Pathology is the investigation of death and disease. It emerged as a discipline from the mid-nineteenth century with the development of the microscope. Physicians began to see that the microscopic examination of tissue was relevant to the study of disease and had practical application in diagnosis and research. Two branches of pathology emerged: (1) anatomic pathology involved the study of cells, tissues, and organs and (2) clinical pathology covered the study of body fluids such as blood, sputum, and urine. The discipline of forensic pathology developed during the twentieth century and is the application of pathology to the investigation of crime, particularly when injury or death has occurred.
Medical Examiner (ME)
The medical examiner (ME) is a key person in a forensic investigation. He or she is charged with looking into any unnatural death reported to them, be it a homicide, suicide, accident, or in any other way suspicious. To this end, their work involves specific tasks, chief of which is the determination of the cause and manner of the death through performing an autopsy. The ME also takes control of the analysis of evidence, works with the police investigating the scene of the crime, and presents evidence in court. Ideally and increasingly, the ME is a forensic pathologist. In practice, they must merely be medically qualified and may not even be a pathologist. In such cases, they may well contract out some of their duties, such as carrying out the autopsy, to a forensic pathologist elsewhere.
Becoming qualified as a forensic pathologist involves a lengthy course of study. After completing an undergraduate degree, the individual completes 4 years of medical school (in the United States; course lengths elsewhere may differ). Then, postgraduate training in pathology, which is done in a teaching hospital, takes at least 4 years more. After that, a further year's training is needed to become a forensic pathologist, and this is usually done in a ME's office, to get the necessary experience. The forensic pathologist can then take an exam to become board certified, which means he or she is finally qualified to assume the job of an ME. Given the strong legal content of the ME's work, some forensic pathologists may also have some training in the law, or even a law degree.
The work of the forensic pathologist is quite varied. They will, like any other physician, often be involved in reviewing a patient's medical history. Many of the apparently suspicious deaths reported to the ME are Page 521 | Top of Articleactually from natural causes and the pathologist must be as aware of common diseases as well as the methods used for homicide and suicide. If it appears as if a crime has been committed, then witness statements will be reviewed and, ideally, the scene of crime visited. Evidence of many types must be considered, from bloodstains and DNA, to toxicological analysis of blood and urine. All of this will help the ME to determine the cause and manner of death.
Perhaps the most important part of the forensic pathologist's job is to carry out the autopsy, if one is required. This is done according to a standard procedure with notes and photographs taken at every stage. The forensic pathologist is also responsible for writing up a report on the investigation, which includes autopsy results and other findings, and presenting this to the court.
The forensic pathologist does not operate alone; he or she is part of an investigating team. In a large jurisdiction, the forensic pathologist may have one or more assistants who may also be medically qualified. There are also posts for those who have degrees in science rather than medicine. A degree in biology, chemistry, or physics may secure a job as a technician, scientist, or laboratory manager in a facility where forensic pathology is done, particularly for candidates who have the appropriate postgraduate training in a branch of forensic science or experience in an appropriate laboratory.
Forensic pathology itself includes a number of subspecialties, including toxicology, serology, odontol-ogy, anthropology, and taphonomy. Laboratories, both governmental and private, devoted to each discipline will have openings for those qualified in medicine or science. A forensic pathologist needs to undertake further training to specialize in any of these disciplines. Toxicology involves the analysis of body fluids and tissues for poisons or drugs of abuse. Work in the toxicology laboratory involves chemical analyses using techniques such as thin-layer chromatography (TLC), gas chromatography-mass spectrometry, and ultraviolet spectros-copy. Technicians may be qualified in chemistry and chemical analysis. The pathology side involves determining the contribution that an individual drug may have made to a death. Drug overdose is involved in many deaths, but it can be challenging to work out whether such a death has been a suicide or an accident. Homicide by poisoning is rare nowadays, thanks, at least in part, to developments in toxicological analysis that make it easy to detect the most common poisons in human tissues.
Forensic serology is the study of blood and other body fluids. The work requires clinical pathology technicians to type blood that can incriminate or eliminate a suspect. Analysis of other body fluids, like semen, can help in the investigation of serious crimes such as rape.
DNA analysis has become the “gold standard” for identifying an individual. Dental records can be very useful in the identification of skeletal remains, one of the main uses of forensic odontology, or the application of dentistry to the investigation of crime. The other major application of forensic odontology is the analysis of bite marks left behind at the scene of a crime. Dental technicians may create casts of impressions of bite evidence; the interpretation of dental evidence is a specialist task involving comparison between dental records or impressions and the evidence. Even if only a few teeth are available with a set of human remains or if a bite mark is incomplete, the forensic odontologist can still offer an opinion as to the age and habits of that person, which can be set into context with other identifying information.
Like teeth, bones are enduring and their forensic analysis can often be used to make an identification. Forensic anthropology is the study of human skeletal remains to estimate, first of all, the age, sex, and race of the deceased. The anthropologist may also use toxicological and DNA analyses if these can be obtained from the remains. If a skull is available, identification can sometimes be made by comparing it with x-rays obtained antemortem (before death). The forensic anthropologist needs a depth of knowledge to be able to estimate the age of bones (they may be so old as to be of little forensic significance), and whether they are indeed human.
The forensic pathologist deals with both a “fresh” body and bones, while the anthropologist just focuses on the bones. The study of the in-between stage, the decomposing body, is the realm of the forensic taphonomist. A human body undergoes specific changes after death. The rate of these changes, however, depends very much on the individual and the environment. Evaluation of these changes may help establish the all-important time of death.
Any pathologist working in the above disciplines may be called in as an expert witness to help resolve cases where the facts are unclear or in need of some explanation. A pathologist can help with the difficult question of cause of death when a body is recovered from water or how long it may have been in a shallow grave.
While most expert witnesses do not make a profession of it, there are some who make it their career. A pathologist who carries out this work does not need to have special Page 522 | Top of Articlelegal qualification. The expert witness is created and recognized as such by the judge and the court; he or she will usually have undergone training in court procedures so they can present their evidence to the best of their ability to help the judge and jury come to their decision.