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Time of death /
Cause of death / Identity of
Important note: This whole section has been compiled from books and
websites, with occasional help from people working in this field. Like the rest
of Deep Background (of which this is only a small part), this information is
designed for writers of X-Files fiction, and covers only those things that they
might be expected to need. It is not a comprehensive guide to the subject.
These are a variety of methods. Some are for the investigators at the crime
scene while some are for the pathologist at the autopsy.
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
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
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
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.
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
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.
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.
- 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.
- 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.)
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
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.
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....
Death is usually caused by one of three ways:
Then there are the Specific causes.
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
- Natural heart failure caused by several degenerative diseases. Can be
exacerbated by shock.
- Some poisons
- Direct injury to heart
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:
- Breathing air that doesn't have enough oxygen
- Obstruction of oxygen supply by air passages being blocked or swollen
- Pressure on chest or abdomen preventing breathing
- Paralysis of repiratory system by electric shock or some poisons.
- Anaemic Anoxia
- 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.
- Obstruction of the supply of oxygen in the blood, as in carbon monoxide
- 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.
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
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:
- Presence of carbon monoxide in blood shows victim was breathing after fire
- Soot in the lungs shows was breathing after fire started
- Inflammation near any wound shows the body was alive at the time
- 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.
- 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
- Drowning - kills by asphyxia, as the lungs fill with liquid.
- Fine white foam at nostrils and mouth
- Wrinkling of skin if has been in water for a while.
- Water weed and the like clutched in the hands
- Lungs are wet and heavy and distended. Tend to balloon out when the body is
- Water in the stomach
- Haemorrhaging in the middle ear caused by pressure
- 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.
- 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
- 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
- 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.
- 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: If there isn't enough oxygen in the air, such as when trapped
in a small space
- Smothering: Caused by an object over the mouth and nose, such as a pillow
or the murderer's hand.
- Choking: Caused by an obstruction in the airway - food, inhaled vomit etc
Seldom used in homide, except when people choke on their gags.
- 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
- 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
- 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.
- 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,
- Limbs: Size, shape, scars, callouses that could indicate
occupation, tattoos etc, social status based on care of hands and feet
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
- 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:
- They are the part of the body that lasts longest after death
- False teeth and other repairs are very resistent to degredation
- Each set of teeth is essentially unique
- X-rays can reveal even more information on the structure of the teeth and
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.
These experts study bones and can tell us some or all of:
- if they belong to a human
- 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
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