Fire Debris Analysis

Eric Stauffer, Julia A. Dolan, Reta Newman

• Publisher: Academic Press
• Year: 2007
• ISBN:
  9780080556260
• Topic: Law
• Subtopic: Forensic Science
• Index: Law

The study of fire debris analysis is vital to the function of all fire investigations, and, as such, Fire Debris Analysis is an essential resource for fire investigators. The present methods of analysis include the use of gas chromatography and gas chromatography-mass spectrometry, techniques which are well established and used by crime laboratories throughout the world. However, despite their universality, this is the first comprehensive resource that addresses their application to fire debris analysis. Fire Debris Analysis covers topics such as the physics and chemistry of fire and liquid fuels, the interpretation of data obtained from fire debris, and the future of the subject. Its cutting-edge material and experienced author team distinguishes this book as a quality reference that should be on the shelves of all crime laboratories.

• Serves as a comprehensive guide to the science of fire debris analysis
• Presents both basic and advanced concepts in an easily readable, logical sequence
• Includes a full-color insert with figures that illustrate key concepts discussed in the text

CHAPTER 1 Introduction

“The journey of a thousand miles begins with a single step.”

Lao Tzu, Chinese philosopher (604 BC-531 BC)

1.1 THE OTHER USE OF GASOLINE AND DIESEL FUEL

For a small single story building, the prescription is two incendiary devices each using 5 gallons of accelerant. […] It is usually unnecessary and a waste of precious time to gather up flammable materials at the scene (e.g. fenceposts, branches, wooden furniture). It is much more valuable to bring more fuel if you are concerned about the success of your fire. Gasoline and diesel are perfectly suited to delivering large quantities of heat, not too fast and not too slow.

These lines, found in the 2001 publication of the Earth Liberation Front entitled, “Setting fires with electrical timers,” summarize relatively well why ignitable liquids often are used as accelerants in committing arson [1]. Fortunately, the average layperson does not comprehend the chemistry and physics of fire and, more particularly, the use of ignitable liquids as accelerants. Thus, it is frequent that a criminal willing to set a structure (building) or a vehicle on fire douses it with an incredibly large amount of gasoline. Although this practice is highly inefficient from a combustion perspective, the resulting fire scene may contain a great amount of gasoline residues—an advantageous situation from a forensic perspective—which can be detected by the fire investigator with the help of the crime laboratory. The identification of ignitable liquid residues (ILR) from fire debris samples collected at a fire scene constitutes the practice of fire debris analysis.

Gasoline was not developed for intentional use by arsonists. As a matter of fact, it was developed in the early 1800s to fight against lice and their eggs pharmaceutically. However, this use was discontinued when it was discovered that gasoline was carcinogenic and led to a greater risk of dermatitis. Additionally, its use against lice usually was not carried out in a very safe manner from a fire safety perspective, which led to serious injuries and deaths [2]. In 1855, Benjamin Silliman Jr. (New Haven, Connecticut, USA) patented the distillation of crude oil into a number of products, including gasoline [3]. As the car industry expanded, gasoline underwent a significant evolution to become the fuel of choice for automotive vehicles. In 1919, gasoline became the most commonly produced petroleum-based product in the United States. In 2006, more than three billion barrels were produced in the United States [4].¹

Gasoline is one of the accelerants of choice for arsonists. Actually, it is the most commonly encountered accelerant in probably every country around the world. The reasons lie in the fact that it is readily available, inexpensive, easy to transport, and more importantly, it is easy to ignite and it provides the necessary energy to accelerate a fire. Arsonists do not travel great distances to find the perfect accelerant; they use whatever works. Although gasoline is the most used accelerant, it is clear that many other ignitable liquids also are used to start fires, such as charcoal lighter fluids, paint thinners, lamp oils, diesel fuels, alcohols, and many other solvents.

Arson v. Incendiary, Intentional, or Deliberate Fire

The term “arson”—from the medieval Latin term arsio, which comes from the Latin verb ardere (to burn)—is a legal term in many countries. Thus, its exact definition varies from one jurisdiction to another. However, a general definition commonly accepted for arson is a criminal act of deliberately setting fire to a property. Arson implies that there is criminal intent and deliberate burning of some object, usually a structure or a vehicle. In some instances, the terms “intentional fire,” “incendiary fire,” or “deliberate fire” are used interchangeably with arson. These terms are used in order to avoid citing the term arson, which would imply a legal meaning. Setting some dead leaves on fire in the backyard (respecting the jurisdiction’s regulations) or lighting a grill to cook some meat are two examples of fires intentionally started. However, typically these are not labeled arson as they do not include a criminal element. Indeed, when the term intentional fire is used, the criminal intent of the fire often is implied, even if not directly stated. Thus, when statistics present “intentional” or “deliberate” fires rather than simply arson, one should consider that they include only fires that have a criminal connotation.

Nevertheless, some jurisdictions prosecute fires that have been accidentally set by a human being. Thus, although these fires are part of a criminal prosecution, they typically do not involve a criminal intent and are not classified as part of the intentional fires nor as part of arson. Throughout this book, the terms arson, deliberate, intentional, and incendiary fires are used interchangeably unless otherwise stated.

Unfortunately, arson is a problem that goes much beyond property crime. It also takes the lives of many people and animals every year, it produces feelings of insecurity to citizens, and it costs enormous amounts of money in damages, victim’s compensation, government services (firefighting, law enforcement, government insurance, etc.), and private insurance services. Nevertheless, it is a crime difficult to prosecute because, by its very nature, it destroys evidence. In the United States, though relatively accessible, statistics in fire and arson investigation are not very accurate and one must be very prudent when interpreting the figures provided. One of the main reasons for such precaution is that the reporting system is based on fire department reports rather than fire investigation reports [5]. Thus, the fire chief responding to the scene may declare a fire electrical without having been trained to investigate fire. The scene might later reveal that the fire was incendiary when subsequently investigated by the fire marshal or a private fire investigator. Furthermore, there is a significant number of fires for which the exact cause remains unknown. The field of fire investigation is very prone to differences of opinion. Thus it is never truly known what caused some fires even after thorough investigation. Finally, though general statistics about fires are readily available (numbers, locations, types, etc.), specific data regarding the use of ignitable liquids or the types of ignitable liquid used in criminal fires is not readily available.

Accelerant v. Ignitable Liquid

The term “accelerant” is often wrongfully used synonymously with “ignitable liquid.” It is important to remember that a material is defined as an ignitable liquid based upon its physical and chemical properties, but a material is defined as an accelerant based upon how it is used. An accelerant is [10]: “a fuel (usually a flammable liquid) that is used to initiate or increase the intensity or speed of spread of fire.” Therefore, not all flammable liquids found at a fire scene are accelerants and conversely, not all accelerants used to commit arson are liquids. A paper trail used by an arsonist to set a house on fire is an accelerant. However, the presence of gasoline on a piece of carpet placed in a garage under vehicles to collect oil stains is not an accelerant; rather, it is defined as an incidental liquid present on the substrate.

As an example, a criminalist in the laboratory receives two liquid samples from an investigator: A and B. Following analysis, both samples are identified as gasoline. At that point, the scientist can state with no further information that both samples A and B are ignitable liquids. The investigator, knowing the sources of the liquids, can infer whether or not they are accelerants. Sharing the information that sample A was retrieved from the gasoline tank of the suspect’s lawnmower, and that sample B was recovered from glass bottle fragments with a wick protruding from the neck portion found at a fire scene, the investigator can infer whether they were used as accelerants or not. Sample B was used for the purpose of initiating a fire; therefore, it is an accelerant. Conversely, sample A simply was used as a fuel for an internal combustion engine, and is therefore not an accelerant. Both samples are ignitable liquids and have the same chemical composition, yet one is an accelerant, and the other is not. It is crucial that the criminalist not refer to ignitable liquids as accelerants based solely on their chemical and physical properties. The term accelerant necessarily refers to the context of the fire and the investigation. This is why, throughout this text, the terms “ignitable liquids” and “ignitable liquid residues” usually are used; only under the rare and appropriate circumstances, do the authors refer to “accelerants.”

In spite of this, it is always interesting to look at some of these numbers and to...

Table of contents

• Cover image
• Title page
• Table of Contents
• Visit the companion website for
• Copyright
• Biographies
• Preface
• Acknowledgments
• Foreword
• Chapter 1: Introduction
• Chapter 2: History
• Chapter 3: Review of Basic Organic Chemistry
• Chapter 4: Chemistry and Physics of Fire and Liquid Fuels
• Chapter 5: Detection of Ignitable Liquid Residues at Fire Scenes
• Chapter 6: Sample Collection
• Chapter 7: Flammable and Combustible Liquids
• Chapter 8: Gas Chromatography and Gas Chromatography—Mass Spectrometry
• Chapter 9: Interpretation of Data Obtained from Neat Ignitable Liquids
• Chapter 10: Preliminary Examination of Evidence
• Chapter 11: Extraction of Ignitable Liquid Residues from Fire Debris
• Chapter 12: Interpretation of Ignitable Liquid Residues Extracted from Fire Debris
• Chapter 13: Other Techniques of Analysis and the Future of Fire Debris Analysis
• Chapter 14: Other Possible Examinations Conducted on Fire Debris
• Chapter 15: Education, Training, and Certification
• Chapter 16: Standardization
• Chapter 17: Accreditation
• Abbreviations
• Index