MEDICO-LEGAL AUTOPSY

Autopsy, necropsy and post-mortem examination are synonymous, although post-mortem examination can have a broader meaning encompassing any examination made after death, including a simple external examination.

In general terms, autopsies can be performed for two reasons: clinical interest and medico-legal purposes.

The clinical autopsy is performed in a hospital mortuary after consent for the examination has been sought from and granted by the relatives of the deceased. The doctors treating the patient should know why their patient has died and be able to complete a death certificate even in the absence of an autopsy.

These examinations have been used in the past for the teaching of medical students etc. and for research.

The medico-legal autopsy is performed on behalf of the state.

A poor autopsy is worse than no autopsy. In medico-legal autopsy, often the history is absent, sketchy, doubtful.

The aims of these examinations are much broader than those of the clinical autopsy and include:

to identity of the body;

• to estimate the time of death;

• to identify and document the nature and number

of injuries;

• to interpret the significance and effect of the injuries;

• to identify the presence of any natural disease;

• to interpret the significance and effect of the natural disease present;

• to identify the presence of poisons; and

• to interpret the effect of any medical or surgical treatment.

Taken at its broadest, autopsies can be performed by any doctor, but ideally they should be performed by a properly trained pathologist in mortuary at day-time, without the presence of any unauthorized person.

Rules for medico-legal autopsy:

1. The body should be labeled as it arrives the mortuary.
2. Conducted never in a private room, only in mortuary.
3. However, autopsy is done at the site when advanced level of putrefaction, causing difficulty in transportation.
4. Conducted only when official order from police or magistrate.
5. Done without undue delay after receiving the order.
6. M.O. should read the inquest report carefully to know the apparent cause and circumstance of the death.
7. Conducted in day light as far as possible.
8. The body must be identified by the police constable who accompanies it.
9. In unidentififed bodies, marks of identification, photographs and finger prints should be taken.
10. No unauthorized person should be present during autopsy.
11. The investigating police officar may be present.
12. The details are noted and sketches are made.
13. Both positive and negative findings should be recorded.
14. After autopsy, the body should be handed to the police constable.
15. The PM report should not be handed to the party.

Autopsy Report:

Consists of

1.The pre-amble: mentions the authority ordering the examination, date and place of the examination, name and sex of the deceased.

2.The body of the report: consists of detailed external and internal examination, focusing nature, direction, exact situation and dimension of the wounds, diagrams are of value.

3.Conclusion: as to the cause of death should be concise in clear language and honest. It should be followed by signature and qualification of the doctor.

External examination:

• The clothing should be listed and examined, type of garment, colour, tears, loss of button indicating a struggle is explained as each item is removed from the body. Blood stain, grease, seminal stain, poison, vomit should be kept for analysis. Clothes should be placed in clean separate bags.
• Nail scrapping- any visible fiber or other matter at the hand should be removed and placed in envelope. Ten small envelopes are labeled, one for each finger.
• Height and weight, general state, body built.
• General condition of the skin- rash, petechiae, colour.
• General description- age, sex, colour, race, nutrition, hair, scar, tatoo, moles, circumcision, pupils.
• Vaginal and anal swaps, pubic hair should be combed through. Matted pubic hair should be cut with scissors and the samples of pubic hair should be taken.

• The stain of mud, vomit, faeces, gun powder described.
• The presence of signs of disease eg., edema of legs, surgical emphysema, skin disease etc.
• The time since death should be noted from rectal temperature, rigor mortis, post-mortem hypostasis, putrefaction.
• The face examined for frothy fluid at the mouth and nose, cyanosis, petechiae, pallor etc.
• The eyes examined for conjunctiva, opacity of the cornea and the lens, petechiae. The ears for leakage of blood or CSF.
• The neck examined for bruises, finger nail abrasion, ligature mark.
• The abdomen, thorax, thyroid, breast, back, external genitalia and the natural orifices should be noted.
• The position of limbs should be noted. Hands examined for injuries, defense wounds, electric mark etc. and anything grasped in the closed fist.

Internal examination:

• Skin incison-

‘I’ shaped from the chin to symphysis pubis.

‘Y’ shaped incision from acromial process down below the breast to xiphoid and down to the symphysis pubis.

Modified ‘Y’ shaped incision- incision made in the midline from supra sternal notch to the symphysis pubis. The incision extends from the suprasternal notch over the clavicle to its centre on both sides and then passes upwards over the neck behind the ear.

• Abdomen- The recti muscle of the abdomen are divided about 5cm above the symphysis pubis, peritoneum is cut upto xiphoid, the condition of abdominal cavity and the organs is observed. Blood, pus if seen in the abdominal cavity, should be measured.

• Neck- a block should be placed under the shoulder to extend the neck, the skin dissection carried out immediately deep to skin to the lower border of lower jaw, sternomastoid muscle is freed from its attachments, the trachea, larynx, pharynx are pulled away from the pre-vertebral tissue by blunt dissection.
• Mouth- a knife inserted under the chin through the floor of mouth, cut along the sides of the mandible, to the angle of mandible dividing the neck muscles attached to the jaw. The soft palate is then cut to include the uvula and tonsils with tongue and neck organs to be removed. The knife is turned backwards and laterally to divide the posterior pharyngeal wall. The larynx and pharynx are pulled down, the dissection is then carried distally through the prevertebral muscles on the anterior surface of the cervical vertebra.

• Chest- pneumothorax should be noted by creating a pocket filled with water before the proper chest dissection. The wall is punctured with the knife under the water. The chest is opened by cutting the costal cartilage beginning from the second cartilage near the costo-chondral junction. The pleural cavity should be examined. Note the lumen of the main pulmonary vessels, right atrium and ventricle for embolism, distension or collapse of lungs, pleural cavity for fluid, pus, adhesions. Note the pericardium for cardiac temponade, collect blood sample from the heart for toxicological examination.
• Air embolism- in the heart can be found by cutting the pericardium anteriorly and grasping the edge with hemostat on each side. The pericardial sac is filled with water and the heart is punctured with scalpel and twisted few times to release escape of bubbles of gas.

• Fat embolism- if suspected the pulmonary artery should be dissected under water and the escape of fat droplets noted.
• There are two distinct methods of removing the viscera from the abdominal cavity and thoracic cavity:

1.Virchows method- removing each organ seperately

2.Rokitansky method- removing all the organs ‘en masse’.

The organ should be described based on size, shape, surface, consistency, cohesion, cut surface.

• Esophagus: the esophagus is cut open from the posterior surface up to the cardiac end of the stomach. If death occurred due to rupture of esophageal varices, the break in the lower end should be noted.

• Lungs: look for thrombi, emboli. The lung organ is crossed across from the apex to the base with a large brain knife, producing an anterio-posterior slice and examined for consolidation, edema, emphysema, tumor, infarction. The smaller bronchi are examined for mucosal thickening, infection and blockage.
• Aorta: whole length of aorta is cut on its posterior surface from the iliac vessels, around the arc upto the aortic valve to note chronic aortitis, obstruction of coronary arteries.
• Heart: is held at the apex and lifted upwards and the vessels are cut as far away as possible. This isolated heart is opened in the direction of the flow of blood. The right atrium is cut between the opening of superior and inferior venecava. Through the right atrium and through the tricuspid orifice, the right ventricle is opened along the lateral margin.

• Note whether the content of right ventricle and auricle is fluid blood, currant jelly clot or chicken-fat clot. The left atrium is cut along the lateral wall, extending through the mitral orifice and passes along the lateral margin of the left ventricle upto the apex. After the blood clots in the cavities are removed, the measurements of the valves, circumference and thickness of ventricles are taken. The coronary arteries are examined by making serial cross sections along the entire course of vessel about 2-3mm apart.
• Agonal thrombi: seen in case of persons dying slowly with circulatory failure, a firm tough pale yellow thrombus, usually on the right side of the heart, filling the right auricle and ventricle and pulmonary artery. It branches like a tree like cast. In the left ventricle, agonal thrombi are not so big.

Post mortem clots: 2 types-

• Black currant jelly: soft, lumpy, uniformly dark red, moist clot formed when the blood clots rapidly.
• Chicken-fat clot: when red cells sediment before the blood coagulates. The red cells produces a clot similar to the first type. Above this a pale or bright yellow layer of serum and fibrin is seen called chicken fat. It is soft, elastic jelly like.
• Usually a mixture of the two is found. Post-mortem clots are moist, smooth, shiny, homogenous, rubbery, not attached to the underlying wall, and there are no fine white lines of fibrin (striae of zahn).

• Stomach: opened along its greater curvature from the cardiac to pyloric end. The contents are examined for food, digestion, smell, colour. In massive hemorrage, the stomach is filled with large soft clots which may take the form of a task of gastric outline.
• Intestine: the superior mesenteric vessels are examined for thrombi, emboli. The small intestine is opened along the line of mesenteric attachment.
• Liver: weight, size, colour, injury are noted. It is cut into slices 2cm thick which run in the long axis. Amoebic abscess are usually single large and confined to the right lobe. Pyogenic abscess are multiple. In fatty liver, cut section is greasy. In portal cirrhosis, the liver is sturded with nodules, 1-3mm in diameter (micro nodular).
• Spleen: removed by cutting through its pedicle. Note the size, weight, rupture.

• Pancreas: sliced by a series of cuts at right angle to the long axis which gives the best exposure of ductal system.
• Kidney: renal artery ostia are examined. The capsule of the kidney is stripped, the kidney is sectioned longitudinally to split in half and open the pelvis to see calculi and inflammation.
• Female genitalia/uterus: the tube, the ovaries and the uterus are freed from the pelvis and are removed. If the uterus contains a fetus, its age should be determined.
• Head: head is fixed by head rest. A coronal incision is made in the scalp from the mastoid process just behind ear and carried over the vertex to the opposite mastoid. The scalp is reflected forwards and backwards. The saw line is made in slightly ‘V’ shaped direction so that the skull cap will fit exactly back into the correct position. The meninges are examined and the brain is examined.

MECHANICAL INJURY

ML Classification of Injury:

MEDICAL

1.Mechanical

A)DUE TO BLUNT FORCE

Abrasion

Contusion

Laceration

Fracturew and dislocation

B)DUE TO SHARP FORCE

a)Incised wound

b) Chop wound

c)Stab wound

C.FIREARM WOUNDS

a) Firearm wound

2.Thermal

DUE TO COLD-frost bite ,immersion foot

DUE TO HEAT-burns,scald

3.Chemical corrosive acid ,corrosive alkali

4.physical- electricity .lightning,Xray.

5.explosions

LEGAL

1.SIMPLE

2.GREVIOUS

MEDICOLEGAL

1.SUICIDE

2.HOMICIDE

3.ACCIDENT

4.FABRICATED

5.DEFENCE

Contusion:

• Surface injury to the skin and sub-cutaneous which leads to an effusion of blood into tissues
• usually caused by blunt trauma.
• Appears 1-2 hours after injury.
• may take the shape of weapon eg railway tract appearance.
• Children, old, obese women bruise easily.
• Mongolian spot shouldn’t be confused with bruise.
• Contusion may be also in the internal organs
• Gravity shifting of bruise may occur in late occuring bruises

Color changes in a bruise:

• 1st day- red
• 2nd day- 3rd day -bluish
• 4th day- brown day(haemosiderin)
• 5th-6th day- green(haematoidin)
• 7th-12th day- yellow(bilirubin)
• 13th-15th day ,2 weeks – normal
• Subconjunctival Hage donot undrego colour change

ML aspect of contusion:

• Patterned bruise-Identification of weapon,ligature,vehicle
• Degree of violence from size
• Time since injury
• Purpose of injury
• Homicidal, suicidal, accidental .position of assylant while arms are grasped

Difference between antemortem and postmortem bruise:

Antemortem contusion

• Swelling present
• Color changes present
• Epithelium abraded
• Clotted blood in tissue present

Postmortem contusion

• Not present
• Not present
• Not present
• Not present

Difference b/n artificial and true bruise

Artificial bruise

• By juice of marking nut,calotropis or plumbago
• At exposed accessible site
• Dark brown colour
• Shape irregular
• Margins well defined and regular
• Itching present
• Positive chemical test

True bruise

• Trauma
• Anywhere
• Typical colour changes
• Usually rounded
• Not well defined,diffuse,no vesicles
• Absent
• negative

Patterned intradermal bruise on the forehead due to a

fall onto ribbed ceramic tiles.

Bruising of the upper arm. The pattern of these bruises

is typical of forceful gripping. Small abrasions from fingernails are

also seen.

Typical ‘railway-line’ bruises caused by a wooden rod.

Note that the centre of the parallel contusions is unmarked.

Recent bruising of the abdominal wall and scrotum due

to kicking.

Abrasion:

• destruction of only superficial layer of epidermis,thickness of skin is 1.6mm.
• Bleed very slightly
• Heal very rapidly
• Leave no scar

Types of abrasions:

• Scratch or linear abrasion-has length but no significant width.eg by pin, thorn, nail etc. very sharp objects
• Graze(sliding,grinding abrasion)-longitudional parallel lines. by rough surface in contact with a broader surface of skin, eg. RTA
• Patterned abrasion (pressure and impact abrasions)- thumb mark in strangulation, ligature mark in hanging, wheel mark of tyre,teethbite mark.

Age of abrasion by color change: exact age cant be determined

• Red color- fresh
• Red scab- 12-24 hours-by dryind of blood and lymph
• Reddish brown scab- 2 to 4 days
• Healing from periphery- 4 to 7 days,dark brown
• Complete healing- 10 to 14 days
• Seperation of scab- 10 to 14 days

ML importance:

• Identification of object
• Direction of injury
• Time since injury
• Possibility of internal injury
• Somtime erosion by ants look like abrasion.d/d-ants produce abrasion that are brown,irregular margin,commonly at mucocutaneous junction about eyelids,nostril,mouth,axilla,by hand lens show multiple cresent shaped,sand like bite marks

Difference

Antemortem abrasion

• has Moist surface
• Bleeding present
• On drying scab formation,scab slightly raised
• Blurred margin
• Inflammation present
• Intravital reaction and congestion seen

Postmortem abrasion

• Dry surface
• No bleeding
• No scab
• Sharply defined margin
• Inflammation absent
• Not seen

Abrasions from scraping against a rough surface

during a fall.

Extensive abrasions caused by stumbling, drunk and

naked, against furniture. The dark leathery appearance is due to

post-mortem drying of the damaged areas of skin

Incised wound:(cut,slash,slice)

• Clean cut through tissues ,usually skin and subcut. By sharp edged or cutting weapon, eg. knife, sword, glass.
• Edges are smooth, clean cut and everted.
• Broader than the edge of weapon
• Length is greater than depth and breadth.
• Bleed profusely
• Superficial towards the end of wound k/a tailing
• Edges may be inverted in case of underlying muscle attached to skin, eg. scrotum.

ML importance:to find homicidal,accidental or suicidal

• Homicidal, anywhere in the body, deep
• Suicidal- multiple, superficially, usually in the left hand
• Accidental- anywhere
• Edges of the wound indicate: antemortem or postmortem, sharp or blunt weapon.

Difference between incised wound

Antemortem

• Bleed freely and profusely
• Arterial spouting present
• Blood is clotted
• Edges gape
• Inflammation present
• Serum serotonin and histamine increased

Postmortem

• Very slight or no hemorrhage
• Not present
• Not clotted
• Edges closely
• Not present
• Not raised

Difference between suicidal and homicidal cut-throat wounds

Suicidal

• Left side of neck,passing across the throat,usually in rt handed
• Level above thyroid cartilage
• Multiple no ,superficial,rarely single
• Edges usually ragged,due to overlapping
• Hesitation cuts present
• Defence wound absent
• Weapon usually present
• Clothes not torn or damaged
• Circumstancial evidence, quite place

Homicidal wounds

• Usually on both sides
• On or below thyroid cartilage
• Multiple .cross each other at a deep level
• Sharp and clean cut,bevelling may be seen

Incised wound to the flank; it is clearly longer than it

is deep

A complex stab wound where all three injuries are

caused by a single action. The first entry is in the right breast; there

is an exit wound in the middle and a re-entry wound over the centre

of the chest.

Stab or punctured wound:

• Type of incised wound whose depth is greatest in dimension.
• Eg. Knife wound, dagger

Types of stab wound:

• Penetrating wound- has only wound of entry
• Perforating wound- has both entry and exit wound

Features of stab wound:

• Aperture is usually smaller than the weapon due to elasticity of the skin
• Depth is greater than breadth and length.
• Very little external hemorrhage but profuse internal hemorrhage

• Shape- Wedge shaped with knife, elliptical with dagger, rounded with needle, slit-like opening with screw driver,
• Margins of entry wound are clean and inverted,
• Margins of exit wound are small and everted
• Direction determined by line joining entry and exit wounds or X-ray after radio-opaque dyes.

ML(medical legal ) importance:

• Nature of weapon
• Direction of wound
• to find Suicidal, homicidal or accidental

Lacerated wound:

• Wound in which skin and underlying tissue is turned due to blunt force application

Classification:

• Split laceration
• Stretch laceration
• Avulsion
• Tears (caused by irregular sharp object)

1.Split laceration (incised looking wound)

• Usually found overlying the bones
• caused by blunt perpendicular impact
• Skin splits between 2 hard objects and simulate an incised wound

2.Stretch laceration:

• Overstretching of skin produces a flap
• Caused by blunt tangential impact
• Also by sudden deformity of bone after a fracture

3. Avulsion:

• Caused by horizontal crushing impact
• Commonly truck, bus wheel, muscles are crushed
• Also known as degloving of skin

Multiple lacerations from a blunt steel bar. These were

initially mistaken by the police for axe wounds. The abraded or

crushed margins can be easily seen.

Laceration of an arm of a pedestrian struck by a car.

The impact has been oblique, causing a flap of skin to tear away

to the right.

Nature of injuries- simple, grievous, dangerous

1.Simple injury:

• Neither serious nor extensive
• Heals rapidly w/o leaving permanent deformity or disfigurement

2. Grievous injury:

• Emasculation
• Permanent loss of sight of either eye
• Permanent loss of hearing of either ear
• Destruction of joint or any member of body eg. Limb
• Permanent disfigurement of head or face
• Fracture or disfigurement of bone or tooth
• Any hurt to be in hospital for 20 days

3. Dangerous injury:

• Compound fracture of skull
• Injury to vital organ eg. spleen, liver
• A wound of large artery eg. radial femoral

INJURY DUE TO HEAT AND ELECTRICITY

The heat source may be dry or wet; where the heat is dry, the resultant injury is called a ‘burn’, whereas with moist heat from hot water, steam and other hot liquids it is known as ‘scalding’.

Burning

1 first degree – erythema and blistering (vesiculation);

2 second degree – burning of the whole thickness of the epidermis and exposure of the dermis;

3 third degree – destruction down to subdermal tissues

Where the burnt area exceeds 50 per cent, the prognosis is poor even in first-degree burns.

Clinical conditions due to high heat exposure

1.Heat cramp- miner’s cramp, fireman’s cramp due to rapid dehydration through loss of water and salt in the sweat, severe and painful paroxysmal cramp of muscles of leg, abdomen, arms.

2.Heat prostration- heat exhaustion, heat syncope, heat collapse.

• Is a condition of collapse without increasing body temperature, which follows exposure to excessive heat.
• Precipitated by muscular work and unsuitable clothing
• Patient usually recovers if placed at rest but death may occur from heart failure.

3.Heat hyperpyrexia or stroke- characterized by rectal temperature more than 41 degree centigrade and neurological disturbance as psychosis occurs.

• Term sunstroke used when direct exposure to sun is there.
• High temperature, increased humidity, muscular activity and lack of acclimatization are the principle factors in initiation of stroke.
• Failure of cutaneous blood flow and sweating, the factors which control the body temperature, lead to breakdown of heat regulating centre of hypothalamus.

Burns in a victim of a house fire.

Scalds:

• Runs or dribbles of hot fluid will leave characteristic areas of scalding – these runs or dribbles will generally flow under the influence of gravity and this can provide a marker to the orientation of the victim at the time the fluid was moving.
• Scalding is seen in industrial accidents where steam pipes or boilers burst and it is also seen in children who pull kettles and cooking pots down upon themselves.

The examination of bodies recovered from fires

• The findings of soot in the airways and carbon monoxide in the blood indicate that the person was breathing after the fire began.

Post mortem findings

A.External:

• Burnt fabrics
• Smell of kerosene, petrol over fabrics
• Postmortem hypostasis and rigor mortis can not be assessed
• Face is swollen and distorted,
• Tongue protruded and swollen and may be burnt
• Froth at mouth and nostril due to pulmonary edema due to heat irritation of air passage and lungs
• Pugilistic attitude (boxing, defense attitude)- characteristic of great heat exposure; the flexor muscles being bulkier than extensor contract more.
• Heat rupture in severe burning or charring, skin contracts and heat ruptures occur
• Flash burn due to sudden ignition or explosion of gases

B.Internal:

1.Heat hematoma- has the appearance of extra dural hemorrhage

• Clot has honey comb appearance
• Parieto-temporal region is the most common site of such hemorrhage

2.Thermal fracture of skull-

3.Laryngeal edema

Scalds of the buttocks and feet on a child who had been dipped into a bath of extremely hot water as a punishment.

Trachea showing soot and mucus following inhalation of fire fumes and smoke.

Skin splits in the victim of a house fire. These splits were initially thought to be incised wounds.

ELECTRICAL INJURY

• Usually, the entry point is a hand that touches an electrical appliance or live conductor,
• The exit is to earth (or ‘ground’), often via the other hand or the feet.
• In either case, the current will cross the thorax, the most dangerous area for a shock because of the risks of cardiac arrest or respiratory paralysis.
• When a live metal conductor is gripped by the hand, pain and muscle twitching will occur if the current reaches about 10 mA.
• If the current in the arm exceeds about 30 mA, the muscles will go into spasm, which cannot be voluntarily released because the flexor muscles are stronger than the extensors; the result is for the hand to grip or to ‘hold on’.
• This ‘hold on’ effect is very dangerous as it may allow the circuit to be maintained for long enough to cause cardiac arrhythmia, whereas the normal response would have been to let go so as to stop the pain.

• If the current across the chest is 50 mA or more, even for only a few seconds, fatal ventricular fibrillation is likely to occur.
• The victims of such an arrhythmia will be pale.
• Even more rare are the instances in which the current has entered the head and caused primary brainstem paralysis, which has resulted in failure of respiration.

The electrical lesion

• Where the skin is wet, there may be no signs at all, as the entrance and exit of the current may be spread over such a wide area that no focal lesion exists.
• Usually, however, there is a discrete focal point of entry.
• The focal electrical lesion is usually a blister, which occurs when the conductor is in firm contact with the skin and which usually collapses soon after infliction, forming a raised rim with a concave centre.

• The skin is pale, often white, and an areola of pallor (due to local vasoconstriction) is a characteristic feature. The blister may vary from a few millimetres to several centimetres.
• The skin often peels off the large blisters leaving a red base.
• The other type of electrical mark is a ‘spark burn’, where there is an air gap between metal and skin.
• Here, a central nodule of fused keratin, brown or yellow in colour, is surrounded by the typical areola of pale skin.

The electric mark (Joule burn):

• It is specific and diagnostic of contact with electricity
• It is found at the entry point.
• These are round or oval, shallow craters, 1-3cm in diameter, and have a ridge of skin of about 1-3 mm height.
• The crater floor is lined by pale flattened skin
• When the contact is prolonged, there may be charring.
• Produced by conversion of electricity into heat within the tissue.

Exit mark:

• Variable feature, but have some of the features of entrance mark
• May be more damage of tissue
• Often seen as splits in the skin, continuous or interrupted
• Ante mortem electric burns can not be distinguished from postmortem electric burns

Multiple minute electrical marks on the hand caused by contact with a faulty electrical drill.

Extensive electrical burns with scorching and blistering.

Electrical mark from a mains wire wrapped around the neck. There is marked hyperaemia and adjacent pallor, with evidence of blistering.

Hyperaemia from a defibrillator paddle, caused during

attempted resuscitation.

IMPOTENCE AND STERILITY

Definitions:

Impotence:

Physical inability of either sex to perform sexual act.

Sterility:

Inability to procreate,

Inability to impregnate in case of males,

Inability to conceive in case of females.

Causes of impotency

1. Pathological

Organic causes,

General diseases.

2. Psychological

Organic causes:

Congenital developmental malformations:

In males:

Absence of penis

Infantile penis

Double penis

Hypospadias & Epispadias

In females:

Absence of vagina

Ill developed or small vagina

Imperforated hymen

Female pseudo hermaphroditism

Acquired conditions:

In males:

Acute diseases of penis

Injuries to penis

Adhesions of penis

Hydrocele, scrotal hernia

Elephantiasis

In females:

Vaginal obstruction

Vaginal strictures

UV prolapse

General diseases

In males:

Heart disease

DM

Acute febrile illness

Chronic general disease

Drug addiction

Masturbation

Neurological diseases

Vit. B deficiency

In females: no general disease renders impotence

Psychological causes:

In males:

Stress

Fear

Guilt

Homosexuality

In females:

Vaginismus (reflex spasm of vaginal orifice & all the muscles of pelvis)

MLI of impotency and sterility:

Divorce

Disputed paternity

Legitimacy

Adoption

Adultery

Rape

Un-natural sexual offences

Forensic Ballistic

Definitions:

• Ballistics: Forensic ballistics is the science dealing with the investigation of the firearms, ammunitions and the problems arising from the use.

• Firearm: A firearm is an instrument which discharges a missile by the expansive force of the gases produced by the combustion of the propellant in a closed space.

Types of Firearm:

• Smooth bored weapon (shot gun)- eg. musket, shotgun.
• Rifled weapon/groove bored firearms- eg. rifle, revolver, pistol, automatic pistols, machine guns.

General make up of firearm:

• A barrel- hollow cylinder closed at the back end called breech end, open at the end called muzzle end
• Inside of barrel consists 3 parts- 1. chamber at the breech end for the cartridge, 2. the taper in rifled arm and chamber cone in smooth bore, connects the chamber to the bore 3. the bore which lies between the taper and the muzzle
• A bolt or block can be opened to insert a fresh cartridge into the chamber

Smooth bored firearm:

• Bore is perfectly smooth from end to end
• They fire round pellets
• The hitting range is quite small
• Muskets- smooth, bored guns used by constables, has a long fore stuck and usually takes a bayonet at the muzzle (military gun)
• Barrel- steel tube, as long as 40-48 inches and as short as 24-30 inches
• May be full-choke (muzzle end is 40/1000inch, less in diameter than the breech end), half-choke (muzzle end is 20/1000 inch less) and unchoked (muzzle end and breech end equal in diameter)
• The function of choking is to decrease the spread of shot.
• May be single barreled or double barreled.
• Are effective upto 30-35meters.

Shot gun cartridge:

• Consists of a case of short metal cylinder which is continuous with a card board or a plastic cylinder
• The case is rimmed to keep cartridge in correct position in chamber
• Length of cartridge= 5-7cm
• The cartridge is filled from base to above with percussion cap, gun powder, a thick felt wad with card board disc lying in front and behind it, the shot and finally the retaining card board disc, over which the edges of the cartridge cylinder walls are pressed.
• The cartridges are numbered according to the size of the shot they contain

Groove bored/rifled firearms:

• Spiral grooves (2-20, usually 6) inside the barrel to impart spin movement to bullet, to keep the bullet in straight line to target.
• Rifles have firing range of 1000m.
• Striking range is small in case of pistol and revolver.
• Rifled firearms are divided into

1. Low velocity <360 m/s
2. Medium velocity 360-750 m/s
3. High velocity >900 m/s
4. The caliber or gauze of rifle is measured between lands, not grooves made by the spirals inside the rifles.

• Rifle may be single shot, repeating, semi-automatic, automatic.
• Revolvers are so called because the cartridge chambers revolve before each shot to bring the next cartridge opposite the barrel
• Revolver has a cylindrical megazine at the back of barrel and can accommodate 5-6 cartridge each in a separate chamber.
• Effective range is 100 m.muzzle velocity is 150 m/s.

Bullet (of Rifle/revolver/pistol)

• Traditionally made of lead with antimony added for hardness, k/a round nose soft bullet.
• Jacketed bullets are of 2 types:

1. Full metal jacket bullet
2. Semi jacketed bullet with nose fully or partly exposed

Air rifles and air pistols

Compressed air supplies the propulsion power instead of ignition powder

Small velocity,80 to 100 metre per second

Striking range about 40 metres

Causes only minor injuries

Muzzle velocity:

Shot gun: 800-1000 ft/sec (240-300 m/s)

Rifles: 2000-3000 ft/sec

Pistol: 1200 ft/sec

Revolver: 600 ft/sec (150-180 m/s)

Air rifle: 400-700 ft/sec

Musket: 1150-1950 ft/sec (350-600 m/s)

Types of projectiles/bullet

• Lead shot: Present in shot gun cartridge, are of different sizes
• Jacketed conical bullets: fully or partially encased with copper or copper nickel, used in rifles.
• Hardened lead bullets: in pistol and revolver
• Tracer bullet: barium peroxide and magnesium are enclosed in base, give light as they pass.
• Incendiary bullet: contains phosphorus, burn the tissue.
• Tandem bullet: two bullets together entering into single entrance wound, when an old rusty weapon’s first bullet comes out only after the second fire.
• Dumdum bullet: expands or mushrooms on striking and produces a large hole
• Plastic bullet: baton round, used for riot control, effective upto 50-70 m, not fired to a person under 20 meter range.

Gun powder: 3 types

Black powder

Contains carbon 15%, sulphur 10%, potassium nitrate 75%

Only 44% of black powder is burnt into gas

The powder grains are black, coarse or fine, burns with production of much heat, flame and smoke

Fine grains travel 60-90 cm or more.

Smokeless powder

Contains nitrocellulose alone or with nitro glycerin

100% smokeless powder is burnt

Produces much less smoke and are more completely burnt than black powder

Semi smokeless powder

Mix of 85% black and 15% smokeless powder

Following things come out of a gun when fired

1. Projectile
2. Blast of highly compressed gases
3. Particle of unburnt /partly burnt powder
4. Smoke
5. Flame
6. Wads (in shotguns)
7. Fine lead fragments (in lead bullets )
8. Grease from the weapon
9. Empty cartridge (smtm in shotgun

Wounds of entrance

• In distant shots ,it s usually smaller than the projectile d/t the elasticity of skin
• Rounded if bullet hits the body at right angles ,oval if obliquely and gutter shaped if tangentially
• Entrance wound is smaller than the exit
• Edges are inverted (except in fat and decomposed)
• Characteristic of wound of entrance found at all ranges is ring of greese and gun powder surrounded by collar of abrasion or contusion
• It may contain wads

Wounds of exit

• Bigger than entrance wounds
• Very irregular and torn, stellate
• Edges everted
• No collar of contusion or abrasion
• No tattooing or scorching or blackening

If a bullet hits bone,

• a clean purched out hole seen in spongy bone,
• It is shattered to small bits d/t great velocity, spin and tailing in compact bone
• Rebound or deviate after striking a hard bone(wound of ricochette)

Typical stellate exit wound with everted margins.

Shot gun wounds in detail based on distance:

contact wound

• results in a circular entrance wound that is about the size of the muzzle.
• The wound edge will be regular and often has a clean-cut appearance with no individual pellet marks apparent.
• There will commonly be smoke soiling of at least some of the margin of the wound.
• There may be a narrow, circular rim of abrasion around some or all of the entrance wound, caused when the gases of the discharge enter through the wound and balloon the tissues upwards so that the skin is pressed against the muzzle.

• If the discharge was over an area supported by bone, the gases cannot disperse as quickly as they would in soft areas such as the abdomen, and the greater ballooning of the skin results in splits of the skin, which often have a radial pattern.
• The wads or plastic cup will usually be recovered along the wound track. The tissues along the wound track will be blackened and the surrounding tissues are said to be pinker than normal as a result of the carbon monoxide contained within the discharge gases.

close discharge,

within a few cm of the surface, will also produce a wound with a similar appearance, but as there is now room for gas escape, there will be no muzzle mark.

More smoke soiling of wound can occur, and burning of skin with singeing and clubbing of melted hairs can be seen around the wound.

There is also, very commonly, powder ‘tattooing’ of the skin around the entry wound. This tattooing is due to burnt and burning flakes of propellant causing tiny burns on the skin and cannot be washed off.

Wads will commonly be found in the wound.

intermediate ranges,

between 20 cm and 1m, there will be diminishing smoke soiling and burning of the skin, but powder tattooing may persist.

The spread of shot will begin, first causing an irregular rim to the wound. Often called a ‘rat-hole’ in the USA because of the nibbled edges, the same appearance is called ‘scalloping’ in the UK.

Separate injuries caused by the wads or plastic shot containers may be seen.

At a range of over 1 m, smoke damage and tattooing do not occur.

With a normal shotgun, satellite pellet holes begin to be seen around the main central wound at a range of about 2–3 m.

.

• important to measure the spread of the shot to establish the range at which a particular spread of shot will occur.
• Estimates based on generalizations about the ratio of the diameter of this spread to the range should no longer be used.

long ranges,

as 20–50 m, there is uniform peppering of shot,rarely fatal.

• Shotguns rarely produce an exit wound.
• Exit wounds seen when fired into the head, neck or mouth. The exit wound in these cases may be a huge ragged aperture, especially in the head, where the skull may virtually explode.
• The spread of shot will begin, Often called a ‘rat-hole’ because of the nibbled edges, the same appearance is also called ‘scalloping’ .
• Separate injuries m/b caused by the wads or plastic shot
• satellite pellet holes begin to be seen around the main central wound at a range of about 2–3 m.

Close discharge of a 12-bore shotgun to the chest.

There is a large hole, partly due to disruption by gas, and no

evidence of pellet scatter is seen.

spread of the shot can be seen.

Wounds from rifled weapons in details based on distance

Bullets fired from rifled weapons will commonly cause both an entry and an exit wound.

However, exceptions to this rule are numerous and many bullets are retained within the body.

Entrance wounds in detail

Contact wounds from a rifled weapon are generally circular, unless over a bony area such as the head, where splitting caused by the propellant gas is common.

• There may be a muzzle mark if the gun is pressed hard against the skin.
• There may be slight escape of smoke with some local burning of skin and hair if the gun is not pressed tightly.
• Bruising around the entry wound is not uncommon.

close range up to about 20 cm, there will be some smoke soiling and powder burns, and skin and hair may be burnt, although this is very variable and depends upon both the gun and the ammunition used.

• The shape of the entry wound gives a guide to the angle that the gun made with that area of skin: a circular hole indicates that the discharge was at right angles to the skin, whereas an oval hole, perhaps with visible undercutting, indicates a more acute angle.
• Examination of the entry wound will show that the skin is inverted; the defect is commonly slightly smaller than the diameter of the missile due to the elasticity of the skin.
• Very commonly, there is an ‘abrasion collar’ or ‘abrasion rim’ around the hole, which is caused by the friction, heating and dirt effect of the missile when it indents the skin during penetration.
• Bruising may or may not be associated with the wound.

Over 1 m or so, there can be no smoke soiling, burning or powder tattooing.

At longer ranges (which may be up to several kilometres with a high-powered rifle), the entrance hole will have the same features of a round or oval defect with an abrasion collar.

Suicidal pistol contact entry wound in the temple.

The skin is burnt and split due to the gases of the discharge.

Pistol entry wound through the eyebrow with adjacent

powder tattooing. The bruising of the eyelid is due to the fractured

skull.

Deaths and Injury in Infancy

• Infant- <1 year
• Infanticide means the unlawful destruction of a child under the age of 1 year.
• Stillbirth and sudden infant death syndrome, which have important medico-legal aspects.

Still birth

• It is the child (born after 28 weeks)which did not breathe or show any sign of life at any time after being expelled from the mother.
• Common causes are prematurity, anoxia, birth trauma especially intracranial hemorrhage due to excess moulding, placental abnormality.

Dead birth:

• Is a child which has died in the utero and shows one of the following signs after complete birth:
• Rigor mortis at delivery
• Maceration (aseptic autolysis after 3-4 days in uterus filled with amniotic fluid and no air). The earliest sign of maceration is skin slippage, which can be seen in 12 hours after death in utero. The body of the macerated fetus is soft, flaccid, and flattens out when placed on a level surface. It has a sweetish disagreeable odor. Spalding’s sign is the loss of alignment and overriding of the bones of the cranial vault.
• Mummification: is the condition in which the fetus dries up, shriveled in the uterus. It occurs when fetus dies from deficient supply of blood, when the liqor amni is scanty and when no air enters the uterus.

A newborn infant showing marked maceration due to an intrauterine death. The cord around the neck is significant, but a full autopsy is required to establish the cause of death.

Signs of live birth:

Shape of chest- flat, circumference

The position of diaphragm- found at the level of 4th or 5th rib if no respiration, 6th or 7th rib after breathing.

Lungs- After respiration, volume is increased, margins become rounded, consistency becomes soft, spongy, elastic and crepitant. The hydrostatic test by placing the lung tied at bronchi into water- if floats suggests respiration but an unexpanded lung may float from putrifaction and the expanded lung may sink from disease like acute edema, pneumonia.

Stomach- air is swallowed into the stomach during respiration.

Other signs of live birth- caput succedaneum, cephalhematoma, air in GI tract, clothed body, vernix caseosa washed.

How long did the child survive?

• Caput succedaneum disappears within 7 days.
• Changes in umbilical cord:

1)Clotting at cut end- 2hours

2)Shrinks and dries- 1st day

3)Cord mummified- 3 to 4 days

4)Cord falls- 5 to 6 days

5)Ulcers heals by scar- 10 to 12 days

Skin changes:

1)Vernix caseosa- persists for a day or 2

2)Color bright red at birth, becomes dark at 2nd or 3rd day

3)Original color 7 to 10 days.

Cause of death:

• Natural- Immaturity; malformation; disease of heart, lungs or brain; meconium aspiration; Rh incompatibility.
• Accidental- cord prolapse; prolonged labor; cord round the neck; placenta previa; death of mother; aspiration of blood or liquor; precipitate labor.
• Criminal- suffocation, strangulation with cord, drowning in milk or water, throttling, failure to tie the cord, removal of child from mother’s charge, omission to feed.

Abrasion of the neck of a baby. These marks were said to have been caused by traction of the neck of the baby by the mother during self-delivery. Similar marks could be caused by strangulation.

Battered baby syndrome/ child abuse syndrome

Also called maltreatment syndrome in children

A child who has received repetitive physical injuries as a result of non-accidental violence produced by a parent or a guardian.

In addition to physical injuries, there may be deprivation of nutrition, care and affection.

The classical discrepancy between the nature of the injuries and explanation offered by parents, and delay between the injury and medication is clear.

Constant repetition of injuries at different dates.

Munchausen’s syndrome by proxy

Is feigning illness or injury and going from hospital to hospital for unnecessary investigations and treatment.

Children are brought to doctors for induced or fabricated signs or symptoms of illness.

Child is frequently admitted to hospital for illness, non existing in real.

These patients appear to be compulsively driven to make the complaints. The parent is aware that he is acting an illness but he can not stop the act.

Method of production of illness- mother pricks her finger and adds blood to the urine sample of her child, a pillow or towel is put over the face of the child and the face is pushed down into bed clothing, mother gives insulin to the child and takes to hospital with hypoglycemia, drugs for diarrhea, vomiting given to the child.

DROWNING (MECHANICAL ASPHYXIA)

Drowning:

• Is a form of asphyxia due to aspiration of fluid into the air passage, due to submersion in fluid or water.
• Complete submersion is not necessary, that of mouth and nose alone for a sufficient period can cause death from drowning.

Bodies recovered from water may have:

• died of natural causes before entering the water; while in the water
• died from exposure and hypothermia in the water;
• died of injuries or other unnatural cause before entering the water; after entering the water;
• died from submersion, but not drowning; or
• died from true drowning as a result of aspiration of water into the lungs.

SIGNS OF IMMERSION

• the skin becomes somewhat opaque and wrinkled. known as ‘washerwoman’s fingers’, develop after a few hours in cold water.
• After a few days, this macerated skin will begin to separate and,
• usually within 1–2 weeks the skin will peel off the hands and feet.
• another early sign of immersion is cutis anserina or ‘gooseflesh’, d/t contraction of the erector pili muscles.
• However, this is partly due to cold (and may be seen in refrigerated bodies) and partly due to rigor mortis.
• Cutis anserina is not a specific sign of immersion.
• in average temperate conditions a body immersed in water will decompose at about half the speed of one left in air.
• After about a week, the body will be bloated and the face, abdomen and genitals will be distended with gas
• As the body is moved by the flow of the water, contact with rocks, piers and many other underwater obstructions can cause damage.

TYPES OF DROWNING:

Wet drowning- water inhaled into lungs, death within minutes of submersion, secondary to cardiac arrest.

Dry drowning- water doesn’t enter the lungs, but death results from immediate laryngeal spasm due to inrush of water into larynx; thick mucus, foam and froth may develop producing a plug; usu. in children and alcoholics.

Secondary drowning- also called ‘near drowning’; refers to a submersion victim who is resuscitated and survives for 24 hrs

Immersion syndrome- also called hydrocution; death results from cardiac arrest due to vagal inhibition from

Cold water stimulating skin,

Cold water striking epigastrium,

Cold water entering ear drum, pharynx, larynx.

Seen in 1-2% of drowning.

Pathophysiology of drowning

The mechanism of death in true drowning is not one of simple hypoxia but differ according to the type of water: hypotonic or hypertonic.

If a dead body is thrown into water, due to hydrostatic pressure, water passes into lungs. This hydrostatic lung will simulate drowning lung; but a fluidy lung with frothy fluid is diagnostic of drowning.

FRESH WATER DROWNING:

Fresh water is hypotonic compared to plasma, so, a rapid transfer of fluid takes place from the alveoli into the vascular system because of the osmotic difference between the water in the lungs and the plasma.

may increase the blood volume by as much as 50% within a minute and this hypervolaemia will place a great strain on the heart.

The lungs are ballooned but light in weight.

The rapid influx of water will render the plasma hypotonic, which will result in haemolysis of RBC.

It was once thought that severe hyperkalaemia caused from the haemolysed RBC contributed significantly to rapid myocardial failure, but more recent work has shown this to be only a relatively minor factor in death in fresh-water drowning.

SEA WATER DROWNING:

Seawater is hypertonic (3% NaCl), so that water is withdrawn by osmosis from the plasma into alveolar spaces in the lungs.

There is also electrolyte transfer, with mainly sodium and chloride passing from the hypertonic inhaled fluid into the blood.

The lack of hypervolaemia, with the consequent absence of strain on the heart, probably accounts for the longer survival times in salt-water submersion.

POST MORTEM FINDING:

Drowning is one of the most difficult modes of death to prove at post mortem.

Post mortem lividity is found on face, hands, upper part of chest, lower arms, feet and the calves.

Weed, grass, leaves etc. present in the water may be firmly grasped in the hands due to cadaveric spasm.

Classically, there will be a plume of froth at the mouth and nostrils, which may sometimes be tinged with blood.

This froth fills the air passages and exudes on to the face. It is composed of water containing plasma protein and surfactant that has been whipped into a froth by the violent terminal respiratory actions..

Externally this may be the only sign, but it is absent more often than it is present, especially when the body has been dead for some time.

The lungs may have a ‘doughy’ texture and remain inflated and spongy to the touch.

Dissection of the lung may show generalized pulmonary oedema, but where any water in the air spaces has been absorbed into the pulmonary circulation, the oedema will be absent – this is the so-called ‘dry-lung drowning’.

In a significant proportion of cases, the person dies quickly, sometimes within seconds of entering the water.

Sometime,The mode of death of these cases is considered to be cardiac arrest, which is most likely to be due to a vagal inhibitory reflex triggered by a sudden stimulation of sensitive areas like larynx, pharynx, skin of the heavily drunk alcoholics.

Profuse blood-tinged froth around the mouth and nose in drowning.

LABORATORY TESTS FOR DROWNING

Microscopic algae, called diatoms, which are often, but not always, present in seawater and unpolluted natural fresh water.

All have an almost indestructible silicaceous capsule.

The theory behind the test is that normal people do not have significant numbers of diatoms in the kidneys, brain, marrow etc., but if a person drowns in diatom-containing water, the algae in that water will reach the lungs and some of them will penetrate the alveolar walls. If the heart is still beating, the diatoms that have entered the bloodstream will be transported around the body in the circulation and may lodge in distant organs such as the kidney, brain and bone marrow before death.

An increase in the number of diatoms in the internal organs was thought to confirm that the body had drowned and, if a sample of the water was also taken at the presumed site of drowning.

The similarity of different species of diatom in the water and the body could be compared.

On the other hand, if a dead body was dropped into water, although diatoms could reach the lung by passive percolation, no circulatory transfer could occur and so (theoretically) no diatoms would be present in the distant organs.

The advantages- could be used even in the presence of putrefaction, if protected tissue such as bone marrow was examined.

Unfortunately, the diatom test is often negative, even in undoubted cases of drowning in waterways full of diatoms, and there have been numerous false positive results.

All in all, this test is now so unreliable that it should only be used, and the results interpreted, with great circumspection.

Diatoms from lake water.

ASPHYXIAL DEATHS

Asphyxia:

Condition in which supply of oxygen to blood and tissues has been reduced below the normal level by some interference with respiration.

1. Disease of circulatory or respiratory system

2. Interferance with respirations

Breathing in atmosphere deficient in oxygen.

Inhalation of irrespirable gases like CO.

Poisoning with respiratory center depression like narcotics & anesthetics.

Mechanical interference with reapiration.

Signs of Asphyxia:

Cyanosis (due to stasis and congestion)

Increased capillary permeability (causing tissue edema)

Petechial hemorrhage

Persistant fluidity of blood (due to fibrinolysis)

Cardiac dilatation.

POST MORTEM FINDING IN DEATH FROM ASPHYXIA

1. Internal findings:

Blood- dark in color, more fluid, coagulate slowly.

Right sided heart-distended with blood

Left- empty

Lungs- Engorged, congested, emphysematous, edematous, exudes copious frothy fluid on cut section.

2.External findings:

Face- Swollen, cyanosed, marked with petechial hemorrhage

Eyes- Open, prominent, pupils dilated, injected conjunctiva

Sub-conjunctival heamorrhage may be present

Lips, ears, finger nails- Deeply cyanosed

Neck veins- Prominent

Mouth & nostrils- Oozing

Hands- Clenched

Hypostasis- Purple in color

Semen may be voided

Urine and feces incontinence

Trachea & bronchi- Congested, contain blood stained frothy fluid

Petechial hemorrhages- can be found on lungs, heart & brain

Abdominal viscera, brain, meninges- Congested

Suffocation:

It includes-

Smothering (obstruction to air passages from outside)

Choking (obstruction to air passages from inside)

Traumatic asphyxia (pressure on chest obstructing respiratory movements)

Smothering:

It is a form of asphyxia caused by mechanical occlusion of external air passage.

Post-mortem findings:

Site of distribution of lividity

Suggestive of suffocation

Bruises & abrasions over mouth & nostrils

Nasal septum may be fractured

Signs of struggle may be present

ML Aspect:

Homicidal (difficult in healthy young adults)

Commoner method for infanticide

Accidental (in children during sleep & breast feeding; may occur in alcoholics or epileptics)

Suicidal (almost impossible, extremely rare)

Choking:

It is a form of asphyxia caused by mechanical occlusion within air passage by a solid object.

Post-mortem findings:

Object responsible for choking is found in respiratory passages,

Other signs of asphyxial death.

ML Aspects of Choking:

Mostly accidental-

Impaction of food, false teeth & other foreign bodies,

Inhalation of vomitus in alcoholics,

Regurgitation of food in infants,

Impaction of coin, pea, grape, or nut,

Tumors of larynx

Diptheria,

T.B. Laryngitis

Homicidal (common for infanticide)

Suicidal (extremely rare)

Traumatic Asphyxia or Crush Asphyxia

It is a form of asphyxia, which results from prevention of respiratory movements by means of mechanical compression.

Post-mortem findings:

Well defined demarcation line between upper (discolored) and lower (normal colored) body part,

Face and neck deeply cyanosed,

Numerous petechiae found over scalp, face, neck and shoulders,

Bilateral, multiple rib fractures (usually at their angles),

Injuries to lungs and heart,

Other signs of asphyxial death.

Traumatic asphyxia due to pressure on the chest from an overturned tractor. The extensive congestion and petechial haemorrhages in the head and neck are typical of this type of asphyxia.

ML Aspects of traumatic asphyxia:

Mainly accidental-

Run over by a car

Fall of a tree

Collapse of a house

In crowds (during Haj)

Bansdola (homicidal compression of chest by means of bamboos)

Hanging:

It is a form of asphyxial death brought about by suspension of the body and constriction of neck by a ligature around it.

Partial hanging- when the feet touch ground

Complete hanging- when feet don’t touch ground

Causes of death in Hanging:

Asphyxia

Cerebral congestion or congestive suboxia

Vasovagal inhibition or shock

Injury to spinal cord

Combination of the above causes.

The spiral weave of the rope can be seen in this

horizontal ligature mark caused by hanging

Suicidal hanging: the rope rises to a point, leaving a

gap in the ligature mark – the suspension point – on the neck.

Post-mortem findings:

1. Nature of ligature:

Time, the body has remained suspended

Intervention of clothes, beard, skull hair etc.

2. Position:

Above thyroid cartilage- 80%

On the thyroid cartilage- in cases of partial

Below thyroid cartilage- very rare

3. Course of direction:

Oblique & interrupted at place-usually of knot

Circular- if suspension is in front

Oblique & circular- if ligature is passed around the neck more than once.

4. Color:

Pale in early period-later on becomes yellowish & brown then dark brown or chocolate colored.

5.External appearances other than ligature mark:

Neck- stretched & elongated, bend to side opposite the knot

Face- swollen & blue

Eyes- protruded, dilated pupils, conjuctivae congested

Tongue- protruded, saliva dribbling from the corner of mouth

Head & neck- petechial hemorrhage

Nails- blue

Sometimes face become pale & eyes and tongue less protruded in case of arteries and veins are compressed together

Genitals- swollen & congested

Rigor mortis- slow and longer

PM lividity- on dependent parts e.g. extremities, breasts, penis & testicles.

6.Abrasions and bruises:

• May be found when ligature is hard & tough.

7.Number: 1-suicidal, >1- homicidal

8.Internal appearance:

• Spinal cord injuries
• Transverse tear of the intima of the carotid arteries & extravasation of blood within the wall
• Pons and medulla may be injured
• Sternocleidomastoid and platysma may be ruptured
• Thyroid cartilage may be fractured
• Heart, right side full of dark blood & left empty
• Abdominal organs congested and bladder empty
• Hyoid bone may be fractured in above 40 age group.

Signs of antemortem hanging:

A suspension mark with signs of vital reaction e.g. hyperemia, ecchymosis, abrasions & bruises.

Ligature mark can be produced 2 hours after death but without vital reaction.

ML Aspects:

Most commonly, it is suicidal

More common in females than males

Direction of ligature mark

Oblique-suicidal

Circular- homicidal

Presence of poison in body suggest suicide

Signs of struggle suggest homicide.

Strangulation:

It is a form of asphyxia caused by constricting the neck by any means other than body weight.

Constricting force being hands- in throttling; elbow- in mugging; knee, foot- bansdola; some hard object.

Causes of death in strangulation:

Asphyxia

Vasovagal inhibition

Cerebral congestion

Combination of above factors

It is well accepted that in some cases of strangulation,and in rather more cases of hanging, the sudden application of pressure onto one or other carotid sinus can initiate rapid death, through the vagally mediated cardiac bradycardia described above, before any congestive or petechial signs have time to appear –and so the victim dies with a pale face and no petechiae.

For congestion and petechae,hypoxia of min 15-30 s is reqd

PM Findings

1. External findings

Neck findings

External findings other than neck

2. Internal findings

External findings

Neck findings

Strangulation by Ligature:

Fragments of epidermis on suspected ligature material, if found.

Usually on or below thyroid cartilage.

Encircle the neck completely

Bruising & ulceration at the site of knot

Throttling or Manual Strangulation:

Marks of fingers & thumb on either side of neck

Look like bruises soon after death

There may be bruises on mouth, nose, cheeks, forehead and lower jaw.

Strangulation by means of a Stick:

Bruises in front of the center of the neck

Similar mark will be present on nape of neck if two sticks are used.

B. External findings other than in neck

• Signs of asphyxia.
• Face- swollen, cyanosed & marked with petechial haemorrhages.
• Eyes- prominent, conjunctiva injected and pupils dilated.
• Lips- blue.
• Bloody froth from mouth, nose & ears.
• Tongue- swollen, bruised & bitten by teeth.
• Hands- clenched.
• Urine, feces and semen may be discharged.
• There may be injuries on chest

Petechial haemorrhages on the eyelid in a case of manual strangulation.

Conjunctival haemorrhages in manual strangulation

Bruising of the neck in manual strangulation.

Homicidal strangulation with a soft silk ligature. The folding of the material has caused the deep grooved mark and the fainter red mark above it.

2. Internal findings

Extravasation of blood into subcutaneous tissue above and below the ligature mark.
Laceration of the superficial muscles of neck.
Fracture of hyoid bone, tracheal rings and cervical vertebrae.
Lungs- dark, frothy blood on section
Heart- right side full of dark blood and left empty
All abdominal organs are congested.