Defense Date
2024
Document Type
Directed Research Project
First Advisor
Sarah Williams
Second Advisor
Eve Tokumaru
Third Advisor
Laura Gaydosh-Combs
Abstract
Forensic laboratories struggle with a backlog of sexual assault cases, prompting the need for effective techniques to develop consistent protocols and address scientific gaps. Challenges in recovering optimal DNA from assault evidence stem from factors like collection timing and sampling variables. Variations in lab protocols can lead to differences in DNA yields and profile success. This was observed in a state lab when protocols were developed allowing the use of acetone to swab sexual assault evidence. The use of acetone originated due to their case-routing protocols in multi-section cases involving latent fingerprints. While not necessary for sexual assault and porous surfaces, the laboratory included swabbing with acetone as an option and thus it is routinely used in sexual assault casework. This study compared various wetting agents, including acetone, for swabbing sexual assault evidence. Each treatment was evaluated by comparing the average spermatozoa observed, total DNA yields, and the success in STR profile development. Direct cuttings yielded the highest sperm count, DNA yields, and STR profile success. While acetone didn't affect sperm integrity, it resulted in lower DNA yields compared to other methods. Depending on the size of the stained area, analysts should prioritize direct cuttings, noting acetone's impact on DNA recovery.
Rights
© The Author(s)
Is Part Of
VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
4-29-2024