Livor Mortis Definition
Livor mortis is a phenomenon that is characteristic of death, where the result of blood cell destruction causes a purple discoloration of the skin, in some depended body parts. It may also be called, simply a purplish discoloration of the skin after death.
Livor Mortis Explanation
The purple color is due to blood banking in one place. Once the heart stops pumping at death, the blood to seep into these lower body areas along gravitational force. The coloration, also called lividity, will not form in areas of the body in contact with the floor because the pressure against capillaries will allow blood to settle. These areas will thus be characteristically white in color, a phenomenon called blanching. (Wagner, S. 2009).
When the heart rate has stopped agitating the blood, heavier red blood cells, will naturally sink through the serum, by the aid of gravitational force. The degree of staining normally depends on the quantity of hemoglobin, that is in reduced state. As the walls of the vessels become porous due to degradation, leakage of the blood occurs through them and a purple pigment is seen. ( Wagner, S. 2009).
This liquidity is vital to the investigator indeed. First, the investigator will have the general estimation, since the time of death. These indicators are influenced by factors like, body mass, temperature as well as the conditions at the time of the crime. Lividity is visible some 1-2hrs after death, after which it becomes fully developed in within 3-4hrs but this could still be altered if the body's was changed. After 12hrs, the discoloration becomes unchangeable. (Wagner, S. 2009).
Another important reason for investigators to note lividity during postmortem is that it can indicate a change in body position. In an example, it is found out that the body face up with the purplish color on the face, it means the body was turned several hours after death. Blanching areas could also help reconstruct the original position of the body.
Blanching might as well even reveal other locations of a crime scene. Hypothetically, if you find of the body, 4 wide slots of blanching alternating with thin purple lines, that may reveal the position of the body, on a nearby wooden deck.
It is worthwhile noting that the suspects may return to the scene due to specific concerns like covering up evidence, or could have forgotten something.