Body Farm (World of Forensic Science)
The Body Farm is more correctly known as the University of Tennessee Forensic Anthropology Research Facility. It was established in 1980 by the pioneering forensic anthropologist William Bass and is dedicated to the study of the rate of decomposition of the human corpse under various conditions that are relevant to crime investigation. Many hallmark scientific papers have come out of the research at the Body Farm and this new knowledge has been crucial in driving forensic investigation into unsolved deaths.
Bass had long experience as a "bone detective," as forensic anthropologists were previously known, and knew that there were many unsolved scientific problems in this area. A major issue was estimating the time of death of a body that is discovered, and this remains a challenge today in difficult cases. The human body undergoes many changes after death. It is colonized by bacteria and insects, the skin falls off, decomposition occurs, and all of this is dependent upon both the circumstances of any crime that has been committed and on the environment into which the body has been placed.
Research at the Body Farm has increased scientific understanding of what happens to the human body after death and this new knowledge has been used in court to convict the guilty in many of the cases that Bass describes. The Body Farm is a research facility close to the forensic labs at the University of Tennessee, where human bodies are allowed to decompose under various different environmental conditions that are relevant to the investigation of crime. The work involves the smell of decomposing bodies and dealing with maggots and flies, but the scientists who work at the Body Farm are dedicated to science and solving crime.
The facility began as a piece of waste ground close to the University of Tennessee in Knoxville. From 1980, Bass and his team began to prepare the site and, in 1981, received their first body for examination. There are two kinds of bodies donated to the Body Farm, with the consent of their next of kin. The first are bodies donated to medical research and the second are corpses that have been involved in crime of some kind. Whatever the cause and circumstances of the death, the mere presence of a corpse at the Body Farm allowed the researchers the first opportunity to study what happens to the human body after death in a controlled fashion. As Bass describes, it took only two weeks for the first body received by the facility to undergo dramatic change. The skull had become bone. The hair slid off in a mat that lay in a greasy pool, while the initially bloated abdomen had collapsed to leave a shrunken belly clinging to the rib cage. This marked a clear transition that was already known; a dead body does initially swell up with gas because of bacterial action, but afterwards it starts to shrink and decompose. At the Body Farm, these changes were observed, documented, and categorized in a scientific manner.
One of the main research aims of the Body Farm is to make it easier for pathologists to determine the time since death when a corpse is discovered. When someone dies, their body starts to decompose and eventually it will become a skeleton. However, the rate at which a body decomposes varies widely. A thin person, especially a child, decomposes more slowly than an obese or older person. Much also depends on climate, geography, and season. In the summer heat of Tennessee, where the Body Farm is situated, a body can become a skeleton in as little as two weeks.
Researchers who have worked at the Body Farm have begun to contribute information that aids in determining time of death with precision. For example, the role of insects in corpse decomposition has been investigated by Bill Rodriquez. His observations back in the early days of the Body Farm showed that blowflies come to a body within minutes of death and feed on bloody areas, where wounds have been inflicted, or on moist areas like the mouth. After this, they go through their life cycle, feeding on the body, and producing eggs and maggots. This kind of evidence can be used in a forensic investigation, but had not been much researched before the advent of the Body Farm. A paper on this work published by Rodriguez in the Journal of Forensic Sciences in 1982, went on to become one of the most cited articles in the field.
Decomposing corpses are consumed by bacteria as well as flies and other predators. Other research carried out by Arpad Vass and colleagues at the Body Farm has shown how bacterial action on a corpse could be used as a forensic clock. As a body decays, a succession of different bacteria preys upon it. Different species have their own feeding requirements. A fresh corpse may not appeal to one bacterial species, but once it is three weeks old, they may start to invade. Bacteria, like all other living things, excrete waste products to the environment. In the case of bacteria feeding on a corpse, this means that analysis of the surrounding soil can be revealing.
Bacteria work inside the body, and more recent research has focused on examining their products in tissues from the decomposing brain, liver, and kidneys. This can help pinpoint the time of death in an even more accurate way, within hours if the corpse is a few weeks old. This type of research is now looking at ways of measuring the distinctive odor of death, that is, the molecules that signify death and decay. It may be possible in the future to transfer this knowledge to portable systems that forensic investigators could use when investigating a burial ground.
It is well known that a body kept in cold conditions is going to decompose slower than one kept at a higher temperature. This makes estimating time of death rather tricky. However, the Body Farm research has come up with a way of controlling for this. A measure called the accumulated degree days, or ADDs, is a method of accounting for the number of days of decomposition at a particular temperature. A measure of 700 would give a specific set of signs of decomposition, but it would have occurred at a certain number of days at one temperature and fewer days at a higher temperature, where the rate of decay would be accelerated. In Body Farm experiments, ADDs were measured from the moment of death, which was known, of the bodies donated to the facility. When a body was being investigated, this knowledge was applied using local climate data and the state of the body. This kind of data helps reveal time of death in the circumstances of the crime.
Despite the unique scientific work it accomplishes, a facility like the Body Farm does not exist without some controversy. Some are concerned that the work does not show proper respect to the dead, although the bodies have always been given to the research with full consent, and are solemnly buried after the conclusion of observations. In the early days, it was local residents who objected to the existence of the Body Farm. If they got close, they could see the bodies decomposing. However, the local community came round when the scientific importance of the work was publicized.
In 1993, novelist Patricia Cornwell, who has a background in forensic science, came to the Body Farm with the intent of trying to have experiments carried out that would help in her latest book. The Body Farm was, by 1996, one of the best-selling detective stories of all time. This meant massive publicity for the Body Farm, which was featured in the book. It helped raise awareness of the importance of forensic anthropology and the emerging science of taphonomy, which is concerned with what happens to a person's body when they die.
The work at the Body Farm is immensely important to forensic investigations. The research that has been done there helps establish time of death more accurately, although it is still hard to be exact. With a time of death, witness and suspect alibis and statements have much more meaning. Further work at the Body Farm, and elsewhere if the facilities can be established, can help set the forensic clock for any body that is discovered under suspicious circumstances.
SEE ALSO Adipocere; Decomposition; Entomology; Taphonomy.