Analysis of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, and Mass Spectrometry Tools

• NCJ Number: 306205
• Author(s): Colby Edward Ott
• Date Published: 2022
• Length: 226 pages
• Grant Number(s): 2018-DU-BX-0186
• Agencies: NIJ-Sponsored
• Publication Type: Thesis/Dissertation
• Award: Fast Screening of Firearm Discharge Residues by Laser-based Spectrochemical Methods, Electrochemical Sensors, and Chemometrics

Annotation

This dissertation uses electrochemistry, spectroscopy, and mass spectrometry to analyze forensically relevant evidence.

Abstract

This dissertation demonstrates the advantages of employing simple, fast, and portable technologies in the screening of common forensic evidence. Electrochemistry, spectroscopy, and spectroelectrochemistry are powerful techniques that can revolutionize analytical schemes used in forensic science, and this research provides the foundations and a path forward. The use of electrochemistry for the screening of gunshot residues from the hands of individuals provides a rapid, inexpensive, simple, and portable screening approach that can improve investigative leads, improve case triage, and lower backlogs and costs associated with gunshot residues. Additionally, the speed of analysis provides the opportunity for investigators to collect more samples and from other surfaces that may not have been done in the past due to the disadvantages of the current methodologies.  This dissertation aims to develop a novel analytical scheme that can provide a more efficient, rapid, and sensitive method that will facilitate adoption in the laboratory and onsite in the field. To this end, electrochemistry and Raman spectroscopy were assessed independently for their use in orthogonal testing scenarios, and in tandem via spectroelectrochemical methods to improve both the sensitivity and selectivity of seized drug screening. Additionally, differentiation of fentanyl analogs was demonstrated to be achievable. Various potentially interfering compounds were assessed including heroin, cocaine, methamphetamine, caffeine, quinine, and others. Quinine was the only compound observed to have significant interference with fentanyl detection. This dissertation also looked at the usefulness of electrochemistry to provide a simple, inexpensive, and portable screening method for the simultaneous analysis of inorganic and organic gunshot residues.