Digital Commons Network^™

Estimating The Age Of A Bloodstain Using Droplet Digital Pcr, Kalee Rae Crampton

Graduate Theses, Dissertations, and Problem Reports

Biological evidence is extremely valuable in the investigation of a crime due to the presence of DNA. DNA evidence is considered the gold standard in court cases due to its ability to link a suspect to a piece of evidence. In addition to DNA evidence, biological stains have the potential to provide a temporal link between an individual and a crime scene. Previous studies have shown that relative rates of RNA degradation can be used in order to estimate the age of bloodstains. Here, we examined the ability of droplet digital PCR to be used in place of quantitative PCR …

Compound-Specific Isotope Analysis Of Amino Acids In Biological Tissues: Applications In Forensic Entomology, Food Authentication And Soft-Biometrics In Humans, Mayara Patricia Viana De Matos

Graduate Theses, Dissertations, and Problem Reports

In this work we demonstrate the power of compound-specific isotope analysis (CSIA) to analyze proteinaceous biological materials in three distinct forensic applications, including: 1) linking necrophagous blow flies in different life stages to their primary carrion diet; 2) identifying the harvesting area of oysters for food authentication purposes; and 3) the ability to predict biometric traits about humans from their hair.

In the first application, we measured the amino-acid-level fractionation that occurs at each major life stage of Calliphora vicina (Robineau-Desvoidy) (Diptera: Calliphoridae) blow flies. Adult blow flies oviposited on raw pork muscle, beef muscle, or chicken liver. Larvae, pupae …

Chemical Analysis Of Firearm Discharge Residues Using Laser Induced Breakdown Spectroscopy, Courtney Helen Vander Pyl

Graduate Theses, Dissertations, and Problem Reports

According to the Gun Violence Archive, in 2017, firearms were involved in 57,134 criminal incidents in the United States. The detection of firearm discharge residues (FDR), including inorganic and organic gunshot residues, can provide essential information in such investigations. For instance, when the question of suicide or murder arises, estimating the barrel to victim distance plays a critical role in the outcome of the case. In addition, clothing, wounds and other target materials are often inspected to determine if a bullet has produced an entry or exit orifice. Currently, the most common method for distance determination and identification of bullet …