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Full-Text Articles in Forensic Science and Technology

Evaluating A Test For Shedding Propensity Using Tape Lifts From Different Skin Locations, Xiao M. Chen Dec 2021

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 …


Reproducibility Of Individual Dna Deposits Detected Through Cellular Fluorescence, Natalee Small-Davidson Dec 2021

Reproducibility Of Individual Dna Deposits Detected Through Cellular Fluorescence, Natalee Small-Davidson

Student Theses

Contact traces are an important part of DNA casework, but the probative value of any identified associations depends on the possibility of passive transfer. There is known individual variation in DNA left behind during contact, this DNA shedding propensity has an effect on whose DNA is detected. This study evaluated this variability using a cell staining approach. Volunteers were asked to deposit a fingerprint on a clean glass slide, then wash their hands and deposit a second fingerprint after a 30-minute wait without touching anything. Three sets of samples were collected over three consecutive weeks. Fingerprints were stained with a …


Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba Dec 2021

Evaluation Of The Trunarc Handheld Narcotics Analyzer As A Pre-Analysis Screening Device For The Orange County Crime Lab, Sarah Yang, D. Bauer, C. Woltz, S. Soto, Michael Ibba

Student Scholar Symposium Abstracts and Posters

Forensic analysis of suspected narcotics is often dangerous as the substances’ composition is unknown. Many techniques for drug identification require handling of the substance outside of its packaging, which can expose the analyst to potentially harmful chemicals. The TruNarc Handheld Narcotics Analyzer is a portable Raman spectroscopy device that is non-destructive of evidence and can be used to screen drugs through simple packaging to minimize the risk of exposure. The Orange County Crime Lab (OCCL) is testing the limits of this device to determine if it can be used to screen new evidence within the Seized Drugs Lab. The OCCL …


Cocaine, Cocaethylene And Ethanol In Postmortem Blood Submitted To The New York City Office Of Chief Medical Examiner, Jada T. Alexis Aug 2021

Cocaine, Cocaethylene And Ethanol In Postmortem Blood Submitted To The New York City Office Of Chief Medical Examiner, Jada T. Alexis

Student Theses

Cocaine overdose deaths are on the rise in the United States. This increase may be due to the co-consumption of cocaine with other drugs. When cocaine is ingested in conjunction with alcohol, a specific metabolite called cocaethylene forms. Information regarding cocaethylene, specifically its interpretive value in post-mortem cases, has not been widely studied. Data from the Office of the Chief Medical Examiner in New York City revealed that there were 195 cases in 2017 positive for cocaethylene. These cases were most likely to involve black (42.1%) males (79.5%) in Manhattan (28.2%) aged 50 - 59 (34.4%). Most of the cases …


Evaluation Of The Effect Of The Humic Acid Inhibitor On Forensic Genetic Investigations Of Human Skeletal Remains, Madeline King May 2021

Evaluation Of The Effect Of The Humic Acid Inhibitor On Forensic Genetic Investigations Of Human Skeletal Remains, Madeline King

Honors Theses

Postmortem survival of DNA in human skeletal remains occurs due to the compact microstructure of the skeleton and its ability to provide a strong, protective physical barrier to environmental insults. On a molecular level, DNA preservation in bones/teeth involves electrostatic interactions between the negatively-charged DNA backbone and positively charged calcium residues in hydroxyapatite, the latter of which is one of the main components of bone microstructure. Despite these protections, over time endogenous DNA becomes damaged, limiting our ability to detect it and affecting its utility in making a positive identification. Hence, forensic genetic investigations of unidentified human remains (UHRs) are …


Extraction Of Human Dna From Soil In A Simulated Clandestine Grave, Arely Joaly Parra Lopez May 2021

Extraction Of Human Dna From Soil In A Simulated Clandestine Grave, Arely Joaly Parra Lopez

Honors Theses

Locard’s Exchange Principle states that “every contact leaves a trace.” The same principle applies when a perpetrator of a homicide decides to bury a victim in a clandestine grave. If a perpetrator originally buried a murder victim in haste to prevent discovery and then decided to later move the victim’s body to a remote location for disposal, decomposition fluids from the victim’s body (which contain cellular material and therefore DNA) would remain in the surrounding grave soil at the original burial site. It is possible that investigators could: 1) prove that a human body had once laid in that location …


Determination Of Human Shedding Propensity Based On Str Results, Genevieve Trapani May 2021

Determination Of Human Shedding Propensity Based On Str Results, Genevieve Trapani

Student Theses

Trace DNA evidence may be discovered at a crime scene after having been deposited by a person of interest via active or passive transfer. Based on previous studies, passive transfer of one’s DNA is influenced by their shedding propensity, or probability of depositing a detectable amount of DNA through touch. Determining the shedding propensity of a person of interest can aid in trace DNA interpretation in forensic casework. This study explored STR profile quality and the presence of a DNA mixture for different skin surface locations, including fingertips before and after handwashing. As expected, unwashed fingers showed a higher prevalence …


How To Get Away With Murder: The Effectiveness Of Blood Detectors On Surfaces Cleaned Of Blood, Grace Cavanaugh Apr 2021

How To Get Away With Murder: The Effectiveness Of Blood Detectors On Surfaces Cleaned Of Blood, Grace Cavanaugh

Undergraduate Theses and Capstone Projects

The purpose of this experiment was to test blood detectors against household cleaners. Similar experiments have been run before, but not on the selected surfaces. It is important to understand what one is looking for at a crime scene, and what a cleaned surface may look like. Four surfaces were chosen for this experiment: ceramic tile as a control, concrete, laminated wood flooring, and drywall. For each surface, 0.5mL of pig’s blood was allowed to dry before being cleaned off with either Clorox bleach, Dawn soap and hot water, a Mr. Clean Magic Eraser, or Mrs. Meyer’s Multi-Purpose Concentrate. Bluestar …


Pornography: Social, Emotional And Mental Implications Among Adolescents, William Kelly Canady Mar 2021

Pornography: Social, Emotional And Mental Implications Among Adolescents, William Kelly Canady

National Youth Advocacy and Resilience Conference

This presentation will explain the historical development of pornography. It will highlight four segments: 1- Porn’s impact on brain development of reward pathways, ultimately increasing the appetite for more porn. 2- Porn can be a false substitute for real intimacy, resulting in decreased sexual satisfaction with a real person and increased verbal and physical aggression. 3- Porn promotes sex trafficking, promotes multiple sex partners and reduced STD prevention. 4- A review of interventions available to assist clients in navigating a lifestyle away from pornography.


Forensic Entomology: Insect Succession – Northern Colorado, Thomas Nissen Jan 2021

Forensic Entomology: Insect Succession – Northern Colorado, Thomas Nissen

Department of Entomology: Distance Master of Science Projects

Forensic entomology is considered a relatively new field of entomology yet insects have been around for millions of years. Insects have been associated with dead animals and humans for centuries. The remains of insects have been recorded from Ancient Egypt to the present time. Recent advancements have been with data presented to the courts that show that there is a specific order to insects arriving on a corpse and that order helps to determine time of death. This study investigates the order of insect succession in the northern front range area of Colorado.