The specific characteristics of a body after death are of particular interest to forensic anthropologists, detectives and medical examiners. These professionals can view a corpse and determine the time of death, a possible cause of death and clues to the circumstances surrounding the death. A body passes through three stages before beginning decomposition.
Livor mortis is known as hypostasis in the medical community. Within two to four hours after death, the blood in the body settles to the portions of the body closest to the ground. The condition becomes "fixed" after eight to 12 hours. This condition is apparent as dark purple bruise-type marks on the person's body. The blood flows from the larger veins, and because of the lack of a heartbeat to continue its movement, it quickly drains into the smaller capillaries, which burst. The skin, which has grown pale, is translucent and the blood is evident.
After livor mortis, the muscles begin to stiffen. This is referred to as rigor mortis. After death, the body continues to use glucose for muscle metabolism, resulting in a lactic acid accumulation. The body's inability to break down the lactic acid causes the muscles to stiffen. The onset of rigor mortis depends on the person's muscular structure, age, sex and physical condition. The condition begins approximately six hours after death and disappears between 12 to 36 hours later.
Algor mortis is the cooling process of the body. Complete cooling, or the time when the body temperature is the same as the current environment temperature, happens between 18 to 24 hours after death. The rate of cooling depends on the temperature of the environment and the clothes on the body. The human body cools between 0.5 and 3 degrees Fahrenheit per hour, according to the Saint Louis University School of Medicine.
Putrefaction is the beginning of the decomposition stage. This stage of death has four categories. Stage one happens with a blue green discoloration of the abdomen. Stage two begins a marbling pattern on the abdomen. Stage three is the bloating stage, beginning with loose skin then expanding to the rest of the body. Stage four is the epidermolysis stage, when the hair and nails begin to fall off and the skin of the hands and feet come off in a glove-type fashion.