Investigating the time of death

Estimating the time of death of a person is very difficult and once the body has been dead for 48 hours it becomes harder still. A number of changes take place in the body of any mammal afetr death with can help estimate TOD (time of death). At death metabolic reactions begin to slow and stop. At the same time heat energy is transferred from the body to its surroundings. This means that the body temperature slowly drops to room temperature. Therefore, body temperature will give some indication of TOD. A number of other factors also affect how quickly body temperature drops. e.g. body fat, mode of death, environment surrounding the body and clothing.

Rigor Mortis - when you die, the heart stops pumbing blood around the body and the brain dies within minutes. However, some tissues have large stores of ATP and so can continue to respire anaerobically for a while. As muscle cells run out of ATP, the muscle fibres become permenantly contracted and lock solid. This is rigor mortis. It starts about 2-4 hours after death. The main factor that will determine how quickly rigor mortis sets in is the amount of ATP in the muscles. The temperature of the person and their surroundings also affects rigor mortis. It isn't permanent, it usually passes…