Forensic Biology Commons^™

Indirect Dna Transfer To Duct Tape Rolls Stored In Cars, Yuching Chung

Student Theses

This project investigated the accumulation of DNA on duct tape rolls stored in cars. Specifically, we analyzed samples recovered from three areas (the inside, outside, and flat sides) of unused duct tape stored under the driver's seat and trunk of cars for seven days. Twelve volunteers were recruited, resulting in 64 DNA samples from 12 cars. We evaluated DNA quantities and STR genotyping outcomes after amplification with the GlobalFiler™ kit. On average, the DNA yields from under the driver's seat were higher than from the trunk, but the difference was not significant. The inside of the tape roll yielded significantly …

Characterization Of Dna Background On Duct Tape Stored In Domestic Environments, Elaan A. Lukasiewicz

Student Theses

With lower detection limits for forensic DNA analysis, it is important to have a better understanding of background DNA levels unrelated to the crime to facilitate accurate data interpretation. Duct tape is used in crimes, e.g. to bind victims and seal drug packaging, and may be tested for DNA. To determine DNA background levels, twelve volunteers were recruited to donate a used roll of duct tape from their home. The duct tape was divided into three areas: inside, outside, and sides of the roll, and swabbed for DNA. The average concentration of DNA was determined for the inside (0.0723 ng/µL …

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.

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 …

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 …

Dna Extraction And Species Determination Of Historic Museum Pelt Samples, Selin Ates

Student Theses

The identity of the fur covering the sculpture named Object in the Museum of Modern Art has remained a mystery since its creation in 1936 by Meret Oppenheim. DNA testing can possibly provide an answer, but to preserve the integrity of the sculpture, only a very small piece of the fur can be sampled. Prior to testing Object, testing using museum samples was performed to determine whether DNA of a sufficient quantity and quality can be extracted and sequenced. Several DNA extraction and sample washing methods were tested to examine the effects on the DNA of museum pelts aged …

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 …

Investigation Into The Microbiome Of Blow Fly Eggs Using Microseqtm Id, Samantha S. Davis, Drusilla Sheridan, Jennifer Rosati

Undergraduate Research

There is little published research characterizing the microbiome associated with blow fly eggs and how they may affect the colonization behaviors of certain blow fly species. Once deposited, blow fly eggs are rapidly introduced to a diverse range of microorganisms, which can vary depending on the species of blow fly, the environment, and the decomposition stage of the substrate (Junqueira et al., 2017). Since blow flies are among the first insects to colonize decomposing remains, the microbial communities present on their eggs could serve as key indicators of the decomposition stage at the time of egg-laying, thus providing a potential …

Passive Dna Transfer To Fidget Blasters Stored In Cars, Rachel Chan

Student Theses

This study evaluated the amount of detectable DNA accumulated on clean plastic fidget blasters, used to simulate firearms, over a seven-day storage period inside a vehicle. Twelve volunteers were asked to place one fidget blaster each in the glove box and underneath the driver’s seat from behind. After the seven-day period, the volunteers returned the fidget blasters, donated a reference sample, and filled out a questionnaire. The grip, slide, and trigger were swabbed for DNA and extracted. The extracts were quantified to determine the concentration of human DNA, and if the samples met the PCR threshold to be genotyped. The …

A Qualitative Nmr And Histological Analysis Of Adipocere Formation In Different Aqueous Environments Using Sus Scrofa Models, Mia M. Sorrentino

Student Theses

Adipocere is a wax-like crust that has the potential to form over corpses in moist, humid, and anaerobic environments, preserving them in a process similar to that of mummification. The substance can be identified within 3-6 months postmortem and is characterized by the ratio of saturated fatty acids to unsaturated fatty acids. Palmitic acid and stearic acid are the most abundant in comparison to myristic and oleic acids. The goal of this study was to investigate factors affecting adipocere formation in different aqueous environments. Pork belly samples were submerged in water samples collected from different places around New York City …

The Chemistry Of Decomposition: The Mechanisms To Decay The Human Body, Lydia J. Buxa

Senior Honors Theses

Taphonomic analysis separates decomposition into four major stages: fresh, early decomposition, advanced decomposition, and skeletonization. It is easy to demarcate the observable changes to the body, but it is far more difficult to know what underlying biochemical processes are occurring. Fresh decomposition begins with algor mortis, livor mortis, and rigor mortis, which sets the stage for the major workforces of decomposition: autolysis and putrefaction. The external signs of decomposition appear in early decomposition, which can be attributed to the breakdown of proteins, lipids, carbohydrates, and nucleic acids. This also leads to major changes in the moisture levels during advanced decomposition, …

Identification Of Areas Of Weakness In Forensic Footwear Research, Kathryn Roy

Honors Projects

Forensic footwear examinations have been carried out for almost a century, but the foundational validity of identifying a questioned impression to a particular shoe has been questioned by the National Research Council and the President’s Council of Advisors on Science and Technology. The focus of this paper was to identify the current weaknesses present in forensic footwear impression research. Additionally, a future experiment was proposed to address these concerns and improve the foundational validity of footwear impression comparisons. A total of 15 footwear research studies varying in methodology and content were analyzed and contrasted. From this, a lack of studies …

Are Blow Flies (Diptera: Calliphoridae) Active Nocturnally In South Georgia?, Breana R. Manning

Honors College Theses

Medicolegal forensic entomology uses insect colonization of remains to estimate minimum post-mortem intervals (mPMI). Blow flies (Diptera: Calliphoridae) are among the earliest colonizers, yet their nocturnal activity remains poorly understood. This study aimed to determine whether blow flies are active at night and whether artificial light influences their behavior. Using baited bottle traps in both artificially lit and unlit environments near Georgia Southern University, flies were collected over two trials in fall 2024. Of the 1,843 blow flies collected, only six were captured at night (0.003%), suggesting minimal nocturnal activity. Lucilia coeruleiviridis preferred unlit environments. In contrast, Cochliomyia macellaria was …

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

College of Graduate Studies: Theses & 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 …

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 …

Hemolytic And Non-Hemolytic Group B Streptococcus Strains’ Impact On Infection And Inflammation In Human Placental And Immune Cells, Olivia S. Harlow, Natalie Anumolu, Shannon Manning, Erica Boldenow

Summer Research

• Group B Streptococcus (GBS) colonizes 10-30% of women.
• GBS remains the leading cause of infectious neonatal morbidity and mortality1
• GBS is defined as being β-hemolytic, but about 3% of strains are non-hemolytic.
• Recent data suggest that non-hemolytic strains also pose health risks to infants2.
• Previous data from our lab demonstrated that GB37 is non-hemolytic when grown on blood agar, but is hemolytic when grown in suspension with red blood cells.

Genotype And Allele Frequencies Of Nine Str Loci In Sikhs From Malaysia., Tan Chin Teck

Student Works (2010-2019)

Allele frequencies for nine short tandem repeats (STRs) gene loci (CSF1PO, TPOX,TH01, F13A01, FESFPS, vWA, D16S539, D7S820, D13S317) were obtained from analyses of saliva DNA from 109 unrelated healthy Sikh individuals residing in Malaysia. DNA was extracted using phenol/chloroform/isoamly alcohol method. 2ng of DNA for each sample was amplified following the instruction in GenePrint® STR Systems (Promega Corporation) CTT, FFv and SilverSTR III Multiplex kits. PCR products were separated in denaturing polyacrylamide gel electrophoresis and silver stained using Promega DNA Silver Staining System. The results were then calculated and processed to establish a statistical database for Sikh community. Chi-square test …