Forensic Science and Technology Commons^™

Performance Of A Dna And Protein Co-Extraction With Trypsin In Comparison To Two Proteinase K Based Dna Extraction Methods, Dinura A. Gunatilake

Student Theses

Effective DNA extraction methods are important for forensic applications. The main goal of this experiment was to determine if a newly developed trypsin based protein/DNA co-extraction method applied to contact traces would yield comparable results to a commercial Proteinase K method (QIAamp DNA Investigator Kit) and a Chelex extraction method with Tween 20 used in forensic laboratories. This was tested on 20 sets of sebaceous fingerprints on glass slides.

The results of this study demonstrate the trypsin co-extraction method yielded the highest amount of DNA. In the first comparison, the mean total DNA yields for the trypsin-co extraction method and …

The Law And Policy Of Client-Side Scanning (Originally Published By Lawfare), Paul Rosenzweig

Joint PIJIP/TLS Research Paper Series

No abstract provided.

The Relationship Between Impact Energy And Glass Fracture Via .177 Caliber Steel Bbs, Jocenel Beach

Student Theses

Fractured glass is often found at shooting scenes and can provide useful information for crime scene reconstruction. Mechanical glass fracture from a projectile impact can result in different types of fracture patterns. The degree of fracture depends on several factors including: type of glass, the thickness of the glass, curvature (if any), distance from the muzzle, contact angle, and type of projectile. Correlating impact energy to the degree of glass fracture can provide useful information regarding the muzzle-to-target distance for a particular firearm/ammunition combination. This research focuses on the projectile impact velocity of .177 steel BBs shot from a pneumatic …

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 …

Computed Tomography In Medicolegal Death Investigation: A Critical Review, Trenton Eames

University Honors Theses

The use of computed tomography (CT) scanning in medicolegal death investigations has increased in frequency in recent years. It can be used by investigators to help identify a victim, find a cause of death, or otherwise reveal legally relevant case details. This meta-analysis aimed to examine the research surrounding the use of CT scanning in medicolegal death investigation, focusing in particular on researchers’ scrutiny of the accuracy and precision of this technique within forensic contexts. Thirty-nine research papers were reviewed, with specific attributes and findings examined together in an effort to contextualize CT scanning in medicolegal death investigations. CT scanning …

Developing A Maceration Method For Isolation Of Dna From Cancellous Bones, Bryan Bernal

Student Theses

Prior to isolating DNA, it is necessary to remove any biological materials that may be present on commingled remains. Manual maceration of the outer surface is time-consuming. This study will address this issue by developing a simple method for processing bone samples prior to DNA isolation. A liquid-based technique was applied to macerate bone fragments by incubating bone fragments in an enzyme solution, removing potential contaminants, followed by a bone tissue disruption. Swine (Sus scrofa) bones were used to simulate human bones. Microscopic analysis suggested this method was effective for surface material removal. The methods effect on the …

The 23: Racial And Other Demographic Differences In The Assignment Of Risk Factors For Individuals Found Not Guilty By Reason Of Insanity In Virginia, Dominique Raquel Blanchette

Psychology Theses & Dissertations

Not Guilty by Reason of Insanity (NGRI) acquittees uniquely walk the line of involvement in both the criminal justice and mental health systems, both of which have literature indicating the presence of underlying racial biases related to practices and outcomes. The current study examined 366 forensic charts from an inpatient psychiatric hospital in Virginia to examine potential differences in the number of risk factors assigned for NGRI acquittees based on a variety of demographic variables. Information about demographic characteristics, psychiatric history, and criminal history was recorded and analyzed. It was hypothesized that younger age, male gender, a psychotic diagnosis, violent …

The Application Of A Simple Tissue-Disruption Method To Dna Extraction For Species Identification, Jordana R. Fox

Student Theses

The TissueLyser II was used to disrupt animal bones and plant tissue without dry ice or liquid nitrogen for species identification. Bone fragments of fresh swine (Sus scrofa) ribs were used. A 521bp fragment of the cyt b locus was analyzed, and the BLASTn results confirmed that the origin of all the samples was swine (E-value = 0.0). Bone fragments of bovine, chicken, duck, fish, sheep, and swine were also used to test the procedure. An approximately 600bp fragment of the COI locus was analyzed, and the BLASTn results confirmed the origin of all the samples (E-value = …

Archaeology Or Crime Scene? Teeth Micro And Macro Structure Analysis As Dating Variable, Jessica A. Vincenty

Student Theses

Simple methods to aid in the determination of forensic or archaeologic relevancy of skeletonized remains have been researched since the 1950s. With advances in microscopic imaging techniques and machine learning computer data analysis methods the relevancy of decontextualized, comingled remains has room for improvement. This thesis is a study done to pioneer a new approach to analyzing dental skeletal remains to determine forensic relevancy.

Archaeological dental samples collected from the ancient city of Ur in modern day southern Iraq in addition to modern dental extractions were processed for scanning electron microscopy imaging. Archaeological and modern samples displayed different surface and …

Semi-Quantitative Detection Of Signature Peptides In Body Fluids By Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Tebah N. Browne

Student Theses

This study covers a modified semi-quantitative approach for liquid chromatography mass spectrometry (LC-MS/MS) signature peptide detection for body fluid identification. Peptide concentrations were measured based on synthetic peptide standards. Samples were processed with varying trypsin digestion and purification protocols, including a three-hour trypsin digestion and Microcon membrane filtration. The Microcon filtration method generates polymerase chain reaction (PCR) compatible DNA and peptide fractions that can be analyzed without any further purification. Preliminary validation tests covered stains on different substrates, semen/ saliva mixtures, minimum sample volume, and repeatability. All signature peptides in the multiplex were present at different concentrations and varied amongst …

Comparing And Implementing Digital Evidence Applications To Reduce Cyber Crime Losses, Colleen Lim

Electronic Theses, Projects, and Dissertations

A massive problem within the United States is the financial loss that occurs through cybercrime. Before a cybercrime investigation can be solved, there needs to be enough gathered evidence. One way to obtain evidence is through processing the individual’s digital files from any electronic device or source, this is called digital evidence. Digital evidence can be obtained through the use of multiple software such as Forensic Toolkit (FTK), Magnet, or Autopsy. Although each software is used for the same goal, to obtain valuable information that can be used as evidence to support an existing case, there are unique features that …

Differences In Characteristics Of Criminal Behavior Between Solo And Team Serial Killers, Matthew Woster

Dissertations

Criminal Profiling and classification of serial killers has been an expanding area of research for decades. Recent research has called into question the accuracy and utility of these systems, and calls for further research and development. This study aims to use the Serial Killer Database (SKDB) to examine and classify differences in criminal behavior between serial killers who act alone versus those who act in pairs, groups, or teams. The specific aim of this study is to examine whether there are significant differences between Solo Serial Killers and Team Serial Killers in the Number of Victims, Length of Career, Method …

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 …

Photofading Of Black Dyes In Cotton And Polyester Fibers Resulting From Environmental Exposure To Sunlight, Maggie E. Mahaney

Honors Theses

Color is one of the most important properties analyzed during forensic fiber examinations due to its discriminatory power. Differing colors in fibers are usually sufficient grounds for exclusion, but in cases where a lengthy period has passed between crime commission and evidence recovery, the high probability of environmental degradation having altered the questioned fibers’ properties could lead to false exclusions. Photofading, the loss of color resulting from exposure to light, is a common form of degradation observed in fibers. Although well-known in the dyeing industry, it is not typically factored into forensic fiber examinations. Published photofading research has been limited …

Investigation Of The History Of Fingerprinting, Advancements In The Field, And Development Of Potential Methods That Could Improve The Detection Of Endogenous And Exogenous Drugs In Latent Prints, Kristen Malloy

Honors Theses

When someone thinks of fingerprinting, they are most likely going to picture how a latent print is matched to the fingerprint of a suspect based on ridge pattern analysis. However, there is much more information that can be obtained from a latent print. The work performed in this thesis focuses the detection of exogenous and endogenous drugs in latent prints. The experiments performed analyzed fingerprints from volunteers that were contaminated with one of three common painkillers: acetaminophen, acetylsalicylic acid (ASA), and ibuprofen. Three different instruments were tested for this purpose: MALDI-MS, ATR-FTIR, and LC-MS. Based on the results gathered, it …

Small Island Taphonomy In Western Australia, Courtney J. Newberry

Honors Theses

Forensic death investigations rely on postmortem interval estimations to establish a timeline surrounding a decedent’s death. Several methods are used, often together, to make such estimations. One of the main methods is the evaluation of the stage of decomposition; although decomposition follows the same general steps, the length of the process can vary by location and environmental factors. Animal scavenging can also impact decomposition by consuming flesh and impacting insect activity on the remains.

This study investigates the scavenging guilds and rate of decomposition of pig (Sus scrofa) legs on Rottnest Island, Australia. Three sites with unique environments were selected …

Frequency Of Lip Print Patterns Among Females And Males At San Jose State University, Daniela Zopiyactle

Themis: Research Journal of Justice Studies and Forensic Science

Lip prints have distinct forms of wrinkles and grooves unique to an individual much like fingerprints, footprints, and palm prints. Cheiloscopy, or the study of the grooves and wrinkles on the labial mucosa, helps classify, document, and evaluate lip print patterns. This article utilizes cheiloscopy to analyze students from the San Jose State University population; including 25 participants: 15 females and 10 males of ages between 18-45 years. Print collection utilized a matte lipstick, evenly applied on the lip, to create an impression using tape and white bond paper. Then, using the Suzui and Tsuchihashi method, researchers classified the lip …

Current Applications And Limitations Of Forensic Entomology, Helena Volckaert

Themis: Research Journal of Justice Studies and Forensic Science

Forensic entomology is the study of arthropods concerning their application in crime scene investigation as a method of predicting postmortem interval (PMI) in deceased or missing individuals. PMI is determined by the life stage of insects present on-scene. Insects used in criminal investigations are primarily beetles, flies, or moths; this may also include various scavenging insects and hitchhiking mites. These creatures help colonize decayed tissue, providing crime scene personnel with live specimens collected and examined for biological evidence. Forensic entomology is currently a niche application in most investigations—as qualified entomologists are often needed—and proper analysis of collected evidence can be …

Qualitative Analysis Of Luminol Efficacy On Bleach-Cleaned And Paint-Concealed Blood, Adam Wykoff

Themis: Research Journal of Justice Studies and Forensic Science

The presence of blood at a crime scene can provide investigators with a treasure trove of information regarding the nature and circumstances of a particular crime and aid in crime scene reconstruction; however, attempts at concealing blood are common scenarios. The development of chemiluminescent and fluorescent-based presumptive tests, such as the luminol and fluorescein tests, have made it more challenging to definitively remove or mask blood on a surface. The purpose of this experiment was to qualitatively measure the overall efficacy of luminol, concerning its ability to positively detect small bloodstains found on common household floor surfaces (wood, carpet, and …

The Ability Of Vitreous Metabolite Concentration To Determine Time Of Death, Victoria Wiggins

Themis: Research Journal of Justice Studies and Forensic Science

This paper analyzes the ability of vitreous fluid to determine time of death. The high variability in current methods used to establish post-mortem interval (PMI), or the amount of time between death and post-mortem examination make it difficult to obtain an accurate estimation. The concentration of metabolites found within vitreous fluid, such as potassium (K+), hypoxanthine (Hx), and magnesium (Mg), are the most researched alternatives to traditional methods in PMI determination because of the relative isolation of vitreous within the body and its ability to withstand degradation. There is no clear consensus on which metabolite provides the most accurate data …