Pathology/Biology

The diverse fields of forensic biology and the life sciences and forensic pathology play important roles in forensic science.  This section of the AAFS comprises a diverse group of members, all with important roles in forensic investigations.

Forensic Pathology

Forensic pathology is the practice of medicine concerning injury analysis and performance of autopsies to determine cause and manner of death.  Although forensic pathologists cannot perform all of the miracles seen on television shows such as “CSI” and “NCIS,” it is an interesting and exciting field and is a popular and competitive career choice.

Pathology is a medical specialty—the study of disease.  Pathologists study disease by performing a type of surgery called an autopsy.  Tissues and organs removed during an autopsy are examined for evidence of disease and injury and may also be examined under the microscope.  Analysis of fluids taken from the body, such as blood or urine, also provides information about disease to the pathologist.

Forensic pathology is the application of the principles of pathology, and of medicine in general, to the legal needs of society.  Forensic pathologists perform autopsies to determine what caused a person’s death.  They are also involved in the investigation of the circumstances surrounding the death.  Knowing about these circumstances allows them to determine the manner of death—natural, accident, suicide, homicide, or undetermined.

Although there is much emphasis on violent deaths, forensic pathologists and biologists also investigate sudden deaths of seemingly healthy individuals, deaths of people who have never seen a doctor, deaths occurring in police custody, suspicious or unusual deaths, deaths resulting from surgical or diagnostic procedures, or some deaths that occur in public institutions.  The law of the specific jurisdiction where the death occurs determines which deaths must be reported to the medical examiner (often a forensic pathologist) or, in some states, the coroner.  Then the medical examiner, or coroner, is responsible for deciding if an autopsy is necessary to determine the cause and manner of death.  A forensic biologist will assist these individuals, along with other investigators, as well as provide insight into the postmortem interval (time elapsed since death) and the location of bodies that have yet to be discovered.


A forensic pathologist begins an autopsy with a thorough 
external examination of the body.

Forensic Biology

Forensic biology is the application of the life sciences to legal and regulatory investigations.  Forensic biology comprises all of the life sciences including, but not limited to, entomology, genetics, microbiology, ecology, and botany.  A forensic biologist studies organisms or cells of organisms that are associated with criminal activity.  Many organisms, including insects, bacteria, plants, and fungi can be used as evidence because they indicate the time at which an event took place, or they associate a particular person with an object or a location.  Genetics are regularly used to confirm the identity of these organisms.  In many instances, forensic practitioners of these disciplines have a broad application for their discipline with a wide range of job opportunities (e.g., casework, research, and teaching).

Scope of Work

Forensic Pathology

The forensic pathologist’s involvement and investigation may include visiting the scene of death.  Forensic pathologists and/or their investigators gather information concerning what happened at the time of death, what the person was doing at the time, and the medical history of the individual.

The forensic examination of a body includes examining the clothing on the body, the body itself, and an internal examination of the decedent’s organs, which is the autopsy.  The body is usually photographed and diagrammed with a detailed written report describing any injuries or disease process.  The autopsy usually includes microscopic examination of the tissues of the body.  X-rays may also be taken to look for bullets, broken bones, or other abnormalities.


Microscopic examination of tissues and consultation with 
colleagues is an important part of some autopsies.

The forensic pathologist works with other branches of the forensic sciences.  The forensic pathologist may collect evidence from the body, such as blood and hairs in an assault case, swabs for examination for semen in rape cases, and fibers from the decedent’s clothing and body.  These are sent to the forensic laboratory for examination by a criminalist—a scientist trained in the examination of physical evidence.  The forensic pathologist also collects specimens, such as blood, urine, bile, stomach contents, and body tissues, for toxicology analysis.  The toxicologist looks for the presence of alcohol, drugs, and other chemicals or poisons in these specimens.  If bullets, shotgun pellets, or wadding are recovered at autopsy, they are also sent to the forensic laboratory for examination.  A firearms examiner analyzes these specimens and is often able to match them to a specific weapon.


Forensic pathologists collect a variety of evidence, such as 
bullets, hairs, fibers, and fluids, that may be useful to other forensic scientists working to solve a case.

Forensic pathologists also work to identify unknown deceased persons by way of medical information, dental records, and other unique features of an individual.  If the body has deteriorated to a skeleton, forensic pathology may determine the race or sex of the individual.  Forensic pathologists are often assisted by forensic odontologists (dentists) and physical anthropologists with the assessment of cases and the identification of deceased individuals.

Examination of the deceased may reveal whether the person received injuries, also called trauma, both prior to (antemortem) and after (postmortem) death, as well as changes to the body that occurred as a result of decomposition after death.

Each type of injury (e.g., gunshot, blunt force, or sharp force) often can be recognized by a distinctive pattern.  Forensic pathologists are trained to recognize these patterns and thereby determine the cause and manner of death.  Injury patterns are especially important in cases of child abuse and elder abuse.

Autopsy findings must correlate with the other known physical and circumstantial evidence.  Sometimes, examination of the body may reveal that the victim died in a distant location and in a very different position from the situation in which the body was actually found.  The forensic pathologist’s opinions and the autopsy results are vital components of any medicolegal death investigation.  The forensic pathologist must maintain accurate and unbiased written and photographic records.  This work may lead to the conviction of the guilty or the exoneration of the innocent.

Another aspect of forensic pathology is the role this science plays in the areas of public health and disease and injury prevention.  The forensic pathologist may be the first to recognize an epidemic disease or document a faulty product design that resulted in injury and death.  Genetic disorders may be identified at autopsy and reported to those surviving family members who may be affected.

An emerging role of the forensic pathologist is that of clinical forensic pathology.  Patterns of injury are not visible only when persons are deceased—they can also be recognized in living patients in emergency rooms and clinics.  This is especially critical in cases of child and elder abuse.  The interpretation of these injuries is invaluable to police or other law enforcement officials in a criminal investigation.  A forensic pathologist’s training can be applied to injury analysis in both living and deceased patients.

The forensic pathologist plays an important role in communication with bereaved families as well as other physicians, attorneys, and law enforcement officers in an effort to provide all those who have need with proper, accurate, and timely information.  Assistance to those who are left to deal with the loss and trauma surrounding the death of a human being is the reason for the work of the forensic pathologist.

Forensic Biology


Forensic Biology/Life Sciences comprises diverse fields including, but not limited to, entomology, genetics, microbiology, ecology, and veterinary medicine.  A forensic biologist’s role in forensic investigations often includes visiting the scene of death. However, because forensic biology is quite diverse, the role(s) of such an individual will be field-specific.  Forensic biologists typically collect evidence concerning perimortem (at the time of death) activity, postmortem interval, and location of relevant evidence. In other investigations, a forensic biologist will receive evidence collected by an investigator.  A forensic biologist will analyze samples they collect or that are provided, as well as photographs and case notes prepared by other investigators including the forensic pathologist.

A forensic biologist typically serves as a forensic specialist and will be called to contribute to medicolegal death investigations when their specialty is needed.  For example, a forensic entomologist will contribute expertise to a death investigation to determine the time of colonization of human remains, which in many cases represents a minimum postmortem interval (time since death).  Forensic entomologists may also provide information from examining insects to help determine when trauma occurred (before or after death), if the remains had been moved from one location to another, identification of the individual (from DNA collected), and toxicology.

One emerging field of forensic biology is forensic microbiology.  Forensic microbiologists use bacteria, Archaea, and microbial eukaryotes to provide insight into several aspects of medicolegal death investigation including cause-of-death, manner-of-death, identification, and postmortem interval.  This is a rapidly developing field that will likely provide several new discoveries over the next few years.

Forensic biology also includes the work of botanists—those plant specialists who provide expertise in interpreting stomach contents or locating clandestine graves.

Forensic veterinary sciences is also an emerging field where veterinarians are called on to examine animals for documentation of trauma.


A forensic veterinarian examining an animal carcass for evidence of trauma.

Education and Training

All forensic pathologists are medical doctors with an MD or DO degree.  Therefore, the training requirements involve many years of studious effort.  After four years of college and four years of medical school, an apprenticeship in pathology, known as a residency, is required.  Forensic pathology is a subspecialty of pathology, so an additional one-year fellowship in forensic pathology is required.  Medical board certification in anatomic pathology and forensic pathology is acquired from The American Board of Pathology.


Forensic pathologist teaching a pathology resident in a modern autopsy suite.

Forensic biologists typically possess a MS and/or PhD in a biological science, such as entomology, microbiology, biochemistry, or ecology.  Many biologists earn a BS in a biological science and then a MS, but some proceed directly into a PhD program from their BS.  Most of these scientists conduct research in a field of biology that can be applied to a forensic investigation.  Many forensic biologists also work in a non-criminal area of life science such as agriculture or conservation.  Certification can be acquired in some areas of forensic biology, such as certification in forensic entomology from the American Board of Forensic Entomology.

Veterinarians must complete a four-year graduate degree program, pass a national board exam, and hold a valid license to practice veterinary medicine within a given locality.  Veterinarians focusing on pathology can undertake a residency program in pathology to further their specialization.

Career Opportunities

Forensic pathologists are usually employed by city, county, or state medical examiner or coroner offices; hospitals; universities; and federal government agencies, such as the Centers for Disease Control (CDC) and the Armed Forces Medical Examiner.  Forensic pathologists may also work for private medical groups as consultants by performing forensic autopsies.

Forensic biologists work in crime laboratories, but are more often associated with universities, museums, or other government agencies.  These scientists typically serve as consultants to medical examiners and coroners while conducting research in an area of forensic biology.

All the forensic specialties play an important role as expert witnesses for attorneys in criminal (both prosecution and defense) and civil cases.

©2021 American Academy of Forensic Sciences