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Forensic Science and Technology Commons

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Full-Text Articles in Forensic Science and Technology

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 …


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 …