Forensic Science and Technology Commons^™

The Development And Evaluation Of A Method For Complete Collagenase I Digestion Of Bos Taurus Bone Samples, Reilly Price

Master of Science in Forensic Science Directed Research Projects

Current methods for processing aged forensic bone samples for DNA analysis involve pulverization and organic extraction, which further destroys already degraded DNA and uses large amounts of limited samples. Additionally, the success rates for this type of analysis vary widely as homogenization incorporates PCR inhibitors into the sample. Little research has explored how pulverization results in DNA damage in profiles obtained from skeletal remains. This study proposes an enzymatic digestion method to separate osteocytes from PCR inhibitors in the extracellular bone matrix to improve the quality and quantity of DNA isolated from aged bone samples. The technique described here used …

Dna Analysis: The Answer For Unsolved Cases?, Sarah Hetchler

Master of Arts in Criminal Justice Leadership

DNA analysis has become a crucial part of solving cases. It has developed significantly since its creation in the mid-1980s. The longing for answers within unsolved cases is historically lengthy, leaving traces of distrust and injustice. Criminologists offer a potential solution to the mess created by connecting DNA analysis to protect victims and communities. DNA evidence and analysis can assist in solving cases and provide answers for exonerees. Like public genealogy websites, law enforcement agencies must acknowledge new methods to solve issues. Not only could law enforcement agencies solve and arrest suspects through DNA analysis, but DNA could also provide …

Dna Transfer And Persistence On Non-Porous Surfaces Submerged In Spring Water [Preliminary Study], Morgan L.. Korzik, Josep De Alcaraz-Fossoul, Michael S. Adamowicz, David San Pietro

Forensic Science: Faculty Publications

Submerged items are often thought to lack evidentiary value. However, previous studies have shown the ability to recover DNA from submerged porous items for upwards of six weeks. The crevices or interweaving fibers in porous items are thought to protect DNA from being washed away. It is hypothesized that, because non-porous surfaces do not have the same traits that might aid in DNA retention, then DNA quantities and the number of donor alleles recovered would decrease over longer submersion periods. Additionally, it is hypothesized that DNA quantity and the number of alleles would be negatively affected by flow conditions. Neat …

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 …

Unraveling The Mummy: The Effects Of Natural Mummification On The Recovery And Degradation Of Dna, Marissa Gandolfo-Muller

Honors Theses

As demonstrated through casework and research studies (Hawass et al., 2010; Gielda & Rigg, 2017), anthropogenic mummification and modern-day embalming can expedite degradation of DNA. Current research in the field of forensic mummification is sparse and little research has been done on quantifying naturally mummified DNA (Leccia et al., 2018; Shved et al., 2014). This research focuses on observing and quantifying the differences in the recovery and degradation of DNA from specimens that have been naturally mummified. This research on natural, forensic mummies is a blend of experimental archeology and postmortem DNA analysis.

In this study, two control specimens and …

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, …

Ethical Implications Of Codis, Lucy Grogan

Masters Theses

CODIS stores and maintains numerous DNA profiles, and is used as a tool by the criminal justice system in order to help solve crime. Deoxyribonucleic Acid, or DNA for short, is the genetic material that an individual inherits from one’s parents (NIH, 2019). Certain portions of this genetic material are selected for use within the CODIS database due to their lack of medically relevant information. There is an immense amount of power associated with DNA and the CODIS database that it is held within, which allows for many ethical issues to arise. In order to create a usable and safe …

Optical Tweezers As An Effective Tool For Spermatozoa Isolation From Mixed Forensic Samples, Nicole Auka, Michael Valle, Bobby D. Cox, Peter D. Wilkerson, Tracey Dawson Cruz, Joseph E. Reiner, Sarah J. Seashols-Williams

Forensic Science Publications

A single focus optical tweezer is formed when a laser beam is launched through a high numerical aperture immersion objective. This objective focuses the beam down to a diffraction-limited spot, which creates an optical trap where cells suspended in aqueous solutions can be held fixed. Spermatozoa, an often probative cell type in forensic investigations, can be captured inside this optical trap and dragged one by one across millimeter-length distances in order to create a cluster of cells which can be subsequently drawn up into a capillary for collection. Sperm cells are then ejected onto a sterile cover slip, counted, and …

Lacking Regulated Policy For Dna Evidence, Maia Lister

Themis: Research Journal of Justice Studies and Forensic Science

Despite its strong presence in criminal justice, DNA analysis is still a minimally regulated area. This minimal regulation devalues DNA evidence through the inconsistencies in these areas. The analysis methods of low template DNA lack a uniform method resulting in varying levels of reliability. Utilizing familial searches to assist in criminal investigations can potentially violate citizen rights. Such violations can also be found in the collection of DNA samples before an arrestee is tried or convicted. There are, however, regulations that could be applied universally to combat the problems that were discussed.

Applications Of Forensic Evidence In Criminal Cases, Emily Wheeler

Themis: Research Journal of Justice Studies and Forensic Science

In 2003, Massachusetts governor Mitt Romney proposed a plan for an infallible death penalty that required irrefutable scientific evidence, effectively removing any doubt regarding potential innocence in death penalty cases. Forensic science encompasses many scientific disciplines including natural sciences and pattern analysis, but not all such areas experience equal amounts of general acceptance or influence in criminal cases. While DNA analysis and fingerprint identification using the Integrated Automated Fingerprint Identification System (IAFIS) are both widely accepted forensic applications, recent events expose concerns regarding the authenticity of other disciplines such as hair and bite mark comparison. Before policymakers address the issue …

After The Dna Wars: Skirmishing With Nrc Ii, Richard O. Lempert

Articles

This article traces some of the controversies surrounding DNA evidence and argues that although many have been laid to rest by scientific developments confirmed in the National Research Council's second DNA report, there remain several problems which are likely to lead to continued questioning of standard ways prosecutors present DNA evidence. Although much about the report is to be commended, it falls short in several ways, the most important of which is in its support for presenting random match probabilities independent of plausible error rates. The article argues that although one can sympathize with the NRC committee's decision as an …