Perceptions Versus Reality Reflection - Scenario Based Activity

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1Forensic Science and Criminalistics

Associated Press

Learning Objectives After reading this chapter, you should be able to do the following:

▪ Define forensic science and how it contributes to a case, as well as explain the CSI Effect and the scientific method.

▪ Summarize the history of forensic science and contributors to the field.

▪ List and describe some forensic science specialties.

▪ Identify the elements of a forensic investigation, how physical evidence can be produced, and forensic analysis.

▪ Describe the work and work product of a forensic scientist.

▪ Describe the U.S. court system, and the key rulings on physical evidence admissibility through expert testimony.

▪ List and discuss major issues in forensic science today.

1Forensic Science and Criminalistics

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Learning Outcomes After reading this chapter, you should be able to

▪ Define forensic science and how it contributes to a case, as well as explain the CSI Effect and the scientific method.

▪ Summarize the history of forensic science and contributors to the field.

▪ List and describe some forensic science specialties.

▪ Identify the elements of a forensic investigation, how physical evidence can be produced, and forensic analysis.

▪ Describe the work and work product of a forensic scientist.

▪ Describe the U.S. court system, and the key rulings on physical evidence admissibility through expert testimony.

▪ List and discuss major issues in forensic science today.

Section 1.1Forensic Science

Introduction In this chapter, we will define forensic science and learn how it contributes to a case. This introduction will frame the context for the rest of the book, particularly in an area of forensic science called criminalistics. An overview of the scientific method will show how it underpins what forensic scientists do.

A summary of the history and development of the subject provides background for where we are today. The next section will cover a number of different specialties under the gen- eral “forensic science” heading. This book is primarily about criminalistics, which includes some, but not all, of those specialties. The elements of a forensic investigation will help you understand the way forensic scientists think about cases, and the methods and approaches employed. These elements will come up throughout the remainder of the chapters. Some of the approaches used have to do with the way physical evidence is produced. We will also dis- cuss the work products of a forensic scientist—what gets generated as a result of our work. A brief description of the American justice system will help you see how our work fits in to the overall scheme of things; the way the justice system treats the admissibility of forensic evi- dence is key to everything. Finally, we’ll cover some of the big issues in forensic science today and how they impact the work of the laboratories and scientists.

1.1 Forensic Science What is forensic science? Ask a forensic scientist or look it up, and you will most often hear or see the definition as “science applied to matters of the law.” That is indeed a broad def- inition of forensic science, but it is not very informative. The word forensic comes from a Latin word meaning “of the forum,” or the Roman Senate, which is associated with debating. We now take this to mean “associated with the law or legal proceedings.” Though you may hear people refer to this discipline as “forensics,” this is not entirely correct. Forensic science encompasses all scientific evaluation of evidence completed in order to assist decision-mak- ing in civil or criminal cases or government inquiries.

In the broadest sense, forensic science is indeed science and technology applied to matters of the law. The science could be a physical science like physics or chemistry, a biological sci- ence like biochemistry, or a biomedical science like pathology. As for technology, it could be a branch of engineering, such as mechanical or electrical, or it could be computer and informa- tion technologies applied to a forensic problem.

Two main features distinguish forensic science from more traditional physical and biological science. The first is that the goal of forensic scientists is to produce results and information for a legal case. The second is that forensic scientists are uniquely concerned with individualiza- tion. Individualization means establishing that a person or thing is unique among members of its class. Identifying a person is an example of individualization. Another example would be showing that a red fiber came from a particular article of clothing (which we cannot do— fibers simply do not have sufficient individualizing features). Identifying individual people is an important part of forensic science, and forensic scientists strive to achieve the individual- ization goal, but we will see that some categories of evidence are individualizable and some are not. Unlike forensic scientists, other scientists are not typically concerned with demonstrating that a substance or material or pattern is unique among the members of its class.

Section 1.1Forensic Science

The CSI Effect The portrayals of forensic science featured on various television programs have not accu- rately defined or depicted forensic science. One of the most successful and well-known is the show CSI: Crime Scene Investigation. The original CSI, set in Las Vegas, spawned new shows based in Miami, New York, and Washington, D.C. In a typical show, a crime is commit- ted, and a team of police officers, who are also state-of-the-art forensic scientists, flies into action and works the case from the scene to the arrest and prosecution. They move effort- lessly between crime scene investigation, police work, and laboratory analysis. Their labs look sleek, modern, and clean and are equipped with devices, computers, and instruments that will accurately and quickly answer any question they might have. Another similar series is called Forensic Files, and features individual cases and the role various forensic sciences have had in solving the case.

One of our goals in this textbook is to show you that the portrayals of forensic science by CSI and similar shows are grossly unrealistic, sometimes even complete fantasy. Criminal justice scholars have begun to study the question of whether citizens who are called to serve on juries bring unrealistic expectations and beliefs to the courtroom as a result of TV programs. The influence that these programs may have on jurors, their expectations, and their decisions is known as the CSI Effect.

Some data suggest that jurors bring expectations to the jury room that are based on watching television, which are then factored into their deliberations (National Forensic Science Tech- nology Center, 2012). Jurors seem to expect sophisticated physical evidence analysis even in cases where prosecutors believe they have readily proven the elements of their case without it. Surveys indicate that jurors seem more concerned with what the prosecution did not do than what it did do, particularly in the absence of direct evidence against the defendant (Shel- ton, 2008). More and more, prosecutors are factoring these potential “CSI expectations” into their pretrial questioning of potential jurors (Thomas, 2006).

Criminalistics As mentioned, we will be covering the area of forensic science called criminalis- tics , which stems from the German word kriminalistik. The person most recognized for defining the boundaries of criminalis- tics is Hans Gross (1847–1915). Gross was an Austrian magistrate and a professor at the University of Czernovitz who pub- lished the two-volume book Handbuch für Untersuchungsrichter als System der Krim- inalistik (Handbook for Examining Magis- trates as a System of Criminalistics) in 1893. This publication was the first of its kind, and, as such, Gross is credited for establishing criminalistics as a defined discipline.

luckyraccoon/iStock/Thinkstock Laboratories play an essential role in assisting with substance and DNA testing. Can you think of more examples of how laboratories could be utilized for solving criminal cases?

Section 1.1Forensic Science

Criminalistics encompasses the activities of a modern-day forensic science laboratory. It includes DNA analysis and the biological testing of blood and body fluid evidence that pre- cedes it (Chapters 10 and 11); the analysis of trace (or materials) evidence, including forensic microscopy and items such as fibers, hair, glass, soil, paint, and fragments of any material (Chapter 6); and drug/controlled substances identification chemistry (Chapter 4). It also includes crime scene investigation and reconstruction (Chapter 2) and pattern evidence specialties, which include fingerprints, questioned documents, and firearms identification (Chapters 8 and 9) and more recently, digital forensics (Chapter 3).

Sometimes when people say forensic science, they are talking about criminalistics. For our purposes, criminalistics is the narrower definition of forensic science. The broader definition, you may recall from above, is science and technology applied to legal matters. Forensic scien- tists working in criminalistics labs may have the job title of criminalists. Since criminalistics is not a mainstream term, the media frequently confuse it with criminology, which is a branch of sociology and has nothing to do with laboratory science. Forensic scientists working in laboratories all have at least Bachelor of Science degrees, usually in chemistry, biochemistry, or biological sciences. In addition to their formal education, they have undergone periods of training in the specific specialties that range from several months to several years. There are now around 100 colleges and universities in the U.S. offering forensic science degree pro- grams both at the bachelor’s and the master’s levels.

Forensic Science’s Contribution to Cases There are a number of things forensic science can contribute to a criminal case. They include establishing elements of a crime; identifying substances, materials, or persons; supporting or casting doubt on statements by witnesses, victims, or suspects; providing investigative leads; and establishing linkages between suspects, victims, and scenes. The contribution that foren- sic science makes depends on the type of case, the issue at hand, and the forensic specialty area. We will now discuss these potential contributions one by one.

Forensic science can help establish elements of a crime. In a criminal case, the state or the government has the burden of proof. To convict someone of a crime, the state must prove the elements of that crime beyond a reasonable doubt. The elements of a crime are called the corpus delicti, or body of the crime. An example can be found in a sexual assault case. The following excerpt is the Illinois Criminal Sexual Assault statute (2011). It states what must be proven if an individual is to be convicted of sexual assault in an Illinois criminal court.

§ 720 ILCS 5/11-1.20. (As renumbered and amended by P.A. 96-1551, effective July 1, 2011) Criminal Sexual Assault

Sec. 11-1.20. (a) A person commits criminal sexual assault if that person commits an act of sexual penetration and:

(1) uses force or threat of force;

(2) knows that the victim is unable to understand the nature of the act or is unable to give knowing consent;

(3) is a family member of the victim, and the victim is under 18 years of age; or

(4) is 17 years of age or over and holds a position of trust, authority, or supervision in relation to the victim, and the victim is at least 13 years of age but under 18 years of age.

Section 1.1Forensic Science

The relevant words for forensic scientists here are “an act of sexual penetration.” A sexual assault evidence collection kit (rape kit) may be taken from a sexual assault complainant (Chapter 10). One item in that kit is a vaginal swab. The lab would examine that swab to see if sperm cells were present on it. If they are, it shows that an act of sexual penetration has occurred, and the finding establishes one of the elements of the crime.

Forensic laboratories are also involved in identifying substances or materials, the most famil- iar example of which is a controlled substance, such as heroin or cocaine. A substance taken from someone accused of controlled substance possession must be identified using chemical techniques to support the charges. Another example in which a forensic laboratory would be utilized is in identifying persons using DNA typing and profiling. This role could come up in a criminal case where blood or body fluids were shed at a scene, or in the case of an unidenti- fied human body.

Another role for the lab’s results is supporting or casting doubt on statements people have made to investigators. People may be untruthful to cover up their involvement in a crime. But peoples’ statements about events can also be unconsciously affected by their perspectives or biases. Physical evidence analysis may provide an objective way of testing these statements.

Laboratory findings can also help investigators by providing leads. This has not been a com- mon role for forensic science labs historically, but a good modern-day example is the use of DNA profile databases of convicted offenders. If a DNA profile developed in a new case matches a DNA profile in an older case, there is strong evidence that the same person was involved, even if the person’s identity is not yet known. We will talk about this more in Chapter 11.

Perhaps the most common contribution forensic science makes in criminal cases is help- ing law enforcement officers establish connections between a suspect and a crime scene or victim. Often, these associations from physical evidence analysis provide circumstantial evi- dence in cases where there is no eyewitness account of what happened. Sometimes, forensic scientists will need to testify to these facts in court as expert witnesses.

Trials are dependent on the testimony of witnesses for the prosecution and defense. Two types of witnesses are involved: the witness of fact and the expert witness. The witness of fact, or lay witness, can only testify regarding their experiences and direct knowledge. The expert witness (such as a forensic scientist) delivers unbiased results and analysis in the form of an opinion in court. Generally, only an expert witness can provide an opinion, as this person demonstrates skills and knowledge above that of the general public, and delivers informa- tion to the trier of fact (judge or jury) that will help prove or disprove the matters at issue. A judge must find a forensic scientist qualified to be an expert witness in an area or discipline

Think About It

Can you think of some examples of how physical evidence analysis might test a statement made by a person in a criminal case?

Section 1.1Forensic Science

every time the scientist appears in court. Later in this chapter, more information on when an expert witness is required or how one is chosen to testify in court will be provided. For now, we’ll move on to the role of the scientific method in forensic science.

The Scientific Method and Forensic Science The scientific method is a model that scientists use to design and execute experiments to test theories about how nature works. This method applies only to questions that can be tested in experiments. Figure 1.1 shows the steps scientists must take in implementing this model.

Figure 1.1: The scientific method

The scientific method is used by scientists to answer questions that can be tested using experiments. What kind of questions do you think can be answered using this method? What are some questions that could not be answered using it?

Observation

Question

Experimentally testable

hypothesis

Experiment

Accept hypothesis Reject hypothesis

Section 1.1Forensic Science

Briefly, the scientific method begins with an observation about which one can ask a question and eventually develop an experimentally testable hypothesis—an educated guess that pro- vides an explanation for the phenomenon observed. The next step is to formulate an experi- ment to test the hypothesis. It is important that the experiments be controlled; that is, that only one parameter or variable is changed at a time. True hypotheses generate true predic- tions, but unfortunately, false hypotheses can also generate some true predictions in addition to false ones. It is thus necessary to do lots of experiments to test a hypothesis.

If more and more experiments yield the same or similar results, scientists will come to call the hypothesis a theory. Thus, a theory is a well-tested hypothesis that has not yet been shown to be incorrect. Some theories are so well-tested that they eventually come to be called natural laws. However, even natural laws can be found to be wrong or incomplete. In sci- ence, no proposition, hypothesis, or theory is too sacred or well-established to be considered permanent. There is always another experiment that can be done that may cast doubt on the proposition. In this way, the scientific method is self-correcting. New information and data supplants older versions and improves or corrects existing hypotheses and theories.

It is important to note that experiments must have reproducibility—that is, they must be repeatable in order to be accepted by all scientists studying the same question. If an experi- ment does not yield the same results across scientists, the results are not accepted by the scientific community. This is sometimes a criticism of forensic science, as conclusions may be drawn from data and observations from a crime scene, and those exact conditions and circumstances cannot be repeated.

In their everyday work with cases, forensic scientists don’t use the scientific method as such, but the tests are all based on principles that have been established using it. Further on in this chapter, and in the next chapter, we will talk more about reconstruction. Reconstruction fol- lows a series of steps that is very similar to those of the scientific method. The difference is that with the crime scene, the data are a given and cannot be altered.

A final topic that should be discussed in connection with the scientific method is the scien- tific literature and peer review. The scientific literature is found in journals, which are the primary means of formal and documented communication among scientists. Observations or data that have not been published are considered anecdotal, and scientists do not take anec- dotal evidence seriously.

Scientists submit their experimental work to journals in their field for review and publica- tion. Only a fraction of all papers submitted to journals are actually published. Some journals are extremely influential and broadly read, such as Science, Nature, the New England Journal of Medicine, and Cell, and are considered important sources of scientific information. They have much lower acceptance rates, probably well under 1%. Because they are so selective, the peer review of papers submitted to those journals is considered more rigorous than the average. Two or more scientists who are familiar with the subject area review papers sub- mitted to a journal. They do not repeat the work, but they make a reasoned judgment on the data’s validity and whether the data support the conclusions. The reviewers may recommend acceptance, modification, major revisions, even more experiments, or outright rejection to the journal’s editor.

Section 1.2A Brief History of Forensic Science

There are variations in the way peer review is done. Some journals conceal the authors’ identity from the reviewers, and almost all journals conceal the reviewers’ identity from the authors. The purpose of this is to “blind” people so that prejudices, scientific competition, and personal likes and dislikes do not come into play. It is not a perfect system, but it has served the scientific community well for many decades.

Peer review does not guarantee that the published work is correct or that the data are real. There have been some spectacular instances of fabrication, falsification, and plagiarism in major scientific literature, and numerous instances of it in less-publicized places. Major jour- nals have had to retract papers as a result. Retraction of a paper is an editor’s only option after the paper has been published and then shown to be defective. In science, there is an assumption of integrity—we believe one another until we have a reason not to. Integrity is at the heart of the process, and people who are caught violating it cannot remain in a scientific or research career.

1.2 A Brief History of Forensic Science Forensic science as we understand it today depends on considerable knowledge from chem- istry, physics, biology, and other basic sciences. It was not until the basic sciences were devel- oped, at least to some extent, that we began to see their applications to legal matters.

The basic sciences began to develop in the late 18th century, and many of the early developments in forensic sciences took place during the 19th century. There is at least one very early work in forensic medi- cine from China that dates back many cen- turies, but the early development of toxi- cology, forensic biology, forensic pathology, and fingerprint comparison occurred between 1820 and 1900.

Forensic Science in Europe One of the earliest pioneers of forensic science was a Spanish doctor, Mathieu Joseph Bonaventure Orfila (1787–1853). He attended medical school in Paris as a young man, and rose to become what we would today call the chief medical

Think About It

Do you see value in peer review? Would you trust something you read in the New England Journal of Medicine more than you would if you read it in your local newspaper? More than you would if you read it in a supermarket checkout tabloid? Why?

Prisma/Album/Superstock Known as the father of forensic toxicology, the work of Mathieu Orfila influenced the development of modern-day criminalistics labs both in Europe and the United States.

Section 1.2A Brief History of Forensic Science

examiner of Paris. His work was primarily focused in forensic pathology, but he was the first to perform toxicology testing based on a basic understanding of chemistry. Because of this, he is sometimes referred to as the father of forensic toxicology. In addition, he devised some very early tests for blood and for determining the species of origin of blood.

Much of the development of forensic medicine and biology took place in Europe, especially in Germany, Austria, France, Italy, and a few other countries. In these countries and those that followed their lead, medico-legal institutes came about in the 19th century and some of these still exist today. The institutes were associated with medical schools and provided autopsy and forensic pathology services as well as laboratory testing. Lab testing included toxicology and, in the early years, blood and body fluid characterization. An autopsy is a dissection and examination of a dead body and its tissues and organs to document wounds, medical history, and any disease conditions present. The objective of an autopsy is to discover the cause of death. In much of continental Europe today, there are still medico-legal institutes providing pathology and toxicology services. Many of the countries have also developed criminalistics labs at the national and/or state level. Those labs are similar to criminalistics labs in the United States.

Forensic Science in the United States In the United States, a few medical schools in eastern cities developed medico-legal institutes, modeled after those in Europe, in the early 20th century. These institutes did not persist in American medical schools, and forensic pathology (medical examiner) services, often with their own toxicology labs, became separate entities of city, county, or state governments. A medical examiner is a medical doctor specialized in forensic pathology and empowered by law to investigate the cause and circumstances of questioned death. Fingerprints also came into use by United States police agencies in the early 20th century. We will discuss the history of fingerprints more in Chapter 8.

Military firearms expert Calvin Goddard was one of the first to use the newly developed tools of forensic firearms identification, and he matched weapons to cartridge cases and bullets recovered from the St. Valentine’s Day Massacre of 1929. Because of this, Goddard is widely regarded as the father of firearms identification. The St. Valentine’s Day massacre was a mass murder of people from one organized crime “family” by members of another. There was quite a bit of violent crime in Chicago at the time because of organized crime activities. Even in a city accustomed to the street violence of the time, the St. Valentine’s Day massacre shocked the public. Goddard’s work on this case led to the formation of a forensic laboratory for Chi- cago that was housed for some time at Northwestern University. This lab was eventually transferred to the city of Chicago.

In August 1923, August Vollmer, another figure who had a strong interest in using modern sci- entific methods and procedures to fight crime, became Chief of the Los Angeles Police Depart- ment. Soon afterward, the first government forensic lab was established within the LAPD. Today, this laboratory is still operating. It, along with the more recently formed Los Angeles County Sheriff ’s forensic lab, is located on the campus of the California State University at Los Angeles.

Dr. Paul L. Kirk (1902–1970) became a professor at the University of California, Berkeley, in 1929. Dr. Kirk’s influence was enormous in forensic science, both in California and across the nation. He was a biochemist who quickly developed an interest in forensic science, and

Section 1.2A Brief History of Forensic Science

developed the subject and its underlying philosophy for many years. He also established degree programs in criminalistics in the School of Criminology. Most of the graduates of Berkeley’s criminalistics program went on to work in forensic labs, and many of the ones who had Doctor of Criminology degrees became faculty members in other forensic science aca- demic programs in the U.S. Dr. Kirk was involved in many cases during his long career. He and his students did research as well as providing forensic lab services. Perhaps his most famous case was that of Dr. Sam Sheppard.

Case Illustration: State of Ohio v. Dr. Sam Sheppard Sam Sheppard was a doctor in a Cleveland, Ohio, suburb called Bay Village in the 1950s. His father was a doctor and so were his brothers, and they had a thriving practice. Sam was married to Marilyn Reese Sheppard in a house located on the shore of Lake Erie.

On the Fourth of July weekend, 1954, Marilyn, who was pregnant at the time, was violently murdered. Sam afterward told police a story about a bushy-haired intruder he had got- ten a look at and confronted. He said he had been sleeping on the sofa downstairs and was aroused by noise from the upstairs bedroom. Running upstairs, he got a glimpse of the intruder who fled. He said he checked Marilyn and found that she had no pulse. He also said he quickly checked on his son sleeping in a nearby room and noticed that he was okay. Running back downstairs, he got another glimpse of the intruder whom he chased outside and down the beach.

The case became a press sensation. Members of the press quickly decided that Sam had killed his wife and wrote stories urging Cleveland authorities to arrest and try Sam. After some time, Ohio authorities did so. The trial was a media circus. There was not a great deal of evidence directly implicating Sam, but many did not accept his story either. During the investigation, it had been revealed that he had had a several-year affair with a nurse, and prosecutors contended that this relationship provided the motive for the crime.

In retrospect, commentators have noted that his defense attorney was not very effective. On the other hand, it is not clear that anyone could have overcome the extreme media storm pressing for Sam’s conviction. Sam had suffered significant injuries, and a physician testified to their severity and to the fact that they could not have been faked. The scene was very bloody, and Sam had only a small spot of blood on his trousers. The Cuyahoga County medical examiner, Dr. Gerber, had testified that certain injury patterns on Marilyn were consistent with having been made by a surgical instrument.

Sam was convicted and sent to the Ohio State Penitentiary with a life sentence. There were many appeals, but none were successful until 1964, when a federal court ordered the state to release Sam or retry him. By then, the famous criminal defense attorney F. Lee Bailey repre- sented him. The federal judge noted that the original trial had been held in a “carnival atmo- sphere,” that the trial judge had refused to sequester the jury, and that at least one juror had told a newspaper columnist that Sam was “guilty as hell” before the trial had ended.

The second trial took place in 1966. F. Lee Bailey had hired Dr. Paul Kirk to examine the case and the blood patterns. Kirk wrote an affidavit, and he also testified. His analysis of the blood patterns led to the conclusion that Marilyn had to have been murdered by some- one left-handed (which Sam was not). There was also a spot of unexplained blood at the scene. In addition, Dr. Gerber, the medical examiner, had to admit under cross-examination at the second trial that he could not say with any certainty that any of Marilyn’s injuries were caused by a surgical instrument. Sam was acquitted at this trial.

(continued on next page)

Section 1.2A Brief History of Forensic Science

The first crime labs were established in California and Chicago in 1924 and 1925. The Federal Bureau of Investigation (FBI) Laboratory was established in 1932 in Washington, D.C. It has grown to be the largest forensic science laboratory in the U.S. For many years, it was located in the FBI’s downtown headquarters building in Washington, D.C., but today it is located on the FBI Academy grounds at Quantico, Virginia.

Many states, counties, and cities in the U.S. established forensic labs in the decades between 1935 and 1975. The majority of these labs were established in law enforcement agencies. At first, many of the employees were police officers. As time passed and specialization began to emerge, civilians gradually took over the duties in drug identification chemistry, biological evidence, and trace evidence sections. Specially trained police officers continued to work in fingerprints, firearms, and questioned documents for many years.

In the mid-1970s, there was a large growth of forensic labs. Existing labs expanded, and new labs came into being. The impetus for this growth was a large amount of new money that became available to the states from the federal government under the Safe Streets Act. This act provided for a large federal bureaucracy within the Department of Justice called the Law Enforcement Assistance Administration. Since that time, this federal agency has become the Office of Justice Programs and the National Institute of Justice.

There are currently about 350 municipal, county, and state government forensic labs in the United States with approximately 30 additional federal laboratories. There are also around 40 private, for-profit laboratories. Besides the FBI, the Drug Enforcement Administration (DEA), the Bureau of Alcohol, Tobacco, Firearms and Explosives (BATF), the U.S. Secret Service, the Immigration and Customs Enforcement unit of the Department of Homeland Security (DHS), and the U.S. military services, among others, maintain forensic laboratories. Most of them are specialized and perform examinations that support the particular enforcement mission of their parent agency.

Case Illustration: State of Ohio v. Dr. Sam Sheppard (continued) The whole episode, perhaps understandably, ruined Sam’s life. He married a couple more times, became a professional wrestler for a short while, drank to excess, and died in 1970, only 46 years old.

Sam’s son, Samuel Reese Sheppard, has devoted considerable time and effort trying to establish that his father was improperly imprisoned. A civil case was eventually brought in 1999. The prospect of other perpetrators of the murder was raised, and there was some suggestive but not definitive evidence. Attorneys wanted to try a DNA paternity test on Marilyn’s unborn child to see if the child was really Sam’s. Her body was exhumed, but embalming preservative made it impossible to do the tests. After a ten-week trial, the civil jury concluded that Mr. Sheppard had not sufficiently established that his father was improperly imprisoned. Later, an appellate court ruled (and the Ohio Supreme Court agreed) that the civil case should not even have gone to the jury—that only Sam himself had legal standing to bring the case. The case remains controversial. It is also fair to say that it remains unsolved.

Reflect On It Do you think this case could be solved today with all the advances that have been made in forensic science? Why or why not? What advances would make a difference?

Section 1.3Forensic Science Specialties

Every state has at least one laboratory, and a number of states have lab systems. California, which is the largest state by population, still has the greatest number of laboratories. The majority of public labs are full-service. That is, they can handle drug identification, biology, trace, and pattern evidence cases. A smaller number of labs handle only certain types of anal- yses, such as only processing drug identifications. A few of the private, for-profit labs are also full-service, but many are specialized. Quite a few private labs offer DNA analysis services and nothing else.

Crime scene services are generally handled by law enforcement agencies and by sworn per- sonnel. Crime scene investigators have special training, but they are not lab scientists. By the same token, lab scientists very rarely go to crime scenes. This is another way that the CSI television series is misleading to the public. The show’s viewers are led to believe that the people who go to crime scenes and collect evidence also analyze evidence in the lab, conduct the investigation, track down and arrest suspects, question suspects, and testify in court. They don’t. The following section will go through some of the major specialties in forensic science to help further differentiate what real forensic scientists do.

1.3 Forensic Science Specialties

Under the larger umbrella of forensic sciences are a number of specialty areas. One way to sum- marize many of the specialties is to state them according to the different sections of the Ameri- can Academy of Forensic Sciences (AAFS). AAFS is the largest, most inclusive forensic science professional organization in the U.S. It is divided into sections according to forensic specialty. The criminalistics section of AAFS is the largest one. As criminalistics was described earlier, we will begin with forensic pathology.

Forensic Pathology Forensic pathology, or forensic medicine, is one of the older specialties. A forensic pathologist,

Think About It

Do you think having all these different forensic labs under federal, state, and city/county jurisdictions is a good thing for efficiently working cases? Would it be better to have fewer, larger, well-resourced labs? Why or why not? What difference would this make to investigators?

KatarzynaBialasiewicz/iStock/Thinkstock Forensic pathologists can be asked to investigate any death that does not occur under medical supervision.

Section 1.3Forensic Science Specialties

or medical examiner, is a board-certified medical doctor specializing in forensic pathology. This doctor is commissioned to investigate questioned deaths, which can be any death that does not occur under medical supervision, i.e., in a hospital or clinic. After investigation, the pathologist issues a medical examiner death certificate ruling on the cause and manner of death. The cause is a medical determination, often ascertained from an examination of the body or death scene, and an autopsy. In a small percentage of cases, the cause of death cannot be determined. The manner of death consists of the circumstances surrounding the death, which could be a homicide, suicide, accident, or natural causes. In most medical-examiner jurisdictions, the forensic pathologist’s ruling is final. Some states have statewide medical examiners, but the doctor does not investigate all questioned deaths in the state. This doctor may see all cases in one locality and have a supervisory authority over the other counties.

The coroner system allows elected officials for a county or municipality, such as a sheriff or local funeral director, to perform the responsibilities of death investigation. However, most coroners do not have medical training, and they sometimes employ the services of forensic pathologists for their death investigations. Coroners’ rulings carry the same legal weight as those of medical examiners. The coroner system is more common than the medical examiner system for investigating questioned deaths in the U.S.

Cause and manner of death can be very important in prosecuting a case. See the case example of State of Florida v. Casey Anthony.

Case Illustration: State of Florida v. Casey Anthony In the 2011 Casey Anthony case in Florida, in which she was tried for the murder of her daughter Caylee, there was considerable public argument over the fact that the jury acquit- ted her of a murder charge.

A big factor in this case was the fact that the child’s remains were in a wooded area for several months, and there wasn’t much left except skeletal remains. The medical examiner was not able to determine a cause of death, although she did rule the death a homicide. Some other pathologists thought that even the homicide ruling was a stretch. The condition of the remains simply didn’t permit a complete autopsy.

The inability to find a cause of death allowed Casey Anthony’s defense to argue that the death might have been accidental. Duct tape found on the mouth of the child’s remains sug- gests but does not by itself prove some sort of foul play. There was circumstantial evidence that made the defendant look like she had a lot to hide and that the child’s body may have been in her car trunk.

Regardless of the way people are divided about the verdict, this case shows how important cause and manner of death can be in a criminal prosecution.

Reflect On It If the cause of death had been determinable in this case, and the medical examiner could have stated unequivocally that this was a homicide, do you think the outcome might have been different? Why or why not?

Section 1.3Forensic Science Specialties

Though not a part of forensic pathology as such, forensic entomology can be an important specialty in figuring out time since death. Entomology itself is the study of insects. If insect eggs, larvae (maggots), or pupae (cocoons) are found at a death scene, a forensic entomolo- gist may be able to identify the insect species and, based on knowledge of the insect life cycle, calculate an estimated time of death.

Forensic Toxicology Forensic toxicology (Chapter 5) involves the action, fate, and effects of toxins and drugs in the body and includes the detection of drugs or toxins in living and deceased persons. There are both public and private forensic toxicology labs. Most of the public labs are dedicated post- mortem toxicology labs within medical examiners’ offices, or labs operated by law enforce- ment or public safety agencies that serve the needs of coroners or medical examiners who don’t have their own labs. Examples of forensic toxicology applied to living persons include forensic urine drug testing and testing sexual assault complainants for “date-rape” drugs.

Forensic Odontology Forensic odontology is forensic dentistry. Forensic dentists are almost all practicing dentists who help with forensic cases as needed. They do two main things: (1) dental identifications of otherwise difficult-to-identify human remains; and (2) bite mark analysis and comparisons.

Dental identification is a method of choice for identifying human remains, particularly in mass disasters. Forensic dentists are called to mass disaster scenes through an organization known as the Disaster Mortuary Operational Response Team (DMORT) to help identify the dead using dental x-rays. Bite marks are difficult to work with because they are nearly always on curved surfaces and are deformable on human skin. These analyses have become less com- mon in recent years, but they were previously used to identify people, such as notorious serial killer Ted Bundy. Today, most forensic odontologists no longer think a specific person can be identified from a bite mark. Specific persons can be excluded on the basis of bite marks, however.

Forensic Anthropology In the context of forensic science, anthropology is physical, not cultural, anthropology. Classi- cally, forensic anthropology involves the examination of human skeletal remains. Forensic anthropologists can tell if a bone or even a bone fragment is human or not and, if human, where it came from in the body. In cases involving skeletal remains, a forensic anthropology analysis is a must. These experts can tell approximately how long the bones have been bur- ied, determine whether the bones are from modern people or older civilizations, and provide estimates about the age, possible racial origin, gender, and stature of the person, depending on which bones are recovered and their condition. They can also spot skeletal abnormali- ties, traumatic injuries such as healed fractures, and external trauma like gunshot wounds to the skull or knife cut marks on bones. This information can help law enforcement identify the remains. Generally, a person cannot be identified (individualized) from anthropological examination of skeletal remains alone.

Section 1.3Forensic Science Specialties

Other activities in which forensic anthropologists participate include searching for human remains that have been buried or that are in heavily wooded, hard-to-search areas. These searches can involve flights by aircraft equipped with special heat-sensing units (decaying remains and maggot-infested soft tissue give off heat), cadaver dogs, and the like. Some foren- sic anthropologists are trained in molecular biology and are specialists in mitochondrial DNA analysis. This analysis has been the method of choice in the DNA analysis of old bones and can help identify skeletal remains.

Forensic Engineering Forensic engineering includes civil, mechanical, electrical, or other engineers with Professional Engineer (P.E.) certifica- tion who specialize in legal matters involv- ing these engineering specialties. One might say that the “bread and butter” of this specialty is automobile accidents. Many of these accidents result in injury or death and lead to legal cases. Forensic engineers are able to reconstruct automo- bile accidents if they have good data from the accident scene. Today, there are com- puter programs that will do much of the number crunching if provided with the accident scene information. Issues such as how fast the cars were going, their direc- tion at the time of impact, whether the brakes had been applied, mechanical problems existing in the vehicles before the accident, and so forth, will have an impact on assigning fault or blame for the accident and in assessing monetary damages.

The U.S. National Transportation Safety Board (NTSB) investigates every train wreck and plane crash to determine the cause. Although these are highly specialized types of investiga- tors, they are at heart forensic engineers. Forensic engineers are also involved in explaining major structural failures, like the I-35 bridge collapse in Minneapolis in 2007 or the FIU foot- bridge failure in 2018. Product failures are another area of forensic engineer involvement. The product can be anything from a tire to a toaster. These are nearly always civil cases, and they involve trying to show that a plaintiff ’s injury or death was caused by a manufacturer’s defect in the product and that the manufacturer knew about it, but didn’t correct it.

Digital Evidence The examination of digital evidence (Chapter 3) is a specialty that has expanded rapidly over the past few decades, as people have become increasingly reliant on computers, mobile phones, and other technology. These devices contain a great deal of information, and it is the digital evidence analyst’s role to sort through it to find information relevant to a case. This

Joe Raedle/Staff/GettyImages Though less known than other roles in forensic science, forensic engineering is an important discipline, especially when investigating cases like the collapse of this pedestrian bridge in Miami, FL, in 2018.

Section 1.3Forensic Science Specialties

area has been called computer forensics, but for the reasons discussed earlier, that term is incorrect and should not be used.

In this age of digital everything, no computer-based activity fails to leave a digital trail. In many criminal cases, these analyses will be fairly straightforward and simple. Is there an informa- tive voicemail message? Does a call history reveal anything useful? Does a history of visited websites help? In complicated cases, more knowledge and expertise could be required, such as recovering deleted files, or trying to trace the source of Web activity that has been pur- posely routed all over the place to conceal its origins. There is also a major national security aspect to this work that goes beyond traditional forensic analysis.

Questioned Documents Questioned document examination is a part of pattern evidence (Chapter 9). The other main pattern specialties have their own separate professional organizations but don’t have their own sections within AAFS. For example, the primary professional organization for fingerprint examiners is the International Association for Identification (IAI); the one for firearms and tool mark examiners is the Association of Firearms and Tool Mark Examiners (AFTE).

Psychiatry and Behavioral Sciences Forensic psychiatrists are medical doctors specialized in forensic psychiatry. There are also forensic psychologists, some of whom do similar work. Some Ph.D. psychologists and M.S.W. holders can obtain state licenses to see and treat patients. Professionals in these specialties examine offenders and make reports to the court to answer questions such as whether a per- son is competent to stand trial. They may also examine children who have been taken away from their families because of parental irresponsibility. They would then advise a court as to whether the children should be returned to the parent or remain in foster care.

A few people in this specialty do criminal profiling. Criminal profiling is relatively rare. You can think of it as a last resort in a case that has not been solved. Profilers try to construct a description of a criminal from an examination of the crime scene, the criminal’s habits, and their experience with other known perpetrators of similar crimes. There have been several TV shows and series based on criminal profiling, such as Profiler, Criminal Minds, and Net- flix’s Mindhunter. Profilers rely to some extent on data from past offenders and past cases. Serial murderers and serial rapists in unsolved cases are probably the most frequently pro- filed offenders.

Jurisprudence and Other Specialties The jurisprudence section of AAFS is made up of attorneys who have special skills, train- ing, and/or interest in forensic sciences. AAFS also has a General Section which has all the members whose specialties do not fit into one of the other established sections. Crime scene investigators who belong to AAFS are in the General Section. So are the forensic nurses. Ini- tially, forensic nursing focused on the treatment of sexual assault cases and the collection and preservation of evidence in emergency department situations.

Section 1.4Elements of Forensic Investigation and Analysis

Common Specialties vs. Occasional Specialties The specialties we have mentioned within criminalistics (drug chemistry, trace and materials, biology and DNA, fingerprints, firearms, and questioned documents) are common in case- work. Full service labs receive these types of cases every day. Medical examiners and coroners are busy. Every case of questioned, sudden, or unexpected death comes to their attention. The psychiatrists and psychologists who evaluate offenders or others for courts are also kept busy. Forensic dentistry, anthropology, and entomology are employed far less frequently. Most of these specialists are full-time professionals or professors who work on forensic cases when the occasional demand arises. Similarly, profiling is comparatively rare. No matter which spe- cialty or specialties are needed, there are four common elements that can be part of a forensic case.

1.4 Elements of Forensic Investigation and Analysis The following are a few elements that are, or can be, part of forensic investigations and analysis.

1. Recognition 2. Classification (Identification) 3. Individualization–Common Origin 4. Reconstruction

These elements provide a helpful way of thinking about the overall analysis of forensic cases and evidence. Not every case nor every specialty includes all the elements. Some specialties are concerned only with a straightforward chemical identification or quantitation. For exam- ple, in most states, a person is considered to be driving under the influence of alcohol if his or her blood alcohol level exceeds 0.08% weight to volume. A blood alcohol analyst uses an instrumental method to determine the ethanol content of someone’s blood, which will either be above or below the legal limit. This is a straightforward measurement.

In complex cases that involve crime scenes, more of the elements will come into play. Rec- ognition is an important element. It means recognizing what is evidence and what is back- ground at a scene or in a case. It is important because unrecognized evidence is not factored into the case, and background items clutter the picture and the laboratory. The best criminal investigators have a knack for this. To some extent, training and education can improve a per- son’s recognition skills, but there is an extent to which this cannot be taught.

Think About It

Some cases can involve many different specialty areas, and as a result many different spe- cialist forensic scientists. What do you think is the best way for all these different experts and their work to be coordinated in a case?

Section 1.4Elements of Forensic Investigation and Analysis

Classification (identification) means stating what something is; that is, placing it into a cat- egory. This exercise can be intuitive, like recognizing a table or chair, or it may require chemi- cal testing, such as with a drug or a red stain thought to be blood. Classification is based on seeing and recognizing class characteristics, those features that cause an item or object to be placed into a class or category. Thus, all people have certain things in common, as do all houses, or all fibers of a certain color.

As defined earlier, individualization is the process of trying to show that a person or thing is unique among members of its class. Examples of this process include proving the identity of human remains, or determining that a particular firearm fired a bullet found at the crime scene, or that a latent fingerprint on a beer bottle was made by the left index finger of a sus- pect. Individualization is based on individual characteristics. Many kinds of physical evi- dence cannot be truly individualized. However, we are able to individualize (identify) people. Another way of looking at this element is through the idea of common origin. Much of forensic analysis is a comparison, and the comparisons are focused on demonstrating that there is or is not common origin. Did a red fiber come from a particular carpet? Did a fragment of glass originally belong to a now-broken automobile headlamp lens? We will get back to this con- cept a little later in the chapter.

Reconstruction is an attempt to determine past occurrences from physical evidence. Crimi- nalists may try to reconstruct the events of a crime from the crime scene and physical evidence left at the crime scene. The process, when done properly, follows the scientific method. The data and observations consist of the crime scene itself, the patterns found there, the results of the physical evidence analysis, the pathologist’s results (if a death is involved), and investiga- tive information. From this information, a hypothesis of what happened can be formulated. If new findings arise, the hypothesis must be adjusted accordingly so it fits all available data. The difference between this sort of reconstruction and the conventional scientific method is that one cannot do controlled experiments to test the hypothesis. The information and data are fixed by the events. Sometimes, experiments may be done to show that certain things could have happened. We will see this in the next chapter in connection with blood patterns.

Reconstruction should not be confused with reenactment. Here, an effort is made to recon- struct events completely from the physical evidence record and investigative findings. Although reenactments are sometimes admitted into evidence in courtrooms, they must be seen for what they are: speculation. There is never enough physical evidence to reconstruct an entire case event in detail. The elements of a forensic investigation and analysis come into play once there is physical evidence to study. Next, we will learn how this evidence is made.

How Physical Evidence Is Produced Thinking about various ways physical evidence can be produced helps us understand the analyses used to examine the evidence. Some evidence is contextual; that is, it is evidence because of the circumstances in which it is found. Examples are human remains at a homicide scene, suspected controlled substances in situations where illegal drugs are likely to be found or exchanged, and so on.

Most physical evidence is produced by transfer actions. Patterns such as imprints, indenta- tions, or striations may be formed on receiving surfaces. An imprint doesn’t have much three- dimensional character—for example, a fingerprint or a tire impression on a hard surface. An indentation is a three-dimensional pattern in a soft receiving surface, like a tire impression in

Section 1.4Elements of Forensic Investigation and Analysis

soft mud, a bite mark in an apple, or a sneaker impression in snow. A striation results from one surface marking another surface by moving along it. The markings on bullets from barrels, and many tool marks, are striations.

Tears, cuts, or breaks might also pro- duce evidence. If these are irregular and random, and not statistically expected to be duplicated, there is the potential for individualization of the evidence through physical matching. Random fractur- ing forms the basis for the individuality attributed to physical pattern matching. Let’s say, for example, a glass was bro- ken during a struggle at a scene. Many of the pieces were still at the scene, but some were missing. Later, a suspect is developed and their clothing searched. A fragment of glass is found in their clothing than can be physically matched back to the broken glass. Do you think this finding is enough to place the suspect at the scene? Do you think we can prove that the fragment could not be randomly replicated by another, different glass breaking?

Transfers can be one-way or mutual. Placing a body in the trunk of a car to move it to a hiding place for disposal might result in blood or body fluid transfers to the car trunk carpeting, as well as carpet fiber transfers to the body. Sexual assault case analyses are based on the trans- fer of semen from a suspect to a complainant and possibly some transfers of cells, hairs, or cosmetic residues to the suspect.

There is a “rule” often discussed in forensic science called the Locard exchange principle. A French criminalist, Edmond Locard (1877–1966) articulated this idea. The principle states that two objects coming into contact with one another will mutually exchange matter; that is, they will leave traces of one another. This idea forms the basis of many types of transfer evi- dence analysis. The point of analyzing trace evidence is that it may have been transferred and can therefore be used to draw inferences about associations between people, things, or places. While it may be true in theory that contact between objects results in the transfer of some material, it is also true that forensic scientists cannot always detect these transfers. Further, transferred trace evidence items must be cautiously interpreted. Someone could have another person’s hair on his or her clothing, and it could then get transferred to a sofa where the per- son sits down. From there, the hair could get transferred to a second person’s clothing.

Con Tanasiuk/Design Pics/Thinkstock Imprints, like tire tracks found at the scene of a case, are just one example of a type of physical evidence. What other examples can you think of?

Think About It

People go to movie theaters and sit on plush seats made of synthetic materials and fibers. If you had known specimens of fibers from the seats in a theater, could you examine the clothing of 100 people on the street outside the theater a few minutes after a performance for fiber transfers and tell which ones had been sitting in the theater? Why or why not?

Section 1.4Elements of Forensic Investigation and Analysis

Evidence can be deposited on a surface, as in a blood spatter pattern. Evidence of where some- thing or someone has been might be gleaned from pollens dispersed by plants and deposited on the person or thing. Latent fingerprints on nonabsorbent surfaces represent residue from friction ridge skin—the flowing ridges of skin on the epidermal and dermal surfaces of pri- mate finger, hand, and foot skin. Keeping in mind the different ways physical evidence can be produced helps investigators recognize potential evidence. It also helps them know what kind of information the evidence may yield in the laboratory. Once physical evidence is pres- ent and collected, the method of comparing unknowns and knowns can be used by forensic scientists to try to individualize it.

Comparing Unknowns and Knowns In the analysis of unknowns, the goals of classification and attempted individualization are often pursued through comparisons with knowns. Unknowns are referred to as questioned specimens and are derived from crimes, scenes, and cases, the nature or individuality of which must be determined. Knowns can be called standard, exemplar, or reference speci- mens, and are of known identity and history. A lot of what goes on in a forensic lab consists of comparing unknowns with knowns. Even in the case of a chemical identification of a drug, the questioned specimen is identified by comparing its properties with those of known drugs by way of an analytical instrument. An analyst could say: “I identified cocaine in the specimen using GC-MS.” GC-MS stands for gas chromatography-mass spectrometry, an established tech- nique for doing chemical identifications. What the analyst has really done is use the instru- ment to generate a spectrum representing the unknown, then used the instrument’s library to compare that spectrum with those of known drug substances, like cocaine, heroin, meth- amphetamine, and so on. If the spectrum of the unknown matches the spectrum of cocaine exactly, the unknown is identified as cocaine. With unknown trace materials, like fibers or glass, the known is the suspected source, like in our broken glass example earlier. With pat- tern evidence, the known is produced by a known source, such as a gun firing a bullet, a finger making a fingerprint, or a sneaker making an imprint.

When we discuss items or patterns from scenes, it is often up to investigators to provide the known with which the unknown is to be compared. For example, if the question is, “Did an unknown fiber come from some source (such as a carpet or an item of clothing)?” then that source or a sample of it must be provided. Sometimes, the known can be produced in the lab. A gun, for example, can be fired and the known bullet or cartridge case then collected. A tool suspected of having made a questioned mark can be used to make known marks for comparison.

Sometimes, it is necessary to use control specimens or samples. Controls are specimens of known origin and history that are used to make sure tests and procedures are working prop- erly. A chemical test for blood may be performed on known blood, for example, to make sure the test gives a positive result. The known blood would be a positive control. Suppose sterile water moistened a Q-tip that was being used to swab some dried blood for testing. The blood test might then also be performed on an unused Q-tip, which would be a blank control. The expected negative result would prove that the Q-tip by itself was not causing the blood test to be posi- tive. Some knowns are not really controls, because their nature and history are not completely known. A carpet, for example, that is thought to be the source of a questioned fiber is not a con- trol, because we don’t know its history. It is a comparison sample or comparison specimen. It is to be used for comparison with the questioned fiber to see if the questioned fiber could have originated from it. Examples of different types of specimens can be found in Table 1.1.

Section 1.5Work Products

Table 1.1: Known, unknown, and control specimens

Type of specimen Properties/description Examples

Exemplar; Known; Reference

History and nature fully known. Certified drug known; blood from a known person; paint from a manufac- turer’s reference library.

Questioned; Unknown Neither history nor nature known; requires testing and/or comparison; originates from cases.

Any item of physical evidence from a case, victim, or suspect that requires analysis and/or comparison.

Control Positive

Negative

Blank

A known specimen that must give a positive result with a specific test. A known specimen that must give a negative result with a specific test. A known specimen “carrier” that must give negative results with a specific test.

Depends on the specific test; e.g., known blood for a blood identification test. Dog blood in a test for human blood. A blank Q-tip or swab in any test that uses them to pick up specimen for testing.

Comparison History and nature are not fully known but the specimen comprises the vehicle or carrier of the evidence specimen.

A specimen of unburned carpet from an area close to burned carpet where an ignitable liquid may have been used to start a fire. An unstained specimen of the mate- rial on which a biological stain was deposited.

1.5 Work Products Forensic scientists produce several types of work products as a result of their analyses: labo- ratory or bench notes, reports, and expert testimony. In a way, these are the most important products of a forensic analysis, because they are the only ones that have an impact on cases in the justice system.

Lab Notes Any time laboratory work is done, there is a contemporaneous record of it. This record may be within an instrument, or on forms specifically for the test that the analyst completes, or written or typed notes within a lab notebook. Depending on the lab, there are guidelines for the way notes are kept and preserved. In research labs, guidelines are set by the principal researcher or in part by the agency or entity that is providing funding. In industrial research labs, guidelines are set by each company. For example, in a drug development company, the guidelines are very stringent because there must be a complete and accurate record of all experiments if a drug is to be submitted for clinical trials. Accredited labs are also subject to stringent guidelines on their lab notes. Many toxicology labs follow good laboratory prac- tices (GLP). Labs accredited under the International Standards Organization standard 17025 (commonly called ISO 17025) must adhere to the standard’s requirements. Generally, lab notes must contain sufficient information detailing what an analyst did and what the find- ings were. The form and format of lab notes in forensic laboratories is universally dictated by the laboratory’s parent agency. In accredited laboratories, the form and format is formalized according to accreditation guidelines.

Section 1.5Work Products

What lab notes look like varies a lot according to the type of evidence. A biological evidence/ DNA analysis typically has a lot of lab notes, and there are printouts and charts from the instruments used as well. A bullet comparison, on the other hand, is primarily visual/micro- scopical. The lab notes in this type of examination are minimal.

Examiners use lab notes to generate their formal lab reports. Notes can also be subpoenaed by attorneys representing a defendant. In cases that have forensic evidence, attorneys for a defendant may decide to hire their own experts. Those experts will want to see the lab notes in addition to the lab report.

Reports A report is a formal summary of laboratory tests or of an expert’s opinion, as well as the con- clusions that can be drawn from the tests. It does not usually contain much detail about the methods used or the underlying principles of the tests, but it must be supported by the lab notes. Accredited laboratories are required to keep a master methods manual or file that details the methods the lab uses for every purpose. These methods must be validated (shown to work properly, predictably, and in the hands of all analysts). The methods manual is avail- able to onsite accreditation inspectors or others having a need for them. The methods manual is also subject to subpoena by attorneys representing defendants.

Forensic analytical reports follow a format dictated by the laboratory administration, which varies among report types. The formal report, which is signed by the analyst who did the work and often by a peer and/or a supervisor, is the laboratory’s official documentation of its work, which goes back to the agencies and agents who submitted the case. In a case, attorneys for the defendant can obtain the report under the rules of discovery. A knowledgeable expert should be able to read the lab notes and determine what the analyst did and what was found, then compare these things with what is written in the report.

Expert Witness Testimony When cases go to trial, expert testimony is the crowning conclusion of a forensic examiner’s analysis. In court, the exam- iner is first qualified by the judge as an expert witness and then is questioned by the prosecution and defense regarding the testing, findings, and conclusions that can be drawn.

Testimony is perhaps the hardest thing forensic experts do, because most of the people listening have no technical train- ing or expertise in the subject. Experts must take complex material, tests, and test results, and simplify them so the aver- age person can understand the informa- tion. This process can greatly oversimplify the science and technical issues, which is

Mary Schwalm/ASSOCIATED PRESS The role of expert witnesses can be difficult, as their job is to present their findings to the court in language that can be easily understood.

Section 1.5Work Products

perhaps the most insidious potential danger of the CSI Effect. Jurors may believe they know as much about a topic as the expert witness and might then second-guess the expert. Scholarly studies on the CSI Effect on jurors have produced mixed results, so it is not clear right now whether juror expectations of forensic scientists are more likely to favor one side or the other.

An important thing to understand about expert testimony in courts, however, is that only a small handful of cases ever get to trial. The majority of criminal cases are settled through a plea bargain, where the attorneys and the court agree on what they deem a fair settlement of the case without a trial. In civil cases, a similar process resulting in a settlement is generally concluded before a trial. The only way a forensic laboratory’s findings will be considered in this process is through a lab report.

Who Testifies? There have recently been three U.S. Supreme Court cases concerning the constitutional rights of criminal defendants “to be confronted by the witnesses against them” as stipulated in the Sixth Amendment. This may sound simple, but for operational forensic science laboratories, it can create difficult problems. Can an affidavit from an analyst be entered into the record, assuming no objection from the defendant, and stand in place of that analyst actually testi- fying? Can a scientist who signed the lab report as the peer reviewer testify in place of the actual analyst? Can a supervisor testify on behalf of an analyst, given that the supervisor was ultimately responsible for the results and interpretation, but did not do the actual work? Over the years, labs have taken steps to improve their efficiency and productivity, and part of this has included not committing analysts to courtroom testimony if it did not seem necessary.

In the 2004 case of Crawford v. Washington, the Supreme Court ruled that testimonial state- ments of a witness could be admitted if the declarant is not available, where the defendant has had a prior opportunity to cross-examine the witness (for example, in a pre-trial deposition). In 2009, Melendez-Diaz v. Massachusetts came to the court. Massachusetts had a practice of submitting affidavits by analysts as to the identity and quantity of controlled substances in drug chemistry cases. Unless the defendant asked for the analyst to be called, the analyst did not appear. Melendez-Diaz argued that the state must produce the analyst if it wanted the drug chemistry results admitted into evidence. The Supreme Court agreed. In a 2011 case, Bullcoming v. New Mexico, a lab report certifying that the defendant’s blood alcohol was well in excess of the state’s driving-under-the-influence level was submitted. The actual analyst was on unpaid leave and was not produced. Another analyst who knew how the test worked, was familiar with the testing instruments, and did a job similar to the signing analyst, was produced. He had not observed the first analyst do the work. The defendant appealed to the New Mexico Supreme Court that, under the Melendez-Diaz ruling, the report should not have been admitted. The state court said that the first analyst was merely acting as a recorder of information produced by an analytical instrument and that there was no confrontation clause error. The U.S. Supreme Court did not agree, and reversed the case.

The U.S. Supreme Court has taken a hard line in these cases about producing the actual ana- lyst who did the testing, and has not appeared willing to carve out exceptions to the rule. The states, on behalf of the labs, have argued that producing the analyst in every instance will reduce a lab’s efficiency. In 2012, the Supreme Court appeared to make a limited exception to their prior rulings. In a 5-4 decision in Williams v. Illinois, they said that an Illinois State Police expert testifying in place of an out-of-state lab analyst on DNA was sufficient to meet the

Section 1.6The Justice System

confrontation rule. With time, more law may be developed in this area. For now, however, analysts will likely have to testify to their evidence if it is to be admitted.

Language and Vocabulary Why would the language or vocabulary used by forensic scientists matter? In a word, it is because the language used by forensic specialists can be “loaded.” Certain words carry impli- cations for the listener that may or may not be intended by the speaker or writer.

One important point here is that different specialties can use the same word to mean differ- ent things. A criminalist might write or testify that, “Blood was identified in specimen # 13.”

This means that specimen # 13 in the case contained an unknown red substance and that lab tests demonstrated that it was blood, though not necessarily human blood. On the other hand, in a case involving a gun and a bullet, let’s say the gun was denoted as item # 7, the questioned bullet as item # 19, and the test-fired known bullet as item # 25. A firearms examiner might write or say: “Item # 19 was compared with item # 25, a bullet fired from the firearm (item # 7), and the firearm was identified as the source of both bullets.” This means that the ques- tioned bullet came from this particular firearm to the exclusion of all others, even of the same make and caliber. In other words, it is an individualization. So, even though both statements use the word “identification,” they don’t have the same meaning.

Forensic scientists have not yet developed a vocabulary across specialties that everyone agrees on. As a result, it may be difficult for a reader of a forensic report to know what an expert means when using certain words. Vocabulary within specialties is agreed upon, and forensic experts share those terms, but the audience for reports or expert testimony may not know the “language” of the discipline and may not correctly understand it.

1.6 The Justice System The justice system is divided into criminal, civil, and regulatory law. Forensic science can apply to all of them. Most of the time, forensic science gets into the press or public view as the result of criminal cases, especially high-profile ones. High profile cases are followed relentlessly and in excruciating detail by the media. Forensic experts testifying in those cases are put in the position of not saying anything at all (for which the media implies they have something to

Think About It

Do you agree with the U.S. Supreme Court on compelling analysts to appear in order for their evidence to be admissible? Why or why not? What are the compelling arguments for having the actual analyst available for cross-examination? What are the compelling argu- ments for allowing an equally knowledgeable expert to provide testimony?

Section 1.6The Justice System

hide) or trying to be forthcoming without compromising the defendant’s right to a fair trial. However, the vast majority of criminal cases do not receive any media attention.

Although the majority of civil cases are not high profile, they can still involve many issues that require forensic analysis. Product failure cases, for example, require expertise on the manu- facturing and engineering of the product. Disputed paternity cases require experts to find out whether the accused man could be a child’s biological father. Regulatory matters can also involve forensic analysis. There are laboratories that try to “fingerprint” an oil spill in a body of water and trace the oil to a particular ship for enforcement action. In states that have horse racing, there are forensic toxicology labs that are dedicated to testing the blood and urine of the winning horses to be sure they have not been given any forbidden drugs or chemical sub- stances that could have enhanced their racing performance.

Admissibility of Scientific and Technical Evidence For forensic scientists and experts, the most important aspects of the judicial sys- tem involve the admissibility of scientific and technical evidence through expert witnesses, and perhaps also the determi- nation of who can testify as an expert. There are federal and state rules on these issues which are set by the judges. Some- times, a state will adopt (or adapt) the fed- eral rules rather than create its own. Gen- erally, these rules govern who can be an expert witness create and what sort of evi- dence is admissible. Sometimes, an appel- late or supreme court hands down an important decision that sets new rules.

The rules concerning admissibility of scientific evidence evolved over the 20th century. The first case that addressed the matter was a Washington, D.C., case called Frye v. United States. The U.S. Court of Appeals for the District of Columbia heard the case and issued a decision in 1923. The issue before the court was the admissibility of polygraph (lie detector) evi- dence. The defendant had requested and passed a polygraph to bolster his claim of innocence. The opinion was important because it became the admissibility precedent for 70 years. The court said:

Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone, the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field to which it belongs. (Frye v. United States, 1923, p. 1)

Fernando Vergara/Associated Press The use of polygraph testing as evidence is highly controversial. What is your opinion on the validity of a lie detector as solid evidence?

Section 1.6The Justice System

Over the years, there has been much controversy over what the court meant by “well-rec- ognized scientific principle,” “general acceptance,” and “particular field to which it belongs.” There have been hundreds of articles by lawyers and law professors defending and damning the Frye principle. The reason behind the Frye opinion and all legal activity surrounding this issue is the attempt to exclude junk science from courtrooms. Junk science refers to an area or test that has all the appearances and trappings of science, but that has not been rigorously tested using proper scientific method.

In 1993, the U.S. Supreme Court heard a scientific evidence admissibility case called Daubert et ux. et al. v. Merrell Dow Pharmaceuticals. The Supreme Court had never examined this mat- ter before, so this was a precedent-setting decision. Between the Frye and Daubert decisions, the federal judiciary had established a rule called Federal Rule (F.R.) 702, which says:

A witness who is qualified as an expert by knowledge, skill, experience, train- ing, or education, may testify in the form of an opinion or otherwise if:

a. the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue. (Committee on the Judiciary, 2014, p. 15)

This appeared to many to lower the standard of admissibility of scientific or technical evi- dence. The criterion seemed now to be whether the testimony would assist the jury. There was also disagreement among lawyers and courts about whether F.R. 702 supplanted Frye as the admissibility standard or was separate from it.

Daubert is an epidemiology case. It was a class action in which Mrs. Daubert and all those in the class took a morning sickness drug (made by Merrell Dow) called Bendectin during preg- nancy. Her baby and those of the others in the class were born with birth defects, and the suit alleged that Bendectin caused these defects and that Merrell Dow knew about this (or should have known about it) and marketed the drug anyway. How can this matter be decided?

Epidemiologists versed in statistical analysis looked at a large population of women who (a) took the drug and (b) did not take the drug during pregnancy, and they examined the rate of birth defects among the two groups. This analysis was done, and there was no difference. But, the plaintiffs persisted. They engaged the services of other academic medical epidemiologists who reexamined the same data and concluded that there was a statistically ascertainable difference. In the U.S. Supreme Court ruling, the justices took a view of science and the sci- entific method espoused by Karl Popper. Popper talked about the concept of the falsifiable hypothesis (Popper, 1959). A property of a hypothesis that allows it to fall within the realm of science is that it can be tested for falsity. The court’s ruling in this case has six prongs, or elements.

1. Is the proposition testable? 2. Has it been tested? 3. Are there accepted standards around the testing? 4. Has there been peer review and/or publication? 5. Is the proposition generally accepted? 6. Is there a known error rate, and, if so, what is it?

Section 1.7Major Issues in Forensic Science Today

The first two elements ask in effect: Is this science? In other words, are we talking about something that lends itself to hypothesis testing in the sense of the scientific method? The rest of the elements are self-explanatory. Recall that we discussed peer review in the context of publication of scientific papers. Peer review can happen without publication too. A scien- tist can independently check another’s work to see if it is scientifically viable. The court did not specify that any particular number or percentage of these elements had to be met. They made the judge the gatekeeper. It would be up to the judge to decide an issue of admissibility under the Daubert standard. Six years later, the Supreme Court decided a tire failure case, Kumho Tire Co. v. Carmichael, which extended the Daubert principles to all technical testi- mony, not just testimony about purely science subjects.

Today, many, but not all, states have adopted the Daubert standard. Those that have not oper- ate under the Frye rule or, often, a tightened up version of it. Much of the discussion about the problems in forensic sciences centers around the Daubert criteria. Do all the specialties qual- ify as science in the Popperian context? And has everything been rigorously tested and found to be reliable? The next section will cover some of the other issues in the forensic sciences.

As we are now immersed in the digital age, the courts are having to come to grips with whether GPS tracking devices or cell phones can be used to track a suspect’s movements and under what circumstances this evidence is admissible. In 2012, the Supreme Court ruled that law enforcement needs a search warrant to use a GPS tracking device on a suspect ( United States v. Jones ), and in 2018 they ruled that a warrant is also needed to track a suspect or access a suspect’s location data through a cell phone (Carpenter v. United States). There will be many more of these cases as technology and procedures continue to evolve.

1.7 Major Issues in Forensic Science Today Although many issues confront forensic science and its role in the justice system today, we will mention here a few of the most prominent ones. There has been a lot of publicity in the last years about some bad laboratories and actors in forensic sciences. By the same token, there has also been substantial progress in developing and maintaining high standards of laboratory practice and testing.

Think About It

Suppose you were the judge in a hotly contested criminal case. The state wanted to intro- duce the results of a test that was known by the state’s own admission to be about 95% accurate. The expert witness would testify not only to the results but also to this accuracy figure, which was empirically determined. The expert witness would say something like: “I tested X and received a positive result. This test is accurate 95% of the time. The other 5% of the time, we do not know what the results mean.” Under the Daubert standard, would you let the evidence and testimony in? Why or why not?

Section 1.7Major Issues in Forensic Science Today

Problems in Some Labs and with Some Scientists No one would argue that the advent of DNA typing and profiling in forensic science is any- thing other than a good development. DNA has served as a means of convicting people by placing their blood or bodily fluids at scenes or in or on other people, but also as a means of establishing the noninvolvement of people who were convicted before DNA testing was avail- able. As these cases accumulated, it became clear that some of the older biological evidence analyses that had served to help prosecutors convict defendants was of poor quality. Uncover- ing this information led to the finding that some labs were generally not doing quality work.

A kind of cottage industry has developed to look for problems in cases with examiners and labs. Although most laboratories do good work, there are unfortunately those that do not. The problems are of various kinds. With individuals, it can be as terrible as dry labbing results— making them up—to fit a preconceived notion. But more often, it’s a matter of ignorance, sloppiness, overconfidence, poor supervision, and the like. With laboratories, there have been cases of poor oversight by the parent agency, which has included law enforcement agencies. People in those labs then develop poor quality work habits, which persist until a problem is revealed and there is a big political blowup. In order to prevent these mishaps, it is important to properly follow standard procedures and learn good practices.

Good Practices, Quality Assurance There have always been good practices and quality assurance guidelines in science laborato- ries. Sometimes, these practices are agreed upon by labs and practitioners, and they may also be imposed on labs through accreditation. Accreditation has become a major force among forensic labs in the United States over the last 30 years or so. Originally, the American Society of Crime Laboratory Directors (ASCLD) set up a separate accrediting body called its Labo- ratory Accreditation Board (ASCLD/LAB). In traditional fashion, lab accreditation involved ASCLD/LAB setting standards covering all aspects of laboratory operations. Labs wishing to apply for accreditation would then prepare a self-study, describing and documenting how they met or exceeded each standard. When the lab was ready, ASCLD/LAB sent in a team of inspectors to ensure that each standard was met and that the laboratory’s description of itself and its operations was sound and accurate. The inspection team reported back to the ASCLD/LAB Board of Directors, which then took action. Labs could be accredited (for a multi- year period, after which they had to undergo reinspection), denied accreditation, or granted probationary accreditation (specific things had to be fixed before the probation was lifted). This program has now largely morphed into a successor program under which laboratories are being accredited under the International Standards Organization standard 17025, specifi- cally designed for analytical testing laboratories. Accreditation is a desirable goal for any ana- lytical lab, but it is usually voluntary. Sometimes, a parent agency may want a lab accredited, or an external regulatory or advisory panel might press for labs to be accredited. Accredita- tion provides assurance that the lab has undergone a thorough inspection and was found to be in compliance with a stringent set of quality control and quality assurance standards.

Accreditation normally applies to laboratories, while certification applies to individual prac- titioners. There are certifying bodies for many of the forensic specialty practitioners. Physi- cians and dentists must be board-certified to practice, while other specialists are not. Cer- tification provides assurance that the practitioner complied with a minimum set of quality standards and presented credentials of appropriate education and training to perform the job.

Section 1.7Major Issues in Forensic Science Today

Laboratory Backlogs For at least a decade, many forensic sci- ence labs have suffered from backlogs. There have not been enough resources to keep up with the cases coming in the door. As a result, cases are triaged. They are pri- oritized according to the seriousness of the offense, calls by prosecutors or courts for results, and so forth. In the end, many cases wind up sitting in backlogs and may never be worked. Backlogs have been a particular problem for DNA cases, in part because DNA has become popular with the media and law enforcement and many cases have been submitted, but also because politicians expanded the scope of DNA casework without providing any additional resources to the labs. However, the backlog problem is no longer limited to DNA. There have been backlogs in drug chemistry, biology/DNA, firearms, latent prints, toxicology, questioned documents, computer crimes, and other specialties. There have been two major studies on this issue (Hickman & Peterson, 2005; Burch, Durose, & Walsh, 2012). In the first, it was found that nationwide, around 300,000 cases were backlogged as of Janu- ary 1, 2002, and that number rose to slightly over 500,000 by December 31. The second found that as of December 31, 2008, the number was 1,184,500, while on December 31, 2009, it was 1,193,800. A more recent census of U.S. forensic labs covering the year 2014 showed that the labs received 3.8 million requests and completed 3.6 million of them. These findings indicate that the labs made considerable progress in reducing their backlogs between 2009 and 2014 (Durose & Burch, 2016).

Formulating Consensus Standards for Forensic Science Starting in the 1980s, forensic science professionals became aware that the discipline needed operational standards for its approaches and methods. The incorporation of DNA analysis methods into forensic science practice was a catalyst for the standardization initiatives. In 1988, DNA analysts, led by the FBI Laboratory, formed a group called the Technical Work- ing Group on DNA Analysis Methods (TWGDAM). A major reason this initiative was impor- tant was that DNA profiles of convicted offenders were going to be developed and stored in databases. The FBI Laboratory would be in charge of the national database. In order for the database to be useful, all the labs had to be using comparable methodologies. Thus, the need

Think About It

What do you think would be the best way of reducing laboratory backlogs?

Pat Sullivan/ASSOCIATED PRESS Laboratory backlogs mean that samples are taken but cases often do not receive the timely attention they deserve, especially with the rise of cases involving DNA evidence. Can you think of any ways this problem could be addressed?

Section 1.7Major Issues in Forensic Science Today

for standardization. Other forensic disciplines formed technical working groups (TWGs) for the same purpose. Some TWGs were renamed scientific working groups (SWGs) to emphasize that the standards were based on scientific knowledge and practice and not just the work of technicians. Between 1988 and 2011, 21 SWGs were formed.

The National Academy of Sciences (NAS) and its associated organizations and academies are often considered the nation’s final word on scientific and technical matters. In 2005, Con- gress authorized the National Research Council (NRC) to do a major study of forensic sciences and issue a report with recommendations. A high-level panel convened and met over several years. They received oral and written testimony from many individuals and organizations that had a stake in the study. Their comprehensive report was issued in 2009. It includes the following recommendations:

1. Establish a National Institute of Forensic Sciences. This may have been to elevate the forensic sciences to a level of prestige enjoyed by the health sciences (National Institutes of Health) and the physical and social sciences (National Science Founda- tion) and to greatly increase and focus federal funding for research, education, qual- ity assurance, and oversight. The Committee envisioned that this National Institute would implement many of the other recommendations.

2. Establish standard terminology to be used in reporting results and develop model reports for different disciplines.

3. Promote research on accuracy and reliability issues, ensuring that all disciplines perform analyses with solid scientific foundation and that the limits and quantifiable measures of accuracy and reliability be established and stated wherever possible.

4. Provide funds to remove forensic science laboratories from the administrative con- trol of law enforcement agencies.

5. Promote research on human observer bias and other sources of human error in forensic science testing, and develop methods to minimize these effects.

6. Provide funding to help the National Institute of Standards and Technology, in con- sultation with SWGs and TWGs, develop tools for advancing measurement, valida- tion, and reliability with a view toward establishing best practices.

7. Make laboratory accreditation and individual analyst certification mandatory. 8. Establish routine QA-QC procedures in forensic labs to ensure accuracy and detect

errors, bias, or fraud. 9. Establish a national code of ethics for all forensic science disciplines. 10. Provide funding for forensic science education, especially at the graduate level. Insti-

tutions operating graduate programs should be research centers. 11. Provide funding for allocation to the state to establish medical examiner systems,

eliminating coroner systems. Funds should be made available to assist in the train- ing of forensic pathologists. A SWG for forensic pathology and medico-legal ques- tioned death investigation should be established to promote standards, education, training, and best practices. Medical examiners’ offices should be accredited, with accreditation a criterion for receipt of federal funds. All medico-legal autopsies should be performed by a board-certified forensic pathologist.

12. Provide funding to launch a broad-based effort in fingerprint database interoper- ability, so that all law enforcement AFIS systems can intercommunicate.

Conclusion

13. Provide funding for a cooperative effort among CDC, FBI, and crime scene investiga- tors for their potential roles in homeland security events.

The Committee also noted that even if the recommended National Institute of Forensic Sci- ences was not brought into existence, many of the ideas and suggestions in the recommenda- tions could still be implemented. Following the NAS/NRC final report, the National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce, took a leading role in the effort toward consensus standard setting. Through an organizational structure called the Organization of Scientific Area Committees for Forensic Science (OSAC) governed by a Forensic Science Standards Board, NIST is bringing about the adoption of stan- dards using carefully defined criteria. Standards that have been adopted by standard-setting organizations (like ASTM, the American Society for Testing and Materials) are reviewed and checked to see that they are in accord with the NIST committee’s criteria. Specialty groups can ask NIST to connect them to a standard-setting entity to help develop a standard. The NIJ also assists in these efforts by providing funding. This work of creating science-based standards for the disciplines of forensic science is in progress, but it is time consuming. A list of OSAC approved standards can be seen at https://www.nist.gov/topics/forensic-science /organization-scientific-area-committees-osac/osac-registry/osac-approved.

Conclusion This chapter has expanded on the definition of forensic science and differentiated it from other physical and biological sciences. The two distinguishing factors of forensic science are that it provides information for legal cases and involves individualization. The branch of crim- inalistics was also defined and will be the focus of this book, as it includes all of the activi- ties in a forensic science laboratory. The elaboration of these terms highlights the inaccurate depiction of forensic science shown by the mass media on television and the possible impact of the CSI Effect on jury verdicts.

The contributions of Hans Gross, Mathieu Joseph Bonaventure Orfila, Calvin Goddard, and Paul L. Kirk helped shape forensic science. An introduction to the various specialties (such as forensic pathology and digital evidence) that fall under forensic science, along with an over- view of the American justice system, outlines the number of ways forensic science can help a case. Using tests formed by following the principles of the scientific method, forensic scien- tists can help establish elements of a crime, identify material, prove or disprove statements, and provide leads that can help solve a case.

Lab notes and reports help track and summarize the procedures and conclusions of methods used by a forensic scientist. Reports can also be used as part of expert testimony in court. Issues with who can testify in court, backlogs, and proper protocols are noted as some of the major problems forensic scientists face today. The National Research Council committee identified a number of problems in the forensic sciences and has provided possible solutions to remedy them. NIST has taken a leading role in coordinating and managing these efforts.

The topics in this chapter will set the foundation of concepts that will be mentioned again in later chapters. These include more details on crime scene analysis and reconstruction, which will be discussed in the next chapter.

Conclusion

Key Ideas

• Forensic science includes any science or technology applied to matters of the law. A narrower sense of the term “forensic science” is criminalistics. Criminalistics has a unique interest in individualizing items and materials. Forensic science in practice is not like the CSI television shows.

• Forensic science can contribute to a case with information about corpus delicti; iden- tifying substances, materials, or persons; testing the truthfulness of witness, victim, or suspect statements; providing linkages between persons and evidence items; and generating investigative leads.

• Other forensic science specialties in addition to criminalistics include forensic medicine, forensic odontology, forensic anthropology, forensic entomology, forensic toxicology, forensic psychiatry and psychology, and digital evidence.

• Elements of a forensic investigation and case can include any or all of recognition, identification (classification), individualization, and reconstruction.

• Forensic analysis is often comparisons between knowns and unknowns, whether the goal is classification (as in a drug case) or individualization (as in a case involving a sneaker impression).

• Forensic scientists produce reports, on which expert testimony is based in court if needed. Language and wording in reports and testimony is generally not standard- ized, so it has the potential to create ambiguity or misunderstanding.

• The justice system has specific rules for the admissibility of scientific and technical evidence through expert witnesses. These rules are based on pronouncements of the U.S. Supreme Court and rules of evidence set forth by councils of judges. The federal rules don’t necessarily apply to the states, though the states are free to adopt them.

• Some major issues in modern-day forensic science include lab backlogs, quality assurance and control guidelines, problems raised by the 2009 NRC report, and recent Supreme Court decisions concerning who can testify to a forensic scientist’s findings and conclusions. NIST is coordinating a national effort to formulate consen- sus standards for forensic sciences.

Critical Thinking Questions

1. Using the scientific method, how would you design a definitive study to find out if there is a “CSI Effect” on criminal trial jurors?

2. What would you think is the most important contribution forensic science could make to a criminal case?

3. How would you go about correcting the case backlog problem in U.S. forensic labs? 4. Given that most cases never go to trial, how would you go about ensuring that the

forensic lab’s analysis and findings were factored into every case disposition? 5. Suppose you were a judge, and a lawyer in a criminal case in your court wanted to

call an astrologist as an expert witness. Would you let him? Why or why not?

Key Terms accreditation A recognition by an external group or organization that a laboratory has met certain, specific, minimum standards of quality.

autopsy A post-mortem dissection of a body by a forensic pathologist to help deter- mine cause and manner of death, collect and preserve bodily organs and tissues as neces- sary, and document and recover evidence related to the death.

Conclusion

burden of proof The obligation by the plaintiff in a legal proceeding (the state or the government in a criminal case; the plain- tiff in the lawsuit if a civil case) to prove his or her case to the trier of fact. The defendant does not have to prove anything.

certification A recognition by a standard- setting body or organization that an indi- vidual has met certain, specific, minimum standards of education, training, and experi- ence, which qualify that person to perform job functions in accordance with those standards.

classification Placing something into the class or category to which it belongs. In criminalistics, equivalent to identification.

class characteristics Characteristics and features that cause items or objects to be placed into a class or category.

common origin In the context of evidence comparison, two items having a common origin are identical. A questioned item that has a common origin with a known item has been individualized.

comparison sample (comparison speci- men) Generally, a sample or specimen associated with the evidence sample or specimen that must be tested to ensure that the test results are originating from the evi- dence item itself, and not from an associated or background item.

control An item of known origin and com- position that is tested along with any ques- tioned or unknown item in a test to ensure that the test itself is working properly.

coroner An elected official, usually in a county, who is responsible for investigating cases of deaths occurring outside medical settings, and ruling on the cause and man- ner of such deaths.

coroner system Allows an elected official for a county or municipality, such as a sher- iff or local funeral director, to perform the responsibilities of death investigation.

corpus delicti Literally, the body of the crime. The set of facts that must be estab- lished and proven to show that a crime has been committed and/or that someone is guilty of having committed that crime.

criminalistics A specialized area of foren- sic science, including drug identification chemistry, trace/materials evidence analy- sis, biological evidence identification and DNA analysis, and certain activities such as crime scene analysis and reconstruc- tion. Some authorities include fingerprint comparison, questioned documents, and firearms and tool mark comparison analyses within criminalistics. Criminalistics can be a synonym for forensic science in the narrow sense.

CSI effect The influence of the CSI televi- sion franchise and similar forensic science shows on jurors.

digital evidence Any item containing digi- tal records of any kind, such as computer drives, cell phones, PDAs, and answering machines, that becomes or contains evi- dence in a case.

epidemiology The study of health-related events, characteristics, or health deter- mining patterns in populations; may also apply to the effects of a drug or toxin on a population.

exemplar A known specimen or sample.

expert witness A witness called to tes- tify in a judicial proceeding who possesses knowledge in a specialized area over and above what a normal person would be expected to know, who is allowed to give an opinion in a judicial proceeding.

Conclusion

fabrication Making up data or results that were not obtained through testing, and recording or reporting them as if they were obtained through testing.

falsifiable hypothesis According to Karl Popper’s view of science and the scientific method, a hypothesis that is capable of being shown to be false through controlled experiments on predictions generated by the hypothesis.

falsification Manipulating research or test materials, equipment, or processes, or changing or omitting data or results, such that the results are not accurate, and may appear to be something they are not.

forensic anthropology A sub-branch of physical anthropology devoted to the iden- tification of the human skeleton, recognition of wounds and trauma on skeletal parts, and/or studies involving human mitochon- drial or human Y-chromosomal DNA for purposes of tracing lineages.

forensic engineering A specialty area of forensic science in which engineering skills are used to help reconstruct events involv- ing transportation accidents, materials or product failures, or structural failures.

forensic entomology The use of knowl- edge about insect life cycles to estimate time since death based on insect eggs, larvae, or pupae at a death scene or on a body.

forensic nursing A branch of nursing devoted to the recognition, collection, and preservation of evidence in criminal cases, generally from persons victimized by the crimes.

forensic odontology Forensic dentistry; a specialty within dentistry concerned with the identification of individuals through their dentition and with bite mark comparisons.

forensic pathology Forensic medicine; a specialty within medicine and pathology concerned with assessing the cause and manner of death in cases that are sudden, unexpected, or occur outside the confines of a medical facility.

forensic science Science or technology applied to matters of law; in a narrow sense, criminalistics.

forensic toxicology A specialty with toxicology concerned with the effects and mechanisms of action of poisons, toxins, and drugs on the human body, and how these may affect human behavior or contribute to death.

friction ridge skin The flowing ridges of skin on the epidermal and dermal surfaces of primate finger, hand, and foot skin; forms fingerprints, palm prints, and footprints.

hypothesis A preliminary guess as to an explanation for a phenomenon in the physi- cal world; must be able to generate testable predictions.

individualization Rendering an item or showing an item to be unique among mem- bers of its class.

individual characteristics Features and characteristics that render a person, item, or object unique among members of its class or category.

known A sample, specimen, or person with a known identity and/or history.

locard exchange principle An idea first stated by the pioneer French criminal- ist Edmond Locard, stating that objects or items that come into contact with one another exchange matter—that is, leave some trace of the exchange on one another.

Conclusion

master methods manual In a laboratory, a collection of every validated method and technique used in the laboratory to measure anything or to conduct any test.

medical examiner A forensic pathologist employed by the government to examine and rule on all cases of questionable death.

natural law An extremely well-tested theory.

peer review Review of test results or of a manuscript submitted to a scientific journal by another expert equally knowledgeable in the subject and able to judge the merits of the results of the testing or the experiments.

plagiarism The appropriation of another person’s ideas, processes, results, or words without giving appropriate credit.

plea bargain The way that a majority of criminal cases are settled; attorneys and the court agree on what they deem a fair settle- ment of the case without a trial.

polygraph A “lie detector” test.

quantitation Determining the amount (quantity) of something.

questioned A synonym for unknown; all crime scene evidence is questioned.

recognition In forensic science, the real- ization that an item, object, or person has evidentiary value.

reconstruction An attempt to piece together past events in space and time based on the physical evidence record left by those events.

reference A known, or exemplar, specimen or person.

reproducibility The quality of being repeatable with the same outcomes; other scientists must be able to repeat a scien- tific experiment and get the same results in order for those results to be accepted by all scientists studying the same question.

retraction An action by a scientific jour- nal editor taken with regard to an already published paper, signifying that the paper contains plagiarized, falsified, or fabricated results or conclusions that were not appar- ent when the paper was published.

scientific literature The body of peer- review journals.

scientific method An approach to discov- ering new knowledge empirically, consisting of hypothesis testing through controlled experiments in a cycle that is ultimately self-correcting.

theory A well-tested hypothesis.

trier of fact The person or persons respon- sible for rendering a verdict in a trial; the trier of fact can be a judge or a jury.

unknown A specimen or sample whose identity and/or history is not known.

witness of fact (lay witness) A person who can only testify regarding their experi- ences and direct knowledge.

Web Resources This site considers issues around the CSI Effect: http://projects.nfstc.org/csieffect/index.html

Conclusion

An article on the CSI Effect: http://www.daytondailynews.com/news/news/judges-lawyers-split-on-csi-effect -on-jurors/nPzNJ/

A Wall Street Journal article on reproducibility of scientific results: http://online.wsj.com/article/SB10001424052970203764804577059841672541590.html

Articles about the problems of diagnosing a cause of death in the Casey Anthony case: http://www.cbsnews.com/8301-504083_162-20070588-504083.html

https://www.palmbeachpost.com/news/crime--law/revisits-casey-anthony-science-tlc -special/3zjccAzd6DJBjFYth57aLO/

This site is about the famous Dr. Sam Sheppard case: http://law2.umkc.edu/faculty/projects/ftrials/sheppard/sheppard.htm

Audio on the CSI Effect and the movement to make law enforcement and forensic investiga- tion more independent of each other: https://www.npr.org/templates/story/story.php?storyId=100831831

For information about OSAC: https://www.nist.gov/topics/forensic-science/organization-scientific-area -committees-osac

NIST OSAC approved standards list: https://www.nist.gov/topics/forensic-science/organization-scientific-area-committees -osac/osac-registry/osac-approved