Methods For Getting The Time Since Death

Methods for Getting the Time since Death

The time since a human died can be hard for an investigator or Police officer to determine. There are a number of factors that can contribute to the time since death and decomposition of the body. Police officers use eight methods to determine the time since death. The eight methods are as follows: examining body temperature, hardening of the body, the eyes, color of the skin, blood pooling, the digestive system, forensic entomology, and visiting "The Body Farm."

The first method that most Police officers use to determine the time since death is trying to determine the body's temperature. If the body is cold, it is obvious that the body has been dead for quite some time, but if the body is warm, the person most likely died quite recently. But for more accurate estimates about the time of death from body temperature, the human is sent out to a forensic pathologist in the forensic laboratory (FSTSD, 1). The pathologist has a formula that takes in the factors of the body's temperature, temperature at the crime scene, and the weight of the victim. The core temperature of the human body drops at an average of 0.8K each hour after death, but can change depending on the temperature of the environment, humidity levels, air movement, and the body's fat percentage. The body fat percentage is a very important element to know because if the body has a low percentage then it will lose heat much quicker then a body with more fat percentage(DDTD, 1). Also, it is important that the body is found as quickly as possible because the less time it is in the environment then the fewer factors there are to worry about.

The second method used to determine the time since death is the hardening of the body or rigor mortis. Rigor mortis is the process where the body's muscles begin to stiffen because oxygenated blood stops flowing in to them. Rigor mortis usually starts occurring anywhere from thirty minutes to three hours after death(FSTSD, 1). The first two areas where the body starts to harden are the eyelids and jaw and then spreads to the whole body in six to twelve hours. But rigor mortis is not evident in the human body the whole time after another six to twelve hours the body will become soft and flexible again. If temperatures where the body is found are low then there is a chance that rigor mortis may not even occur. If the human was running or using his muscles in anyway before death then rigor mortis can take place much quicker then if he was just sitting around. Also as the same with the temperature of the body the longer the body has been sitting out the less likely evidence of rigor mortis will be used for a case(DDTD, 1).

The third method used to determine the time since death is examining the corpse's eyes. If the body's eyes have developed a cloudy fluid over them it can be hypothesized that death occurred approximately within three hours (FSTSD, 1). The eye balls become softer as a result of less fluid behind them. The degree of the softness can be an indicator of the time of death. This procedure is less useful if the body was dead for extended period of time.

The fourth method used is called blood pooling or hypostasis. Hypostasis occurs when the blood stops flowing and settles in the lowest parts of the body and causes the skin to turn red and pink(FSTSD, 1). The blood will usually settle in the lowest parts in six hours after death. The main purpose of hypostasis is to determine how the person died and whether the body was upright or upside down.

The fifth method used to determine the time since death is looking at the body's skin color. This method helps determine the time since death if the body has been dead for at least forty-eight hours. The reason for this is that after about forty-eight hours bacteria start to form giving the skin a green tone(FSTSD, 1). This usually starts in the abdominal region and spreads out hitting the hands and feet last. Four to seven days after death, the veins come towards the skin giving the person a marble like appearance.

The sixth method used to determine the time since death is to examine the human digestive system. After a person eats food it will travel down the esophagus and into the stomach within seconds of swallowing the food. After the food sits and digests in the stomach for about three hours it moves into the small intestines(FSTSD, 1). After about six hours of being in the small intestine the food will start moving into the large intestine so if the victim's small intestine is empty it points to the fact that the person ate his last meal about eight hours before death. The complete digestive process of a human usually takes a little over twenty-four hours, but can be affected by these factors: sickness, liquid intake, fear, or drug intake. There are also cases of people trying to manually feed processed food in to the victim to try to bring the time of the victim's last meal forward. The reason for this is to try to give the murderer a better alibi for the murder. Most pathologists can tell the difference though because the stomach is not making anymore movements to break the food down although the stomach acids are still present the food is not as broken down as it would be the human was alive when the food was ingested. But the factors that where spoken above like sickness can make the food seem undigested also(FSTSD, 1).

The seventh method used to determine the time since death is forensic entomology. This is the study of flies and maggots that specifically feed on the human body. This process is usually only useful if the body has been dead for quite some time(DDTD, 1). The larvae cycles of the insects can determine whether a corpse has been dead for one day or three to four weeks. In the beginning stages, up to three days, the body's proteins and carbohydrates begin to break down and attract blowflies, Bluebottle flies, and Syrphidae flies. In four to seven days, the body starts to decay and the abdomen starts to inflate do to gases this would attract flying larvae and beetles, but specifically rove beetles. In eight to eighteen days, decay is quite prominent and the abdomen's walls start to break down beginning to attract ants, cockroaches, beetles, and flies (FSTSD, 1). In nineteen to thirty days, the body enters a stage known as post decay in wet humid conditions the body will be sticky and wet, but in dry conditions the body will be dried out. Beetles, mites, acari, nematocera, and brachycera are present during this stage. The specific type of beetle present at this stage would be a springtail beetle and nematocera are only present during winter months(FSTSD, 1). Anytime the body has been out for a longer period then thirty days, the body