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...