Forensic Science and Technology Commons^™

A Quantifiler Trio-Based Hrm Mixture Screening Assay For The Quantstudio 6 Flex Qpcr Platform, Dayanara A. Torres

Master of Science in Forensic Science Directed Research Projects

At present, the forensic DNA workflow is not capable of providing information about the contributor status (single source vs. mixtures) of evidentiary samples prior to end-point analysis. This shortcoming can exacerbate the challenges inherent to mixtures and low-template DNA samples. Provided additional sample information earlier in the workflow, protocols could be implemented to mitigate these challenges. High-resolution melt (HRM) curve analysis is a technique used to detect genetic variation in DNA fragments and in the last decade has been evaluated for use in differentiation of samples by genotype and/or contributor status. To this end, a proof-of-concept HRM assay using the …

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 …

The Understanding Of Digital And Multimedia Evidence (Dme) By Attorneys And Digital Forensic Examiners (Dfe) Within The United States Criminal Justice System, Joseph Levi White

Dissertations

One goal of this research was to determine potential themes that may influence the understanding of Digital and Multimedia Evidence (DME) by attorneys and Digital Forensic Examiners (DFE) within the United States Criminal Justice System. Qualitative semi-structured interviews were conducted to gather information from experienced criminal attorneys and DFEs regarding potential influences on their understanding of DME. The results of these interviews were transcribed, and the data coded to allow for qualitative analysis. Five themes were developed from this data and are thought to play a role in understanding of DME by attorneys and DFEs: motivation for involvement in the …

Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar

Dissertations, Theses, and Capstone Projects

Soil, that complex mixture of minerals, organic particles, chemicals, and anthropogenic materials, is ubiquitous and easily transferred, which gives it forensic relevance. Forensic soil analysis has traditionally included the identification and comparison of both organic and inorganic components, the inorganic portion being most commonly examined by light microscopy and other instrumental techniques. Predominantly, the inorganic materials in soil are naturally-occurring minerals, contributed as grains from the surrounding bedrock, which gives a soil its regional character. That parent material then undergoes physical, chemical, and anthropogenic changes producing wide geographic variation within a single region. This variation forms the basis for potential …

The Absence Or Misuse Of Statistics In Forensic Science As A Contributor To Wrongful Convictions: From Pattern Matching To Medical Opinions About Child Abuse, Keith A. Findley

Dickinson Law Review (2017-Present)

The new scrutiny that has been applied to the forensic sciences since the emergence of DNA profiling as the gold standard three decades ago has identified numerous concerns about the absence of a solid scientific footing for most disciplines. This article examines one of the lesser-considered problems that afflicts virtually all of the pattern-matching (or “individualization”) disciplines (largely apart from DNA), and even undermines the validity of other forensic disciplines like forensic pathology and medical determinations about child abuse, particularly Shaken Baby Syndrome/Abusive Head Trauma (SBS/AHT). That problem is the absence or misuse of statistics. This article begins by applying …

Creation And Optimization Of An Optical Trapping Microfluidic Device For The Separation Of Mock Forensic Sexual Assault Samples, Mackenzie Lally

Master of Science in Forensic Science Directed Research Projects

Cell mixtures are often seen in forensic samples and commonly involve sexual assault cases where mixtures of sperm cells and vaginal epithelial cells are frequently encountered. This produces challenges in downstream analysis in the form of STR mixture profiles. The only method currently in use in crime laboratories for front-end sperm and epithelial cell separation is differential extraction. This method often results in STR mixture profiles due to carryover into both the male and female fractions and suffers from a wide range of efficiency depending on the laboratory or individual processing the sample. Optical trapping offers an alternative method for …

Powerplex® Fusion 6c System Versus Powerplex® Fusion 5c: A Comparison Of Performance Metrics, Caitlin M. Mccaughan

Master of Science in Forensic Science Directed Research Projects

Following the FBI mandated expansion of the CODIS core loci from 13 to 20, several manufacturers developed short tandem repeat (STR) typing kits in response to the new criteria. One such manufacturer was the Promega Corporation, which released the PowerPlex® Fusion 5C megaplex STR typing kit (Fusion 5C) in 2012. Currently, the Virginia Department of Forensic Science (VDFS) utilizes this amplification kit for both casework and database applications. In 2015, Promega released the PowerPlex® Fusion 6C STR typing kit (Fusion 6C), which contains three additional loci beyond those included in PowerPlex® Fusion 5C, and a sixth color channel. The power …

Evaluation Of Dna Extraction Efficiencies Of Promega’S Dna Iq™ Methods And Casework Extraction Kit For Low Template Samples, Emily M. Anderson

Master of Science in Forensic Science Directed Research Projects

Biological evidence from crime scene samples frequently contain low levels of DNA, such as the most predominant form of evidence, which is DNA deposited by handling objects or “touch evidence”. To maximize the DNA yield recovered from theses challenging samples, forensic laboratories must optimize the extraction methods utilized to isolate and purify DNA for downstream short tandem repeat (STR) amplifications. Currently, the Virginia Department of Forensic Science (VADFS) uses a DNA IQ™ System (DNA IQ) extraction method for isolation of DNA from most forensic samples. This extraction procedure, which combines DNA IQ™ lysis buffer and Dithiothreitol (DTT), has been validated …

Evaluation Of Cell Lysis Techniques For Direct Amplification Of Sexual Assault Samples, Sarah Schellhammer

Master of Science in Forensic Science Directed Research Projects

Sexual assault is one of the most common crimes committed today with a delay in sample processing, resulting in the “rape kit backlog”. The traditional method to extract DNA from these samples containing both male and female DNA is a differential extraction; taking hours to process. This study examined a variety of different cell lysis techniques to develop a method which can consistently generate high-quality profiles at a fast rate and with low volumes when compared to the currently used method in our laboratory.

Six lysis methods, in addition to the currently used forensicGEM™ Sperm kit, were performed on …

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 …

Postmortem Interval Estimation Based On Eukaryotic Community Associated With Soil Under Decomposing Porcine Remains, Amanda M. Haase

Master of Science in Forensic Science Directed Research Projects

Recent studies have shown that bacteria associated with soils under a carcass change significantly both temporally and spatially. These studies were done in both laboratory and field conditions, but with limited replications. In addition, limited information exists on temporal and spatial changes in eukaryotic community structure associated with soil under decomposing remains. This study was designed to fill in these gaps and expand on previous studies to improve postmortem interval (PMI) estimation techniques as well as to identify cadaver decomposition islands (CDI) based on eukaryotic community structure associated with soil under vertebrate remains. To accomplish this goal, soil samples were …

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 …

Expanded Testing Of An Integrated Qpcr Mixture Screening Assay Using High Resolution Melt Curve Analysis And Support Vector Machine Modeling, Andrea L. Williams

Master of Science in Forensic Science Directed Research Projects

In the conventional forensic DNA workflow, the number of contributors in a sample is unknown until the final step of STR analysis. We propose a high-resolution melt curve (HRM) mixture screening assay, which uses support vector machine (SVM) modeling of melt morphologies of D5S818 and D18S51 amplicons integrated into a common qPCR-based human DNA quantification kit, to differentiate between single-source samples (and their genotypes) and mixtures at an earlier stage in the DNA workflow (quantification). Previously, using data generated from whole melt curves, 87.5% of single-source samples and 100% of 1:1 mixture samples (2 contributors) classified accurately.

In this study, …

Statistical Evaluation Of Randomly Acquired Characteristics On Outsoles With Implications Regarding Chance Co-Occurrence And Spatial Randomness, Nicole Richetelli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Footwear evidence holds tremendous forensic value, owing to its ability to formulate linkages between victims, suspects and scenes. Naturally, the strength of these linkages is a function of the perceived clarity, quality and rarity of class, subclass and randomly acquired characteristics (RACs), which are the fundamental outsole features used to formulate source associations. In order to reach a conclusion when performing a footwear comparison, forensic examiners must assign value to the observed similarities and differences that exist between questioned crime scene and test impressions. Embedded within this process is an evaluation of the random association between unrelated shoes as a …

Validation Of Fast Spectrochemical Screening Methods For The Identification Of Counterfeit Pharmaceutical Packaging, Emily Ann Haase

Graduate Theses, Dissertations, and Problem Reports (ETD)

Counterfeit pharmaceuticals are an actively developing health and economic threat worldwide. Particularly prevalent are counterfeit pharmaceuticals distributed in emerging nations and through internet pharmacies or e-pharmacies. Although technology has been developed that discourages anti-counterfeiting practices (such as optically variable devices, invisible ink, and track-and-trace technology), it remains somewhat novel and expensive to implement on a widespread scale.

In this study, Laser Induced Breakdown Spectroscopy (LIBS) and Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) were proposed as fast and non-invasive tools for the identification of counterfeit pharmaceutical packages. The main objective of this research was to develop and evaluate the capabilities …

The Forensic Analysis Of Adult Temporary Tattoos, Paige Cooper

Student Theses

Adult temporary tattoos have become more popular, yet there is very little research on them, especially regarding their use in forensics. This poses a problem because forensic investigators may not be able to distinguish a temporary tattoo from a real tattoo, possibly hindering their investigation. In this study, various types of adult temporary tattoos were examined and analyzed in attempts to identify and distinguish them, both from each other and from permanent tattoos. Infrared spectroscopy, specifically attenuated total reflection (ATR), proved to be more useful than ultra-violet visible light spectroscopy in terms of analyzing the samples. The natural adult temporary …

Novice Ideas: Handwriting Comparisons Conducted By An Untrained Individual, Maia Lister

Themis: Research Journal of Justice Studies and Forensic Science

Forensic analysis of questioned documents includes chemical analyses of paper and ink as well as handwriting comparisons. Several elements affect handwriting analyses, including the presence of discriminatory factors that can individualize a handwriting sample and whether the handwriting has been disguised. Five handwriting samples were gathered from six individuals comprising of one reference, three natural unknowns, and one disguised sample per person. A novice conducted analyses on every collected sample and conducted comparisons of the reference sample to the unknown and disguised samples in an attempt to correctly source the unknown and disguised samples. The novice showed a high level …

The Accumulation Of Wear On Footwear Pattern Analysis, Sarah Pawloski

Themis: Research Journal of Justice Studies and Forensic Science

Wear is defined as the erosion of a shoe’s outsole or the loss of tread pattern, and it happens gradually over time with use. After a shoeprint is collected from a crime scene, it is questioned whether an individualization can be made if an exemplar is created after additional use of the shoe. The shoes of ten volunteers at San Jose State University were analyzed over a period of 40-45 days. Wear and Randomly Acquired Characteristics (RACs) were analyzed over time to determine if there were any observable changes or additions to the already present wear. It was hypothesized that …

Analysis Of Error Within Forensic Measurements And Photogrammetry Programs, Amy Douglas

Honors Program: Senior Projects (Public)

Digital images and photography have been considered commonplace in forensic science since the late 1990’s. Photogrammetry is a tool used in forensic science to measure objects within photographs that contain a scale or programs that are able to measure items in 3D images. Items at crime scenes often need to be measured and forensic scientists may not know what the best option is for their situation. This research will be conducted to show which type of measurement technique is most accurate, calculated against NIST traceable measurements, at various sizes of objects. The measurement techniques that will be tested are standard, …

Determination Of Vehicle Speed From Recorded Video Using Reverse Projection Photogrammetry And File Metadata, Brandon Epstein, Bryce Westlake

Faculty Publications

The prevalence of security and in‐car video has increased the number of motor vehicle accidents captured on digital video. However, inconsistencies in how to accurately determine time and distance for vehicle speed has led to examinations with varying results. A potential solution for calculating time intervals is to use frame timing contained within many digital video file's metadata, recorded with 0.000001 sec precision. This paper examines a fatal motor vehicle accident where frame timing information was used with distance measurements from reverse projection photogrammetry to calculate vehicle speed. A margin of error was then calculated based on the accuracy in …

The Potential Interference Of Body Products And Substrates To The Identification Of Ignitable Liquid Residues On Worn Clothing, Gina Guerrera, Erika Chen, Robert Powers, Brooke Weinger Kammrath

Forensic Science Publications

The question of whether deposits on clothing as well as their chemical composition are being mistaken for ignitable fluids is a concern for forensic analysts. Body products and oil secretions can have similar chemical profiles to ignitable liquid residues (ILRs) as a result of comparable chemical compounds that may be found in both sources. This study investigated whether substrates of unworn and worn clothing, with endogenous body secretions and body products could interfere with ILR analysis. Sample extraction was completed by passive headspace concentration with activated charcoal strips (ACS) and desorption with carbon disulfide followed by analysis with gas chromatography-mass …

Optimizing Methods For Separation Of Adhesive Tape From Fabrics And Obtaining Latent Prints From Adhesive And Non-Adhesive Sides, Elizabeth Vosburgh

Forensic Science Theses

Fingerprinting is a valued part of forensic science analysis. It has been around for decades, and has advanced with the passing of time. There have been numerous studies of the different ways analysts have encountered fingerprints in the field—but none on those deal with the removal of tape from fabric. To investigate this, eight fabric types (a cotton/polyester mix, spandex, denim, jeans, fleece, flannel, polyester, and vinyl), three commercially available tapes (duct tape, black electrical tape, and packaging tape), have been stuck together and separated with four different techniques (manual pulling apart, Un-Du commercial adhesive remover, liquid nitrogen, and a …

Assessing The Reliability Of Physical End Matching And Chemical Comparison Of Pressure Sensitive Tapes, Meghan Nicole Prusinowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pressure sensitive tapes are a common evidence type in a variety of forensic cases, including violent crimes, drug trafficking, and terrorism. Forensic laboratories are often requested to analyze tape samples for composition and potential source identification. Tape samples manufactured from different sources are often distinguishable when using a combination of sensitive analytical techniques. Nonetheless, the interpretation of the data remains challenging due to a lack of standard criteria and guidelines from which examiners can support their conclusions. As a result, there is a need to standardize the protocols of interpretation of physical and chemical comparisons of tape evidence.

The manufacture …

Open-Source Tools For Dense Facial Tissue Depth Mapping (Ftdm) Of Computed Tomography Models, Terrie Simmons-Ehrhardt, Catyana Falsetti, Anthony B. Falsetti, Christopher J. Ehrhardt

Human Biology Open Access Pre-Prints

Computed tomography (CT) scans provide anthropologists with a resource to generate three- dimensional (3D) digital skeletal material to expand quantification methods and build more standardized reference collections. The ability to visualize and manipulate the bone and skin of the face simultaneously in a 3D digital environment introduces a new way for forensic facial approximation practitioners to access and study the face. Craniofacial relationships can be quantified with landmarks or with surface processing software that can quantify the geometric properties of the entire 3D facial surface. This paper describes tools for the generation of dense facial tissue depth maps (FTDMs) using …

Is Forensic Science In Danger Of Extinction?, David San Pietro, Brooke Weinger Kammrath, Peter R. De Forest

Forensic Science Publications

Observations of modern day forensic science has prompted asking the question of whether this field is in danger of extinction. Although there have undoubtedly been meaningful advancements in analytical capabilities, we have overlooked several unintended practical and philosophical consequences. This article addresses three main areas of concern: the declining role of the generalist in an era of increased specialization, the role of education in preparing the next generation of forensic scientists, and the implementation of advanced instrumentation with a focus on statistical significance and field deployable instrumentation.

The Effect Of Fabric Type And Laundering Conditions On The Detection Of Semen Stains, Tyler G. Schlagetter, Claire L. Glynn

Forensic Science Publications

There has been little research into the effect of fabric type and different laundering conditions on the ability to detect semen stains on washed fabrics. This study aimed to investigate three potential factors affecting semen identification on laundered clothing: fabric type, water temperature during washing, and whether the stain was dry at the time of washing. Following laundering, semen stains on four fabric types (cotton, polyester, denim, and wool) were examined and tested with three common methods used to detect semen; screening with an alternate light source, acid phosphatase press test, and histological staining of spermatazoa. It was determined that …

The Advanced Spectroscopic Analysis Of Organic Gunshot Residue And Explosives, Jennifer M. Leonard

Dissertations, Theses, and Capstone Projects

With the prevalence of shooting cases and terrorist attacks/or threats that plague the current state of the criminal justice system, it is of paramount importance to be able to detect, identify and interpret the presence of gunshot residue or explosives material. This concern is seen in law enforcement agencies and the media throughout the United States and abroad.

Currently, the typical method of analyzing gunshot residue in most crime laboratories serves to identify the inorganic constituents of the primer residue, namely lead, barium and antimony. However, it is possible that the organic matter from the propellant could provide different information …

Forensics’ Fight: A Need For Aggressive Strategies Against Confirmation Bias, Madison Mcgowan

Themis: Research Journal of Justice Studies and Forensic Science

In 2009, the National Academy of Sciences produced a lengthy report illuminating significant weaknesses present within the forensic community. One complex fault found in forensics was conformation bias. Since it is within human nature to make decisions based on contextual information, assumptions, and pre-held opinions, confirmation bias is an issue that will continue to persist. Therefore, stronger efforts must be made to recognize and abate the problem of bias within the field of forensics in order to preserve the notion that forensic science exists to serve principles of both truth and justice. Accordingly, this paper argues for the fight against …

Quantitative Analysis Of Opioids And Cannabinoids In Wastewater Samples, Alethea Jacox, Jillian Wetzel, Shu-Yuan Cheng, Marta Concheiro-Guisan

Publications and Research

Wastewater-based epidemiology is an innovative approach that uses the analysis of human excretion products in wastewater to obtain information about exposure to drugs in defined population groups. We developed and validated an analytical method for the simultaneous determination of opioids (morphine, oxycodone, hydrocodone, oxymorphone and hydromorphone), and cannabinoids (Δ⁹-tetrahydrocannabinol, 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH) and THCCOOH-glucuronide) in raw-influent wastewater samples by ultra-high performance liquid chromatography-tandem mass spectrometry. Method validation included linearity (5–1 000 ng/L for opioids, 10–1 000 ng/L for cannabinoids), imprecision (<21.2%), accuracy (83%–131%), matrix effect (from –35.1% to –14.7%) and extraction efficiency (25%–84%), limit of detection (1–5 ng/L) and quantification (5–10 ng/L) and auto-sampler stability (no loss detected). River and wastewater samples were collected in triplicate from different locations in New York City and stored at −20 °C until analysis. Water from sewage overflow location tested positive for morphine (10.7 ng/L), oxycodone (4.2–23.5 ng/L), oxymorphone (4.8 ng/L) and hydromorphone (4.2 ng/L). Raw influent wastewater samples tested positive for morphine (133.0–258.3 ng/L), oxycodone (31.1–63.6 ng/L), oxymorphone (16.0–56.8 ng/L), hydromorphone (6.8–18.0 ng/L), hydrocodone (4.0–12.8 ng/L) and THCCOOH (168.2–772.0 ng/L). This method is sensitive and specific for opioids and marijuana determination in wastewater samples.

Testing A Novel 3d Printed Radiographic Imaging Device For Use In Forensic Odontology, Tara L. Newcomb, Ann M. Bruhn, Bridget Giles, Hector M. Garcia, M. Arch, Norou Diawara

Dental Hygiene Faculty Publications

There are specific challenges related to forensic dental radiology and difficulties in aligning X-ray equipment to teeth of interest. Researchers used 3D printing to create a new device, the combined holding and aiming device (CHAD), to address the positioning limitations of current dental X-ray devices. Participants (N = 24) used the CHAD, soft dental wax, and a modified external aiming device (MEAD) to determine device preference, radiographer's efficiency, and technique errors. Each participant exposed six X-rays per device for a total of 432 X-rays scored. A significant difference was found at the 0.05 level between the three devices ( …