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About this book

This text provides training on the fundamental tools and methodologies used in active forensic laboratories for the complicated analysis of fire debris and explosives evidence. It is intended to serve as a gateway for students and transitioning forensic science or chemistry professionals. The book is divided between the two disciplines of fire debris and explosives, with a final pair of chapters devoted to the interplay between the two disciplines and with other disciplines, such as DNA and fingerprint analysis. It brings together a multi-national group of technical experts, ranging from academic researchers to active practitioners, including members of some of the premier forensic agencies of the world. Readers will gain knowledge of practical methods of analysis and will develop a strong foundation for laboratory work in forensic chemistry. End-of-chapter questions based on relevant topics and real-world data provide a realistic arena for learners to test newly-acquired techniques.

Table of Contents

Frontmatter

Chapter 1. An Introduction to Instrumentation Used in Fire Debris and Explosive Analysis

Abstract
Instrumentation is essential to forensic analysis of fire debris and explosives. Coupled gas chromatograph-mass spectrometer instruments are used extensively in the analysis of fire debris. The molecular compositions of explosives are analyzed with a variety of methods including gas and liquid chromatography, mass spectrometry, X-ray diffraction, and vibrational spectroscopy. The inorganic and elemental composition of explosives and related materials can be interrogated using techniques such as ion chromatography, vibrational spectroscopy, X-ray fluorescence, and scanning electron microscopy–energy-dispersive spectroscopy. Each instrumental technique has advantages and disadvantages for different types and forms of samples. A basic understanding of each method and the underlying theory will inform the development of effective analytical schemes for samples.
Kenyon Evans-Nguyen

Chapter 2. Introduction to Fire Debris Analysis

Abstract
This chapter serves as an introduction to the fire debris analysis discipline. It covers a wide range of topics including an introduction to fire investigation, analysis of fire debris evidence, classification of ignitable liquids, gas chromatography-mass spectrometry data interpretation, other fire debris examinations, and report writing. Though this chapter cannot cover every aspect of fire debris analysis in details, it should provide a great foundation and starting point for students and examiners working in this discipline.
Jamie Baerncopf, Sherrie Thomas

Chapter 3. Background Interference in Fire Debris Analysis

Abstract
In fire debris analysis, the presence of any volatile compounds in the sample that may interfere with the identification of an ignitable liquid is known as the background. These volatile and semi-volatile background compounds may originate from both burned and unburned materials (substrates) at the fire scene, from fire suppression activities, and even from materials brought to the scene by fire investigators. Background compounds that originate from burned and unburned materials typically arise via three different mechanisms: pyrolysis, combustion, and distillation. The interfering compounds generated from different burned materials, such as wood, plastics, and human remains, and unburned materials, such as building materials, clothing, and decomposing human remains, are discussed. An overview of the chemical reactions that give rise to some of the more commonly encountered substrates of wood and plastic is given. In addition, the background compounds that may be introduced to a fire scene as a result of fire suppression activities (i.e., foams), as well as materials used by investigators to collect samples at a fire scene (i.e., gloves and absorbents), are reviewed. Finally, the importance of generating pyrolysis data from a variety of burned and unburned substrates, and how this data assists in identifying which compounds extracted from a sample of fire debris originated from the substrate and which came from an ignitable liquid, is presented.
P. Mark L. Sandercock

Chapter 4. Vegetable Oil, Biodiesel and Ethanol Alternative Fuels

Abstract
While fire debris analysis is largely focused on petroleum-based ignitable liquids, other liquid fuels such as vegetable oils and alternative fuels may also fall within the scope of analysis of a fire debris examiner. The identification of vegetable oils, which can include cooking oils, stains, and drying oils, is potentially important in the context of fire investigation. Alternative fuels are becoming more common based on changes in fuel standards, which have increased general consumer use of biofuels and ethanol-based fuels. As such, these fuels are increasingly seen in casework.
Douglas Byron

Chapter 5. Variation Within Ignitable Liquid Classes

Abstract
Classification implies similarity of the members within a class; however, there is still variation within a class. Some classes have more variation within them than other classes. Classes with broader class characteristics tend to have more variation. Classes with more chemically complex ignitable liquids have more variation than classes with simpler chemical composition. This chapter will provide insight into the reasons for variation within ASTM E1618 classes of ignitable liquids and present examples demonstrating the variation.
Mary R. Williams, Susan Seebode Hetzel

Chapter 6. Microbial Degradation of Ignitable Liquids

Abstract
Ignitable liquids in fire debris samples that are biologically active, such as soil or moldy building materials, can be subject to degradation through microbial metabolism. Unlike weathering, where compounds are lost in a predictable fashion based on volatility, microbial degradation alters ignitable liquids in an unpredictable fashion. The general trends in chemical losses and the factors that affect microbial degradation will be discussed.
Katherine Hutches

Chapter 7. Introduction to the Forensic Analysis of Intact Explosives

Abstract
This introduction to the forensic analysis of intact explosives will give the reader a fundamental understanding of the different classes and types of explosives commonly submitted to laboratories for analysis and identification. The content is augmented with original photographs, flowcharts, and instrument data. Safety is of primary importance when dealing with explosives and safe handling practices and appropriate packaging of samples for submission to the laboratory are described. A typical analysis scheme and the criteria for identification of a range of explosives are explained and illustrated using a real case study. The chapter concludes with a description of how the findings are combined and reported in a clear and concise report.
H. E. Hutson, E. McGee

Chapter 8. Explosive Analysis: Introduction to Post-Blast Analysis

Abstract
The job of the forensic chemist in post-blast analysis is to look for the presence of explosive residues by conducting a visual examination and chemical analysis of evidence submitted. Analytical schemes are used to gather data in order to identify the explosive. Data interpretation can be challenging and report wording must be carefully considered to accurately present the analytical results.
B. M. Crane Calhoun, R. F. Mothershead

Chapter 9. Explosive Device Componentry and Evaluation

Abstract
Forensic analysis of improvised explosive and incendiary devices poses unique challenges. Such devices can incorporate a vast array of components, assembled in configurations limited by only the laws of physics and the creativity of their builder. The job of the device examiner is to determine what components were present in the device and how they all functioned in concert to allow it to function. Device examination spans various technical fields. The process used to interpret the chaos left in the wake of such contrivances is explained with real-world examples used to emphasize critical teaching points.
Kirk Yeager, John Jermain

Chapter 10. Bridging Explosives and Fire Debris Analyses

Abstract
Forensic laboratories occasionally receive cases that require both fire debris and explosive expertise to examine the evidence. Other times, cases do not fit neatly into either of these two categories, but fall somewhere in the middle. Examples of these include particular types of explosives, incendiary mixtures, and cases where investigators may not know if an explosion caused a fire or a fire caused an explosion. Potential approaches to analyzing the evidence, including data interpretation and reporting wording, are discussed.
Michelle Evans

Chapter 11. Interacting with Other Disciplines

Abstract
Frequently, cases that are received for fire debris or explosives analysis will also require other examinations, such as DNA, latent print, trace, and forensic engineering analyses. Fire debris and explosives examiners must consider taking precautions during their analyses so that other types of forensic tests are not compromised. In this chapter, experts from various fields discuss how their examinations interact with fire debris and explosives examinations. Considerations such as the order of examinations, the ‘best evidence’, and segregation of evidence are also discussed.
Carl E. Chasteen

Backmatter

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