9781422273449

Forensic Chemistry Detecting Drugs and Poisons

Crime Scene Collecting Physical Evidence Digital Forensics

Investigating Data DNA Profiling

Linking the Suspect to the Evidence Forensic Anthropology Identifying Human Remains Forensic Chemistry Detecting Drugs and Poisons Forensic Psychology

Probing the Criminal Mind Impression Evidence Identifying Fingerprints, Bite Marks, and Tire Treads Pathology Examining the Body for Clues

Forensic Chemistry Detecting Drugs and Poisons

By Katherine Lacaze

MASON CREST PH I L ADELPH I A | MI AMI

Mason Crest PO Box 221876, Hollywood, FL 33022 (866) MCP-BOOK (toll-free) • www.masoncrest.com

Copyright © 2022 by Mason Crest, an imprint of National Highlights, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, taping, or any information storage and retrieval system, without permission in writing from the publisher. Printed in the United States of America First printing 9 8 7 6 5 4 3 2 1 Series ISBN: 978-1-4222-4464-7 Hardcover ISBN: 978-1-4222-4469-2 ebook ISBN: 978-1-4222-7344-9 Cataloging-in-Publication Data on file with the Library of Congress

Developed and Produced by Print Matters Productions, Inc. Cover and Interior Design by Torque Advertising+Design

Publisher’s Note: Websites listed in this book were active at the time of publication. The publisher is not responsible for websites that have changed their address or discontinued operation since the date of publication. The publisher reviews and updates the websites each time the book is reprinted.

QR CODES AND LINKS TO THIRD-PARTY CONTENT You may gain access to certain third-party content (“Third-Party Sites”) by scanning and using the QR Codes that appear in this publication (the “QR Codes”). We do not operate or control in any respect any information, products, or services on such Third-Party Sites linked to by us via the QR Codes included in this publication, and we assume no responsibility for any materials you may access using the QR Codes. Your use of the QR Codes may be subject to terms, limitations, or restrictions set forth in the applicable terms of use or otherwise established by the owners of the Third-Party Sites. Our linking to such Third-Party Sites via the QR Codes does not imply an endorsement or sponsorship of such Third-Party Sites or the information, products, or services offered on or through the Third-Party Sites, nor does it imply an endorsement or sponsorship of this publication by the owners of such Third-Party Sites.

Introduction: Bringing Chemistry to the Crime Scene . ....... 7 Chapter 1: Detecting Drugs and Poisons . ........................... 17 Chapter 2: Exploring Explosives and Gunshot Residue .... 31 Chapter 3: Detecting Fire Accelerants and Arson . ............ 45 Chapter 4: Analyzing Physical and Biological Trace Evidence ..................................................... 59 Chapter 5: Analysis and Testing ........................................... 73 Series Glossary of Key Terms ................................................. 86 Further Reading & Internet Resources ................................. 90 Index . ........................................................................................ 92 Author’s Biography ................................................................. 95 Credits . ..................................................................................... 96 K E Y I C O N S T O L O O K F O R Words to Understand: These words with their easy-to-understand definitions will increase reader’s understanding of the text while building vocabulary skills. Sidebars: This boxed material within the main text allows readers to build knowledge, gain insights, explore possibilities, and broaden their perspectives by weaving together additional information to provide realistic and holistic perspectives. Educational Videos: Readers can view videos by scanning our QR codes, providing them with additional educational content to supplement the text.

Text-Dependent Questions: These questions send the reader back to the text for more careful attention to the evidence presented there.

Research Projects: Readers are pointed toward areas of further inquiry connected to each chapter. Suggestions are provided for projects that encourage deeper research and analysis. Series Glossary of Key Terms: This back-of-the-book glossary contains terminology used throughout this series. Words found here increase the reader’s ability to read and comprehend higher-level books and articles in this field.

Forensic chemists analyze physical evidence from the victim’s body and the crime scene.

6

Bringing Chemistry to the Crime Scene

From the moment a perpetrator enters a crime scene, they begin leaving behind traces of evidence that give away their identity, their behavior, and their instruments or weapons. From fingerprints and dirt tracked in on shoes to bullet casings, biological materials, and pieces of thread from clothes, these pieces of evidence—though microscopic—are invaluable to investigating and prosecuting crimes. To analyze these types of evidence, investigators rely on the help of forensic chemists, who may work in a variety of specialties, such as serology (the study of blood and other bodily fluids) and toxicology (the study of poisons). Using a range of laboratory equipment, tests, and scientific methods, forensic chemists help process and analyze physical evidence and samples collected from the victim’s body and the crime scene. While the term crime scene makes it seem that criminal offenses transpire in single locations, crime scenes can vary in size, depending on the nature of the crime and the behavior of the perpetrator. At the least, crime scenes include the precise location where the offense occurred, as well as entrances and exits from the area and any places where evidence can be found. For example, sometimes criminals use a vehicle to leave the location where the offense took place. If they’re transporting evidence— such as stolen goods or a victim’s body in the case of a murder—the vehicle would become part of the crime scene, along with any places where the evidence was taken or stored. For a suspicious fire, investigators would look at the entire structure and its perimeter to figure out how the fire could have been started and how it spread. With such a vast physical location to consider, it takes a keen eye and meticulous investigation to find samples of unknown substances that can be analyzed in a laboratory to provide important data for solving crimes.

7

An undergraduate degree in chemistry, forensic science, or a similar subject is necessary to become a forensic chemist.

8

Forensic Chemistry

Becoming a Forensic Chemist Forensic chemistry simply refers to the idea of applying the study of chemistry and its sub-disciplines—such as toxicology—to the criminal justice system, from investigating crimes and analyzing evidence to narrowing down suspects and defending an interpretation of evidence in court. A majority of this practice happens in the laboratory, where chemists use their specialized scientific knowledge and abilities to help with a very specific part of the judicial process. To enter the field and work in crime labs, prospective practitioners must obtain at least an undergraduate degree in chemistry, forensic science, natural science, or a similar subject. Their course work should include a fair amount of chemistry, biology, and mathematics. However, to obtain a more advanced position, such as a lab manager or director position, prospective forensic chemists are often required to obtain a master’s or doctoral degree. A PhD is necessary for someone to get a position doing forensic research at an academic institution. Students should also consider what specialty of forensic chemistry they are most interested in pursuing. According to the American Chemical Society (ACS), students who would like to work with trace evidence—including fibers, glass, and gunshot residue—should take courses in materials science, geology, and soil chemistry and develop instrumentation skills. Microbiology, biochemistry, and genetics courses are useful for those interested in pursuing forensic biology. For toxicology, or the practice of obtaining and interpreting toxicology reports, it is recommended that students study chemistry, biochemistry, and physiology. Beyond education, prospective forensic chemists also must complete extensive practical and on-the-job training. The length of training may vary, depending on which particular field or practice a forensic scientist wants to focus on. For instance, learning how to conduct DNA analysis takes about six months to a year of on-the-job training, while firearms analysis can require up to three years. Professionals must demonstrate a level of proficiency in a field before they are permitted to work on their own. To improve their job prospects, graduates who are looking to pursue a career in forensic chemistry should obtain certification from a variety of professional organizations, such as the American Academy of Forensic Sciences (AAFS), the American Board of Criminalistics (ABC), the American

9

Introduction: Bringing Chemistry to the Crime Scene

Forensic Association (AFA), and the Association of Forensic DNA Analysts and Administrators (AFDAA). Throughout their careers, it’s also important for forensic chemists to stay up to date with scientific advances related to the collection or analysis of evidence. Through continuing education and hands-on field work, they can learn how to apply new techniques and methods that become best practices for the industry.

Forensic Chemistry: Fact and Fiction

Using science to solve crimes can be traced back not to a real person but rather a fictional one. In Sir Arthur Conan Doyle’s book A Study in Scarlet, his protagonist, Sherlock Holmes, creates a chemical that he uses to determine whether a suspicious stain is blood. Holmes also explains in the course of the book how bloodstains can be used as evidence in criminal trials. In Doyle’s other books, as well as cinematic adaptations of his work, the famous detective frequently can be found applying chemistry and other sciences to investigate and solve crimes. Austrian jurist and criminologist Hans Gustav Adolf Gross is considered to have been the first real-life forensic scientist and is renowned for his contributions to the field. In 1893, he published a treatise that helped establish the practice of applying scientific methods to criminal investigations. His work was especially important for its research on cross-transfers of trace evidence—such as hair, dirt, and fibers—from the criminal to the victim. Other experts continued contributing to the field of forensic chemistry over the next century and a half to establish its important status in the world of criminal law.

10

Forensic Chemistry

Using science to solve crimes can be traced back to Sir Arthur Conan Doyle’s protagonist, Sherlock Holmes.

Potential Career Paths According to the American Chemical Society, about 90 percent of forensic chemists in the United States work in labs affiliated with federal, state, or local law enforcement agencies; fire departments; the military; medical examiner’s offices; forensic services labs; or branches of the Federal Bureau of Investigation (FBI). Additionally, there are some private labs that do forensic analysis, and they partner with investigating agencies on a contractual basis. Regardless of which agency forensic chemists work for, there are basic qualities and skills that are essential for specialists to acquire. As forensic chemists use a variety of methods and tools to help identify unknown materials or analyze recognizable samples collected from

11

Introduction: Bringing Chemistry to the Crime Scene

crime scenes, they should have a strong background in quantitative and qualitative analysis, instrumentation, and experimentation. Additionally, criminalists who deal with forensic chemistry must pay meticulous attention to detail, as they conduct numerous tests and analyses where even the smallest error can negatively alter the outcome in a big way. Applying analytical techniques to evidence can be rigorous, time- consuming, and exhausting, so patience, persistence, and the ability to stay calm when handling biological material are also vital. While a majority of forensic chemistry transpires in a lab, these specialists may also be called to a crime scene. They might examine blood patterns to investigate whether a death was accidental or intentional, or whether fire patterns are related to a case of potential arson. When out in the field, forensic chemists have to be comfortable functioning in a chaotic or gruesome environment and carrying out their tasks in a collaborative manner alongside other criminologists. The data that forensic chemists gather from samples, as well as their scientific interpretations, can make a significant difference in how a civil or criminal investigation plays out. That’s why it is also important for these professionals to have strong written and other verbal skills. Not only do they write detailed reports of their findings that have to withstand scrutiny, but they also are often called on to give testimony during trials and defend their work in a court of law. They must be able to stay composed, concise, and clear while undergoing direct and cross- examination by the prosecution and defense. Throughout their career, a forensic chemist may advance through a particular agency or department, transitioning to a lab supervisor or director role, or may establish a private practice and work as a consultant. There are also career opportunities for forensic chemists in academia and administration for those who are more interested in theory and research than the day-to-day, hands-on work in the field. Employment Outlook The forensic science field shows promise for prospective professionals but with a few caveats. According to the U.S. Department of Labor’s Bureau of Labor Statistics, employment of forensic science technicians, which includes forensic chemists, is projected to grow 14 percent from 2018 to 2028, which is significantly faster than the average for all occupations. However, the Bureau adds, because this is a relatively small occupation,

12

Forensic Chemistry

Forensic chemists have to be comfortable functioning in a chaotic and often gruesome environment.

the fast growth will only result in about 2,400 new jobs over the ten-year period. Combined with the popularity of crime shows and appealing media representation of forensic scientists, competition for these types of jobs is expected to be strong in the coming years. Additionally, according to the American Chemical Society, new forensic labs are rarely established, which means that job openings for prospective forensic chemists at existing labs are generally the results of current employees retiring or being promoted. Applicants who have a master’s degree or additional certifications and areas of specialty are expected to have the best opportunities. Another factor that may affect the job market for forensic scientists is the increasing pressure for governments at all levels to reduce their budgets. However, according to the Bureau of Labor Statistics (BLS), there is still the expectation that both state and local governments will need to

13

Introduction: Bringing Chemistry to the Crime Scene

The Classes and Characteristics of Evidence

hire forensic scientists to help process their heavy caseloads. Additionally, the BLS states that as technology and scientific methods evolve, and practitioners discover new ways to apply these practices to the criminal justice system, “the availability, reliability, and usefulness of objective forensic information used as evidence in trials” is expected to increase steadily. As a result, “forensic science technicians will be able to provide even greater value than before, and more forensic science technicians will be needed to provide timely forensics information to law enforcement agencies and courts.” may give them a different perspective when analyzing data. Circumstantial evidence is then sorted into other categories: physical, biological, reconstructive, or associative. Reconstructive evidence is anything that can help investigators get a better sense of what transpired at the scene during a crime—or in other words, reconstruct it. It deals with who did what, when, where, and how. Associative evidence is anything that links a specific suspect to the crime scene. It includes hairs, fibers, bodily fluids, footprints, paint, or weapons. Evidence will also bear class characteristics, or properties that place it in a group of objects. Better yet, some pieces of evidence possess individual characteristics, or properties that narrow down the source to a single person or a small group with relative certainty. There are several types of evidence utilized in the process of investigating and prosecuting crimes. To begin with, evidence is categorized as either direct or circumstantial. Direct evidence encompasses things like a confession from a perpetrator or a victim’s statement, which essentially establishes a fact. In contrast, circumstantial evidence is more objective data, although it doesn’t provide solid proof and must be interpreted by a judge or jury. Forensic scientists, including chemists, are more apt to deal with circumstantial evidence—fingerprints, hairs or fibers, bloodstains, drugs, or fire- starters—than direct evidence, although a witness or victim’s testimony

14

Forensic Chemistry