Coin Under Body by: Glenn Wilcher Forensdic Technician
As a Forensic Technician at external examination we often find foreign objects 'stuck' to the back of bodies when we turn them over to examine the back.
Related is the post mortem change in the body known as hypostasis also known as post mortem staining and suggilation.
When a body is lying on the ground the blood in the venous vessels settles to the lower dependent part of the body producing initially a temporary redy purple discolouration. The first couple of hours this reddening blanches on fingertoip pressure. After a period of time the 'staining' becomes permanent.
The forensic significance of this is determining if the body has been moved after death. If a body hypothetically is found in a prone position and the lividity or hypostasis is on the top of the body it would indicate the body was moved and turned over.
In relation to foreign objects if the coin was underneath the body under the buttocks or shoulder blades you may get an outline of the coin. A good example is with elastized clothing or underwear with the brand name...you get the outline of the brand name due to the pressure on the skin. The areas on the body that are in contact with an object or surface is usually pale and referred to as contact flattening. The shoulders, buttocks would be blanched and the small of the back and between the shoulder blades would be the purple colour due to the settling of the blood.
I have seen objects such as scizzors which have left a patterned outline of them on the body.
Go to a forensic site (forensic science links) and look up hypostasis or lividity or postmortem staining and you may see examples. I would think there would be no reaction chemically with the coin unless the surface the body was on had some chemical constituents e.g very acidic that may react with the alloys of the coin, such as a copper coin and the chemical composition of the soil caused a reaction which may lead to a blue copper colouration as an example.
