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In This Chapter

▶ Checking out the duties of criminalists

▶ Looking at forensic science specialties

▶ Understanding the medical examiner’s duties

▶ Getting to know the forensic investigator

▶ Offering expert testimony in court

TV forensics teams have it good: There’s a specialist for every possible field of study and a fancy piece of equipment for analyzing whatever evidence comes in. Unfortunately, that’s not the case even in larger, more sophisticated jurisdictions, much less in smaller ones where law enforcement officers or a single or very small number of criminalists perform all the required duties.

More often than not, this is due to funding shortfalls. The truth is that most crime labs are severely underfunded. This fact led author Jan Burke to create the Crime Lab Project (https://crimelabproject.wordpress.com), a site that helps raise public awareness of this national problem.

Police typically are the first officials to arrive at any crime scene. After they determine the nature and exact location of the criminal act and secure the scene, they call in various forensic specialists to document and gather evidence, and then transport it to the crime lab for further testing. Who shows up to handle these duties depends upon the resources and structure of the jurisdiction.

Larger crime labs may have a special crime-scene investigation unit (CSIU) that consists of individuals trained in evidence recognition, collection, and preservation. They are also skilled in performing many of the field tests and screening tests that must be done at a crime scene. Although their exact titles and duties vary from jurisdiction to jurisdiction, these specialists can be divided into two groups. I use the terms criminalists or forensic investigators for those who deal with the physical evidence and coroner’s technicians to refer to those who deal with the body in cases of death.

Gathering the Evidence: The Criminalist at Work

Criminalist is a relatively new term and one that’s not easy to define. It covers a wide range of abilities, responsibilities, and training. Some, such as serologists and chemists, are scientists, while others, such as fingerprint and firearms examiners, are likely to be ex-police officers who have no true scientific training. Still others are technicians with on-the-job training.

No matter what their specialty or education, the bottom line is that criminalists work with evidence. That can mean a lot of things, from looking for poisons in blood samples to authenticating written documents, but all of it falls under the banner of criminalist.

In spite of what you see on TV and in the movies, criminalists aren’t cops (although, in some cases, they are former police officers). They don’t carry guns, interrogate suspects or witnesses, or make arrests. They don’t treat the injured or deal with a dead body. They collect and analyze evidence. That’s it.

Common job titles for criminalists include the following:

✔ Crime-scene investigator: These are the CSI guys and gals who visit the crime scene to locate, collect, protect, and transport any and all evidence to the crime lab. They document the scene by sketching and photographing it, unless there is a sketch artist or photographer on the scene to take over this duty at their direction.

✔ Latent print examiner: These specialists examine fingerprints as well as palm and footprints and compare them with prints obtained from suspects, other crime scenes, or print databases. Chapter 5 gives you the skinny on fingerprints.

✔ Firearms examiner: The duties of this individual include examining and identifying firearms, comparing bullets and shell casings, and searching for and identifying gunshot residue. Chapter 18 gives you the details.

✔ Tool-mark examiner: Like fingers, tools leave behind distinct markings that may connect them to a crime scene. Tool-mark examiners compare these marks to suspect tools. I cover this practice in Chapter 7.

✔ Document examiner: These experts examine various documents to determine their authenticity and authorship and to look for any alterations in a document’s original content. They may also be asked to identify whether a particular typewriter or copier produced a certain document. Check out Chapter 19 for more.

✔ Trace evidence examiner: These specialists analyze and compare hair, fibers, glass, soils, and paints to determine their type and origin. Chapter 17 tells you more about analyzing trace evidence.

Looking into the CSI Effect

I’m sure you’re familiar with the TV series CSI: Crime Scene Investigation and its many spin-off shows. How could you not be? Though they more often than not get the science right, they create an unrealistic picture of what a crime lab looks like, how well equipped it is, and what CSI and lab techs actually do. But, like other more scientifically based shows like Forensic Files, for example, these shows have raised public awareness of forensic science and introduced viewers to the world of forensic investigation.

One unintended consequence of these shows and the raised public awareness of forensic science procedures is the CSI Effect. Though controversial as to whether it actually exists, many experts believe it does, while others feel it doesn’t. Regardless, it makes sense that saturating the public with all this forensic science would naturally change its view on criminal investigation and prosecution. Those who support the existence of this effect point to three major areas: the public, and thus jurors; judges, prosecutors, and defense attorneys; and criminals.

Whenever a high-profile case pops up on the news, the public seems to immediately jump to whether there is DNA evidence or not. If there is, the suspect must be guilty, and if not, he must be innocent. The facts are that DNA analysis is only relevant in a very small percentage of cases, perhaps as low as 5 percent. Most crimes are solved by good police work, not the crime lab. This attitude naturally enters the courtroom where jurors are asking the same question: Why is there no DNA? Did the police do something wrong by not collecting it? Is there no DNA because the defendant is innocent? You can see how this complicates the job of prosecutors and defense attorneys. If jurors expect forensic evidence to be presented to support their cases, these attorneys need to explain any absence of such evidence.

And what about criminals? They watch these shows. They learn what law enforcement and crime labs can do. They wear gloves when breaking into a home to avoid leaving fingerprints, they wear condoms in rapes to avoid leaving behind DNA evidence, and they take other steps to avoid detection. Fortunately, a little knowledge is a dangerous thing, and as you see in the remainder of this book, criminals may avoid leaving behind one type of evidence while ignoring other, equally damning, evidence. And that’s a good thing.

From Analyzing Blood to Identifying Bugs: Forensic Science Specialists

If you need to find out how a victim died or identify a piece of a plant found at a crime scene, you call on a forensic scientist trained in pathology or botany, respectively. Professionals who work in the various forensic biological sciences are among the most highly trained and skilled members of the forensics team. They include the following:

✔ Pathologist: A forensic pathologist is a licensed physician with specialty training in pathology, which deals with the nature of disease and the structural and functional changes it causes in the human body. In addition, the forensic pathologist takes subspecialty training in forensic pathology, the application of pathological science to the law.

The forensic pathologist is in charge of the body and all the evidence that is gleaned from its examination. He uses the autopsy, police report, medical records if indicated, suspect and witness interviews, the results of crime lab evidence evaluations, and much more in the pursuit of answers. The forensic pathologist also examines living victims to determine the causes and ages of injuries, particularly in cases of assault, rape, or abuse. Part III of this book focuses on forensic pathology.

✔ Anthropologist: The forensic anthropologist studies human skeletal remains to determine the age, sex, and race of the deceased, identify any illnesses or injuries that the victim may have suffered, and to estimate the time of death. The forensic anthropologist examines not only the recovered bones, but also the location and circumstances in which they were found. Toxicological, chemical, and DNA analyses also are used by the forensic anthropologist. Other responsibilities may include identifying victims of mass disasters and those interred in mass graves. You can find out more about forensic anthropology in Chapter 10.

✔ Odontologist: A forensic odontologist (or forensic dentist) helps identify unknown corpses by matching dental patterns with previous X-rays, dental casts, or photographs. Because dental enamel is the hardest substance in the human body, forensic dental services can help with identifying homicide victims, victims of mass disasters, and skeletal remains. Forensic odontologists are called upon to match a suspect’s teeth with bite marks on the victim or on food products such as cheese or apples. Chapter 10 tells you more about forensic odontology.

✔ Entomologist: Entomology is the study of insects. The forensic entomologist uses knowledge of the life cycles of flies and various other insects that feed on corpses to determine the approximate time of death. Likewise, the forensic entomologist uses knowledge of insect habitats to determine whether a body has been moved from one location to another. Find out more in Chapter 11.

✔ Psychiatrist: The forensic psychiatrist may be asked to address someone’s sanity or competence to stand trial, sign documents, or give informed medical consent. In suicide cases, forensic psychiatrists may be asked to conduct psychological autopsies to determine possible motivations of the deceased. A forensic psychiatrist may also be asked to provide a psychological profile of an unknown perpetrator. Check out Chapter 4 for the lowdown on forensic psychiatry.

✔ Serologist: The serology lab deals with blood and other bodily fluids such as saliva and semen, identifying the presence or absence of antigens and antibodies in those fluids. Blood typing, paternity testing, and in some labs even DNA profiling are conducted by the serologist. Turn to Chapter 14 for more.

✔ Toxicologist: Toxicology is the study of drugs and poisons. The forensic toxicologist determines whether drugs or poisons are present in the living and the deceased, often to assess how those substances contributed to aberrant behavior or death. The forensic toxicologist also determines whether drivers were intoxicated or workers violated company drug-use policies. Check out Chapter 16 for the full scoop on toxicology.

✔ Botanist: Examining plant residues, one of the tasks performed by a forensic botanist, is sometimes crucial to solving a crime. Plant fragments, seeds, pollen, and soil may be used to place a suspect at the crime scene. For example, pollen found on the clothing of a suspect can be matched to that of a rural crime scene, thus suggesting that the suspect was in the same area. Plant and pollen evidence also can reveal that a corpse has been moved. Find out more about forensic botany in Chapter 17.

Forensic Investigation’s Head Honcho: The Medical Examiner

Coroners and medical examiners are charged with determining the cause and manner of death, overseeing the analysis of evidence, and presenting their findings in court. They often work with the police to help guide ongoing investigations by supplying them with the results of any forensic tests that have been performed. The responsibilities of these two offices cover every aspect of investigating a death.

The terms coroner and medical examiner (ME) are often used interchangeably, but they are, at least theoretically, quite different (see the following section for details). Regardless of which system is employed, in death investigations many of the duties of the coroner or the ME are similar. I use the term ME throughout the remainder of this book, even though some jurisdictions employ coroners for handling the legalities of death.

Looking at two forensic systems

In the United States, two types of forensic investigative systems exist: the coroner system and the medical examiner system. Fortunately, the trend is toward the latter system, though it is far from perfect.

The coroner is an appointed or elected position that, unfortunately, requires no special medical or forensic skills. The sole criterion seems to be the ability of the person seeking the office to be elected or appointed. The coroner could be the sheriff, a newspaper publisher, a neighborhood café owner, or the local funeral director. They too often possess little or no medical training or experience.

During the past several decades, the politics of the office have evolved so that today many jurisdictions require the coroner to be a licensed physician. He may be an internist, an obstetrician, or a dermatologist but doesn’t necessarily have to be a pathologist and certainly not a forensic pathologist. Thus, the coroner may not actually be qualified to perform many of the duties of the office. This deficiency led to the creation of the medical examiner system.

In theory, a medical examiner (ME) is a physician licensed to practice medicine, and many are trained in pathology and forensic pathology, meaning that ideally they are medical doctors with special training in pathology and experience and training in forensic pathology. A forensic pathologist is a clinical pathologist who has taken extra forensic training. He usually heads up the crime lab and oversees all aspects of death and criminal injury. The heart of the forensic pathologist’s job is performing forensic autopsies, which are designed to help determine the cause and manner of death.

In an ideal world, every jurisdiction would have a medical examiner who also is a board-certified forensic pathologist, qualified to fulfill all the duties of his office. The world, as you know, is not ideal, and even today in many jurisdictions nonmedically trained coroners and MEs continue serving as local public officials charged with investigating death. This solution is a practical, money-saving one because these areas simply don’t have the population base to justify the presence of a forensic pathologist. Under these circumstances, the coroner/ME has several alternatives for acquiring the needed specialized pathological services.

If the coroner/ME is not a pathologist and not licensed to practice medicine, he must contract with larger regional or state medical examiner’s offices for pathological examinations and laboratory testing or hire a forensic pathologist to serve as an assistant coroner or medical examiner. Under the legal umbrella of the coroner’s or ME’s office, the assistant coroner then performs autopsies, testifies in court, and oversees the crime lab.

Checking out the duties of a coroner or medical examiner

The duties of the coroner and ME are diverse, but many of them relate to the forensic investigation of death, including

✔ Determining the cause and manner of death

✔ Establishing the identity of any unnamed corpses

✔ Estimating the time of death

✔ Supervising the collection of evidence from the body

✔ Searching for any contributory factors such as disease

✔ Correlating wounds with the weapons that may have been used to inflict them

✔ Certifying or signing the death certificate

In fulfilling these duties, the coroner or ME uses any and all available information. Reviewing witness statements, visiting crime scenes, reviewing collected evidence and the results of crime lab testing, and, if a pathologist, performing autopsies are part of this endeavor.

In addition, the coroner or ME performs other duties not directly related to death investigations. These include

✔ Examining injuries of the living and determining their cause and timing

✔ Providing expert testimony in court

✔ Overseeing the crime lab (in some areas)

Following the medical examiner in action

When faced with an unexplained death, the ME takes a systematic approach to evaluating the case. This approach is similar to the one taken by physicians who treat the ill. Good physicians take a complete patient history, perform a thorough physical exam, order appropriate laboratory tests, and make an informed diagnosis. Only after this process can treatment begin.

The ME, on the other hand, obviously cannot obtain a direct history from the deceased but nevertheless can obtain information from police reports, medical records, witness statements, and interviews with family members, law enforcement, and other medical personnel. To help gather the needed information, the ME may possess (in some jurisdictions) or receive subpoena power from the court and can therefore legally require someone to provide information or evidence such as a blood sample, fingerprint, or shoe impression.

If no evidence of any potentially lethal trauma is seen, the ME then looks for natural causes of death by reviewing medical records, perhaps discussing the death with the person’s physician or performing an autopsy when necessary. These investigations may lead the ME to conclude that the person died as a result of a natural cause, such as a heart attack, an infection, diabetes, or any number of other diseases.

When no natural cause is present or evident, however, the ME explores other manners of death, looking for less-obvious forms of trauma, poisons or drugs, or other signs of accidental, suicidal, or homicidal death.

After the analysis is complete, the ME files a report in which the essentials of the case are laid out and a conclusion is reached regarding the cause, mechanism, and manner of death.

The manner of death is an opinion expressed by the ME based upon all the circumstances leading to and surrounding the death. The ME’s opinion may or may not be accepted by the courts, law enforcement, attorneys, or the victim’s family. Even if the ME concludes that a death was a homicide, prosecutors may disagree and file no criminal charges. Likewise, surviving family members may sue the coroner’s office for any number of reasons to change the manner of death, particularly in situations in which the manner of death has been ruled a suicide.

The ME’s opinion is not written in stone and can change if new evidence comes to light that suggests a previously ruled natural death may not have been so natural after all.

Dealing with the Dead: The Coroner’s Technician

The coroner’s technician is an extension of the coroner/ME and is indeed the ME’s representative at the crime scene and works with the ME at the morgue. These technicians are often the ones who actually deal with the body at any crime scene where a death has occurred.

As an extension of the ME, the technician has legal authority over the body. The crime scene may be the domain of the police and the criminalists, but the body belongs to the medical examiner.

The coroner’s technician may do the following:

✔ Make a cursory examination of the body

✔ Obtain a core (liver) body temperature, which is critical in determining the time of death (see Chapter 11)

✔ Direct the taking of photographs of the body

✔ Collect any trace or insect evidence from the body

✔ Wrap and transport the body to the ME’s office

The technician may also assist the ME in all the examiner’s duties at the morgue and may

✔ Perform or help with the performance of autopsies

✔ Prepare the autopsy report at the direction of the ME

✔ Communicate with the public, the media, and law enforcement on issues relating to the medical examiner’s office

✔ Explain the autopsy procedure and its results to family members of the deceased

✔ Testify in court as the ME’s representative

Testifying as an Expert

After they have analyzed the evidence, members of the forensics team may be called upon to explain it in court. Expert testimony can often make or break a case, and experts – be they medical examiners, crime-scene investigators, toxicologists, or other key players – can be called to testify by either the prosecution or the defense. In turn, their testimony may be refuted by the testimony of experts with different opinions.

The sworn duty of the ME is to present the facts in court and offer an unbiased opinion based on those facts. She is solely responsible for presenting evidence in court because she is in many ways an officer of the court. The ME may ask a member of her staff or of the crime lab to present evidence, but the ME is the one who is ultimately responsible to the court.

The ME may be asked to discuss and explain the forensic evidence and render an expert opinion regarding the evidence to the judge and jury. In this regard, the ME acts as an educator as well as a scientist. The ME often is the only person from whom a jury hears complex scientific information presented in an understandable way. At other times, the ME must pit knowledge and communication skills against other experts with different opinions.

Standardizing the science

Many of the procedures that are commonly employed in criminal cases, and that are discussed in this book, have never been adequately subjected to scientific scrutiny. Bite mark analysis, trace evidence such as hair and fiber analysis, and even fingerprints, to name a few, have been questioned in the courts and in scientific circles. The facts are that none of these techniques have ever been adequately tested for accuracy or reliability. Does this mean that they are no longer viable forensic scientific procedures? Not at all. It simply means that the techniques used in their analysis and the qualifications of the examiners must be better defined and standardized.

The 2009 study done by the National Academy of Sciences (NAS) titled Strengthening Forensic Science in the United States: A Path Forward started the ball rolling. Since then, organizations such as the National Institute of Standards and Technology (NIST), the Organization of Scientific Area Committees (OSAC), and others have made great strides in the standardization of forensic science. The goal is to make each scientific procedure reliable, reproducible, and uniform in every crime lab across the country as well as to establish standards and qualifications for experts in each area of forensic science. It’s a tall order and will take time, but these organizations, and the working groups and committees they have established, are moving in the right direction.

Added to this is the problem of examiner bias, laziness, and corruption. Many cases of “experts” falsifying or “dry labbing” the evidence have cropped up in recent years. Dry labbing simply means coming up with results without actually doing the testing. We have seen this with DNA, fingerprints, bite marks, and other forensic techniques. Part of the work of the organizations previously mentioned is to identify and remove such individuals from the scientific community.

What does this mean for the current state of forensic science? Simply that the quality of the evidence uncovered and the expertise and honesty of the examiners is critical to the reliability of the results, and any move to improve that is a positive change. For example, if a good-quality fingerprint is found at a crime scene and it is examined and compared by a qualified expert, the results are very reliable. Even though no true scientific evaluation of fingerprint techniques has been done, the facts are that despite countless millions of fingerprints being obtained around the world, no two have ever been shown to be identical. Even identical twins have different fingerprints. So forensic science is sound; it simply needs to be standardized and uniformly applied.

Understanding the court system

The court system in the United States is adversarial by nature, meaning that each side attempts to outfox or outargue the other. The prosecutor and defense attorney attempt to present evidence that favors their respective side and spin any contrary evidence in a manner that supports their theory regarding the case. This locking of horns can put the forensic expert in a difficult position. Each side is likely to bring in outside experts to support or refute the testimony of the ME. These experts may even be other forensic pathologists, toxicologists, firearms experts, or someone from any of the other forensic areas.

Each expert can expect to be qualified before the jury, meaning that the opposing attorneys ask questions about the expert’s credentials, training, experience, areas of expertise, teaching positions, publications in the field in question, and anything else they think will support or undermine the expert’s true qualifications. In general, the side that calls on an expert as a witness asks easy, supportive questions, and the opposing side asks tougher questions aimed at impeaching, or refuting, the qualifications and any testimony the expert gives. Expert witnesses must be prepared for potentially unsettling questions.

Experts presenting testimony need to be honest and measured, trying not to oversell their points of view, but making their honest opinions clear, concise, and believable. That is, experts must appear neither too sure nor too unsure of their opinions. The former may alienate a jury, and the latter may undermine the expert’s credibility.

Getting to the heart of the “truth”

The real goal of court proceedings is not so much to uncover the absolute truth as it is to provide enough evidence so a jury can reach an understandable version of the truth based on the applicable rules of law. Getting to that version is complicated by the fact that certain items of evidence may not be admissible (allowed into the courtroom at the time of trial) in court, because they were obtained improperly, contaminated, or overly inflammatory or prejudicial.

So, you may be wondering: “If some evidence is excluded, how can the absolute truth be found? Isn’t that like trying to solve a math problem with only half the numbers?” You’re mostly right, but the expert can’t change but rather must work within the law. She can present only the information the court allows and must explain it as fully as possible in a true and unbiased opinion. Doing so helps the jury get as close to the truth as possible.

Understanding the role of expert testimony

Judges typically allow a great deal of leeway with regard to how expert witnesses present information to the jury. Most witnesses are permitted only to answer questions. If they attempt to move too far afield of the question, the judge will rein them in. Experts, on the other hand, are allowed to depart from the normal Q-and-A format because their often-technical testimony necessitates explanation. Indeed, the expert teaches the judge and jury. For example, understanding the impact of DNA evidence is difficult for the average juror when presented simply from a series of questions with yes or no answers. Enabling the expert to explain what DNA is, how it is tested, and what the results of the testing mean gives the jurors the knowledge they need to understand and evaluate the evidence.

Rarely will an expert witness express testimony as an absolute fact, especially when being challenged by the other side. Instead, the wise expert uses phrases such as “similar to,” “consistent with,” “not dissimilar from,” “compatible with,” or “shares many characteristics with.” Why is this? The truth is that forensic evidence rarely, if ever, is absolute but rather states probabilities. For example, except for identical twins, no two people have the same DNA, but the testifying expert should never say the DNA “absolutely matches” that of the defendant. Instead, the expert should say that the probability that it matches someone other than the suspect is a billion to one. That is almost, but not quite, absolute.

Holding testimony to standards of acceptance

Regardless of who presents the information, by virtue of Frye v. United States, judges require that the science behind the evidence be real and not junk science coming from someone merely spouting personal beliefs without any scientific support.

In 1923, the District of Columbia Circuit Court addressed whether the results of a polygraph examination (lie detector test) were admissible as evidence in that case. The landmark decision in Frye v. United States set what later became known as the Frye Standard for presenting scientific evidence before the courts. The standard states that the court can accept expert testimony on “well-recognized scientific principle and discovery,” if it is “sufficiently established” and has achieved “general acceptance” in the scientific community. This acceptance enables new scientific tests to be presented, but only after they’ve been thoroughly hashed out and accepted.

Although Frye was the standard for many years, and still is followed in many jurisdictions, it more recently was replaced by Daubert v. Merrell Dow Pharmaceutical, Inc., or Rule 702 of the Federal Rules of evidence, which states that judges may use their discretion to admit expert testimony to “understand the evidence” and to “determine a fact in issue.” Rule 702 was upheld and amplified in 1993 by the United States Supreme Court, which held that the “general acceptance” clause in Frye was not absolute, thus handing judges wider discretion as to what expert testimony they can allow in any given case. To further help judges, the court offered several guidelines. For a new scientific technique or theory to be acceptable to the court, it must

✔ Be subject to testing and to peer review

✔ Be standardized with recognized maintenance of such standards

✔ Have a known and accepted error rate

✔ Attain widespread acceptance

The high court’s ruling basically means that the technique or theory must be spelled out, tested, reviewed, accepted, and continually monitored for accuracy.

Whether scientific evidence and testimony are admissible often is hammered out by attorneys and the judge in pretrial hearings and motions that the jury never hears. If the evidence to be presented by the expert passes the Frye or Daubert standards, the judge allows the jury to hear the expert testimony. If not, the judge may exclude it from the trial.