Forensic Biology Commons^™

Color Tests For The Presumptive Identification Of A Range Of Benzodiazepines, Regan Mulvin

Honors Projects

Color tests are presumptive chemical tests that determine the class of drug in both laboratory and field settings. Despite the rising popularity of benzodiazepines and the usefulness of color tests, there is no widely accepted color test for identifying them. This study tested six different color tests against five benzodiazepines, including diazepam, clonazepam, lorazepam, alprazolam, and flualprazolam, to identify which of the tests would work most generally across all benzodiazepines. Of the six tests, the McKibben test, the Janovsky test, and the Zimmerman test all showed potential usefulness as a presumptive color test. More studies should be done on a …

Decomposition Processes And Insect Indicators In Forensic Investigations, Eli Taylor

University Honors Theses

Insects play an essential biological and ecological role in human life, and their predictable relationship with decomposing remains has positioned them as a cornerstone of modern forensic science. Since the early 20th century, forensic entomology has provided critical evidence for estimating the postmortem interval (PMI), relying on patterns of colonization, species succession, and insect developmental timelines. Accurate PMI estimations are vital to medicolegal investigations, influencing the interpretation of biological evidence, guiding resource allocation, and informing determinations of cause and manner of death. However, insect activity is profoundly shaped by environmental and ecological variables, including temperature, humidity, seasonal shifts, and geographic …

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

Str Analysis Performance Comparison For Two Capillary Electrophoresis Instruments: The Seqstudio And The 3500 Genetic Analyzers, Yana Leichyk

Student Theses

This study compares the performance of two capillary electrophoresis instruments—the SeqStudio™ Genetic Analyzer and the 3500™ Genetic Analyzer—for forensic short tandem repeat (STR) analysis. Using the GlobalFiler STR kit and certified reference material (SRM 2391d), five key performance metrics were evaluated: sizing precision, signal reproducibility, detection sensitivity, mixture resolution, and overload tolerance. STR profiles were generated from single-source and mixture samples with DNA inputs ranging from 500 pg to 15.6 pg. Both instruments met the < 0.15 bp sizing precision requirement for forensic casework. Signal reproducibility tests showed that the SeqStudio often produced higher average RFU values, but with greater variability, while the 3500 demonstrated more stable signal performance across days and samples. Mixture detection was effective on both platforms up to 1:10 ratios. Dropout of minor alleles began to appear at 1:20 ratios, especially in green and yellow dye channels, on both instruments. Sensitivity studies confirmed full profile recovery down to 62.5 pg, with increasing allelic and locus dropout at lower inputs. Enhanced injection voltage (1.5 kV) did not improve low-template performance. In overload testing (1–5 ng input), the 3500 maintained a consistent signal output, while the SeqStudio exhibited signal suppression at 5 ng, likely due to internal normalization. The SeqStudio exhibited better spectral overlap compensation, with fewer occurrences of spectral bleed-through artifacts. These findings support the use of both platforms in forensic casework, while emphasizing the importance of platform-specific calibration and analytical threshold settings for optimal performance.

Investigating Concealments In Infanticide: Incidents And Forensic Entomological Implications, Gillian Johnson

Electronic Theses and Dissertations

Forensic entomology plays a critical role in estimating the minimum postmortem interval (mPMIs), based on insect evidence. When victims are concealed, this can complicate mPMI estimates. Utilizing data from the National Violent Death Reporting System (NVDRS) from 2018 to 2021, I found that victims of infanticides and neonaticides are often concealed. I first investigated the demographics of offenders and victims, how often victims are concealed, and the most common means of concealment. I found that victims of infanticide were likely to be concealed 5% of the time, and neonaticides 50% of the time. Next, I investigated how concealment alters insect …

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 …

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 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 …

Rehumanizing Anatomized Individuals: Using Osteobiographies As A Step Towards Reparative Justice, Lillie 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, …

From Prairie To Practice: Forensic Taphonomy, Ethics, And Regional Ecology In Southeastern Nebraska, Jessica 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 …

Advancement Of Wrongful Conviction Prevention Strategies In Forensic Science, Isabella Pinto

Honors Projects

The National Registry of Exonerations (NRE) has identified 1,051 of its logged cases to involve forensic evidence in some way, nearly one-third of the total 3,600 exonerations in its database. Analysis of the NRE and Innocence Project databases revealed the most common factors in forensic-related wrongful convictions: expert testimony, flawed methodologies (most of which are no longer in use), and statistical misinterpretations of results. The majority of scholars agree that oversight in forensic casework must be improved in order to meaningfully resolve issues. Creation of commissions in each state would address all of the identified errors, though not a catch-all …