Defense Date
2023
Document Type
Directed Research Project
First Advisor
Christopher Ehrhardt
Second Advisor
Eric Hazelrigg
Third Advisor
Joseph Turner
Abstract
Drywall is found in most homes built in the United States of America because it is cost effective, light weight, and easy to install. Its brittle nature makes it less resistant to impact which can cause dust to form if a force is exerted on it. Airborne dust can settle on anything or anyone around it and can be considered trace evidence for its ability to connect suspects, victims, and scenes; however, this type of dust is not emphasized as trace evidence and is not always collected due to a lack of understanding of their forensic signatures.The seven producers of gypsum wallboard in the United States include American Gypsum, CertainTeed Gypsum, Georgia-Pacific, Lafarge North America, National Gypsum/Gold Bond (GB), PABCO, and United States Gypsum (USG). Because gypsum can be sourced from mines across the US, it is possible that compositional differences may exist between these brands. Each of these brands also offer drywall consisting of the five types: regular board, moisture resistant, mold resistant, fire resistant, soundproof, or a combination. Additives, such as fiberglass or oils, are used to make the different types of boards. This study looked at the differences between the brands National Gypsum/Gold Bond and United States Gypsum and the types regular, moisture/ mold resistant, fire resistant, and moisture/ mold/ fire resistant. The purpose of this study is to compare the trace elemental composition of different drywall brands/types to determine if differentiation is possible. Inductively coupled plasma- optical emission spectroscopy (ICP-OES) and multivariate statistics were used to determine trace elemental composition and variability. Fourier- transform infrared spectroscopy (FT-IR) and TQ Analyst was used to determine if there are spectral differences that can distinguish samples. Results showed that the best differentiation was observed between the drywall types using the axial data from the ICP-OES, particularly in the concentration of nickel. FT-IR analysis resolved additives or impurities in some of the drywall samples and that they could be used to distinguish some types of drywall. Overall these results suggest that the types of drywall can be distinguished from one another whereas there is less ability to determine the brand.
Rights
© The Author(s)
Is Part Of
VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
7-28-2023