Date of Degree

6-2017

Document Type

Dissertation

Degree Name

Ph.D.

Program

Criminal Justice

Advisor(s)

Thomas A. Kubic

Committee Members

John R. Lombardi

Nicholas D. K. Petraco

Subject Categories

Criminology and Criminal Justice | Forensic Science and Technology | Other Chemistry

Keywords

Raman spectroscopy, SERS, Forensic science, organic gunshot residue, explosives, surface enhanced Raman spectroscopy

Abstract

With the prevalence of shooting cases and terrorist attacks/or threats that plague the current state of the criminal justice system, it is of paramount importance to be able to detect, identify and interpret the presence of gunshot residue or explosives material. This concern is seen in law enforcement agencies and the media throughout the United States and abroad.

Currently, the typical method of analyzing gunshot residue in most crime laboratories serves to identify the inorganic constituents of the primer residue, namely lead, barium and antimony. However, it is possible that the organic matter from the propellant could provide different information to help detect the presence of gunshot residue or maybe even classify which kind of ammunition was used. There have been a few studies that have attempted to use vibrational spectroscopy to do so, however, the majority of these studies focused on a limited number of components or lack real-life samples. The additional benefits of the surface enhanced Raman technique explored in this study could offer a more successful method for analysis. In addition, the methods developed herein for organic gunshot residue are also applied to the analysis and identification of explosive compounds.

This research focused upon the use of Raman spectroscopy and surface enhanced Raman spectroscopy to analyze the chemical makeup of organic gunshot residue. In addition, this analysis scheme was expanded to include the analysis of some common explosive materials and was considered successful for a large number of standard chemicals and “real-world” samples. Different substrates and methods for analysis (such as agar gels, agar gels made with silver colloids, TLC-SERS, etc.) are also presented herein. Several suggestions for implementation and improvement on these findings are also reported.

There is a substantial need in the criminal justice system for a systematic approach to the analysis of organic gunshot residue and explosives. There is an obvious benefit to this rapid and non-destructive method that can detect both oGSR and explosives in a variety of circumstances. This project will have an impact on the criminal justice system and state of forensic science as it offers novel and straightforward means of analyzing gunshot residue and explosives.

 
 

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