The Rate of Decay in a Corpse
The rate of decay within the human body after death is normally split into two distinct categories. These are:
- Autolysis: A process of self-digestion where the body's enzymes contained within cells begin to go into a post death meltdown. The process can be speeded up by extreme heat and likewise slowed down by extreme cold.
- Putrefaction: Bacteria that escape from the body's intestinal tract after the deceased has died are released into the body and begin the process of literally melting the body down.
What is Putrefaction?Putrefaction follows a predetermined timetable in nature and after the first 36 hours the neck, the abdomen, the shoulders and the head begin to turn a discoloured green. This is then followed by bloating – an accumulation of gas that is produced by bacteria toiling away within the deceased. This bloating is most visible around the face where the eyes and the tongue protrude as the gas inside pushes them forward.
As the body continues to putrefy, the skin blisters, hair falls out and the fingernails of the deceased began to sink back into the fingers. These skin blisters are also filled with large amounts of liquid just as in a blister you might get from running or walking too far.
The body's skin tone then becomes what is known as 'marbled'; an intricate pattern of blood vessels in the face, abdomen, chest and other extremities becomes visible. This is the result of the body's red blood vessels breaking down, which in turn release Haemoglobin.
As the process reaches its conclusion, the body will now be almost black-green and the fluids – known as purge fluid – will drain from the corpse. This happens normally from the mouth and nose but can also occur from other orifices. The body's tissues then begin to break open and will release gas and other fluids in the same way as a fruit that has been left too long in the sun.
It is also important to note that the internal organs of the deceased will begin to decay in a particular order; beginning with the intestines, which as well as holding bacteria also hold various levels of acidic fluid which – when unable to circulate – begin to eat through their surrounding tissues. As the intestinal organs decay so too do the liver, kidneys, lungs and brain. The contents of the stomach may also slow down the rate of decay if there is undigested food in and around that area.
The last organs to give way to decay are the prostate and/or the uterus. Again, this may sound all very unpleasant but it is a natural calendar of events for the body to go through and one which the pathologist and Scenes of Crime Officer (SOCO) will find useful in their quest to Determine the Time of Death.
Be aware also that hot temperatures will speed up this process, while cooler temperatures will slow it down. Also, a person who has died with a septic wound will suffer the effects of putrefaction faster, as the bacteria from sepsis spreads quickly and does damage on a larger and faster scale.