Liver Mortis ( Blood pooling) & Pallor Mortis

  Livor mortis is the process whereby blood settles in the lower parts of the body. It is also known as postmortem lividity and is a sign of death. This process results in a purple-red discoloration. As the heart no longer pumps blood to the body, red blood cells, due to gravity, will sink through the blood plasma without clotting factors, also known as serum. The amount of reduced haemoglobin affects how dark the blood is. However, this process does not take place in the areas with contact with the objects or the ground as the capillaries are pressed against. During decomposition, blood would seep through the vessel wall as they become permeable. Thus, staining the tissues. This is why blood accumulates in a specific part of the body due to poor circulation(hypostasis).

Livor Mortis

Livor mortis begins between twenty minutes and three hours after death. During this time, the skin of the body would be blotchy. The blood changes from a fluid to a solid or rigid state in the capillaries four to five hours after death. After five or six hours, the skin would turn white when touched even though the blotches have joined up. Between six and twelve hours, livor mortis is at its maximum. After ten or twelve hours, the skin would be blue whether it is pressed or not. The blood gathers at the interstitial tissues.

Blood pooling

nazigassings.com

The presence or absence of livor mortis can act as a way of determining the time of death. Although it would appear like bruises, experts would be able to tell if it was a discoloration. Also, the discoloration reacts with poison. For example, the skin turns cherry pink if carbon monoxide was added. If they find out that livor mortis is present, it suggests that beginning or continuing CPR would be ineffective. Also, this process helps to indicate if a body had been moved. For example, if a body was facing down when found while the blood is accumulating at the back, it would show that the body was facing up at first.

Pallor Mortis

Pallor mortis is an earlier stage of livor mortis and it occurs almost right after death. The corpse's skin would begin to turn pale as there is no blood circulating in the body anymore. Thus, the blood in the body would sink to the part of the body nearest the surface due to gravity.

http://decompositionnotes.weebly.com/human-decomposition.html

http://en.wikipedia.org/wiki/Livor_mortis

 http://www.mitchpileggi.net/Deep_Background/resources/forensics/bodies.htm

Algor Mortis (Body Temperature)

The body temperature of a dead body will decline until it reaches the temperature of its surroundings which takes about 8 to 12 hours on the skin, but the centre of the body will take much longer, probably three times the time to cool.




Body after death temperature graph

www.skepticaljuror.com

To determine the rate of cooling, the rectal temperature of the body and its surroundings will be taken at the place where the person died and before it is removed to the mortuary. However it varies as the location of the body and the temperature of the room they died in affects the cooling rate.

The time of death could be deduced using the body temperature as a factor, but many other factors can influence this estimate.  By assuming the body temperature loss is one and a half degrees Fahrenheit per hour and the normal body temperature is 98.4, an estimate of the time of death could be deduced.

http://www.mitchpileggi.net/Deep_Background/resources/forensics/bodies.htm

http://dying.about.com/od/thedyingprocess/a/My_Body_Postmortem.htm

What happens to the body after death?

 

Diagram of human skeleton                      
www.enchantedlearning.com

Hardening of the corpse




The stiffening of the corpse is called rigor mortis, it is between 30 minutes to 3 hours after death. This happens as the body muscles start to stiffen because of the lack of oxygen and blood. Sometimes, the hardening of the body may not occur if the surrounding temperature is too low, while it occurs in muscles that were active before death. Rigor mortis is most noticeable in the eyelids and jaws, after that, it spreads throughout the body in 6 to 12 hours, before it recedes again in another 6 to 12 hours. However, if the body has been left alone for a long peiod of time since death, the evidence of level of stiffening will not be that useful.

Skin colour

From about 48 hours onwards, the colour of the skin can help to predict the time of death. Bacteria starts to breed on the skin of the victim, giving it a greenish colour. It begins in the lower stomach area, before spreading out until it reaches the hands and feet. The skin will have a marble-like appearance 4 to 7 days after, as the veins become closer to the surface and it becomes more obvious.

Blood pooling

The pooling of blood is known as hypostasis, it is completed in up to 6 hours after death. The skin is pink and red, as blood stops flowing and it settles on the lowest part of the body. The location of the blood pools can determine the upright position of the body during blood pooling, thus it helps to predict the death manner.


Blood pooling in a corpse
www.flickr.com

Digestive System

Diagram of digestive system:mouth>oesophagus>stomach>small intestine(3hrs later)>large intestine(6 hrs later)
www.daviddarling.info

If the victim's small intestine is empty, it shows that the victim's previous meal was 8 hours before death.Chewed food will then be passe through the oesophagus first then down to the stomach within seconds. 3 hours later, the food will leave for the small intestine. After 6 hours, the food will be halfway through the small intestine and is beginning to move through the large intestine. However, the digestive process may be affected by illness, drugs, and fear.The correct level of food digestion also corresponds to its location. If a clever murderer wants to attempt to bring the victim's last meal forward so as to trick the investigators, he would stuffed processed food into the victim's mouth. However, the food collected in the stomach will be less digested than normal, since the periodic motion stops after death. The food may be broken down slightly with the help of stomach acids, but some abnormal problems will be detected. in older people or sick people, the process food digestion may alters.

Insects

a blowfly

These insects lay eggs on dead corpse.If the body is died for:

~0-3 days- proteins and carbohydrates are broken down in the body [e.g.Blowflies:Bluebottle flies]
~4-7 days- abdomen is inflated because of the gases inside , body starts to decay [e.g.Fly larvae and beetle:Rove beetles]

rove beetles

~8-18 days- abdomen wall starts to break down [e.g.ants, cockroaches,        flies, beetles]
~19-30 days- decaying body reaches the stage, will be dried out.In wet and humid conditions, the body will be sticky and dry. [e.g.beetles and mites: Springtail beetle,acari]

an acari

~Over 31 days- bones, skin and hair no longer give off a smell and will smell just like the surrounding soil.













Source:
http://library.thinkquest.org/04oct/00206/autopsy.htm?tql-iframe

https://www.google.com.sg/search?hl=en&site=imghp&tbm=isch&sa=1&q=acari&oq=acari&gs_l=img.3..0l10.426619.427185.8.427471.5.5.0.0.0.0.71.248.5.5.0...0.0...1c.1.5.img.xICv4FUrlic&biw=1120&bih=639&cad=cbv&sei=tOs7UdXAMM3prQeK5YHIDw#hl=en&site=imghp&tbm=isch&sa=1&q=rove+beetles&oq=rove+beetles&gs_l=img.3...8874.9652.2.9730.4.4.0.0.0.0.0.0..0.0...0.0...1c.1.5.img._6jELqC3EKc&bav=on.2,or.r_qf.&bvm=bv.43287494,d.bmk&fp=601004e9de3eb21c&biw=1120&bih=639

https://www.google.com.sg/search?hl=en&site=imghp&tbm=isch&sa=1&q=acari&oq=acari&gs_l=img.3..0l10.426619.427185.8.427471.5.5.0.0.0.0.71.248.5.5.0...0.0...1c.1.5.img.xICv4FUrlic&biw=1120&bih=639&cad=cbv&sei=tOs7UdXAMM3prQeK5YHIDw

http://www.oisat.org/control_methods/natural_enemies/predators/rove_beetles.html