Forensic Science and Technology Commons^™

Viability Of Manually Passing Projectiles Through The Barrel Of A Firearm In Lieu Of Test Firing, Mara V. Mineo

Student Theses

Forensic examinations of discharged projectiles are made possible by the toolmarks and striations made by the barrel the projectiles pass through. Suspect barrels are attached to firearms and test fired to compare these toolmarks and striations with found evidence. However, physically damaged barrels could potentially be unable to produce exemplars. This study tests the viability of manually passing projectiles through stationary barrels as a meaningful and accurate means to produce acceptable exemplars that are able to be compared against recovered evidence. A total of 18 projectiles were manually passed between two distinct Glock handgun barrels and viewed under a comparison …

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 …

Adversarial Robustness Of Perceptual Hashing Systems: A Unified Security Evaluation Framework, Avijit Roy

Student Theses

Social network platforms, child safety organizations, and image provenance systems use perceptual hashing to identify known child sexual abuse material (CSAM), support content moderation and reverse image search, and verify image integrity. Perceptual hashing works by producing similar fingerprints for visually similar images, even after common transformations such as compression, resizing, or minor brightness changes. This useful similarity-preserving property also creates an adversarial attack surface, as attackers can use AI-assisted or conventional image manipulation techniques to move a hash across a matching threshold while maintaining visual similarity, often without access to specialized hardware.

The security failures produced by adversarial attacks …

A Qualitative And Quantitative Comparative Analysis Of Ballistic Bone Trauma From Frangible And Full Metal Jacket Projectiles, Hajar S. Hassan

Student Theses

Ballistic bone research is essential as 90% of homicides with the use of a firearm include injuries to bone. Forensic anthropologists use ballistic bone trauma to gather details and reconstruct an event, but ballistic bone trauma depends on many intrinsic and extrinsic factors. These factors include the type of bone, the type of firearm, and the type of ammunition. As new ammunition and firearms emerge, the literature on ballistic bone trauma remains limited. This novel study compares the bone trauma from the most common projectile, the full metal jacket, to a frangible projectile which is made to break upon impact. …

Method Development And Optimization For The Detection Of Synthetic Cannabinoids In Hair Using Lc-Msms, Linda K. Obeng

Student Theses

Synthetic cannabinoids represent one of the most prevalent and high-risk classes of New Psychoactive Substances (NPS), continuously evolving in structure and potency. Their widespread presence in seized materials and toxicology casework underscores the growing need for reliable analytical methods capable of detecting these compounds in biological matrices. Hair offers several advantages for drug testing, including a long detection window, minimal invasiveness, and resistance to adulteration; however, detecting synthetic cannabinoids in hair remains challenging due to their low incorporation levels and structural diversity. This study focuses on the method development and optimization of an LC-MS/MS technique for the detection of selected …

Fast & Forensic: Rapid Detection & Quantitation Of 30 + Emerging Novel Psychoactive Substances In Hair Using Lc-Ms/Ms, Seokjin Hwang

Student Theses

The continuous emergence of novel psychoactive substances (NPS) poses a significant challenge for forensic and clinical toxicologists, due to their structural diversity, rapid turnover on the illicit drug market, and limited toxicological information. Hair is a powerful matrix for retrospective drug exposure assessment and monitoring NPS worldwide. Not only does it provide a broad window of detection but also a simple sample exchange amongst laboratories. However, the extraction of multi-class NPS in a single method remains an analytical challenge. Therefore, there is an urgent need for extraction techniques and analytical methods that are both rapid and capable of multi-class quantitation …

Eyewitness Consent To Be Video Recorded: Implications For Identification Accuracy And Confidence, Sarah Argüelles

Student Theses

Recently, a recommendation has emerged for law enforcement to record the full eyewitness identification procedure, recognizing the critical role eyewitness testimony plays in the justice system (Wells et al., 2020). However, in some states, such as New York, law enforcement is required to seek consent from witnesses before recording (Municipal Police Training Council & Division of Criminal Justice Services, 2017). Since this practice is relatively new, there has been limited research on how obtaining consent may affect eyewitness accuracy. It was hypothesized that obtaining consent to video record could be linked to a witness’s confidence in their identification, with higher …

Effects Of Rapid Shearing Depending On Environmental Factors: Acrylic, Modacrylic, And Polypropylene Fibers, Charles K. Jin

Student Theses

Textiles can often be found damaged in forensic casework, and analysis of these defects can yield valuable information. Different methods of fiber fracture leave behind varying alterations in structure on individual fiber ends, leading to their possible identification and connection to a case. Interactions between high-speed impacts and synthetic fabrics composed of thermoplastic fibers are classified as rapid shear or high-speed tensile breaks. In these situations, unique fiber end characteristics can form due to excessive heat generation that is unable to dissipate quickly enough to prevent fiber end morphology from changing.

This study aimed to explore how different external conditions …

Exploring Variability Of The Cg18562578 Methylquant Assay For The Forensic Discrimination Of Monozygotic Twins, Sydney E. Arnold

Student Theses

Monozygotic (MZ) twins possess identical DNA sequences, posing a problem for forensic scientists, as they are incapable of distinguishing MZ twins from each other using traditional DNA identification methods. However, the epigenomes of MZ twins will differ and might be used for their forensic discrimination. Here, we explored the variability of an assay previously developed by our laboratory that showed high discrimination potential for MZ twins using buccal swab DNA, cg18562578 MethylQuant. We measured precision at each step: bisulfite conversion, nested PCR, and qPCR, reproducibility, and repeatability. DNA methylation ratios were compared between two analysts carrying each step using the …

Further Investigation Of Environmental Factors On Rapid Shear In Fibers Of A Polyester-Cotton Blend, Daniel K. Oh

Student Theses

Rapid shear is a process that occurs in thermoplastic materials when they interact with a high-velocity impact. In forensics, these interactions would typically be from a bullet interacting with clothing that consisted of synthetic fibers. When the interaction occurs, bulb-like shapes appear on damaged fiber ends, distinguishing them from other kinds of damage. The reason why these shapes occur is varied, but one prevailing factor seems to be the heat generated by the impact.

In prior experiments, the factor of temperature being important to the formation of the phenomenon, different environmental simulations that affected the sample’s temperature were done on …

Non-Destructive Dry Vacuum Recovery Of Dna From Fabric, Emily Sam-Zee-Moi

Student Theses

Trace DNA has proved to be a reliable forensic tool when investigating crimes. Current methods of trace DNA recovery from fabric include cutting, swabbing, scraping, and tape lifting. A dry vacuum collection method originally developed for paper evidence is an alternative nondestructive option for DNA collection from fabric. This research evaluated the success of the dry vacuum technique on pieces of cotton fabric that had been briefly touched as well as the effectiveness of different moistening agents and filters. The samples were designed to simulate an assault with the suspect grabbing the clothing of their victim. Volunteers created samples by …

The Effect Of Bullet Morphology And Intermediate Targets On Bullet Path, Natalia Aguilar

Student Theses

A key feature of shooting reconstruction is trajectory analysis. There are several different methods of assessing this from the bullet impact mark including: best-fit ellipse, lead-in, trajectory rod, 3D laser scanning, and machine learning. While these function in differently, many share a common fault. Few trajectory analysis techniques evaluate the difference in bullet path for bullet morphology. This raises the question: does the morphology of a bullet influence its degree of deviation when interacting with a target material? This study investigates the difference in bullet trajectories through drywall for 9mm full metal jacket (FMJ) and jacketed hollow point (JHP) ammunition …

Bullet Ricochet And Tunnelling Of Wood Substrates, Abdelrahman Khalifa

Student Theses

With the overall rise in shooting incidents throughout the country, most notably in urban areas, the capabilities and limitations of current forensic examinations of firearms-related incidents have become more apparent. An underappreciated aspect of shooting incidents is the phenomenon of bullet ricochet, which has led to ricochet-related injuries, with some cases proving fatal. Although there are processes and generally accepted standards for bullet trajectory analysis, ricochet analysis typically requires outside input from firearm examiners. Additionally, current research regarding ricochet on wood surfaces remains less thoroughly investigated than ricochet analysis on other yielding surfaces. The goal of this research was to …

Transfer Of Material Derived From Polymer-Jacketed Bullets During Cycling And Discharge, Ethan A. Frazer

Student Theses

The goal of this study was to determine alternative ways to connect a polymer-coated bullet to the handgun from which it was fired. Polymer-coated bullets are lead projectiles encased in a synthetic coating, which may vary between brands and/or models, to reduce barrel friction and heavy metal exposure. Federal Syntech^® Total Synthetic Jacket (TSJ) ammunition presents unique challenges to firearms examiners as its synthetic coating may not retain the individualizing striations found in traditional unjacketed or metal-jacketed bullets.

In this study, 9mm TSJ ammunition was fired through multiple traditionally rifled aftermarket Glock barrels. Cloth targets were set up at …

Overlooking The Utility Of The Tattoo As An Investigatory Lead: An Exploratory Study Of Tattoo Documentation Quality Among Investigators And Medical Examiners, Deanna Corsetti

Student Theses

Tattoos have not only served as a subject of interest across cultures and disciplines for centuries, but also serve as a critical component of forensic investigations. Tattoos as traces–when properly identified and documented–serve as a valuable investigatory lead in cold, missing persons and unidentified remains cases. By examining the locations, dimensions, colors, and overall imagery of tattoos, investigators are able to use tattoos as a method of rapid, tentative identification of human remains (Miranda 2019). This study seeks to evaluate the quality and scope of tattoo documentation in cases classified as being unsolved. Specifically, tattoo data was collected from redacted …

Development Of A Rapid Method For Pfas Detection And Quantitation In Human Hair, Justin M. Allen

Student Theses

In recent years, per- and polyfluoroalkyl substances (PFAS) have emerged as a critical focus in environmental and public health research due to their persistent nature and widespread use in products ranging from non-stick cookware to firefighting foams. These "forever chemicals" resist degradation, posing significant ecological and human health risks. While extensive studies have explored PFAS in environmental matrices, research into their presence in human hair remains limited, with only a handful of studies addressing this biomarker's potential. This thesis aims to develop a robust analytical method for detecting PFAS in human hair, leveraging its unique properties to provide a long-term …

An Internal Validation Of The Ande Rapid Dna Instrument For Bone, Tissue, And Blood Samples, Alexandra Leichnam

Student Theses

The goal of this study is to internally validate the ANDE 6C Rapid DNA I-Chip reagent for use on disaster victim identification (DVI) samples. The internal validation tested nine samples each of postmortem blood, tissue, and bone. This study tested the instrument’s precision, accuracy, repeatability, and reproducibility. Precision and accuracy were tested by confirming that the same sample run on the ANDE instrument and the Power Plex Fusion amplification system produced a DNA profile that is consistent with the known profile. Repeatability was tested through confirming the correct results are obtained for sample runs performed by the same operator. Reproducibility …

Determination Of Common Drugs Of Abuse And Metabolites In Oral Fluid: Comparison Of Different Extraction Procedures, Melissa Koffer

Student Theses

Oral fluid has been gaining importance in forensic and clinical toxicology for many different drug testing scenarios. Oral fluid is composed of saliva, along with gingival fluid, bacteria, and food residues. Drug testing using oral fluid has many advantages over other matrices (blood, urine) such as the non-invasive collection, reduced risk of tampering, and shorter detection windows which show recent drug use. The purpose of this study was to develop an analytical method for the determination of 19 drugs of abuse and metabolites in oral fluid by liquid chromatography tandem mass spectrometry (LC-MS/MS) and compare three different extraction methods: liquid-liquid …

Comparing Bone Histology, Topography, And Other Physical Attributes To The Presence Of Viable Dna After Interval Cremation, Eldad Cano Jr

Student Theses

This research aims to compare the resulting characteristics caused by thermal exposure to bone samples – such as physical composition, microscopic histology, and scanning electron microscopy (SEM) analysis – to the qualitative and quantitative DNA analysis within the samples. By using kilns to cremate sus scrofa domesticus bone samples at five different temperatures, cortical and cancellous bones of the tibia, humerus, femur, and fibula will be analyzed and compared to determine any correlation with these factors and the presence of viable DNA. This contribution to research within the realm of forensic anthropology can grant a better understanding of how bone …

Investigation Into The Utility Of The Submaxillary Gland Androgen-Regulated Protein 3b (Smr3b) As A Normalizing Factor In Oral Fluid, Alejandro Ocampo

Student Theses

Oral fluid is a biological sample of increasing interest in clinical and forensic toxicology. This matrix is easy to obtain, it shows a low biohazard risk, and it reflects recent drug exposure. However, the interpretation of its quantitative values is limited, due to the high inter- and intraindividual variability. The investigation of normalization factors in this biological matrix may improve the interpretation value of oral fluid. This study investigated the potential of two signature peptides from the submaxillary gland androgen-regulated protein 3B (SMR3B) as normalization factors in oral fluid. SMR3B was digested in trypsin and the signature peptides SMR3B-1 and …

Method Development And Validation Of Controlled Substances On A Gas Chromatography - Fourier Transform Infrared Spectrophotometer, Regina E. Filus

Student Theses

The goal of this project was to perform a validation and a method development for an Agilent 7890 Gas Chromatograph connected to a Thermo iS50 Fourier Transform Infrared Spectrophotometer in order to put the instrument into functional and operational use. Both instruments are connected via an interface allowing for simultaneous analysis of a sample. A custom-made in-house library was created in order to search and compare to future unknown case samples. Reference materials were run and reviewed in order to determine which method and concentrations would provide the best infrared scans, and the sample repeatability runs were used to develop …

The Effect Of Resource Quality And Species Interactions On Dermestes Maculatus, Sarah Aliahmad

Student Theses

Forensic entomology is the use and application of insect information in legal matters, particularly in death investigations as insects utilize decomposing remains as a food source to complete their life cycle. Dermestes maculatus (DeGeer), larder beetles belonging to the family Dermestidae, are of considerable forensic importance since their larvae are typically found on human corpses during the later stages of decomposition – the advanced and dry/skeletal stages. Dermestes maculatus can be useful in estimating the post-mortem interval (PMI) of a cadaver with advanced decomposition. The purpose of this study was to investigate the colonization (egg-laying) behavior of D. maculatus; …

Dna Shedding Propensity And Individual Characteristics, Genesis Echavarria

Student Theses

This study attempted to correlate individual biological characteristics to the amount of DNA recovered from a person’s hands (representative of shedding propensity). We used adhesive D-Squame tape to collect DNA from the fingers of more than 100 volunteers with and without controlled activity after handwashing. Two no-activity samples were taken after 30 min from the non-dominant hand and two samples from the dominant hand were collected after 60 min of controlled activity. Involuntary touches during the 60-min activity period were counted. All samples were extracted for DNA, quantitated, and genotyped to detect mixtures. Skin measurements for hydration, sebum, and melanin …

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 …

Comparison Of Hydrolysis Efficiency And Performance Of Four Recombinant Β- Glucuronidase Enzymes For The Detection Of Opioids In Urine Samples By Lc-Ms/Ms, Christina Fernandez

Student Theses

The United States has been experiencing a nationwide public health crisis since introducing prescription opioids in the 1990s. A central problem with opioids is their highly addictive nature causing a dose-dependent respiratory depression leading to overdoses and deaths. Drug overdose deaths have risen in the past two decades, with opioids being the dominant driver of this epidemic. Given the circumstances, accurate and efficient confirmatory analysis of opioids in urine is essential to monitoring patients’ compliance and preventing drug diversion in clinical and forensic settings. The development of recombinant β-glucuronidases allows for the hydrolysis of glucuronidated opioids using a shorter incubation …

Detection Of Delta-9-Tetrahydrocannabinol And Cannabidiol In Utero Exposure By Umbilical Cord Analysis, Emily Pagano

Student Theses

With the rising consumption of cannabis and cannabinoid-containing products among different demographics, including pregnant women, it is increasingly necessary to develop analytical tools to be able to determine prenatal cannabis exposure. The aim of this study was to develop and validate a sensitive and specific method, using umbilical cord, to determine in utero exposure to delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). After homogenization and hydrolysis, samples were extracted using liquid-liquid extraction and analyzed by liquid chromatography-tandem mass spectrometry (LC-MSMS). MS analysis was performed in electrospray ionization negative mode and two multiple reaction monitoring (MRM) transitions were monitored per analyte. The linearity …

Identification Of Different Hair Dyes In Dyed Hair Using Attenuated Total Reflectance (Atr Ft-Ir), Surface Enhancing Raman Spectroscopy (Sers) Techniques, Nicholas Lovera

Student Theses

This investigation compares the ability of Attenuated Total Reflection Fourier Transfer Infrared Spectroscopy (ATR FT-IR) and Surface Enhance Raman Spectroscopy (SERS) to identify and differentiate different hair dye brands on dyed hair samples. Hair is a common type of trace evidence found at crime scenes and can provide numerous information through forensic hair analysis. Cosmetic hair treatment such as dying the hair different colors has grown and became popular, thus it can be a very common type of trace evidence. This study can provide a forensic scientist an additional method for analyzing dyed hair samples. The goal was to compare …

Impact Of Blood Preservatives And Anticoagulants On Cannabinoid Quantitative Analysis, Bridget O'Leary

Student Theses

The expanded use of recreational and medicinal cannabis products, as well as the appearance of new cannabinoid derivatives, increases the importance of implementing pre-analytical (sample collection) protocols and the development of recommendations for cannabinoid testing in biological samples. The accurate quantification of cannabinoids in biological samples is critical for providing a correct result interpretation, especially if specific thresholds have been legally set, as in drugs and driving cases in certain states. Previous studies have mainly focused on the impact of time and temperature on the stability of delta-9-tetrahydrocannabinol (delta-9-THC) and metabolites in blood samples; however, the influence of the type …

Open Fire: The Expansion Of 9mm Hollow Point Bullets In Relation To Tissue Thickness, Abigail Wilson

Student Theses

Bullets can be broadly differentiated into jacketed and unjacketed groups. Jacketed ammunition can be further broken down based on the bullet’s design, one of which is hollow points. This research examines a representative brand of jacketed hollow point bullets used in a common caliber cartridge, the 9mm Luger. A jacketed hollow point bullet is designed to expand when it encounters a viscous medium such as tissue. This experiment simulated tissue using ballistic gelatin and simulated skin using a chamois overlay. As a positive and negative control, a series of bullets were fired into a full-size block of gelatin to achieve …

The Effect Of Henna And Bleach Treatments On Cocaine Hair External Contamination, Alexandra Dombroski

Student Theses

Hair external contamination is a challenging phenomenon that may compromise hair testing interpretation. Previous research has found that cosmetic hair treatments can decrease concentrations of drugs that are already present in the hair shaft, however little is known about the impact of these treatments on the hair when the drugs are deposited externally. The aims of the present study were to explore how henna and bleach treatments influence cocaine external contamination. Sixteen authentic hair samples were collected from volunteers with varying hair colors and shapes and were confirmed negative for cocaine and benzoylecgonine by a fully validated LC-MS/MS method. Each …