TERM DEFINITION

Agonal period A period of time where a person is actively dying

Moribund Close to death

Death Rattle Rasping noise, gurgling

Agonal Hypostasis Before death, the settling of blood due to gravity

Agonal coagulation Before death, blood slows, formed elements begin to clot

Interstitial fluid blood plasma that has leaked out into surrounding tissue

Somatic death Death of the whole organism

Clinical deaththe cessation of circulation and respiration. Only death that can be brought back from

Biological death flat brain wave. Death of the brain. Can not be brought back from

Postmortem cellular death Cells die after death from anoxia

Arteries Vessels that bring blood away from heart

Veins Vessels that bring blood to the heart

Algor Mortis Physical Change- Cooling of body to temperature of environment

Dehydration Physical Change- Loss of moisture from body to environment

Postmortem hypostasisPhysical Change- After death, gravitation of blood and fluids to dependent areas of body

Postmortem caloricityChemical change- Temporary rise in body temperature after death due to continued metabolism

Agonal fever An increase in body temp just prior to death

Livor MortisPhysical change- Postmortem intravascular blood discoloration brought about by the presence of blood to dependent areas of the body ( develops from hypostasis)

Increase in blood viscosityPhysical change- Thickening of blood after death caused primarily by the loss of the liquid portion of the blood to the tissue spaces

Change in body pHChemical change- Change in body tissues from alkaline in life, to acidic in rigor, then a return to alkaline in decomposition

Rigor MortisChemical change- Temporary postmortem stiffening of body muscles by natural body processes

Postmortem StainChemical change-Extravascular blood discoloration brought about by hemolysis. Cannot be removed, permanent

DecompositionChemical change- Seperation of compounds into simpler substances by the action of bacterial/autolytic enzymes

Hemolysis The breakdown of red blood cells after death

3 forms of dehydration 1) Surface Evaporation 2) Imbibition 3) Gravity Filtration

Hydrolysis The breakdown of protein by water

Intermediate products of protein decomposition

Polypeptides, Proteoses, and Peptones

Final Products of protein decomposition

Skatole, Indole, Cadaverine, Ptomaine, Putrescine, and Mercaptans

Decay Proteins that break down under aerobic conditions

Putrefaction Protein that breaks down under anaerobic conditions

Fermentation The breakdown or decomposition of carbohydrates

Product of fermentation monosaccharide and polysaccharide, final- water

Lypolysis The breakdown or decomposition of fats

Final products of Lipolysis Glycerol and fatty acids

Adipocere Grave Wax. White crumbly from saponification of fats

Translocation The movement of microorganisms from intestines to other parts of body

Saprophytes Dead-tissue loving bacteria

Formaldehyde Gray Mixture of embalming chemicals and a postmortem stain

5 signs of decomposition color, odor, skin slip, purge, and gas

Expert tests for death Stethoscope, ophthalmoscope, EEG, EKG

Inexpert Tests Ligature test, ammonia injection test, pulse, listening for respiration or heart

Primary flaccidity The period before rigor mortis sets in, death to 5th hour, alkaline

Secondary flaccidity After rigor mortis has passed from the body, body alkaline again

Formaldehyde Gas, compound, made from methanol

Paraformaldehyde A solid, powder version of formaldehyde, use in coveralls

FTC Purpose is to protect the consumer

OSHA Purpose is to protect the employee

8 hour exposure limit 0.5 p.p.m.

Short-term exposure limit 15 minutes

2.0 p.p.m.

Index The percent of formaldehyde gas in a bottle

15 days How long OSHA has to get back to you with results from packet

Clostridium perferingens The causative agent of tissue gas

High Level DisinfectantsLevel of disinfectant that brings about sterilization, Absence of bacteria and their products, kills spores

Low Level DisinfectantsLevel of disinfectants only used to clean inanimate objects, never use on body, Zepharin Chloride

Autoclave Steam under pressure, instantly kills bacteria and spores, sterilization, 185C

Time weighted average .75 p.p.m.

Permissible exposure limit 2.0 p.p.m.

Ammonia Chemically neutralizes formaldehyde

Asepsis Without infection

Sepsis Bacteria multiplication in the blood

Bacteremia Presence of bacteria in blood

Bacteriocidal Kills bacteria

Urosepsis Multiplication of bacteria in the urinary tract

Bacteriostatic Inhibition of growth of bacteria, but does not kill bacteria

DisinfectantAn agent, usually chemical, applied to inanimate objects to destroy disease causing microbial agents, but not bacterial spores

GermicideLike disinfectants, can be used to clean inanimate objects, but can also be used to clean hands

Sanitization Chemical, as well as physical means, to clean an inanimate object or surface

Sterilization Kills bacteria and their products, which are spores

Copper The catalyst in production of formaldehyde

Dead Bodies

Determining time since death

These are a variety of methods. Some are for the investigators at the crime scene while some are for the pathologist at the autopsy.

Rigor Mortis

This is not the most reliable of methods.

After death, all muscles relax

About three hours after that, they start going rigid, as glycogen is converted into lactic acid. This starts at the eyelids, works through the face and down the body and is usually complete within about 12 hours. It then starts to wear off after about 36 hours.

However, temperature, climate etc affect this, Heat acceperates the process and cold slows it down. Illnesses also make a difference. Also, faced with a limp body, it could be a body that has not yet started to stiffen, or a body that has stiffened then relaxed again.

Just to complicate matters, people killed in intense heat tend to stiffen anyway, straight away, and stay that way. Also, sometimes a person stiffens at the exact time of death, such as clutching convulsively onto the gun they used to kill themselves.

Livor Mortis (Discoloration)

Livor mortis is the settling of blood. It is also called Hypostasis.

When the heart stops, the blood stops circulating and gravity makes it settle. This makes the areas where the blood has settled turn dark blue or purple.

This starts happening immediately and is visible with a couple of hours. At this point skin is bluish and blotchy. After five or six hours the blotches have joined up but the skin still goes white when pressed. After ten to twelve hours the blue colour remains even when pressed.

The lividity doesn't show where the body is in contact with something. This a body lying on its back will show lividity in the small of its back, its neck etc but not is parts of the body directly touching the ground. This a very useful when determining if a body has been moved after death.

The discolouration looks like a bruise, but experts can easily tell them apart.

With some poisons the discoloration is different. Carbon Monoxide, for example, turns the skin cherry pink.

Algor Mortis (Body Temperature)

After death, body temperature declines progressively until it reaches the temperature of its surroundings. This process generally takes about 8 to 12 hours on the skin, but the centre of the body takes aboue three times as long to cool.

At the crime scene, it is vital to take the rectal temperature of the body as well as the air temperature. If possible, the same temperatures should be taken again just before the body is removed to the mortuary to determine the rate of cooling.

A rough estimate of the time of death can be obtained by assuming a temperature loss of one and a half degrees Fehernheit per hour, and assuming the normal body temperature of 98.4. However, many factors may influence the rate of heat loss and this is only an estimate.

Eyes

Within minutes the cornea films over, and the white of the eye goes grey.

After around two hours the cornea goes cloudy, and within a day or two it goes opaque.

On the third day the gas makes the eyes bulge.

With advanced decomposition, the eyes retract.

Food in the stomach

(Found at autopsy)

A light meal is out of the stomach within 1 ½ - 2 hours

A medium meal is out of the stomach within 3 - 4 hours

A heavy meal is out if the stomach within 4 - 6 hours

There are variations: Liquid is digested faster than semi-solid food, which is digested fasted than solid food. Emotional state may also influence the rate of stomach emptying.

Vitreous Potassium

There is potassium in the body's intercellular fluid - much more than there is in the plasma, on the other side of the cell membrane. After death it starts to leak out so there is the same amount on either side of the membrane. This happens at a nice steady rate, allowing time of death to be established. Samples are normally taken from the vitreous fluid of the eye.

Insects

Body Lice: they outlive their host by 3 - 6 days. Various insects: They like to lay their eggs on very fresh corpses. The eggs hatch out

within 8-14 hours. After another 8-14 hours it sheds its skin and emerges as a bigger larva. This process is repeated several times, taking 10-12 days in total. People who know about insects (Bambi?) can therefore look at the larva, see which stage it is at, and work out time of death.

Samples should be taken and preserved and given to an emtomologist.

Plants

Grass/plants beneath an object wilt, turn yellow or brown and dies. The rate depends on type of plant, season, climate, etc.

Seasonal plants or remnants may help indicate a range of time.

Samples should be collected and shown to a botanist (or to Pendrell, who did a nice job with that rare African plant thing in Teliko.)

Putrefraction

Begins after about 2 days. The process is faster in damp places or when the body is exposed to air. Decay is about eight times faster in the air than underground. Too cold or too hot and the process won't happen. In very hot temperatures the body will dry out and mummify instead.

People with a lot of fat will decay faster. People who died of bacterial disease will also decay faster. However, some poisons preserve the body.

2-3 days: green staining begins on the right side of the abdomen. Body begins to swell.

3-4 days: staining spreads. Veins go "marbled" - a browny black discoloration

5-6 days: abdomen swells with gas. Skin blisters

2 weeks: abdomen very tight and swollen.

3 weeks: tissue softens. Organs and cavities bursting. Nails fall off.

4 weeks: soft tissues begin to liquefy. Face becoming unrecognisable

4-6 months: formation of adipocere, if in damp place. This is when the fat goes all hard and waxy.

Anamnestic Evidence:

Nothing medical about this. This simply means evidence taken from the victim's daily habits. For example, three days' uncollected newspapers would suggest he has been dead three days. If he missed an appointment on a particular day then he was probably dead then. If all his food in the refrigerator is rotten and horrid it suggests he's been dead a while. And so on....

Determining cause of death

Death is usually caused by one of three ways:

Coma (failure of brain) Syncope (failure of heart) Asphyxia (failure of lungs)

Then there are the Specific causes.

Coma

Usually caused on one of four ways:

Depressed fracture of the skull, compressing the brain. In homicide, this is usually caused by a direct head injury by bludgeoning by a blunt implement, or in car accidents.

Some poisons Some narcotic and hypnotic drugs Medical conditions such as cerebral haemorrhage and brain tumour. Also some diseases

poison the brain as a by-product

Syncope

Natural heart failure caused by several degenerative diseases. Can be exacerbated by shock.

Some poisons Direct injury to heart

Asphyxia

Anoxia means "lack of oxygen". Is it the main cause of death in homicide. There are four main types.

Anoxic Anoxia (Asphyxia) This also also called "manual anoxia". It is caused by: o Breathing air that doesn't have enough oxygen o Obstruction of oxygen supply by air passages being blocked or swollen o Pressure on chest or abdomen preventing breathing o Paralysis of repiratory system by electric shock or some poisons.

Anaemic Anoxia o Insuffient supply of oxygen to the body due to blood loss or obstruction of the

arteries. This is what happens when you bleed to death. o Obstruction of the supply of oxygen in the blood, as in carbon monoxide

poisoning. Histotoxic Anoxia Some poisons, eg cyanide, paralyze the body tissues preventing them

from using oxygen. Stagnant Anoxia Where the blood circulation is stopped, such as with a shock, heart

failure or an embolism.

Specific causes

Sometimes it is clear - eg a great rope tight around the victim's neck. Even so, the pathologisy will normally wait until performing the autopsy before pronouncing.

Common specific causes of death include:

Blugeoning with a blunt instrument. Only likely to be fatal if is on the head. Even then, sometimes needs a hail of blows to kill, and the assailant will get very bloody. Death is usually from skull fracture pushing fragments of bone into the brain, or internal bleeding between the skull and the dura - the membrane covering the brain. The exact appearance of the injury can usually show what the weapon was.

Burning - usually kills by asphyxia from smoke inhalation. Bodies exposed to intense heat are stiffened, posed like a boxer ready to fight. As burning is sometimes used to cover up other crimes the presence of burns on the body needn't imply that this was the cause of death.

To determine if the burns were caused after death or before death, there are a few tests:

o Presence of carbon monoxide in blood shows victim was breathing after fire started

o Soot in the lungs shows was breathing after fire started o Inflammation near any wound shows the body was alive at the time o Blisters on the skin made after death don't contain fluid. Blisters obtained when

alive contain protein (will solidify when heated in a test tube) but blisters obtained after death don't.

o Heat can cause ruptures that look a little wounds caused by violent attack, but they are different as there is no bruising around the site, and little bleeding.

Drowning - kills by asphyxia, as the lungs fill with liquid. Post-mortem signs: o Fine white foam at nostrils and mouth o Wrinkling of skin if has been in water for a while. o Water weed and the like clutched in the hands o Lungs are wet and heavy and distended. Tend to balloon out when the body is

opened. o Water in the stomach o Haemorrhaging in the middle ear caused by pressure

o Diatoms throughout the body, if person was still alive when entered the water, and it it was fresh water. Diatoms are often pretty localised so studying them can reveal the place the person drowned.

o Fresh water dilutes the blood. Salt water extracts water from the blood and increases chloride concentration.

Must catalogue every wound and injury to find cause of drowning, but these may just be wound when struck a rock etc. In addition, the affects of water make wounds odd, and hard to see if they are caused before or after death.

Also look for signs of alcohol and drugs which could cause accidental drowning.

Embolism - clogging of the blood vessels with air, or sometimes fat. This blocks blood supply to the heart or brain. A fat embolism is rare but can happen when burning or other injury releases fat particles into the blood.

Explosives - kills in a variety of ways: flash burns, disintergration of body, effects of air pressure. Also by the results of the explosion - flying glass, collapsing buildings etc

Gunshot wounds See the firearms page and the medical page Knife wounds Of two types - incised, which bleed alot but aren't as dangerous, unless

they cut an artery, and stab wounds, which don't bleed much but can cause serious internal damage. It can be hard to identify the type of weapon by the size of wound as the skin stretches and then retracts back to shape when the knife is removed.

Suicide and homicide can normally be distinguished by the direction of the thrust. Also, suicides normally take the clothing off the part of the body there are going to stab.

Poison Strangulation - by hand, a ligature, or hanging. Death is by asphyxia. Ligature marks

show up as a furrow on the neck. If it is hanging, this will be high up on the neck as gravity pulls the body down. Homicidal strangulation will almost always fracture the hyiod bone. Manual strangulation tends to leave finger-shaped bruises and sometimes nail marks in the skin.

Suffocation o Suffocation: If there isn't enough oxygen in the air, such as when trapped in a

small space o Smothering: Caused by an object over the mouth and nose, such as a pillow or the

murderer's hand. o Choking: Caused by an obstruction in the airway - food, inhaled vomit etc Seldom

used in homide, except when people choke on their gags. o Crush asphyxia: Caused by pressure on the chest, such as a collapsed building, or

in a crowd. Post-mortem appearances include a lot of haemorrhaging between the chest and head, cyanosis, bulging eyes etc

Identifying the body

Basic facts - sex, age, height etc Topographical features - physical description of exterior of body Pathological information - evidence of diseases, past surgery etc Special Procedures - X-rays, teeth etc Forensic anthropology

Basic facts

Sex - Look at genitalia. Of decayed, the uterus is the last organ of the body to putrefy. If there are only bones, the skull and pelvis can indicate sex. Serology (studying blood) can do a test for female body cells.

Age - Easy to do when the body is under 25, mainly by looking at teeth. After the age of about 40, the sutures in the skull start to close at a fairly steady rate. An expert can examine for arthritis, arterial degeneration etc.

Height - Easy when body is all in one piece. When dismembered, have to do a calculation based on some standard formulae. For example, to work out the height of a female when you only have their tibia, you multiply that length by 2.533, then add 28.533 inches. A special board is used to measure the bones, not a tape measure

Race If can't tell by skin color, as skin has decomposed, can make deductions based on skull measurements etc.

Fingerprints Special methods must be used to get prints from decomposed bodies. Mummified hands must be softened over several weeks in a solution of glycol, lactic acid and water. Skin wrinkled by damp can be smoothed out by glycerine or paraffin wax injections, by gentle pressure with the fingers, or by slicing off the layers of skin and mounting them. Skin on bodies emersed in water can be peeled off like a surgical glove, put over the pathologist's hand and printed from there.

Blood group Useful mainly as elimation of people if can't be.

Topographical features

Head and face: eye shape and colour, nose shape, hair colour, mouth, teeth, ears, shape of skull, scars and birth marks.

Trunk: Shape, clothing - size, make etc, tattoos, scars, circumcision. Limbs: Size, shape, scars, callouses that could indicate occupation, tattoos etc, social

status based on care of hands and feet (Well-Manicured Man?)

Pathological information

All revealed by autopsy. Reveals evidence of past medical treatment that would show up on medical records.

Current medical conditions. Gall stones, fibroids etc Past surgical treatment - scars, absence of organs etc Evidence of past accidents - scars, mended fractures etc Changes that may indicate age - arthritis, cardiovascular disease etc Pathological conditions - malaria, sickle cell anaemia etc

Special procedures

X-rays of bones Special study of tissues Photography - such as superimposing a photo of the person the remains are suspected to

belong to over the remains and seeing if they look like a match (as we see in "Tooms") Forensic odontology (dentistry) - This is vital. In badly decayed bodies, teeth are the

only method of identification. This is because: o They are the part of the body that lasts longest after death o False teeth and other repairs are very resistent to degredation o Each set of teeth is essentially unique o X-rays can reveal even more information on the structure of the teeth and jaws.

The forensic dentist studies number of teeth, false teeth (that have name stamped on the bottom), cavities and fillings, spacing, and evidence that suggests a certain job - eg musicians who play wind instruments.

Age can be worked out below the age of around 25. Gender can't be, unless there is also some of the dental pulp (only for about 5 months after death). Race can be estimated as each main racial group has certain characteristics.

However, the only way full identification is possible is if the records can be compared with records made before death.

Forensic anthropology:

These experts study bones and can tell us some or all of:

if they belong to a human gender age at death appearance - stature, bone structure, something of their facial features. This can done

through Facial Reconstruction, where modelling (clay or computer) is used to add tissue and literally flesh out the skull. However this is not all that accurate and isn't really scientifically accepted. (As in "Tooms", when the forensic anthropologist consulted by Scully would only pronounce on the appearance of the dead man when it was off the record)

how long the bones have been there cause of death