Application of the science of anthropology in a legal setting
Forensic anthropology is the application of the anatomical science of anthropology and its various subfields, including forensic archaeology and forensic taphonomy, in a legal setting. A forensic anthropologist can assist in the identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable, as might happen in a plane crash. Forensic anthropologists are also instrumental in the investigation and documentation of genocide and mass graves. Along with forensic pathologists, forensic dentists, and homicide investigators, forensic anthropologists commonly testify in court as expert witnesses. Using physical markers present on a skeleton, a forensic anthropologist can potentially determine a person's age, sex, stature, and race. In addition to identifying physical characteristics of the individual, forensic anthropologists can use skeletal abnormalities to potentially determine cause of death, past trauma such as broken bones or medical procedures, as well as diseases such as bone cancer.
The methods used to identify a person from a skeleton relies on the past contributions of various anthropologists and the study of human skeletal differences. Through the collection of thousands of specimens and the analysis of differences within a population, estimations can be made based on physical characteristics. Through these, a set of remains can potentially be identified. The field of forensic anthropology grew during the twentieth century into a fully recognized forensic specialty involving trained anthropologists as well as numerous research institutions gathering data on decomposition and the effects it can have on the skeleton.
Modern uses.
Today, forensic anthropology is a well-established discipline within the forensic field. Anthropologists are called upon to investigate remains and to help identify individuals from bones when other physical characteristics that could be used to identify a body no longer exist. Forensic anthropologists work in conjunction with forensic pathologists to identify remains based on their skeletal characteristics. If the victim is not found for a lengthy period or has been eaten by scavengers, flesh markers used for identification would be destroyed, making normal identification difficult if not impossible. Forensic anthropologists can provide physical characteristics of the person to input into missing person databases such as that of the National Crime Information Center in the US or INTERPOL's yellow notice database.
In addition to these duties, forensic anthropologists often assist in the investigation of war crimes and mass fatality investigations. Anthropologists have been tasked with helping to identify victims of the 9/11 terrorist attacks, as well as plane crashes such as the Arrow Air Flight 1285 disaster and the USAir Flight 427 disaster where the flesh had been vaporized or so badly mangled that normal identification was impossible. Anthropologists have also helped identify victims of genocide in countries around the world, often long after the actual event. War crimes anthropologists have helped investigate include the Rwandan genocide and the Srebrenica Genocide. Organizations such as the Forensic Anthropology Society of Europe, the British Association for Forensic Anthropology, and the American Society of Forensic Anthropologists continue to provide guidelines for the improvement of forensic anthropology and the development of standards within the discipline.
With hundreds missing and bodies burnt beyond recognition by Hamas militants during its October 7 attack of Israel, Israeli authorities assembled recovery teams that included archaeologists from the Israel Antiquities Authority. The team used their specialized skills in excavating and identifying fragmentary ancient remains to sift through ash and rubble for bone fragments overlooked by other forensic teams. Archeologists systematically searched rooms, dividing them into grids and carefully extracting bone shards. At one house, the archeology team found a bloodstain under ash that they determined was the outline of a body, later identified through DNA analysis.
History.
Early history.
The use of anthropology in the forensic investigation of remains grew out of the recognition of anthropology as a distinct scientific discipline and the growth of physical anthropology. The field of anthropology began in the United States and struggled to obtain recognition as a legitimate science during the early years of the twentieth century. Earnest Hooton pioneered the field of physical anthropology and became the first physical anthropologist to hold a full-time teaching position in the United States. He was an organizing committee member of the American Association of Physical Anthropologists along with its founder Aleš Hrdlička. Hooton's students created some of the first doctoral programs in physical anthropology during the early 20th century. In addition to physical anthropology, Hooton was a proponent of criminal anthropology. Now considered a pseudoscience, criminal anthropologists believed that phrenology and physiognomy could link a person's behavior to specific physical characteristics. The use of criminal anthropology to try to explain certain criminal behaviors arose out of the eugenics movement, popular at the time. It is because of these ideas that skeletal differences were measured in earnest eventually leading to the development of anthropometry and the Bertillon method of skeletal measurement by Alphonse Bertillon. The study of this information helped shape anthropologists' understanding of the human skeleton and the multiple skeletal differences that can occur.
Another prominent early anthropologist, Thomas Wingate Todd, was primarily responsible for the creation of the first large collection of human skeletons in 1912. In total, Todd acquired 3,300 human skulls and skeletons, 600 anthropoid skulls and skeletons, and 3,000 mammalian skulls and skeletons. Todd's contributions to the field of anthropology remain in use in the modern era and include various studies regarding suture closures on the skull and timing of teeth eruption in the mandible. Todd also developed age estimates based on physical characteristics of the pubic symphysis. Though the standards have been updated, these estimates are still used by forensic anthropologists to narrow down an age range of skeletonized remains. These early pioneers legitimized the field of anthropology, but it was not until the 1940s, with the help of Todd's student, Wilton M. Krogman, that forensic anthropology gained recognition as a legitimate subdiscipline.
The growth of forensic anthropology.
During the 1940s, Krogman was the first anthropologist to actively publicize anthropologists' potential forensic value, going as far as placing advertisements in the FBI Law Enforcement Bulletin informing agencies of the ability of anthropologists to assist in the identification of skeletal remains. This period saw the first official use of anthropologists by federal agencies including the FBI. During the 1950s, the U.S. Army Quartermaster Corps employed forensic anthropologists in the identification of war casualties during the Korean War. It was at this time that forensic anthropology officially began. The sudden influx of available skeletons for anthropologists to study, whose identities were eventually confirmed, allowed for the creation of more accurate formulas for the identification of sex, age, and stature based solely on skeletal characteristics. These formulas, developed in the 1940s and refined by war, are still in use by modern forensic anthropologists.
The professionalization of the field began soon after, during the 1950s and 1960s. This move coincided with the replacement of coroners with medical examiners in many locations around the country. It was during this time that the field of forensic anthropology gained recognition as a separate field within the American Academy of Forensic Sciences and the first forensic anthropology research facility and body farm was opened by William M. Bass. Public attention and interest in forensic anthropology began to increase around this time as forensic anthropologists started working on more high-profile cases. One of the major cases of the era involved anthropologist Charles Merbs who helped identify the victims murdered by Ed Gein.
Methods.
One of the main tools forensic anthropologists use in the identification of remains is their knowledge of osteology and the differences that occur within the human skeleton. During an investigation, anthropologists are often tasked with helping to determinate an individual's sex, stature, age, and ancestry. To do this, anthropologists must be aware of how the human skeleton can differ between individuals.
Determination of sex.
Depending on which bones are present, sex can be determined by looking for distinctive sexual dimorphisms. When available, the pelvis is extremely useful in the determination of sex and when properly examined can achieve sex determination with a great level of accuracy. The examination of the pubic arch and the location of the sacrum can help determine sex.
However, the pelvis is not always present, so forensic anthropologists must be aware of other areas on the skeleton that have distinct characteristics between sexes. The skull also contains multiple markers that can be used to determine sex. Specific markers on the skull include the temporal line, the eye sockets, the supraorbital ridge, as well as the nuchal lines, and the mastoid process. In general, male skulls tend to be larger and thicker than female skulls, and to have more pronounced ridges.
Forensic anthropologists need to take into account all available markers in the determination of sex due to the differences that can occur between individuals of the same sex. For example, a female may have a slightly more narrow than a normal pubic arch. It is for this reason that anthropologists usually classify sex as one of five possibilities: male, maybe male, indeterminate, maybe female, or female. In addition, forensic anthropologists are generally unable to make a sex determination unless the individual was an adult at the time of death. The sexual dimorphisms present in the skeleton begin to occur during puberty and are not fully pronounced until after sexual maturation.
Consequently, there is currently no reliable method of sex determination of juvenile remains from cranial or post-cranial skeletal elements since dimorphic traits only become apparent after puberty, and this represents a fundamental problem in archaeological and forensic investigations. However, teeth may assist in estimating sex since both sets of teeth are formed well before puberty. Sexual dimorphism has been observed in both deciduous and permanent dentition, although it is much less in deciduous teeth. On average, male teeth are slightly larger than female teeth, with the greatest difference observed in the canine teeth. Examination of internal dental tissues has also shown that male teeth consist of absolutely and proportionately greater quantities of dentine than females. Such differences in dental tissue proportions could also be useful in sex determination.
Determination of stature.
The estimation of stature by anthropologists is based on a series of formulas that have been developed over time by the examination of multiple different skeletons from a multitude of different regions and backgrounds. Stature is given as a range of possible values, in centimeters, and typically computed by measuring the bones of the leg. The three bones that are used are the femur, the tibia, and the fibula. In addition to the leg bones, the bones of the arm, humerus, ulna, and radius can be used. The formulas that are used to determine stature rely on various information regarding the individual. Sex, ancestry, and age should be determined before attempting to ascertain height, if possible. This is due to the differences that occur between populations, sexes, and age groups. By knowing all the variables associated with height, a more accurate estimate can be made. For example, a male formula for stature estimation using the femur is 2.32 × femur length + 65.53 ± 3.94 cm. A female of the same ancestry would use the formula, 2.47 × femur length + 54.10 ± 3.72 cm. It is also important to note an individual's approximate age when determining stature. This is due to the shrinkage of the skeleton that naturally occurs as a person ages. After age 30, a person loses approximately one centimeter of their height every decade.
Determination of age.
The determination of an individual's age by anthropologists depends on whether or not the individual was an adult or a child. The determination of the age of children, under the age of 21, is usually performed by examining the teeth. When teeth are not available, children can be aged based on which growth plates are sealed. The tibia plate seals around age 16 or 17 in girls and around 18 or 19 in boys. The clavicle is the last bone to complete growth and the plate is sealed around age 25. In addition, if a complete skeleton is available anthropologists can count the number of bones. While adults have 206 bones, the bones of a child have not yet fused resulting in a much higher number.
The aging of adult skeletons is not as straightforward as aging a child's skeleton as the skeleton changes little once adulthood is reached. One possible way to estimate the age of an adult skeleton is to look at bone osteons