Abrasion

ABRASION

Destruction of the skin-loss of superficial epithelial layers of the skin.

Heals rapidly without scar formationCausative agents Blow Fall Finger nail Thorn Tooth-bite

ABRASION

TYPES

Scratch Graze Pressure abrasion Impact abrasion

SCRATCH

Caused by sharp instruments

Eg- pin, thorn, finger- nail

CHARACTER Head-clean seen at

beginning) Tail- tagging of skin at

end)

GRAZE ABRASION

CAUSATIVE FACTOR traffic accident, fall while running

CHARACTER

long parallel lines

head is clean

skin heaped up at tail

PRESSURE ABRASION/IMPACT ABRASION

PRESSURE ABRASION & IMPACT ABRASION

PRESSURE ABRASION

CAUSE- force perpendicular to skin

CHARACTER-

Skin crushed

Surrounding area contused Eg-ligature mark

(hanging), teeth bite mark

IMPACT ABRASION CAUSE-impact with rough

object

Eg – tyre tread, radiator grill, rope( hanging)

THESE TWO COMMONLY KNOWN AS PATTERNED ABRASIONS

AGE OF ABRASION

Fresh -bright red color 12-24 hours -scab formation 2 days -scab reddish brown color 4-7 days -epithelium covers After 7 days -scab falls off

M.L.POINTS OF ABRASION

Nature of injury Site of impact Direction of force Ext. sign of int. injury Patterned abrasion-

identifies objecteg)eliptical/circular,2-4

marks –teeth bite with bruised intervening space

Nature of crime from the site of abrasion

a) Neck-throttlingb) Around mouth &nose-

smotheringc) breast, genitalia&thighs-sexual assaultsd) Site of Crime-presence

of mud, grass, straw etc

ANTE&POST MORTEM ABRASIONS

Feature Ante mortem Post mortem

Bleeding Bleeding surface seen Complete absence of bleeding

Scald Forms within a day or two

Not forming

Site Any where in body Over bony prominences (due to hardening and drying of underlying skin)

CONTUSION/BRUISES

BRUSES/CONTUSIONS

Definition- Effusion of blood into the tissues, due to the rupture of subcutaneous vessels

CAUSE -impact of blunt forceEg- stone, fist, stick, bar….

CHARACTER Painful swelling & crushing of surrounding

tissues Continuity of skin maintained

SIZE -varies from pin head to large Minor trauma cause large bruises in areas where tissues are loose and vascular

Eg-face ,scrotum, vaginaModerate violence produce small bruise if tissues are strongly supported, fibrousand covered with thick dermis

Eg-scalp, palm, sole, abdomenMARKED ABRASION SEEN on tissues overlying bones on women, children, old age on fair skinned personSMALL BRUISE DEVELOP IN hemophilia, whooping cough, scurvy, leuckaemia

SITE -it may not indicate the site of violence

due to gravity shifting of blood

eg-blow to forehead shows around the eye

-kick to calf muscle shows around ankle

SHAPE -usually round

-patterned abrasion represents the object

-elongated shape - stick, whip, cane

-radiator grill shape -in road accident

AGE OF BRUISE Fresh -red Hours to 3days - blue 4thday -blue black/brown 4-6 days -greenish 7-12 days -yellow 2 weeks -normalM.L.POINTS -patterned bruise indicate weapon or object -size indicate degree of violence -age of injury -manner of assault (throttling-seen neck,) -contusion to internal organs lead to death

DIFFERENCES B/W ACCIDENTAL,HOMICIDALAND SELF INFLATED BRUISES

Accidental Homicidal Self inflated

Presence of natural items seen on the site of crime like sand ,gravel

Size and shape of bruise will corresponds to the weapon used

Bruise formed by chitraka

Color-dark brown

Margins –with vesicles

Surrounding tissues-

Red and inflamed

Scraping of mark responds to the test to identify the material

DIFFERENCE B/W ANTE MORTEM &POST MORTEM BRUISE

Features Ante mortem Post mortem

Swelling Present Absent

Color change Present Absent

In case of severe trauma

Present any where of body

Present only body prominent area

Feature Artificial bruise True bruise

1 Cause Arka / bhallataka juice Physical violence

2 Situation Accessible area Anywhere

3 Shape Irregular Round

4 Margins Regular, well defined, small vesicles

Diffuse, irregular,no vesicles

5 Color Dark brown Typical changes

6 Inflammation Of surrounding area At the site

7 Contents Acid serum Blood

8 Itching Present Absent

9 Vesicles May found on finger tip &other part of body

Absent

DIFFERENCE B/W TRUE AND ARTIFICIAL BRUISE

INCISED WOUNDS/SLASH WOUND

definition- it’s a clean cut through the tissues

CAUSE

by sharp cutting weapons

eg-knife, scalpel

CHARACTER

Edges are clean cut, well defined & everted

Width is greater than the edge of weapon (due to retraction)

Length is greater than width or depth

Shape- spindle shaped Hemorrhage is more vessels

are clean cut) Deeper at head -start due to

more pressure) Shallow at tail A curved weapon like sickle

produce a stab first then an incised one

AGE OF WOUND12 hours-edges red,

swollen and adherent

24 hours-vascular buds

begins36 hours-capillary net

work complete3-5 days-vessels

thickened,obliterations start

1-2 weeks-scar tissue

M.L.POINTS size indicate degree of

violence age of injury direction of force by

detecting head foreign bodies on

wound leads to crime site

CHOP WOUND

A type of incised wound caused by cutting edge of fairly heavy weapon(axe)

CHARACTER Margin sharp Margin bruised and abraded Dimension corresponds to the cross section of blade Complete or incomplete amputation of fingers or bones Usually homicidal Accidental by power fans, ship propellers etc…

SUICIDAL INCISED WOUNDSMultiple& parallel in any one area

Seen on accessible areas

Hesitation marks /tentative cuts seen

Hesitation marks-multiple, small, superficial cuts seen at the head of wound

CUT THROAT

DIFFERENCE B/W SUICIDAL AND HOMICIDAL CUT-THROAT WOUND

Sl no Feature Suicidal Homicidal

1 Situation Left side ,passing front(rt hand)

On sides

2 Level Above thyroid cartilage On or below

3 Direction Above downwards &lt to rt Transverse/below upwards

4 Edges Ragged due to hesitation mark Sharp &clean cut

5 Hesitation cuts Multiple at head Absent

6 Severity Less severe More severe

7 Tailing Present Absent

8 Vessels Carotid art do not injured Jugular and carotid cut

9 No of wound Multiple (20-30),superficial Not multiple ,deep level

10 Defense wound Absent Present

11 Wounds of other part

Incised may be wrist, thigh, groin

Severe injury over

head

12 Weapons Present at site Absent

13 Cadaveric spasm Weapon may grasped Fragments of cloth, hair, etc

14 Blood stain If in front of body &cloths If sleep on either sides, palms

15 Cloths Not damaged May cut, disarrangement, tear

16 Circumstantial Quiet, suicidal note, in front of mirror

Disturbance at scene

STAB WOUND/PUNCTURED WOUND

MULTIPLE STAB WOUND STAB WOUND

STAB WOUND/PUNCTURED WOUND

This type wound penetrate skin and deeper tissuesCAUSE-

sharp objects like knife, dagger, arrow,spear,needlePENETRATE WOUND-

if enters body cavityPERFORATED WOUND

if weapon comes out on other sideit have two type of wounds

-ENTRY WOUND LargeInverted

-EXIT WOUNDSmallEverted

CHARACTERS Length less than width of weapon Depth is greater than length or width Margins clear cut without abrasion Shape corresponds to the weapon

Elliptical -single edged weapon

Circular -round weapon

Cruciform -square weapon Direction can made out

CONCEALED PUNCTURE WOUNDSeen on canceled part of bodyEg-vagina,rectum,eye,nostrils,nape of neck,fontanelle(brugma region)

DEATH RESULT-needle push to brain through fontanelles or

cantus of eyepin push into medulla through nape of neck

ML POINTSDirection of wound detect whether it is

suicidal/homicidal/accidentalPosition of victim give inference position of

accusedSite of wound detect type of deathCondition of clothing detect any violence

LACERATION WOUND

Tear or splits of skin and subcutaneous tissues by the blow from blunt objects.

Eg-hard projecting surfaces, machinery & railway accidents, wheel crushing

CHARACTER OF LACERATION WOUND Margins are irregular and ragged Ends are torn Margins or subcutaneous tissues contused Deeper tissues are irregularly torn Hair bulbs crushed Hemorrhage is less (irregularly torn vessels) Depth varies Shape and size does not corresponds to object Skin opposite to the force is torn Foreign bodies may present Underlying bones likely to be fractured Internal hemorrhage may be profuse and lethal

TYPES -4 TYPES Split laceration Stretch laceration Avulsion Cut laceration (chop wound)

SPLIT LACERATION

CAUSEcrushing skin between 2 hard objects

CHARACTERIncised like wounds seen

Seen areas like -areas where skin tightly stretched over bones -areas where subcutaneous tissues are less Eg-scalp, eyebrow, cheek bones, chin

STRETCH LACERATIONCAUSE

fixed skin when get over stretched Eg-run over motor accident, compound fracture

AVULSION LACERATIONCAUSE

grinding compression by weight Eg-lorry wheel passing over a limb

CUT LACERATIONCAUSE

blow with heavy sharp edged weapon Eg- axe

DIFFERENCE B/W ANTEMORTEM AND POST MPRTEM LACERATIONSi no Feature Ante mortem Post mortem

1 Contusion Present Absent

2 Everson Present Absent

3 Gaping of margins Present Absent

4 Vital reaction Present Absent

ML POINTS OF LACERATION WOUND

Direction of force can detect

Site of crime or accident from the foreign bodies in wound

Mode of death Lesion whether ante mortem or post mortem Approximate cause can drawn

DEFENCE WOUNDS

Wound received by victim during attackto save himself byraising hand and grasping weaponSITES-

Usually on palm, ulnar border of forearm, back of hands

TYPE OF WOUND Depend on the weapon used varies Contusion, Abrasion, Laceration, Incised, Stab It indicate homicideCONDITIONS FOR THE ABSENCE OFDEFENSE WOUND Attack at victim is unconscious Attacked suddenly

SELF-INFLATED AND FABRICATED WOUND

SYNONYMS -FICTITIOUS / FORGED WOUNDS Wounds produced by a person by himself Wounds produced by some other on a person with his consent

AIM Falsely blame an enemy for revenge or jealousyCHARACTER Mostly incised or stab wounds Produce by application of some irritant juices or burns Laceration and contusions are rare Site will be exposed and accessible areas of bodyEg front of wrist, neck, front or out side of lt arm, front or outer of thigh,

Front of chest, abdomen Injuries are multiple and superficial Cloths are not damaged

FIRE ARM WOUND

FIRE ARM CONSIST OF Hollow metal barrel Front open end – Muzzle end Closed back end- Breech end Posterior part- Butt

CLASSIFICATION OF FIRE ARM1) SMOOTH –BORED WEAPON(SHORT-GUN) single barrel double barrel repeating or self loading2) RIFLED WEAPONS rifle

a)0.22 riflesb)military riflesc)air –rifles

single shot pistols automatic pistols revolver automatic weapons

SMOOTH –BORED WEAPON(SHORT-GUN)

double barrelsingle barrel

repeating or self loading

TECHNICAL TERMS

1)CALIBER / GAUGE Internal dimension of barrel Measured in inches or centimeters Measured with the help of lead ball’s size which fits the barrel

MEASURING THE DIAMETER OF BARREL

2)CHOCKING OF GUN

Distal3/4th of barrel is narrow CHOCKING OF GUN

Degree of narrowing is chocking It’s of 3 types

-full chock-half chock-quarter chock

BENEFITS OF CHOCKING Chocking increases

explosive force velocity of shot

Chocking less the rate of spread of shot

3)RIFLING

In some weapons the bore is Marked internally with spiral grooves No: of spirals varies from 4 -7 They run parallel to each other but twisted spirally They extended from breech end to muzzle end These grooves are known as rifling The ridges between the grooves are known as lands

4)CARTRIDGE Ammunition (projectiles to be fired from a gun)

consisting of a cylindrical casing containing an explosive

charge and a bullet; fired from a rifle or handgun

Its of two types

a) shot-gun cartridge

b) cartridge for rifled weapon

a) SHORT GUN CARTRIDGELength 5-7 cm

The case consist of-short metallic cylinder

it is rimmed to keep in position it help the extraction

-long card board cylinder

CASE IS FILLED FROM BASE TO UP Percussion cap in centre of base

(containing priming mixture) Gun powder Felt wad with cardboard disc front & behind Shot Cardboard disc

Felt wad =Hold the powder and allow sufficient buildup of gas pressure when fired

b) CARTRIDGE FOR RIFLED WEAPON

It consist of Elongated metal cylinder

(it is rimmed except in automatic weapon) Distal end tightly grips base of bullet The powder charge lies between detonator and bullet Bullets are conical in shape

WOUNDS FROM SHOT –GUN

The wound depends on

Distance from which weapon fired Size of shot Nature of explosive The gun Elasticity of skin and organs Fragmentation of bullet

WOUND DEPEND S ON THE DISTANCE OF WEAPON

If the gun fired in contact or a few inches of bodya) Shot enters in one mass as single bulletb) Large irregular entry woundc) Margins of the wound bruisedd) Deeper tissues are ruptured and laceratede) Unburned powder particles found in wound f) Unburned powder embedded in surrounding skin produce tattooingg) Margins of the wound are burnt by flameh) Margins of the wound are black due to smokei) Shape of the burned area depends on the angle of fire

Circular-if fired at rt angleOval -if fired at a different angle

j) If body covered burning, blackening & tattooing seen not over skink) On head contact wound causeLarge, irregular holes on skullFissured fractures or bursting open with scattered

If the gun within 6 inches tissues are signed and blackened over broader

area margins are cleanIf the gun between 1-3 feet single round wound 1-1.5 inches diameter Irregular edges 1-3 inches

Tissues are much damaged due to the spreading of shotIf the gun above 3 feet

Shot begin to spreadIf the gun at 6 feet

Wound is surrounded by separate opening in an area of 2 inchesIf the gun at 12 feet

Shot spreads widely and produce separate opening in an area of 4 inches

If the gun at 20 yardsOnly skin or muscle penetrate

12 feet

B) SIZE OF SHOTSmaller shot-minute irregular edged woundLarge shot -pass deep to body

C) NATURE OF EXPLOSIVESmokeless powder - less blackening and tattooingBlack powder - marked blackening

and tattooing

D) THE GUNWOUND DEPEND UPON

1) Length of barrel

2) Bore of barrel3) Chocking of barrel

The spread of shot in inches is roughly equal to range of fire in yards

WOUNDS FROM REVOLVERS OR PISTOLS

DISCHARGES FROM THE GUN Gases, Smoke, Flame, Powder, Metallic particles.Flame extends - 2-3 inchesSmoke extends -12 inchesPowder granules -18-24 inchesMetallic particles -18-24 inches

Shots are of4 types depends on the distance of the weapon contact shot close shot near shot distant shot

CONTACT SHOT

All the discharges from the gun pass into the wound Burning, blackening are not seen around wound entrance The wound is large Shape of wound Irregular, Stellate, Cruciate

Elliptical, Triangular These different shapes due to the

expansion of gases in the tissues On head the wound will be

Large and cruciform with Everted margins(due to the expansion of gases in between scalp and

skull)Skull bone burst open

Abdominal wound produce cavitations The imprint of muzzle of gun may seen as patterned abrasion The tissue around the bullet track may pink color (CO contained

gas)

2) CLOSE SHOT

The range is 1-3 inches Very close or contact range is called Point Blank Wound is round Margins singed, black and tattooed Hair are singed (burned) As bullet enters the body skin is inverted, stretched and splits The gyrated bullet (revolve around a fixed point or axis)

produce abrasion round the wound due to rubbing of bullet with skin

Collar-the elevated area seen around the wound produce by the bullet

Since abrasion is present around the wound it is known as Abrasion collar

Abrasion collar-Type of bullet -gyrated bullet Due to rubbing with skin abrasion seen around the wound

It is of two types Grease/dirt collar Contusion colla

Grease/dirt collar-Type of bullet -lubricated or soiled bullet

Grease or dirt attached to the skin around the hole These may seen over the abrasion

Contusion collar-Type of bullet - gyrated bullet

Contusion also may seen along with abrasion Contusion seen over the margins

If the weapon fired at right angle

The wound become circular with abraded collar around

If the weapon fired at an angleo An eccentric hole with abraded collaro Collar will be wider on one side than othero Wider area indicates the direction of bullet

If the weapon fired from a distance of 6 inches wound is round size of wound represents the size of bullet margins show bruising, blackening and tattooing it will not produce burning

3) NEAR SHOT

Range of shot -12-18 inches Wound is smaller than size of bullet Blackening and tattooing seen over wide area

Burning and singing is not seen

4) DISTANT SHOT

Range of shot -above 18 inches Wound is round and smaller than bullet Blackening and tattooing absent Abrasion collar present

DIFFERENCE BETWEEN ENTRANCE AND EXIT WOUND

Entrance wound Exit wound

Sl no

Feature Entrance wound Exit wound

1 Size Smaller than bullet except in contact

bigger than bullet

2 Edges Inverted Everted , torn

3 Abrasion and grease collar

Present Absent

4 Burning, blackening and tattooing

May present Absent

5 Bleeding Less More

6 Tissues May cherry red due to CO no color change

7 Fibers of cloth May found Absent

8 Metal ring May seen around wound Absent

9 Skull Punched in hole in outer table;

Punched out opening in inner table

RICOCHET BULLET

Ricochet - To rebound at least once from a surface.

Ricochet bullet is that which strikes an intervening object first, then rebounds, then hit the target aimed.

It occurs with low quality fir arms If the velocity of bullet is low

When bullet hit hard, flat surface it may deformed then if it hit body the wound

Large Irregularly oval, triangular or cruciate Abrasion collar, burning, blackening … are absent Abrasion and contusion of skin may seen

TANDEM BULLET

Two bullets inside the body with single entrance wound

Multiple bullets fired separately entering through a single entrance 

SITE OF SELECTION FOR SUICIDE Temple, Centre of fore head, Roof of mouth, Midline behind the chin, Front of chest

BOMB EXPLOSION WOUNDS

If burst at close range Expanding gases shatter or obliterate body

If burst at distance The person is thrown to a distance Blunt force injuries will develop Burn may be develop Death may occur due to CO if occur in room Internal organs show congestion, minute hemorrhage & rupture

FRACTURE OF SKULL

There are 7 types

1) Fissured fracture

2) Depressed fracture

3) Comminuted fracture

4) Pond or indented fracture

5) Gutter fracture

6) Ring or foramen fracture

7) Penetrating fracture

1) FISSURED FRACTURE

CAUSATIVE FACTOR physical violence to the head fall on feet or buttocksCHARACTER These are cracks or linear fractures It may involve one or both tables Fracture starts at point of impact It runs parallel to direction of force If head is supported the fracture starts at counter pressure* area

*COUNTER PRESSURE -Force or pressure that acts in a contrary direction to some other opposing pressure. 

In bilateral compression it may start at vertex or base

2) DEPRESSED FRACTURE CAUSATIVE FACTOR Heavy weapon with small striking surface

Eg-stick, stone,

CHARACTER Fractured bone driven inward Shape of wound indicate the type of weapon

Eg-hammer – fracture shape is circular

3) COMMINUTED FRACTURE

CAUSATIVE FACTOR Traffic accident Blow with weapons with large striking surface Fall from height

CHARACTER Bone broken into pieces

4) POND OR INDENTED FRACTURE CHARACTER Seen only in infants. Bone is indented*

*Make a dent or depression in.5) GUTTER FRACTURECAUSATIVE FACTOR Glancing bullet woundCHARACTER Thickness of the wound is

removed

GUTTER FRACTURE

6) RING OR FORAMEN FRACTURE

CAUSATIVE FACTOR Fall from height on feet or buttocks Sudden violent turn of head on spine

CHARACTER Fissured fracture encircles the skull It separate ant. 1/3rd with post.1/3rd of skull It also seen in base encircling foramen

magnum,& separate skull from spine

7) PENETRATING FRACTURE

CAUSATIVE FACTOR Sharp weapons like knife, dagger

CHARACTER Clean-cut opening Penetrating the skull

CONTRE-COUP INJURIES

COUP INJURY The injury seen under the area of

impact

CONTRE-COUP INJURIES The injury which is situated opposite side

of area of impact These injuries seen only when the head

is free to move

CAUSATIVE FACTOR Local distortion of head due to blow

Eg-occipital injuries produce lesions at

base of frontal lobe or tip of temporal lobe

CONCUSSION OF BRAIN/ STUNNING OF HEAD

Diffuse injury to nerve cells and fibers due to violence caused concussion

It is an un-consciousness produced by violence applied to skull It resolves spontaneously After some time patient again unconscious There will be an interval between two unconsciousness times called

lucid interval At autopsy no lesions are found in brain (petechial hemorrhage seen

some cases)TYPES . Concussion is divided into two groups: Simple and Complex. Simple concussion:  The symptoms gradually resolve The patient returns to normal function in

7 - 10 days.  Complex concussion:  The symptoms persist and thought processes

are affected. Patients with repeated concussions fall