How to Determine a Body's Time of Death. When someone dies and foul play is suspected, time of death is crucial to finding the person's killer. Determine a body's time of death by checking for discoloration, temperature and rigor. Only professionals can accurately determine a time of death, but here are the things they look for.
Check the stomach for signs of digestion. Most meals leave the stomach and enter the large intestine within three or four hours. This method is not entirely accurate for determining time of death though, as many things can have a factor in food digestion such as exercise after eating.
Determine the body's temperature, or algor mortis by inserting a special thermometer into the chest cavity. When you are alive, your body maintains its temperature of 98.6 degrees. Once you have died, your body is no longer able to do that. The body cools at a rate of one to one and a half degrees per hour until you meet the temperature of your surroundings. Again, several factors can influence the accuracy of this test, such as it being a very cold causing the body to cool much quicker.
Look for signs of discoloration, or livor mortis. This is the purplish coloring of the body's lowest parts. It's caused by the heart no longer pumping blood and gravity pulling it down. This begins about two hours post mortem and is fixed at about ten hours.
Find the degree of rigor mortis. The body enters rigor mortis within fifteen minutes after death and continues to stiffen for up to fifteen hours. Only professionals can really detect the degree of rigor mortis in a body.
See how decomposed or decayed the body is. The longer a person has been dead, the more decayed it is.