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Forensic medicine and Toxicology.
Death is not a moment but a Continuous Process:
It is a process rather than an event, except in situationswhere death
occur instantaneouslylike bomb blast, crushing of head in Road side
Definition of death:
“Complete, permanent and irreversible stoppage of respiration,
circulationand brain functions”.
Section 2b of the Registration of Births and Deaths Act defines
“Permanent disappearanceof all evidences of life at any time after
live birth has taken place”
Defined by Physician as
“Total stoppage of circulationand cessation of vitalfunctions,
such as respirationand pulsation”
Shapiro (1969) defines death as
“The irreversible loss of the properties of livingmatter”
Calne (1970) states that
“ When destruction of the brain has been established,the individual
has died no matter what the state of rest of his body, giving four
signs for diagnosis:
1. Deep irreversible coma
2. Fixed dilated pupil
3. Absent cranial reflexes
4. No spontaneous respiration
5. Absence of electrical brain activity
6. Cessation of circulation in the retinal vessels
Rantoul and Smith (1973):-
“ Complete and persistent cessation of respiration and circulation”
DEFINITION of death.
1. “Complete and irreversible stoppage of respiration, circulation
and brain functions.”
Thus Death was classified into 2 Groups.
Body may be dead
Organs may survive = in the same body
The livingbody dependsupon the integrity of three systems,
interdependentupon each other, these systems are
The failure of one of them will cause failure of other two
this lead to the death of an individual.
1. There are two phases of death
1. Extinction of the personality OR Somatic Death
2. Progressive disintegrationof the body tissue OR Molecular
Death / CellularDeath
i. Somatic Death (Soma-Body)
Irreversible loss of integrating and co-coordinating functionsof
the organism as a whole is labeledas Somatic Death.
It is the complete and persistent loss of coordinatedfunctioning of
tripod of life i.e stoppage of Functioning- and failure to return
Somatic death is also called
ii. Molecular Death
It is the death of individual organsand/ortissues (which persisted
individuallyafter somatic death)
In 1967- Single Organ, – Shifted from a dead unit to another living
During interval – it was kept alive to avoid moleculardeath.
Till it was shifted to already prepared body – Ready to receive –
Heart of Dead
Time – Interval between Somatic & Molecular stages
Heart 60 mins
Liver 15 mins
Kidney 45 mins
Blood 6 hrs
1. Brain death.
Means irreversible loss of brain and brain stem functions
2. It does not include the death of cortical area of brain.
1. Brain is responsible for all the coordination between the organs.
2. Once brain stem death has established, no matter how healthy an
individual, Life will not return to the patient.
3. Even with continuous cardiopulmonary support
Complete loss of consciousness/ absence of brainstem function /
Criteria for determining permanent non functioning of the brain.
1. Unreceptivity and unresponsivity
2. No movements and breathing
3. No reflexes
4. Flat EEG (confirmatory test)
DIAGNOSIS OF DEATH
Brain death is declared – when there is
1. Permanent, fixed bilateraldilatationof pupils.
2. Absent – all nerve reflexes
3. Cessation of respiration (without aids.)
4. Cessation of cardiac activity (COMPLETE FLAT ECG)
D/D of Death
1. Suspended animation
2. Barbiturate poisoning
Immediate physical changes
1. Loss of tripod of life
2. Absence of brain function
3. Loss of muscle tone
4. Onset of muscular flaccidity / primary flaccidity
5. Loss of reflexes
6. Dropping of lower jaw
7. Looseness of limbs
8. No response to external stimuli
9. Cooling of body
Definition: WHO defines it as a death which occurs within24 hrs
from the onset of first symptom.
But this time period is considered too long by some pathologistsand
they accept death within one hr, from the onset of symptoms.
The death is so sudden and unexpected that suspicion of foul
play may arise.
80% of such deathsare natural and 20% are un-natural
Natural deaths. Thisoccurs due to some disease, pathological
condition,old age and debility.
The un-natural may be
Caused by the application offorce or by poisoning.
(Note: list of naturalcauses in parikh page 3.4 edition8th
Manner of death
1. Cerebral thrombosis and subsequent infarction
2. Cerebral embolism
4. Tumor of brain producing pressure
5. Tumor of brain with sudden hemorrhage
6. Metabolicdisorders e.g. uremia
7. Cardiovascularconditione.g. MI
8. Respiratory conditione.g. Asthma, COPD
1. Accidentalhead injuries e.g. RTA
2. Homicidalhead injuries e.g. stab, lacerated, incised,
3. Suicidalhead injuries e.g. firearm injury
4. Poisoning e.g. Opium, alcohol
MODE OF DEATH
Stoppage or failure of vital system.
MANNER OF DEATH.
It is way, fashion or circumstances of death.
- natural– when due to disease
- Unnatural – causes other then disease
Mode of Death
It is stoppage or failure of vital system
1. Coma :- failure of function of brain
2. Syncope :- failure of function of heart
3. Asphyxia :- failure of function of respiratory system
1. Coma:- failure of function of brain and irreversible damage
to its vital centers
1. Raised Intracranial Pressure, due to injuries
to or diseases of brain e.g meningitis
2. Poisons such as opioidsand alcohol
3. Metabolicdisorders like Uremia
Post mortem :-
edema and congestion of brain and membranes
1. Syncope :- death due to failure of function of heart due to
decrease flow of blood to brain and leading to hypoxia of
2. Due to
1. Heart diseases
2. Diseases of blood
4. Poisoning due to digitalis,aconite, potassium.
Viscera appearpale and capillariesappearcongested
1. Asphyxia :- is death due to failure of respiratorysystem.
2. Due to
1. Lung diseases e.g pneumonia,
2. Paralysis of respiratory centers,
4. Breathing of irrespirable gases
5. Traumatic asphyxia
Cyanosis, petechialhemorrhages, visceral congestion, injury
mark on neck.
CRITERIA TO DIAGNOSE DEATH
HOWARD’s Criteria:It is followed in majority of the countries .The
basis of diagnosisis as follows:
1) Non receptive for stimuli & there is no response.
2) No movement for one hr & no breathing.
3) No spontaneousbreathing for 3 min after switching off the
4) No reflexes.
5) Flat EEG.
Suspended Animation (Apparent death)
It is a condition in which the vital functions of the body (heart
beat and respiration) are at such a low pitch that they cannot be
detected by routine methods of clinical examination.
Drowned person Yogis
POST MORTEM PHENOMENON OR CHANGES AFTER DEATH
Changes after Death
1. Immediate changes
2. Early changes
3. Late changes
These are the changes which occur simultaneouslywith the onset of
clinicaldeaths. These include
2. Loss of reflexes.
3. Flat EEG rhythm.
4. Cessation of Respiration.
5. Cessation of Circulation.
1. Eye Changes.
2. Skin Changes.
3. Primary muscularflaccidity.
4. Contact flattening with pallor.
5. Algor Mortis.
6. Postmortem Lividity/ postmortem staining.
7. Rigor mortis
2. Adipocere Formation
Cessation of Respiration. TEST.
1. AUSCULTATION No respiratory sounds
2. MIRROR TEST Dimness of Mirror
3. FEATHER TEST No movement of Feather
4. WINSLOW TEST No movement of water when we put a glass
Cessation of Circulation
1. MAGNUS LIGATURE TEST
2. FINGER NAIL TEST
3. DIAPHENOUS TEST
4. HEAT TEST
5. ARTERY INCISION TEST
6. Auscultation.No heart soundsfor 5 minutes.
7. Flat ECG for 5 minutes.
MAGNUS LIGATURE TEST
1. Tying a ligature tightly at the base of the finger, sufficient to cut
off venouschannelsexcluding arteries.
2. Finger remains white if circulationhas stopped otherwise the
area beyond ligature graduallybecomes blue and swollen.
FINGER NAIL TEST
When the pressure is appliedon nailbed it turns pale if circulationis
going on and when pressure is withdrawn, it becomes red
1. The handis to be held against a strong source of light.
2. During life it is red and translucent.
3. But After death it is opaqueand yellow
1. During life on the application ofheat to skin, true blister
appearsalong with the line of redness.
1. When a small artery is cut there is no jerky flow of bloodafter
1. AT THE TIME OF DEATH
1. At the time of death eyes seem to stare.
2. Pupilsbecome fixed and dilated.
3. Corneal and light reflex disappeared.
2. WITH IN 10 SECONDS
The bloodin retinal vessels rapidlybecomes dotted first and
then break up into segments called“Cattle trucking”.
WITH IN FEW MINUTES
3. Drying of cornea can produce haziness, if the eye lids are
opened and atmosphere is dry.
4. Tachynoires appear on sclera within 3 hours of death, if eyes
Tachynoires are brown-blackishdiscoloration,due to
formation of cellulardebris and dust settling on sclera.
5. Intra ocular Tension becomes 14 g immediately after death from
the normal value of 14-25 g and by the end of two hours it
6. Optic disc becomes Hazy in about 6 to 10 hours after death.
With the cessation of circulationthe blood drainsfrom the vessels of
skin and skin becomes pale and ashy white.
Skin loses its elasticity
MUSCULAR FLACIDITY/ RELAXATION
1. The muscles relax and lose their natural tone at about the time
of death which results in
2. Droppingof lower jaw.
4. Limbs become loose.
5. Relaxation of facial muscles leadsto ironing of skin crease &
sometimes makes a person look younger.
The muscular changes also affect the smooth muscles of body as a
1. Pupils dilated.
2. Sphinters relax resulting in incontinence of urine and feaces.
It persist till the rigor mortis is developed
COOLING OF BODY/ Algor Mortis
Algor- Coldness, mortis means Death
1. Algor Mortis is one of the earliest sign of death.
2. It Indicatestime elapsed since Death
TAKING THE TEMPERATURE
1. It is measured by inserting a chemical thermometer, known as
Thanotometerwhich is 25 cm long, in to the rectum having
reading from 00
2. The alternativesites for putting thermometer are
i. Sub hepatic
iv. Auditory meatus
Rate of Cooling
1. Mean atmosphere temperature.
2. Clothingand other covering on body.
3. Air movement and its humidity.
4. State of nutrition and developmentof body.
7. Coolingin fluid medium e.g water.
8. Temperature of body before death.
Estimation of Rate of Cooling
1. General FORMULA
Normal body temperature — Rectal temperature
1. Time since death=
Average rate of fall of temperature per hour(0.6 o
According to Simpson
1. The body looses temperature at the rate of 1.5 o
C/ hour during
the first six hours after death
2. Followed by 0.9o
C -1.2 o
C/hour in the next six hours when the
body is clothed.
The surface of body takes about 12 hours and internalorgans take
about 20-24 hours to reach the temperature of the environment
Glaister & Rantoul Formula
1. In 1966 calculatedthe time interval after death in hours as
C – Rectal temp.
Time interval after death=
Rate of fall of temp / Hour
Post Mortem Caloricity
Post means After & Mortem means Death,
Calor means Heat.
After the initialrise of temperature the body begins to cool as
usual. This is known as Postmortem Caloricity.
Post Mortem CaloricityCauses are:
1. Pontine hemorrhage
2. Tetanus& strychnine poisoning
3. Acute Bacterial or viral infections
4. Intense Asphyxial conditions.
SUBCUTANEOUS HYPOSTASIS or POSTMORTEM LIVIDITY Or
POSTMORTEM STAINING or LIVOR MORTIS or SUGGILATION or
Hypostasis is the bluish purple discolorationof the skin and organs
due to accumulationof bloodin the toneless capillariesand small
veins of the dependent parts of the body.
Post mortem Lividity is produced because
1. Stoppage of Circulation
2. Stagnationof bloodin bloodvessels.
3. Tendency of the blood to sink by force of gravity.
Time of Hypostasis
PML begins as a series of mottled patches on the dependentparts of
the body within 1-3 hours
These patches increase in size & coalesce in 3-6 hours and
Lividity is fully developed & fixed in about 6-8 hours of Hypostasis
FIXITY OF HYPOSTASIS
1. Fixation of PMS occurs when the body remains static for 6-8
hours at one place .
2. This is due to the fact that the coagulationin the capillaries
takes place in 6-8 hours making the staining permanent.
3. Nevertheless there will be no fixation if the blood remains
persistently fluid due to fibrinolysis.
4. Significance:To check whether Lividity has fixed or not apply
thumb area pressure. If the area pressed does not blanch it
means time since death is more than 8 hours.
SHIFTING OF HYPOSTASIS
1. PMS can shift from one part of the body to another due to the
movement of the body after death.
2. This is due to the fact that it takes about 6-8 hours for the stain
to fix and prior to that period , the staining can keep on shifting
as the blood remains fluid .
3. PMS at different areas of the body indicatesthe different
positionof the body after death.
DISTRIBUTION OF HYPOSTASIS
1. Distributionof PML is patchy to start but with passage of time ,
it graduallyenlarges to cover all the dependentareas of the
2. IN SUPINE POSITION back and is deepest in lumber region,
Except the areas of contact flatteningi.e. back of shoulders,
buttocks, and calves due to pressure on skin is sufficient to prevent
the subcutaneousveinsfrom filling with blood).
Any pressure anywhere on the body will prevent the capillariesfrom
filling & that is why the pressure areas due to wt of the body, wrist
watch, belt & bracelets do not show hypostasis.
DISTRIBUTION OF HYPOSTASIS
IN FACE DOWNWARDS POSITION
Hypostasis is found on front of body.
and areas of contact flattening are on cheeks, breast , abdomen and
knees and sides of the foot.
IN SITTING POSITION
Lower half of trunk, back of thighs, legs, below the knees,
Hypostasis is confined to lower abdomen, hands, thighs, and
Over the front of the Head, Neck, upper part of the chest and
Cause of Death
Colour of Hypostasis Cause of Death
Cherry Red Carbon monoxide
Bright Red Hydrocyanic acid, Burns
Reddish Brown, brown or deep blue Nitrates, Potassium Chlorate
Dark brown Phosphate poisoning
Pink Cold & refrigerated bodies
COLOR OF HYPOSTASIS Depends on
1. Color of blood
2. Mode of death
Hypostasis may appearbefore death in those
who die from prolonged illness, in which a
terminal circulatory failure permit some ante
mortem poolingof bloodat the back of the
In death due to anemia and in deaths due
to considerable loss of blood.
Belts, ligature, clothing , e,g brassiere.
1. It is reliablesign of death.
2. A parameter for time since death.
3. Cause of death from color.
4. Manner of death ---in hanging and drowning distributionof
hypostasisfrom parts of body on which it appears.
5. Position of body at time of death and weather the position has
been changed or not.
6. To differentiate from ante mortem bruise.
7. To differentiate it from congestion.
1. Those parts of body subjected to pressure become
flattened due to loss of muscle tone.
2. Thus when a corpse which hasbeen lying on its back on a
flat surface is turned over, the muscles of buttocks, calves,
3. Contact palloralso occur internally
1. Rigor------A rigidity
2. Mortis-----death/derived from mortic.
3. This is the stiffening of the muscles after death which follows
the period of primary flaccidity.
4. Every muscle in the body both voluntaryas well as
involuntaryundergoes rigor mortis.
CAUSE OR MECHANISM
1. 1. It is due to chemical changes involvingthe proteins of the
2. 2. As the myofibrils are made up of actin and myosin
filamentswhich are protein in nature.
3. 3. During life the separation of actin and myosin filaments
and energy needed for contractionare all dependentupon
ATP which is in high concentration in resting muscles and is in
4. 4. After death no more ATP is synthesized and its
concentrationfalls within the muscles, both actin and myosin
become stiff and get converted into a rigid gel havingno
reaction to electrical stimuli.
The terminal phase of rigor in which ATP disappearsfrom muscles
and the muscles become inelastic.
SEQUENCE OF APPEARANCE
1. All muscles of body both voluntaryas well as involuntary
undergo rigor mortis.
2. When it is fully developedin the skeletal muscles the body
assumes a BOARD LIKE RIGIDITY.
3. Rigor mortis is said to appearfirst in involuntarymuscles,
then in voluntary muscles.
4. Although the progress of rigor is simultaneousin all muscles,
they become more apparent and observable in smaller
muscles of body.
5. It first appearsin the face, then spread to neck, and upper
limb and trunk and last in the lower limb.
SEQUENCE OF APPEARANCE
1. 1. Eye lids-------------------------2--4 hours.
2. 2. Face-----------------------------4--5 hours.
3. 3. Neck and trunk----------------5--7 hours.
4. 4. Upper extremities-------------7--9 hours.
5. 5. Legs-----------------------------9--11hours.
6. 6. Finger and toes---------------11--12hours.
7. In our country rigor appearsin 3 hours, is fully developedin
12 hours , persist for an other 12 hours & passes off in
another 12 hours, its called RULE of 12.
POSITION OF BODY WHEN RIGOR IS FULLY ESTABLISHED
1. The jaw, neck, and extremities become fixed in position with
arms bent at elbow and legs at knees and movement at joint
are possible only within a very limitedrange.
BREAKING OF RIGOR
1. Forcible bending at jointsagainst the force of rigor actually
tears the muscles and stiffening of the joints, it will never
2. Rigor of heart produces a firm thickened and contracted left
ventricle which containslittle blood.
3. Rigor of seminal vesicles may cause discharge of seminal fluid
Rigor of erector pilaemuscles produce GOOSE SKIN or CUTIS
PASSING OFF OF RIGOR
1. It passes off in the same order in which it occurred due to
autolysisof muscle proteins, from above downward and
takes 12 hours to pass off completely.
2. Those muscles first to developedrigor are first to become
flaccid again and the rigor usuallystays longer in lower limbs.
FACTORS INFLUENCING RIGOR
1. 1. In fetus the onset is rapid and passes off quickly.
2. 2. In early youth and old age its onset is earlier than in adult
3. 3. The onset of rigor is later and durationis longer in strong
4. The more feeble and exhausted the muscular condition, the
more rapid onset and shorter is the duration
As a rule longer it takes to appear, the longer it stays.
The rapidity of rigor mortis depends upon glycogen reserves
in the muscles.
In prolonged febrile illness and chronic diseases and in some
convulsive disorders, rigor may appear early and passes off
quickly due to depletion of glycogen reserves. Rigor is
frequently absent in septicemic conditions.
TEMPERATURE OF SURROUNDING
1. The higher the temperature, the sooner rigor appears after
CONDITION SIMULATING RIGOR MORTIS
1. 1. Cadavericspasm.
2. 2. Heat stiffening.
3. Cold stiffening.
CADAVERIC SPASM/ Instantaneousspasm/ Catalepticrigidity
1. It is the form of muscularstiffening which occurs at the time
of death and is not preceded by primaryrelaxation of
2. It persist until rigor mortis develops.
Cause of CADAVERIC SPASM
Its exact cause is unknown but it is usuallyseen in
1. Violent deaths in circumstances of intense emotions.
2. Muscular exertion before death
Involves groups of muscles (forearm and hands)
But in cases of extreme tension whole body is affected.
1. Usually occur in war time.
2. Soldiersfound in kneeling posture taking the aim
with his rifle.
3. Tea party
. Weeds held in the handsof person trying to save himself
2. Gun or knife held in hands of person in case of suicide
1. 1. It records the last act of life.
2. 2. Weeds indicate that the person was alive when he
entered in water.
3. 3. Manner of death. It pointstowards suicide when
weapon is held in hand.
4. 4. IDENTIFICATIONof assailant In case of homicidewhen
some portion of clothing or hair of assailantmay found in
1. Heat as by burning
2. Immersion in hot liquidand
Coagulationof muscle proteins.
The skin of body becomes severely scorched
The muscles are: Pale pink ,
Stiff but tear easily,
Considerableshortening of muscles.,
PUGILISTIC ATTITUDE/ BOXER`S ATTITUDE:
Stiffening and Shortening of muscles give pugilistic
attitude to the body.
1. Flexion of elbow, knee and hip joints.
2. Shortening of muscles where it is not present in rigor mortis.
Stiffening and Freezing of body due to cold environment.
In mortuary at 4 degree will produce a notablesolidity of
subcutaneousfat and muscles.
On thawing out, the stiffening will disappearsand rigor mortis will
Late changes after death
1. Putrefaction is defined as that it is the last stage in the
resolution of body from organic to inorganic state and is an
absolute sign of death.
2. Bacterial action
3. It is the softening and liquefactionof the body tissue.
1. Self destruction by enzymes released from cells after death
It is prevented by freezing of tissues
1. It commences 3-4 hours after death.
2. Up to 2-3 days and sometimes longer.
1. Most of bacteria come from bowels,
2. Chiefly Clostridium Welchii, and other includestreptococci,
staph, E Coli, etc.
Warmth, moist and air.
Relates to the rate of putrefaction.
The process of putrefaction in air is twice as rapid as in water and
eight times as rapid as in the soil.
1 wk of putrefactionin air = 2 wk in water = 8 wk in soil.
CHANGES IN PUTREFACTION
2. Developmentof foul smelling gases.
3. Pressure effect of gases.
4. Appearanceof maggots.
5. Other sequelae
1. COLOR CHANGES
1. The first sign of putrefaction. It is the greenish discolorationof
It is first seen on right side over the caecum, gradually spread over
the whole abdomen and then the chest
Microorganisms in the bowels produce Hydrogen sulphidewhich
acts with Hb and converts it to sulph-met –Hb.
Over right iliacfossa in 12 –24 hours (36 hours)
whole body 48 hours up to 72 hours.
May appearas early as in six hours in summer.
The veinsbecome visible as bluish or greenish lines due to pigments
of decomposing blood.
Mostly around the shoulders, upper chest, abdomen and groin,
This is called MARBELLING OF SKIN.
It starts after 24 hours.
2. GASES OF PUTREFACTION
Formation of gases start from 12-18 hours.
The gases responsible are
Carbon dioxide etc.
In 12-18 hours in summer gases collect in intestine and
distended the abdomen.
From 18-36 hours or 48 hours gases collect in tissues and
hollow viscera and cause false rigidity and pressure effects.
Gases cause a generalized swelling of the body and distention is
greater in these areas where the tissues are loose e.g., scrotum and
The outer layer of skin loosensand can be rubbed off easily
with pressure to leave a shiny moist pink base.
This is called SKIN SLIP.
Skin from Hand or foot may peel off like a glove / stocking in
3. PRESSURE EFFECT OF GASES
1. Bloatingof features.
2. Shifting of areas of hypostasis.
3. Changes in skin and wound.
4. Extrusion of fluid from mouth
5. Emptying of heart.
6. Changes in the emptying of genitals
Bloating of Features
it developsin 36-48 hours.
Face becomes swollen
Eyes bulge from their sockets
& tongue becomes swollen
Bloating of Features
Breasts are enormously swollen.
In 48-72 hours the rectum protrudes
2.Shifting of areas of hypostasis
Owing to pressure of gases , PMS may be displaced in any
3. Changes in skin and wound
1. Putrefactive blisters are appearingunder the skin in 36-48
2. It containsmainlygas and a little reddish colored fluid.
3. Hairs become loose and can be pulledout easily.
4. Extrusion of fluid from the Nose & mouth
1. Due to pressure of gases in the abdomen, the diaphragmis
forced upwardscompressing the lungs & heart.
2. Blood stained froth comes from the nose & mouth.
Contents of stomach may be forced out / in lung
Emptying of heart
Heart is commonly found empty.
ENTOMOLOGICAL FACTORS IN PUTREFECTION
The study of insects that infest dead body in known as Forensic
It is of Medicolegal importance in
1. estimation of time since death.
2. Maggots also reveals about the drug.
3. Place of death
4. Manner of Death
Flies are attracted towards putrefying bodies and lay eggs on
the body especially in
open wounds, exposed moist, sheltered naturalorifices such as the
by about 18-36 hours after death They appearas creamy clusters
deposited on corps
INJURY BY RODENTS
1. Rodents attack the body withinhours after death.
2. They can bare the bone within 12 hours.
FACTORS AFFECTING PUTREFECTION
2. Bacterial contents of tissues.
3. Air and moisture.
4. Clothing of body.
5. Presence of body fat.
6. Presence of injuries.
8. Manner of burial.
9. Decomposition in water.
Adipos= Soft fat, cera means wax
Also called as saponification,grave or mortuarywax
It is the formation of soft whitish, crumbly or greasy material in
the soft tissues of the body after death.
It is yellowishwhite, greasy wax like substance with a rancid
Its mechanism is not fully known but it is believed that
clostridium Welchi initiatesthe processof hydrolysis &
hydrogenationof body fats.
Unsaturated lequidfats convert to saturated solid fats by
bacterial fat splitting enzymes.
It hasbeen noticed that superficial fats are initiallyaffected in
patches , being first seen in Cheeks , breasts & buttocks. Finally
the process spreads to the whole body .
Once formed it is relativelypermanent.
starts 2-3 weeks to months are required for Adipocere
CONDITIONS FACILITATING ADIPOCERE FORMATION
1.MOISTURE----It is prerequisite for Adipocere formation..
2. Warm TEMPERTURE Retarded by cold.
3. lack of air
4.BACTERIA----Facilitated by postmortem invasionof
The putrefaction is inhibited because of increasing acidityand
It indicatestime elapsed since death.
It establishes the identityof a person
It indicatesthe burialplace
Modificationof process of putrefaction.
There is dehydrationor desiccationof body tissues & viscera
The idealconditionsfor its formation are
high atmospheric temperature,
devoid of moisture,
free circulationof air,
Skin is dry, shrunken, leathery, rusty brown or black adhering to
Soft parts shrivel up but retain the naturalappearances and
Internal organs becomes dried mass.
Factors affecting mummification
Free circulationof air
Absence of moisture.
Time required 3-12 months are required for mummification
1. It indicatestime elapsed since death
2. It indicatescause of death
3. It establishidentity of the person
4. It indicatesthe burialsite
Preservation of Dead Bodies
1. Adipocere formation
* Artificial preservation
4. Cold storage or refrigeration
The process of preservation of dead bodies by
artificialmummification by injecting certain fluidsin to the
dead body is calledembalming.
The fluidsusually contains:
Formaldehyde, Solutionsof arsenic , lead sulphide,
The usual site of injections:
Femoral arteries , neck arteries, and aorta
The process is adoptedfor
1. In medical colleges to preserve dead bodies for purpose
2. Where dead bodies have to be taken from one country
to another for burial.
3. The tissues of body are hardened & stay preserved by
1. The methods involveputting a canolainto an artery and
injecting the preserving fluid.
2. The presence of fluid prevents the growth of microorganisms
and swells the features of the body.
The embalmingwill destroy any evidence In case of poisoning;
therefore removal of specimen should be completed before
Time Since Death Also called as postmortem interval.
It is the time between the death & postmortem examination.
Methodsof Estimationof Time since Death
1. Rate Method
2. Concurrence Method
Measuring the changes produced by a process which takes
place at a known rate which was either initiatedor stopped.
Examples include the
1. distributionof rigor mortis
2. Change in body temperature
3. Degree of putrefaction of the body.
Comparing the occurrence of events which took place at known
times with the time of occurrence of the event under
1. A wrist watch stopped by a blow during an assault, or
in drowning case.
The extent of digestion of the last known meal
The pointsto be ascertained are
1. 1. Coolingof body.
2. 2. Postmortem Lividity.
3. 3. Rigor mortis.
4. 4. Decompositionchanges.
5. 5. Content of stomach and bowel.
6. 6. Content of urinary bladder.
Cooling of Body
1. Rate of cooling is not uniform but is almost proportionalto the
difference in temperature between the body & its
2. Average heat loss is roughly 0.5 to 0.7 C.
3. Body attainsenvironmentaltemperature in about 16-20 hours
PML begins as a series of mottled patches on the dependent
parts of the body within 1-3 hours.
These patches increase in size & coalesce in 3-6 hours.
Lividity is fully developed & fixed in about 6-8 hours
1. Rigor appears in ------------- 2-3 hours,
2. Fully developed in------------- 12 hours ,
3. Persist for an other ----------- 12 hours &
4. Passes off in another ----------- 12 hours.
5. Eye lids------------------------- 3-4 hours.
6. Face----------------------------- 4--5 hours.
7. Neck and trunk---------------- 5--7 hours.
8. Upper extremities------------- 7--9 hours.
9. Legs----------------------------- 9--11hours.
10. Finger and toes--------------- 11--12hours.
1. It commences 3-4 hours after death
2. Continues steadily for 2-3 days and sometimes longer.
2. Color ChangesGreenish discoloration
1. May appear as early as in six hours in summer.
2. Over right iliac fossa in 12 –24 hours (36 hours)
3. whole body 48 hours up to 72 hours.
3. MARBELLING OF SKIN.
1. It commences after 24 hours ,
2. Seen prominently in 36-48 hours in summer
4. Skin from Hand or foot may peel off like a glove / stocking in
48-72 hours in 7 days
5. Postmortem Blister formation within in 36-48 hours
6. The teeth fall out of sockets in 7-10 days
7. The formation of gases - beginning of 2nd week
but It may occur in 12-18 hours in summer
CHANGES OBSERVED TIME SINCE DEATH
1.Bloating of facial features 36-48 hours.
2.Putrefactive blister formation 36-48 hours
3.Postmortem pulling of skin 48-72 hours
of hands and feet.
4.Changes in external 48-72 hours
5.Bursting of abdomen 48-72 hours.
3-6 weeks are required for adipocere formation.
Mummification which takes 3 to 12 months.
Contents Of Stomach & Bowels
1. Milk, tea , coffee leave stomach fairly rapidly (15-20 min).
2. Chappaties stay in the stomach for a long time
3. Mixed diets ( Chappaties, meat , vegetables ) exit the stomach
in 4-5 hours.
4. Rice retain their form upto 6 hours & LEAVE The stomach in
about 7-8 hours.
5. Vegetable diet containing vegetables, pulses, starchy roots take
6-7 hours to leave the stomach.
6. Conditions like fear, anxiety, shock & coma delaying emptying
rate & power of digestion
Contents of Urinary Bladder
The amount of urine in bladder may give some indication of
time since last micturation
Contents of Urinary Bladder
The amount of urine in bladder may give some indicationof
time since last micturation
1. Chemical constituentsof CSF such as lactic acid , Non protein
nitrogen & amino acid contents increase in the first 15 hours
after death but rise is not uniform
2. Potassium content of the vitreous humor of eye steadily rises
Biochemical Changes after Death
1. A. CHANGES IN BLOOD
2. B) CHANGES IN CSF
3. C) CHANGES IN OCCULAR FLUID
CHANGES IN BLOOD
CHANGES AT THE TIME OF DEATH
Agonal acidosisresult of tissue break down:
1. 1. lactic acid
2. 2. Non protein nitrogen ( over 100 mg%)
3. 3.Urea nitrogen (over 75mg%)
4. 4.Amino acid nitrogen( over 12mg%)
CHANGES AFTER DEATH;
PH at first drops due to
1. 1.Terminal accumulationof CO2 .
4. 4.Accumulationof phosphoricacid and lactic acid.
5. 5.Splitting of amino acids and fatty acids.
Then PH rises due to
Production of ammoniafrom enzymatic protein breakdown.
There is gradual rise of NPN to 50mg % in first 12 hours.
The Free amino acid nitrogen usuallyrises to 10mg% in first 12
Rises to 10 mg % in first 12 hours.
Soon after death the concentrationof chloridebecomes
equal in plasma and erythrocytes and is equalto concentration in
whole blood i.e 74 mmol/ L
As putrefaction begins serum magnesium level rises and can
reach 8 times to normal in 72 hours.
The level rises owing to diffusion from vascular endothelium.
PM ACCUMULATION OFENZYMES
The enzymes are transaminase , lactic dehydrogenase,
PATTERN OF ENZYME CONCENTRATION
First few hours ------ rapid rise.
Next 2-3 days ----- show linearrise.
Afterwards--------a fall in concentration as proteolysis
PEAK ENZYME ACTIVITY
Phosphatase and amylase-------36-48 hours.
day( 72-96 hours)
In right side of heart and inferior vena cava :
1. The blood concentrationrises up to 300 mg % in first 12 hours.
2. This is because of breakdown of liver glycogen and the
accumulationof dextrose in inferior vena cava and right side of
3. The diffusion does not extend beyond the heart because the
lungs provide an effective barrier.
In 6-8 hours after death free dextrose disappearsfrom
Thisis due to breakdown of dextrose in the body after death.
MEDICO LEGAL IMPORTANCE
1. Dextrose level of blood in right side of heart and inferior
vena cava is not helpful.
2. The dextrose level in limbs:
If the level raised above 200mg % some hours after death, this
is confirmatory evidence of hyperglycemia
BLOOD UREA & SERUM CREATININE
1. Blood urea rises in an irregular manner and is due to
2. Serum concentrationwithin first 48 hours is never above
100mg% unlessthere has been an increased urea concentration
3. In case of uremia the serum creatinine usually rises above 6
1. The urea concentrationabove 300 mg% and serum creatinine
concentrationabove 10 mg % indicaterenal failure with
B) CHANGES IN CSF
1. VOLUME Soon after death volume of CSF is above 150 ml but
after 24-48 hours it graduallydisappears.
Study of chemical changes in CSF is a better indicatorof time
since death than the same study in blood.
Rises after death in a linearpattern
Its concentrationin CSF is higher than blood and increase
further after death.
In first 10 hours -- less then 14 mg%
In first 24 hours -- non protein nitrogen concentrationunder
d) CREATININE VALUE
Under 5mg%----------up to 10 hours.
Under 10 mg% -------up to 30 hours
A concentration greater than 15 mg% ---- death more than 10
f ) DEATH FROM RENAL INSUFFICIENCY
3. CSF urea above 120 mg %.
4. CSF creatinine 3.5 mg %.
C) CHANGES IN OCCULAR FLUID
The fluid within eye ballconsist of
1. 1.Aqueousfluid-------in the anteriorand posterior chambers.
2. 2.Vitreoushumour------in the body of eye ball.
Their compositionis similar and the component is easier to use
as it is less contaminatedby blood &bacteria than CSF.
It is not difficult to withdraw up to 2 ml from each eye ballby
gentle suction with 20 bore needle and syringe.
It is highest in the body.
Fallsslowly in over 20 hours.
The concentrationdecreases but range is small.
c)NON PROTEIN NITROGEN
It is helpfulin cases where postmortem interval is more than 24