Decomposition - is the process whereby bodily tissues are broken down into smaller molecules after death. The physical and chemical properties observed during decay are categorized into five stages: (1) fresh, (2) putrefaction, (3) black putrefaction, (4) butyric fermentation, and (5) dry decay
Time of Death
General factors used to estimate time of death are:
Body temperature, rigor mortis, postmortem lividity, appearance of the eyes, stomach contents, stage of decomposition and evidence suggesting a change in the victim’s normal routine.
Flies and Human Decomposition
A human body provides sustenance and a great place for insects to lay eggs. A fly trying to find its way in this crazy, mixed-up world can eat well on a corpse, and then lay up to 300 eggs upon it that will hatch within a day.
Maggots — the larvae that emerge from these eggs — are extremely efficient and thorough flesh-eaters. Starting on the outside of the body where they hatched, maggots use mouth hooks to scoop up the fluids oozing out of the corpse. Within a day’s time, the maggots will have entered the second stage of their larval lives, as well as burrowing into the corpse.
Moving around as a social mass, maggots feed on decaying flesh and spread enzymes that help turn the body into delectable goo. The breathing mechanism of a maggot is located on the opposite end of its mouth, enabling it to simultaneously eat and breathe without interruption around the clock. While a first-stage larva is about 2 millimeters long, by the time it exits the third stage and leaves the body as a prepupa, it may be as large as 20 millimeters — 10 times its initial length. Maggots can consume up to 60 percent of a human body in under seven days
According to Colombian police, Luis Alfredo Garavito is a glib predator and a “solitary sadist” who stands accused as one of the world’s worst serial killers. In 1999, Garavito, a 42-year-old drifter, confessed to the slayings of at least 140 boys between the ages of 8 and 16 during a 5-year killing spree. Garavito would befriend the children and take them on long walks until they were tired. Then he would tie them up with nylon rope, slit their throats or behead them, and then bury their bodies. Most of Garavito’s victims were street children, children from poor families, or children seperated from their parents by poverty or political violence. Authorities said it was beacause there was no one to notice that the children were missing or to inquire about their whereabouts that Garavito was able to go on killing for so long without being detected.
For their betrayal of humanity, (murderers) deserve no better fate than to be permanently excised from the social order. Their only value is as objects of study.
- Elliot Leyton (via virgineunuchother)
Human Death and Decay
The environment in which a dead body is placed also affects its rate of decay. For instance, bodies in water decompose twice as fast as those left unburied on land. Decomposition is slowest underground — especially in clay or other solid substances that prevent air from reaching the body since most bacteria require oxygen to survive.
Rigor Mortis (latin: stiffness after death)
Caused by a chemical reaction in the muscles after death
a good determination of the time of death - it begins a few hours post-mortem, reaches it’s maximum at about 12 hours, and then gradually decreased for about 3 days. Environmental factors, such as temperature, can speed up or slow down the process.
Forensic Entomology is the use of the insects, and their arthropod relatives that inhabit decomposing remains to aid legal investigations. The broad field of forensic entomology is commonly broken down into three general areas: medicolegal, urban, and stored product pests. The medicolegal section focuses on the criminal component of the legal system and deals with the necrophagous (or carrion) feeding insects that typically infest human remains. The urban aspect deals with the insects that affect man and his immediate environment. This area has both criminal and civil components as urban pests may feed on both the living and the dead. The damage caused by their mandibles (or mouthparts) as they feed can produce markings and wounds on the skin that may be misinterpreted as prior abuse. Urban pests are of great economic importance and the forensic entomologist may become involved in civil proceedings over monetary damages.
Also known as “grave wax,” adipocere (from the Latin, adipo for fat and cera for wax) is a grayish-white postmortem (after death) matter caused by fat decomposition, which results from hydrolysis and hydrogenation of the lipids (fatty cells) that compose subcutaneous (under the skin) fat tissues.
Although decomposition of fatty tissues starts almost immediately after death, adipocere formation time may vary from two weeks to one or two months, on average, due to several factors, such as temperature, embalming and burial conditions, and materials surrounding the corpse. For instance, the subcutaneous adipose (fatty) tissue of corpses immersed in cold water or kept in plastic bags may undergo a uniform adipocere formation with the superficial layers of skin slipping off.
Several studies have been conducted in the last ten years to understand and determine the rate of adipocere formation under different conditions. Other studies also investigated the influence of some bacteria and chemicals, present in grave soils, in adipocere decomposition. Although this issue remains a challenging one, the purpose of such studies is to establish standard parameters for possible application in forensic analysis, such as the estimation of time elapsed since death when insect activity is not present. In forensics, adipocere is also important because preserved body remains may offer other clues associated either with the circumstances surrounding or the cause of death. The ability of adipocere to preserve a body has been well illustrated in exhumed corpses, even after a century.
Adipose cells are rich in glycerol molecules and are formed by triglycerols (or triglycerides). Bacterial activity releases enzymes that break these triglycerides into a mixture of saturated and unsaturated free fatty acids, a process known as hydrolysis. In the presence of enough water and enzymes, triglycerol hydrolysis will proceed until all molecules are reduced to free fatty acids. Unsaturated free fatty acids, such as palmitoleic and linoleic acids, react with hydrogen to form hydroxystearic, hydroxypalmitic acids and other stearic compounds, a process known as saponification, or turning into soap.
This final product of fat decomposition, or adipocere, can be stable for long periods of time due to its considerable resistance to bacterial action. This resistance allows for slower decomposition of those areas of a corpse where adipose tissues are present, such as cheeks, thighs, and buttocks. When a corpse is exposed to insects, however, adipocere probably will not be formed, as body decomposition will be much faster because of the insects’ action. Animal scavenging of a dead body will also prevent adipocere formation.
Cremation is one option after death. An average human body takes from two to three hours to burn completely and will produce an average of 3 to 9 pounds (1.4 to 4.1 kilograms) of ash