How Body Farms Work

In order to understand how body farms work, it helps to know some basics about human death and decay. Though it sounds pretty macabre, it's perfectly normal for your body to go through some radical changes when you die.

To begin with, when your heart stops beating, your body's cells and tissues stop receiving oxygen. Brain cells are the first to die -- usually within three to seven minutes [source: Macnair]. (Bone and skin cells, though, will survive for several days.) Blood begins draining from the capillaries, pooling in lower-lying portions of the body, creating a pale appearance in some places and a darker appearance in others.

About three hours after death, rigor mortis -- a stiffening of muscles -- sets in. Around 12 hours after death, the body will feel cool, and within 24 hours (depending on body fat and external temperatures), it will lose all internal heat in a process called algor mortis. The muscle tissue begins to lose its stiffness after about 36 hours, and within about 72 hours of dying, the body's rigor mortis will subside.

As the cells die, bacteria within the body begin breaking them down. Enzymes in the pancreas cause the organ to digest itself. The body soon takes on a gruesome appearance and smell. Decomposing tissue emits a green substance, as well as gasses such as methane and hydrogen sulfide. The lungs expel fluid through the mouth and nose.

Insects and animals certainly take notice of all this. A human body provides sustenance and a great place for insects to lay eggs. A fly trying to find its way in this crazy, mixed-up world can eat well on a corpse, and then lay up to 300 eggs upon it that will hatch within a day.

Maggots -- the larvae that emerge from these eggs -- are extremely efficient and thorough flesh-eaters. Starting on the outside of the body where they hatched, maggots use mouth hooks to scoop up the fluids oozing out of the corpse. Within a day's time, the maggots will have entered the second stage of their larval lives, as well as burrowing into the corpse.

Moving around as a social mass, maggots feed on decaying flesh and spread enzymes that help turn the body into delectable goo. The breathing mechanism of a maggot is located on the opposite end of its mouth, enabling it to simultaneously eat and breathe without interruption around the clock. While a first-stage larva is about 2 millimeters long, by the time it exits the third stage and leaves the body as a prepupa, it may be as large as 20 millimeters -- 10 times its initial length. Maggots can consume up to 60 percent of a human body in under seven days [source: Australian Museum].

The environment in which a dead body is placed also affects its rate of decay. For instance, bodies in water decompose twice as fast as those left unburied on land. Decomposition is slowest underground -- especially in clay or other solid substances that prevent air from reaching the body since most bacteria require oxygen to survive.

Now that we know more about human decay, we'll look at a group of people whose workplace smacks strongly of it: forensic anthropologists.

Depending on how deep a coffin is buried, the body inside may be completely stripped of its tissue or flesh within 40 to 50 years. Bodies left unprotected from the elements will decompose to a skeletal state much sooner. However, it may take hundreds of years for bones to decompose entirely.

Although most bodies are discovered long before dust has returned to dust, enough time -- anywhere, say, from a few days to many years -- has often passed that it's impossible to visually determine the identity of a body found under mysterious circumstances. Skin, muscle and other tissue matter may have decomposed and been consumed or scattered by wild animals. What's most likely to remain is the skeleton, and that's often where the answers must be found.

Forensic anthropology is the study and analysis of human remains for purposes of assisting a criminal investigation. Forensic anthropologists provide information about the origin and identity of a body and the means and time of its death. Forensics has many different branches -- everything from forensic entomology (study of insect evidence) to odontology (analysis of dental evidence). A forensic anthropologist may consult and confer with an odontologist, for example, to more accurately determine an age range for a human skull.

When a body is discovered, a forensic anthropologist is summoned to the crime scene to help find and collect the human remains. It's not always as simple as it sounds. There may be two bodies tangled together in a shallow grave, or the body may be located among animal bones left by hunters. The forensic anthropologist will separate the bones from other matter, take them back to a lab, clean them and examine them. Analysis is complicated by countless factors. For instance, trauma to a bone may have been caused by a struggle with the killer -- or it could just be the result of a childhood accident. A forensic examination of the body can help determine which may be the case. Forensic anthropologists also provide court testimony about their findings -- reaffirming for the record their professional opinion on the identity or profile of the individual and the presence of bone or skull trauma.

When forensic scientists are represented on televised crime dramas, their roles are often combined and exaggerated. A forensic anthropologist studies only the bones and decomposed remains of an individual -- not the mysterious, bloody note clenched in a fist, the half-chewed bubble gum in the victim's mouth or the peculiar pattern of a bloodstain on the wall behind the body. Some tasks not handled by forensic anthropologists include:

So even if forensic anthropologists don't really cover all the ground they do on TV, they still have their work cut out for them. And to correctly analyze corpses, they've got to learn about decomposition. It helps to have firsthand experience -- that's where body farms come in. Body farms are like a hands-on laboratory where forensic anthropology students can learn about the environment's effects on a body, as well as observe the decomposition process up close. On the next page, learn about the colleges that consider a field full of rotting bodies to be a bountiful harvest.­

The first body farm (officially known as the University of Tennessee Forensic Anthropology Facility) was opened by Dr. William Bass in 1971. Bass recognized the need for research into human decomposition after police repeatedly asked for his help analyzing bodies in criminal cases. What started as a small area with one body has developed into a 3-acre complex that contains remains of around 40 individuals at any one time. The facility became famous (and gained its moniker) after it inspired Patricia Cornwell's 1995 novel, "The Body Farm."

Where do these bodies come from? When Dr. Bass first started the body farm, he used unclaimed bodies from medical examiners' offices. Later, people started donating their bodies to the facility to help with forensic studies.

There's no common set of standards or guidelines that body farms adhere to, other than safety, security and privacy. Even the dimensions of the facilities vary. Western Carolina University's body farm is about 59-feet (18 m) squared and is built to hold about six to 10 bodies at a time, while the body farm at the University of Tennessee holds around 40 bodies and covers nearly 3 acres. And even body farms are bigger in Texas: The facility at University of Texas-San Marcos covers about 5 acres.

Each facility also has a different focus. The Tennessee body farm pursues a broad range of study into decomposition under all conditions -- buried, unburied, underwater and even in the trunks of cars. The body farm at Western Carolina places emphasis on decomposition in the mountainous region of the Carolinas. Texas' body farm also provides region-specific data. Forensic anthropologists from states like New Mexico are waiting on data from Texas so they can comprehensively study decomposition in desert climates.

Generally, when a facility accepts a body, it's placed in a refrigerator (not unlike one found in a morgue). The body is then assigned an identifying number and placed in a specific location on the grounds of the body farm. The location of each body is carefully mapped. Students learn how to maintain the chain of evidence when working with the bodies. In a criminal case, it's imperative that anyone coming into contact with human remains logs that he or she handled it. This way, no legal questions can be raised about the integrity of the evidence or possible gaps in its custody.

The bodies are allowed to decompose for various amounts of time. Then students practice locating, collecting and removing the remains from the area. The remains are taken to a laboratory and further analyzed. When analysis is finished, the skeleton may be returned to the family of the deceased for burial, if requested. Otherwise, it will likely remain in the department's collection of skeletons. U of T-Knoxville boasts a collection of skeletal remains from more than 700 people.

Body farms may or may not cover the bodies with wire cages. Doing so prevents coyotes in Texas from making off with body parts, but security fencing at the much smaller Western Carolina facility is sufficient.

What are students learning on the body farm? And how is their research helping in real criminal investigations? Find out next.

In the last section, we learned about the basic setup and operation of a body farm. Now let's look at what scientists learn at these facilities.

Body farms allow scientists to study the natural decay of the human body as well as how a decomposing body affects the world around it. For instance, entire insect populations will rise or fall based on the presence of a corpse. A decaying body will even affect surrounding vegetation, killing off some flora with digestive enzymes.

Forensic anthropologists can determine an individual's age, sex, race and body type by looking at the corpse's bones. There's normally not enough difference between genders in the skeletal remains of preadolescent children to identify the sex of the child. The easiest way to detect the gender of an adult skeleton is to simply look at the size of the bones -- males' bones are normally larger, as are the areas where muscle connections are made. There are many differences in the pelvic bone, the most obvious of which is the size of the pelvic inlet (the space inside the pelvic bone). The inlet is larger in women to aid in the birthing process.

The skull also offers clues to facilitate sex determination. Males tend to have backward-slanting foreheads while females' are rounder. Females' chins often come to a point, and male chins are generally more squared off.

Not every bone helps establish an age or range of ages for a set of remains. Forensic anthropologists look for certain things in a very young child -- such as whether or not teeth have come in -- that obviously won't help in analyzing older specimens. Conversely, when they're identifying older bodies, other observations can be made. Ribs can be a helpful determining factor of age. As we get older, the ends of our ribs become more ragged and less flat where they meet the cartilage that connects to the sternum. Therefore, the more ragged the ribs, the older the body. Regardless of what forensic anthropologists examine, there's no way to determine the precise age of an individual, only a general approximation.

When determining the race of a deceased individual, forensic anthropologists seek to place the body in one of three broad groups: African, Asian or European.

This isn't an easy task. Most differences are found in the skull. The distance between eyes or the shape of the teeth help determine ethnicity, as well as more specific genetic background, such as commonalities found in people from certain parts of Asia that other Asians do not share. There are actually more differences within each racial group than there are between each group [source: Ubelaker].

Once age, sex and ethnicity have been determined, this data --combined with bone measurements -- can be used to determine an individual's approximate predeath height and weight.

Though they provide a wealth of useful information, body farms do cause some raised eyebrows, as we'll discuss in the next section.

Leaving dead bodies out in the open isn't for everyone. Beliefs and traditions concerning burial of the dead vary greatly across cultural, religious and geographic divides. The ancient Egyptians maintained elaborate ceremonies and funerary preparations, such as embalming the dead, which is still common today. Tibetan Buddhists may opt for a sky burial, in which one's remains are left exposed to be consumed by vultures. Some people plan to be cremated when they die while others may find the thought of destroying their body by fire -- even after they're dead -- to be disturbing.

Some citizens in San Marcos, Texas, balked when they learned that nearby Texas State University planned on building a body farm. Concerns were raised about smell, possible unsightliness and even the chance of coyotes redistributing decaying body parts around town. When a new site was proposed, it was a notably Texas-style problem that halted construction -- buzzards. Citizens feared that the body farm would attract buzzards and other birds of prey, and that these creatures would be a risk to low-flying aircraft taking off and landing at a nearby airport. Texas State University assuaged concerns by announcing that the body farm would be located within a 3,000-acre property and would be at least a mile away from any properties that border the site. The isolation and privacy of this final location satisfied local residents.

Another common fear associated with body farms is contamination or the spread of disease. The faculty in charge of running these decomposition facilities do everything they can to alleviate such worries. Body farms don't accept any bodies that test positive for infectious diseases. Additionally, anyone who has proximity to corpses must have a round of vaccinations to prevent catching hepatitis, tetanus and other diseases. The bodies themselves, though, actually prevent disease from spreading. When bodies go through the putrification process, disease-causing organisms also decompose, rendering the remains harmless.

More body farms are needed across the nation because research done on corpses in any given environment provides the most applicable data to bodies found under those same environmental conditions. While this may not pose a problem for bodies found in states like Georgia or Virginia, the effects of decomposition vary greatly for a body in a desert climate, such as Arizona or New Mexico. This specific problem spurred the creation of the Texas body farm. Ideally, there would be at least one body farm operating in each state -- but it may take many more years for that goal to be realized.

For body farms to exist, there have to be bodies -- and yours could be one of them. If you want to donate your body to a forensic anthropology facility, you should make arrangements with the body farm of your choice before you die. You should also tell family members or an attorney about your decision so that the body farm can be notified of your death -- and the farm's imminent acquisition. Generally, the university will collect the donated body after funeral services have been held. However, depending on the distance between the body and the university, it may be necessary for your estate to pay to ship your body.

In the next section, we'll look at some mysteries solved through skills and knowledge being learned at body farms.

The FBI has long shown a keen interest in using the applications of anthropology to solve crimes. The agency began utilizing the anthropological laboratories -- and experts -- of the Smithsonian Institute in 1936, and continues to do so. The body farm at University of Tennessee-Knoxville arranges reproductions of crime scenes and likely criminal scenarios using bodies designated for FBI training and research. FBI teams will periodically perform excavations at the body farm to sharpen their corpse-collecting and bone-identifying skills in the field. The FBI has also raised the possibility of testing radar at the facility that would enable it to find bodies buried under concrete.

Skills learned at body farms can help across the globe. When mass graves are found in places like Kosovo, Iraq or Rwanda, examiners can determine the corpses' race and time of death, which helps identify the regime responsible for their death. It can also be determined if the victims were shot, beaten or killed with a blow to the head.

Serial killer John Wayne Gacy killed 33 young men, 29 of whom were buried right below his own house. When investigators discovered these corpses, many of which had been stacked on top of one another, they relied on forensic anthropologists to help them begin the identification process for the badly decomposed bodies. By establishing height and weight and profiling their bones, authorities were able to begin matching this data against information provided by families or from unsolved missing-persons cases.

For years, there were rumors about the death of the Big Bopper (musician J.P. Richardson), who died in a plane crash with Ritchie Valens and Buddy Holly. The distance of Richardson's body from the plane -- 40 feet (12 m) -- raised questions about whether or not he had survived the plane crash but died walking away in search of help. Richardson's son contacted Dr. Bass to put the mystery to rest. Bass agreed to examine the body, which was being exhumed for other purposes.

After examining the body (which was, 48 years later, reportedly still recognizable as the Big Bopper), Bass determined that there was absolutely no way Richardson could have survived the crash. Nearly every bone in his body was broken, meaning he must have been thrown -- and did not walk -- away from the plane.

Forensic anthropology can also help close cold cases. In 1933, the body of 7-year-old Dalbert Aposhian was found floating in San Diego Bay. After examining the body, an autopsy surgeon declared it had been sodomized and mutilated. No one was ever arrested for the crime. In September of 2005, the San Diego County crime lab received funds to reopen cold cases. After re-examining reports and pictures taken during the initial investigation, the medical examiner's office determined that the young man simply drowned. The original report that said he was sexually assaulted and mutilated was actually a misunderstanding of how a body reacts to water [source: Shearer].

For more information on body farms and other related topics, follow the links on the next page.