Explaining Forensics

Open Posted By: ahmad8858 Date: 01/05/2021 High School Essay Writing


Assignment Content

  1. The field of forensic science spans multiple disciplines and plays a major role in solving crime. Over the years, as technology has advanced, the capabilities of forensic science units have increased. The purpose of this assignment is to show you understand the scope of work in forensic science.  

    Write short-answer responses between 100 and 225 words each in response to the following:
    • Describe the evolution of forensic sciences over time, including the role of key pioneers.
    • Differentiate 2-3 of the 11 forensic science disciplines outlined in this week’s reading used to aid law enforcement officials in conducting their investigations. Provide examples of their scope of work and the role it plays in criminal investigations.
    • Explain how forensic science is used in the criminal justice system.
    • Cite the sources used to support your assignment.

      Note: In the criminal justice field, your written communication skills are paramount since many of these career options require report writing. Be certain to follow the rules of grammar, so that flow of thought is maintained for the reader. 




Review the American Academy of Forensic Sciences website.

Access the Career Brochure PDF located below the disciplines section list on the site for detailed information on each role. This will help you as you complete this week's assignment.

Consider the information found about this career field as you prepare for this week’s assignment.

Category: Business & Management Subjects: Human Resource Management Deadline: 24 Hours Budget: $80 - $120 Pages: 2-3 Pages (Short Assignment)

Attachment 1

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1 Introduction

Red Huber-Pool/Getty Images

Learning Objectives

After studying this chapter, you should be able to:

Distinguish between forensic science and criminalistics.

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Outline the main historical developments of forensic science. Describe the organization and services of a typical comprehensive crime laboratory in the criminal justice system. Understand what specialized forensic services, aside from the crime laboratory, are generally available to law enforcement personnel. Explain how physical evidence is analyzed and presented in the courtroom by the forensic scientist, and how admissibility of evidence is determined in the courtroom.

Casey Anthony: The Csi Effect?

Few criminal proceedings have captured the attention of the American public or have invoked stronger emotions than the Casey Anthony murder trial. How could a defendant who failed to report her two-year-old child missing for thirty-one days walk away scot-free from a murder conviction? This case had all the makings of a strong circumstantial case for the state.

The state’s theory was that Casey used chloroform to render her daughter unconscious, placed duct tape over Caylee’s mouth and nose, and kept the body in the trunk for several days before disposing of it. Caylee’s decomposed remains were discovered more than five months after she was reported missing.

Have TV forensic dramas created an environment in the courtroom that necessitates the existence of physical evidence to directly link a defendant to a crime scene? The closest the state came to a direct link was a hair found in the trunk of Casey’s car. However, the DNA test on the hair could link the hair only to Caylee’s maternal relatives: Casey, Casey’s mother (Caylee’s maternal grandmother), and Casey’s brother (Caylee’s uncle). And Caylee herself. No unique characteristics were found to link the duct tape on the body with that found in the Anthony home.

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No DNA, no fingerprints, no conviction.

Go to www.pearsonhighered.com/careersresources to access Webextras for this chapter.

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Definition and Scope of Forensic Science Forensic science, in its broadest definition, is the application of science to law. As our society has grown more complex, it has become more dependent on rules of law to regulate the activities of its members. Forensic science applies the knowledge and technology of science to the definition and enforcement of such laws.

Each year, as government finds it increasingly necessary to regulate the activities that most intimately influence our daily lives, science merges more closely with civil and criminal law. Consider, for example, the laws and agencies that regulate the quality of our food, the nature and potency of drugs, the extent of automobile emissions, the kind of fuel oil we burn, the purity of our drinking water, and the pesticides we use on our crops and plants. It would be difficult to conceive of a food or drug regulation or environmental protection act that could be effectively monitored and enforced without the assistance of scientific technology and the skill of the scientific community.

Laws are continually being broadened and revised to counter the alarming increase in crime rates. In response to public concern, law enforcement agencies have expanded their patrol and investigative functions, hoping to stem the rising tide of crime. At the same time, they are looking more to the scientific community for advice and technical support for their efforts.

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Can the technology that put astronauts on the moon, split the atom, and eradicated most dreaded diseases be enlisted in this critical battle?

Unfortunately, science cannot offer final and authoritative solutions to problems that stem from a maze of social and psychological factors. However, as the content of this book attests, science occupies an important and unique role in the criminal justice system—a role that relates to the scientist’s ability to supply accurate and objective information about the events that have occurred at a crime scene. A good deal of work remains to be done if the full potential of science as applied to criminal investigations is to be realized.

Because of the vast array of civil and criminal laws that regulate society, forensic science, in its broadest sense, has become so comprehensive a subject that a meaningful introductory textbook treating its role and techniques would be difficult to create and probably overwhelming to read. For this reason, we have narrowed the scope of the subject according to the most common definition: Forensic science is the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system. “Forensic science” is an umbrella term encompassing a myriad of professions that use their skills to aid law enforcement officials in conducting their investigations.

The diversity of professions practicing forensic science is illustrated by the eleven sections of the American Academy of Forensic Sciences, the largest forensic science organization in the world:

1. Criminalistics 2. Digital and Multimedia Sciences 3. Engineering Science 4. General 5. Jurisprudence

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�. Odontology 7. Pathology/Biology �. Physical Anthropology 9. Psychiatry/Behavioral Science

10. Questioned Documents 11. Toxicology

Even this list of professions is not exclusive. It does not encompass skills such as fingerprint examination, firearm and tool mark examination, and photography.

Obviously, to author a book covering all of the major activities of forensic science as they apply to the enforcement of criminal and civil laws by police agencies would be a major undertaking. Thus, this book will further restrict itself to discussions of the subjects of chemistry, biology, physics, geology, and computer technology, which are useful for determining the evidential value of crime-scene and related evidence. Forensic pathology, psychology, anthropology, and odontology also encompass important and relevant areas of knowledge and practice in law enforcement, each being an integral part of the total forensic science service that is provided to any up-to-date criminal justice system. However, these subjects go beyond the intended scope of this book, and except for brief discussions, along with pointing the reader to relevant websites, the reader is referred elsewhere for discussions of their applications and techniques. Instead, this book focuses on the services of what has popularly become known as the crime laboratory, where the principles and techniques of the physical and natural sciences are practiced and applied to the analysis of crime-scene evidence.

For many, the term “criminalistics” seems more descriptive than “forensic science” for describing the services of a crime laboratory. Regardless of his or her title—“criminalist” or “forensic scientist”—the trend of events has

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made the scientist in the crime laboratory an active participant in the criminal justice system.

The CSI Effect

Prime-time television shows like CSI: Crime Scene Investigation have greatly increased the public’s awareness of the use of science in criminal and civil investigations (see Figure 1-1 ). However, by simplifying scientific procedures to fit the allotted airtime, these shows have created within both the public and the legal community, unrealistic expectations of forensic science. In these shows, members of the CSI team collect evidence at the crime scene, process all evidence, question witnesses, interrogate suspects, carry out search warrants, and testify in court. In the real world, these tasks are almost always delegated to different people in different parts of the criminal justice system. Procedures that in reality could take days, weeks, months, or years appear on these shows to take mere minutes. This false image is significantly responsible for the public’s high interest in and expectations for DNA evidence.

Figure 1-1

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A scene from CSI, a forensic science television show. SUN/Newscom

The dramatization of forensic science on television has led the public to believe that every crime scene will yield forensic evidence, and it produces unrealistic expectations that a prosecutor’s case should always be bolstered and supported by forensic evidence. This phenomenon is known as the “CSI effect.” Some jurists believe that this phenomenon ultimately detracts from the search for truth and justice in the courtroom.

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History and Development of Forensic Science Forensic science owes its origins, first, to the individuals who developed the principles and techniques needed to identify or compare physical evidence and, second, to those who recognized the need to merge these principles into a coherent discipline that could be practically applied to a criminal justice system.

The roots of forensic science reach back many centuries, and history records a number of instances in which individuals closely observed evidence and applied basic scientific principles to solve crimes. Not until relatively recently, however, did forensic science take on the more careful and systematic approach that characterizes the modern discipline.

Early Developments

One of the earliest records of applying forensics to solve criminal cases comes from third-century China. A manuscript titled Yi Yu Ji (“A Collection of Criminal Cases”) reports how a coroner solved a case in which a woman was suspected of murdering her husband and burning the body, claiming that he died in an accidental fire. Noticing that the husband’s corpse had no ashes in its mouth, the coroner performed an experiment to test the

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woman’s story. He burned two pigs—one alive and one dead—and then checked for ashes inside the mouth of each. He found ashes in the mouth of the pig that was alive before it was burned, but none in the mouth of the pig that was dead beforehand. The coroner thus concluded that the husband, too, was dead before his body was burned. Confronted with this evidence, the woman admitted her guilt. The Chinese were also among the first to recognize the potential of fingerprints as a means of identification.

Although cases such as that of the Chinese coroner are noteworthy, this kind of scientific approach to criminal investigation was for many years the exception rather than the rule. Limited knowledge of anatomy and pathology hampered the development of forensic science until the late seventeenth and early eighteenth centuries. For example, the first recorded notes about fingerprint characteristics were prepared in 1686 by Marcello Malpighi, a professor of anatomy at the University of Bologna in Italy. Malpighi, however, did not acknowledge the value of fingerprints as a method of identification. The first scientific paper about the nature of fingerprints did not appear until more than a century later, but it also did not recognize their potential as a form of identification.

Initial Scientific Advances

As physicians gained a greater understanding of the workings of the body, the first scientific treatises on forensic science began to appear, such as the 1798 work “A Treatise on Forensic Medicine and Public Health” by the French physician François-Emanuel Fodéré. Breakthroughs in chemistry at this time also helped forensic science take significant strides forward. In 1775, the Swedish chemist Carl Wilhelm Scheele devised the first successful test for detecting the poison arsenic in corpses. By 1806, the German chemist Valentin Ross had discovered a more precise method for

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detecting small amounts of arsenic in the walls of a victim’s stomach. The most significant early figure in this area was Mathieu Orfila (see Figure 1- 2 ), a Spaniard who is considered the father of forensic toxicology. In 1814, Orfila published the first scientific treatise on the detection of poisons and their effects on animals. This treatise established forensic toxicology as a legitimate scientific endeavor.

Figure 1-2

Mathieu Orfila. Matthieu Orfila/The Granger Collection

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The mid-1800s saw a spate of advances in several scientific disciplines that furthered the field of forensic science. In 1828, William Nichol invented the polarizing microscope. Eleven years later, Henri-Louis Bayard formulated the first procedures for microscopic detection of sperm. Other developments during this time included the first microcrystalline test for hemoglobin (1853) and the first presumptive test for blood (1863). Such tests soon found practical applications in criminal trials. Toxicological evidence at trial was first used in 1839, when a Scottish chemist named James Marsh testified that he had detected arsenic in a victim’s body. During the 1850s and 1860s, the new science of photography was also used in forensics to record images of prisoners and crime scenes.

Late-Nineteenth-Century Progress

By the late nineteenth century, public officials were beginning to apply knowledge from virtually all scientific disciplines to the study of crime. Anthropology and morphology (the study of the structure of living organisms) were applied to the first system of personal identification, devised by the French scientist Alphonse Bertillon in 1879. Bertillon’s system, which he dubbed “anthropometry,” was a procedure that involved taking a series of bodily measurements as a means of distinguishing one individual from another (see Figure 1-3 ). For nearly two decades, this system was considered the most accurate method of personal identification. Bertillon’s early efforts earned him the distinction of being known as the “father of criminal identification.”

Figure 1-3

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Bertillon’s system of bodily measurements used for the identification of an individual. Sirchie Finger Print Laboratories, Youngsville, NC, www.sirchie.com

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The Advent of Fingerprinting

Bertillon’s anthropometry, however, would soon be supplanted by a more reliable method of identification: fingerprinting. Two years before the publication of Bertillon’s system, U.S. microscopist Thomas Taylor had suggested that fingerprints could be used as a means of identification, but his ideas were not immediately followed up. Three years later, the Scottish physician Henry Faulds made a similar assertion in a paper published in the journal Nature. However, it was the Englishman Francis Henry Galton who undertook the first definitive study of fingerprints and developed a methodology of classifying them for filing. In 1892, Galton published a book titled Finger Prints that contained the first statistical proof supporting the uniqueness of fingerprints and the effectiveness of his method. His book went on to describe the basic principles that would form our present system of identification by fingerprints.

The first treatise describing the application of scientific disciplines to the field of criminal investigation was written by Hans Gross in 1893. Gross, a public prosecutor and judge in Graz, Austria, spent many years studying and developing principles of criminal investigation. In his classic book Handbuch für Untersuchungsrichter als System der Kriminalistik (later published in English under the title Criminal Investigation), he detailed the assistance that investigators could expect from the fields of microscopy, chemistry, physics, mineralogy, zoology, botany, anthropometry, and fingerprinting. He later introduced the forensic journal Archiv für Kriminal Anthropologie und Kriminalistik, which still reports improved methods of scientific crime detection.

Ironically, the best-known figure in nineteenth-century forensics is not a real person but a fictional character: the legendary detective Sherlock Holmes (see Figure 1-4 ). Many people today believe that Holmes’s creator, Sir

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Arthur Conan Doyle, had a considerable influence on popularizing scientific crime-detection methods. In adventures with his partner and biographer, Dr. John Watson, Holmes was the first to apply the newly developing principles of serology (the study of blood and bodily fluids), fingerprinting, firearms identification, and questioned-document examination long before their value was recognized and accepted by real-life criminal investigators. Holmes’s feats excited the imagination of an emerging generation of forensic scientists and criminal investigators. Even in the first Sherlock Holmes novel, A Study in Scarlet, published in 1887, we find examples of Doyle’s uncanny ability to describe scientific methods of detection years before they were actually discovered and implemented. For instance, here Holmes explains the potential usefulness of forensic serology to criminal investigation:

Figure 1-4

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Sir Arthur Conan Doyle’s legendary detective Sherlock Holmes applied many of the principles of modern forensic science long before they were adopted widely by real-life police. Ostill/Shutterstock

“I’ve found it. I’ve found it,” he shouted to my companion, running toward us with a test tube in his hand. “I have found a reagent which is precipitated by hemoglobin and by nothing else… . Why, man, it is the most practical medico-legal discovery for years. Don’t you see that it gives us an infallible test for bloodstains?… The old guaiacum test was very clumsy and uncertain. So is the microscopic examination for blood corpuscles. The latter is valueless if the stains are a few hours old. Now, this appears to act as well whether the blood is old or new. Had this test been invented, there are hundreds of men now walking the earth who would long ago

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have paid the penalty of their crimes… . Criminal cases are continually hinging upon that one point. A man is suspected of a crime months perhaps after it has been committed. His linen or clothes are examined and brownish stains discovered upon them. Are they bloodstains, or rust stains, or fruit stains, or what are they? That is a question which has puzzled many an expert, and why? Because there was no reliable test. Now we have the Sherlock Holmes test, and there will no longer be any difficulty.”

Twentieth-Century Breakthroughs

The pace of technological change quickened considerably in the twentieth century, and with it the rate of advancements in forensic science. In 1901, Dr. Karl Landsteiner discovered that blood can be grouped into different categories, now recognized as the blood types A, B, AB, and O. The possibility that blood grouping could be useful in identifying an individual intrigued Dr. Leone Lattes, a professor at the Institute of Forensic Medicine at the University of Turin in Italy. In 1915, Lattes devised a relatively simple procedure for determining the blood group of the dried blood in a bloodstain, a technique that he immediately applied to criminal investigations.

At around the same time, Albert S. Osborn was conducting pioneering work in document examination. In 1910, Osborn wrote the first significant text in this field, Questioned Documents. This book is still a primary reference for document examiners. Osborn’s development of fundamental principles of document examination was responsible for the acceptance of documents as scientific evidence by the courts.

One of the most important contributors to the field in the early twentieth century was the Frenchman Edmond Locard (see Figure 1-5 ). Although

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Hans Gross was a pioneering advocate for the use of the scientific method in criminal investigations, Locard first demonstrated how the principles enunciated by Gross could be incorporated within a workable crime laboratory. Locard’s formal education was in both medicine and law. In 1910, he persuaded the Lyons Police Department to give him two attic rooms and two assistants to start a police laboratory. During Locard’s first years of work, the instruments available to him were a microscope and a rudimentary spectrometer. However, his enthusiasm quickly overcame the technical and budgetary deficiencies he encountered, and from these modest beginnings, Locard conducted research and made discoveries that became known throughout the world by forensic scientists and criminal investigators. Eventually he became the founder and director of the Institute of Criminalistics at the University of Lyons, which quickly developed into a leading international center for study and research in forensic science.

Figure 1-5

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Edmond Locard. Roger Viollet/The Image Works

Locard asserted that when two objects come into contact with each other a cross-transfer of materials occurs (Locard’s exchange principle ). He strongly believed that every criminal can be connected to a crime by dust particles carried from the crime scene. This concept was reinforced by a series of successful and well-publicized investigations. In one case, presented with counterfeit coins and the names of three suspects, Locard urged the police to bring the suspects’ clothing to his laboratory. On careful examination, he located small metallic particles in all the garments. Chemical analysis revealed that the particles and coins were composed of exactly the same metallic elements. Confronted with this evidence, the suspects were arrested and soon confessed to the crime. After World War

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I, Locard’s successes inspired the formation of police laboratories in Vienna, Berlin, Sweden, Finland, and Holland.

The Rise of the Microscope

The microscope came into widespread use in forensic science during the twentieth century, and its applications grew dramatically. Perhaps the leading figure in the field of microscopy was Dr. Walter C. McCrone. During his lifetime, McCrone became the world’s preeminent microscopist. Through his books, journal publications, and research institute, he was a tireless advocate for applying microscopy to analytical problems, particularly forensic science cases. McCrone’s exceptional communication skills made him a much-sought-after instructor, and he educated thousands of forensic scientists throughout the world in the application of microscopic techniques. Dr. McCrone used microscopy, often in conjunction with other analytical methodologies, to examine evidence in thousands of criminal and civil cases throughout his long and illustrious career.

Another trailblazer in forensic applications of microscopy was U.S. Army Colonel Calvin Goddard, who refined the techniques of firearms examination by using the comparison microscope. Goddard’s work allows investigators to determine whether a particular gun has fired a bullet by comparing the bullet with another that is test-fired from the suspect’s weapon. From the mid-1920s on, his expertise established the comparison microscope as the indispensable tool of the modern firearms examiner.

Modern Scientific Advances

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Since the mid-twentieth century, a revolution in computer technology has made possible a quantum leap forward in human knowledge. The resulting explosion of scientific advances has had a dramatic impact on the field of forensic science by introducing a wide array of sophisticated techniques for analyzing evidence related to a crime. Procedures such as chromatography, spectrophotometry, and electrophoresis (all discussed in later chapters) allow the modern forensic scientist to determine with astounding accuracy the identity of a substance and to connect even tiny fragments of evidence to a particular person and place.

Undoubtedly the most significant modern advance in forensic science has been the discovery and refinement of DNA typing in the late twentieth and early twenty-first centuries. Sir Alec Jeffreys developed the first DNA profiling test in 1984, and two years later he applied it for the first time to solve a crime, identifying Colin Pitchfork as the murderer of two young English girls. The same case also marked the first time DNA profiling established the innocence of a criminal suspect. Made possible by scientific breakthroughs in the 1950s and 1960s, DNA typing offers law enforcement officials a powerful tool for establishing the precise identity of a suspect, even when only a small amount of physical evidence is available. Combined with the modern analytical tools mentioned earlier, DNA typing has revolutionized the practice of forensic science (see Figure 1-6 ).

Figure 1-6

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Sir Alec Jeffreys. Homer Sykes/Alamy

Another significant recent development in forensics is the establishment of computerized databases to store information on physical evidence such as fingerprints, markings on bullets and shell casings, and DNA. These databases have proved to be invaluable, enabling law enforcement officials to compare evidence found at crime scenes to thousands of pieces of similar information. This has significantly reduced the time required to analyze evidence and increased the accuracy of the work done by police and forensic investigators.

Although this brief narrative is by no means a complete summary of historical advances in forensics, it provides an idea of the progress that has been made in the field by dedicated scientists and law enforcement personnel. Even Sherlock Holmes probably couldn’t have imagined the

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extent to which science is applied in the service of criminal investigation today.

Quick Review Forensic science is the application of science to criminal and civil laws that are enforced by police agencies in a criminal justice system. The first system of personal identification was called “anthropometry.” It distinguished one individual from another based on a series of bodily measurements. Forensic science owes its origins to individuals such as Bertillon, Galton, Lattes, Goddard, Osborn, and Locard, who developed the principles and techniques needed to identify and compare physical evidence. Locard’s exchange principle states that when two objects come into contact with each other, a cross-transfer of materials occurs that can connect a criminal suspect to his or her victim.

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History and Organization of Crime Laboratories The steady advance of forensic science technologies during the twentieth century led to the establishment of the first facilities specifically dedicated to forensic analysis of criminal evidence. These crime laboratories are now the centers for both forensic investigation of ongoing criminal cases and research into new techniques and procedures to aid investigators in the future.

History of Crime Labs in the United States

The oldest forensic laboratory in the United States is the Los Angeles Police Department, created in 1923 by August Vollmer, a police chief from Berkeley, California. In the 1930s, Vollmer headed the first U.S. university institute for criminology and criminalistics at the University of California at Berkeley. However, this institute lacked any official status in the university until 1948, when a school of criminology was formed. The famous criminalist Paul Kirk was selected to head the school’s criminalistics department. Many graduates of this school have gone on to develop forensic laboratories in other parts of the state and country.

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In 1932, the Federal Bureau of Investigation (FBI), under the directorship of J. Edgar Hoover, organized a national laboratory that offered forensic services to all law enforcement agencies in the country. During its formative stages, Hoover consulted extensively with business executives, manufacturers, and scientists, whose knowledge and experience guided the new facility through its infancy. The FBI Laboratory is now the world’s largest forensic laboratory, performing more than one million examinations every year (see Figure 1-7 ). Its accomplishments have earned it worldwide recognition, and its structure and organization have served …