable proteins. The goal of this project was to develop a DNA/protein co-extraction method to facilitate DNA and protein testing on the same evidence item. Existing DNA extraction methods were carefully adjusted to allow for downstream mass spectrometry analysis. Initial experiments on saliva and fingerprints placed on glass suggested that trypsin …

Species Identification Of Necrophagous Insect Eggs Based On Amino Acid Profile Differences Revealed By Direct Analysis In Real Time-High Resolution Mass Spectrometry, Justine E. Giffen, Jennifer Y. Rosati, Cameron M. Longo, Rabi A. Musah

Publications and Research

The colonization of decomposing remains by necrophagous insects such as blow flies is of forensic importance because the progression through the various stages of insect development can be correlated to time of death. The ability to infer this information hinges on accurate determination of the fly species that are associated with the entomological evidence collected. This evidence can include eggs, larvae, pupae, and puparial casings. Determination of the egg’s identity is particularly challenging because the eggs of multiple species are morphologically very similar. We report here that the species identity of fly eggs can be determined from their chemical fingerprint …

High Resolution Melt Analysis Of Samples With Differential Dna Methylation To Identify Tissue Source Of Origin, Stephanie M. Ledgerwood

Master's Theses

In Forensic Science casework, identifying the source of a tissue can assist in crime scene reconstruction. Currently, presumptive testing methods to identify tissue type are utilized in crime scene laboratories, but there is a need for a more reliable confirmatory test for tissue type identification. High Resolution Melt (HRM) analysis is an innovative technology that has the potential to determine tissue types through variations in DNA methylation patterns. Recently, DNA methylation patterns have been found to correspond with specific tissue types in particular regions of DNA. Two markers, B_SPTB_03 and DDX4 have been effective in differentiating sperm from other tissue …

Isolation Of Secreted Micrornas (Mirnas) From Cell-Conditioned Media, Claire L. Glynn, Sonja Khan, Michael J. Kerin, Roisin M. Dwyer

Forensic Science Publications

MicroRNAs (miRNAs) have been found to be stable in the circulation of cancer patients raising their potential as circulating biomarkers of disease. The specific source and role, however, of miRNAs in the circulation is unknown and requires elucidation to determine their true potential. In this study, along with primary tissue explants and primary stromal cells, three breast cancer cell lines were employed, including T47D, MDA-MB-231 and SK-BR-3. Tissue explants were harvested in theatre, with informed patient consent, and included tumour, tumour associated normal, and diseased lymph node samples. Cell-conditioned media containing all factors secreted by the cells were harvested. MiRNAs …