In the middle of the woods, just a few miles from Alcoa Highway in Tennessee, you may come across a 1-hectare (2.5-acre) plot surrounded by a razor-wire fence.
The plot, which we'd highly advise you don't enter if you're squeamish, is home to the world's first "body farm", where human bodies are left to rot in the open, locked in trunks of cars, or submerged in water, all watched closely by scientists to see what happens next.
Body farms as a concept are a surprisingly late invention, conceived by anthropologist William M. Bass in 1971. Bass had spent most of his career in Kansas. In the state, given the massive amounts of land, it was often the case that bodies weren't discovered for years, meaning when he was asked to identify remains, he was generally working on a skeleton.
"Then in 1971, I came to the University of Tennessee, and instead of just skeletal remains, about half the first 10 cases were maggot-covered bodies. In those cases, the police don't ask, 'Who is that?' They ask, 'How long have they been there?'" Bass told Wired in 2007.
"I didn’t know anything about maggots and thought if I'll be talking to police about how long somebody has been dead, I'd better know something about it."
This need for better information became more pressing, when he was asked for his help on an unusual case. Police had discovered a Civil War grave that had been disturbed, and the corpse inside looked suspiciously fresh for a man who supposedly died over a hundred years ago. They believed the grave may have contained the body of someone recently murdered and then placed in the grave where Colonel William Shy once lay.
Bass headed to the scene to see the body in situ. What he saw was a grave that had recently been disturbed, with soil dug out three or four feet down, and the headless corpse of a man sitting up on top of the casket, dressed in a tuxedo.
Bass looked inside the iron casket itself and found it empty, which he put down to the body and bones having been broken down in the intervening years. When he examined the corpse, he found it to be decayed but with plenty of flesh and joints still attached. Given the corpse's pink flesh, Bass too believed the body had been switched. He suggested that the body had been deposited there some 2-6 months ago, and the police that graverobbers had looted Colonel Shy's body while depositing their own, but were disturbed before they could complete their task.
But they were all wrong.
In the new year, police re-examined the grave and found the skull. Shattered into fragments, the skull showed signs that its owner had been killed by gunshot. However, the odd thing about it was that the man had clearly never been to a dentist, despite many dental problems. Next, the police discovered that his clothes were entirely without labels. They were all extremly old.
Further analysis of the body's teeth would confirm that it was Col. Shy, who had been killed by a bullet wound in the Civil War, and his body had been well-preserved due to the tight seal of his iron casket, and the embalming process he'd gone through.
This error convinced Bass that further study on corpse decomposition was urgently needed. He believed knowing the exact process and the variables that can affect it, like temperature and exposure, could help law enforcement figure out useful clues, such as time and circumstances of death when a body is found, so he set up the world's first body farm to do just that.
Initially, Bass relied on using unclaimed bodies from medical examiners before people began to donate their bodies to science. Now there are seven body farms operating across the US, all studying different aspects of decomposition, providing training to forensic investigators on how to handle a body at a crime scene, and providing vital clues to law enforcement when it comes to investigations of death.
A look inside a body farm at Texas State University. Be warned, it contains graphic images of decomposing bodies.
The farms all work in roughly the same way, though procedures will vary from facility to facility. Bodies arrive at the farm and are photographed, measured, and sampled (blood samples, there is no cannibalism involved – that's a big no-no and will likely earn you a stern chat with HR) before being taken out to the grounds. Here they are placed in whatever situation the forensic team is planning on studying, be it exposure to sunlight, buried underneath soil or foilage, or submerged in water. Sometimes the bodies are placed under cages to prevent animals from gnawing at the corpses, though sometimes they are left exposed specifically to observe what happens to the bodies left to scavengers.
Assuming the bodies haven't been scoffed by a cat, the scientists then watch the bodies as they decompose. Depending on what stage of composition they are studying, they may collect samples from the body at different times. Sometimes bodies are left for weeks, sometimes for years.
There is a lot these facilities can learn through watching corpses decompose, from how insect populations are affected by the presence of a rotting corpse, to how a decaying body affects the surrounding flora and fauna. Recently it's been suggested that flourishing plants could help investigators spot where a body is buried due to the nutrients in the ground. Last year, investigators discovered that corpses move for up to a year after death, with their arms even moving 90° from the body.
Grim it may sound, but the work carried out on these farms has advanced the field of forensics from not knowing if a body was over 100 years old to being able to determine things like if a body has been moved, based on microbes present in the soil.
Just, if you come across a fenced-off area in the middle of a wood, maybe don't do any investigations of your own.