Any forensics people out there? How long does it take for a body to decompose and leave only bones?

Moment of Death:
1} The heart stops
2} The skin gets tight and grey in color
3} All the muscles relax
4} The bladder and bowels empty
5} The body’s temperature will typically drop 1.5 degrees F. per hour unless outside environment is a factor. The liver is the organ that stays warmest the longest, and this temperature is used to establish time of death if the body is found within that time frame.
After 30 minutes:
6} The skin gets purple and waxy
7} The lips, finger- and toe nails fade to a pale color or turn white as the blood leaves.
8} Blood pools at the lowest parts of the body leaving a dark purple-black stain called lividity
9} The hands and feet turn blue {because of lack of oxygenation to the tissues}
10} The eyes start to sink into the skull
After 4 hours:
11} Rigor mortis starts to set in
12} The purpling of the skin and pooling of blood continue
13} Rigor Mortis begins to tighten the muscles for about another 24 hours, then will reverse and the body will return to a limp state.
After 12 hours:
14} The body is in full rigor mortis.
After 24 hours:
15} The body is now the temperature of the surrounding environment
16} In males, the spermatozoa die.
17} The head and neck are now a greenish-blue color
18} The greenish-blue color continues to spread to the rest of the body
19} There is the strong smell of rotting meat {unless the corpse is in an extremelly frigid environment}
20} The face of the person is essentially no longer recognizable
After 3 days:
21} The gases in the body tissues form large blisters on the skin
22} The whole body begins to bloat and swell grotesquely. This process is speeded up if victim is in a hot environment, or in water
23} Fluids leak from the mouth, nose, eyes, ears and rectum and urinary opening
After 3 weeks:
24} The skin, hair, and nails are so loose they can be easily pulled off the corpse
25} The skin cracks and bursts open in many places because of the pressure of Internal gases and the breakdown of the skin itself
26} Decomposition will continue until body is nothing but skeletal remains, which can take as little as a month in hot climates and two months in cold climates. The teeth are often the only thing left, years and centuries later, because tooth enamel is the strongest substance in the body. The jawbone is the densest, so that usually will also remain.

The University of Tennessee Forensic Anthropology Center (aka The Body Farm) studies decomposition, so that police can compare a found body with known results.

They put cadavers out in various states – buried, not buried, wrapped up, clothed, naked, etc – and they record how they decay.

“The Anthropological Research Facility allows actualistic studies evaluating human decomposition to be conducted in a controlled, scientific setting. These studies have had significant ramifications for forensic investigations. Donated cadavers are used to study the precise nature and timing of decomposition events. More than 1,000 bodies have been donated, and more than 2,000 individuals are registered for donation on their death.” – NIH.gov

UT Knoxville

@KNOWITALL‘s answer is all that’s required, even though it creeped me the fuck out!

@KNOWITALL – thanks for the answer, this is great information. I have to ask – how much of that did you know BEFORE you answered :-)

@jaytkay – I’ve heard of the body farm before, but didn’t realize it was so close to where I live.

You’d have to know the whole story. That is, the exact placement of the body, for example: a body in a cave, where an injured person might go to recover from serious wounds, may take much longer to decompose than one where a person dropped dead of the wound in a field, for example. (Some bodies in some caves may even mummify.)

Altitude can play a part. Bodies at higher elevations may not suffer accelerated tissue loss from animals and insects, for example. (That may also be true for the body found in a cave.)

Bodies with a southern exposure vs. northern exposure will weather differently. Same with rainfall and snow: a body that gets covered by leaves may not decompose the same as one that is always exposed to weather.

Details are crucial in all of this. Read some Patricia Cornwell, and you’ll learn more than you ever wanted to about forensic investigation. One of her novels, in fact, is “The Body Farm”, with many details about the UT facility.

@ucme I like to know how thing’s work, engines, brains, bodies, etc…

@elbanditoroso I wanted to be a doc when I was a pre-teen and was in a local Medical Explorers program so anything medical intrigues me. So enough I guess. :)

@KNOWITALL The bit where the eyes sink into the skull made me wince most, pleased i’d already eaten.

@ucme Not #16? So could you have a baby by a dead guy? :)

@KNOWITALL – collecting child support would be a real challenge :-(

@KNOWITALL Nah, I figure after 24hrs my penis is pretty much useless anyway, maybe the sperm hang around to pay their respects to a once proud member.