Forensic Science-Injuries, Types of injuries .....full

1. INJURIES
Forensic Science(Biology)
Bahauddin Science College, Junagadh

2. INTRODUCTION
DEFINATION
Medical Definition
 Breach of Continuity
of any tissue of the
body
Legal Definition
 Any harm caused
illegally to a person,
i.e. to his body, mind,
reputation or property

3. INJURY
Causative factor According to Severity Medicological Classification Moment of Death
• Simple Injury
• Grievous Injury
• Self infected
• Homicidal
• Accidental
• Defense wound
• Ante mortem
• Post mortem
Miscellaneous InjuriesChemical InjuriesThermal InjuriesMechanical Factors
• Abrasions
• Bruise(Contusions)
• Lacerations
• Incised wound
• Stab wounds
• Firearm wounds
• Fracture OR
Dislocation
• Due to heat
– Burns
– Scalds
• Due to cold
– Frostbite
– Trench foot
– Immersion
foot
• Corrosive acids
• Corrosive
alkalis
• Self inflicted
injuries
• Defense injuries
• Offensive injuries
• Unintentional
injuries
• Fatal and Non-fatal
Injuries

4. CLASSIFICATION BY CAUSATIVE FACTORS
Abrasions (Blunt impact injury)
• An abrasion is a destruction of the skin which usually involves the superficial layers
of the epidermis only.
• Weapon used :
– Hard/Blunt or Rough Object
– Stone, Stick, Nail, Needle, etc…..
MECHANICAL OR PHYSICAL INJURIES
(PRODUCED BY APPLICATION OF MECHANICAL FORCE)

5. ABRASION
Features of Abrasion
• Abrasions are superficial injuries but often it is deeper in tissue.
• At the site of abrasion, there may be oozing of lymph and some time,
very slight, oozing of blood.
• The lymph or blood which oozes out and the denuded epithelial debris
dry up within a few hours to form a scab.
• Abrasions heal without formation of permanent scars.
CLASSIFICATION BY CAUSATIVE FACTORS - ABRASIONS

6. ABRASIONS
Types of Abrasions
Scratches / Linear
(pointed weapon)
Grazes / Sliding
(Wide rough Surface)
Pressure Imprint / Patterned
• Causes :
– Horizontal /
tangential
friction
– Perpendicular
friction
• Causes :
Horizontal /
tangential
friction between the
epidermis and
wider part of
rough surface of
an object,
weapon or
ground
• Causes :
Result of more or
less perpendicular
application of force
on body surface
• Examples :
Ligature marks
Nail abrasions
Teeth bite
abresions
• Causes :
The design of the
weapon with its
shape may be left
imprinted on the
abresion
• Example:
Cycle chain
Automobile grill
Tyre of a wheel
• Varieties of pressure
abresions
CLASSIFICATION BY CAUSATIVE FACTORS - ABRASIONS

7. Medicolegal Importance of Abrasions
1. They indicates site of impact and direction of force.
2. They may be the only external science of serious internal injury.
3. Pattern abrasions are helpful in connecting the crime with the object which produce
them.
4. The age of the injury can be known.
5. In open wounds, dirt, dust, greace or grit are usually present which may connect the
injuries to the scene of crime.
6. Manner of injury may be known from its distribution
a) In throttling, curved abrasion due to finger-nails are found on the neck.
b) In smothering, abrasions may be seen around the mouth and the nose.
c) In sexual assaults, abrasions may be found on the breasts, genitals, inside of the thighs and
around the anus.
d) Abrasions on the face or body of the assailant indicate a struggle.
ABRASIONS
CLASSIFICATION BY CAUSATIVE FACTORS - ABRASIONS

8. CONDITION OF ABRASION BY TIME-TAKEN
Time Condition
Fresh Bright Red
12 to 24 hours Lymph and blood dries up producing a bright red scab
2 to 3 days Reddish brown scab
4 to 7 days Epithelium covers the defect under the scab
After 7 days Scab dries, shrinks and falls off
CLASSIFICATION BY CAUSATIVE FACTORS

9. ANTE-MORTEM VS POST-MORTEM
Points Ante-mortem abrasion Post-mortem abrasion
1. Site Anywhere on the body Over exposed bony prominences
2. Oozing of Lymph Present Absent
3. Scab formation Present Absent
4. Color changes Present Absent, mostly yellowish
5. Parchmentisation Absent Present
CLASSIFICATION BY CAUSATIVE FACTORS - ABRASIONS

10. BRUISE(CONTUSIONS)
• In bruise or contusion, there is ecchymoses or effusion of blood in the subcutaneous
or submucus tissue for extravasation of blood due to rupture of capillaries, caused by
application of hard blunt force.
• There is no solution or breach of continuity of the covering skin but the epidermis
may occasionally be abraded.
• Weapon used :
– Hard blunt weapon
– Stone, Stick, Fist-blow
CLASSIFICATION BY CAUSATIVE FACTORS - BRUISE

11. FEATURES OF BRUISE
• Patterned Bruising : A bruise is usually round but it may indicate the nature of the
weapon used
• Proof of Bruising :
– Contusions in the subcutaneous tissue may be detected by parallel incisions through the skin.
– Deep Bruises are detected by deep incisions made into muscles.
– Contusions of the scalp can be detected by reflecting the scalp and making incisions from the
aponeurotic surface.
– When in doubt, a portion must be taken for microscopy.
CLASSIFICATION BY CAUSATIVE FACTORS - BRUISE

12. CONDITION OF BRUISE BY TIME-TAKEN
• Appearance of Bruises: A superficial bruise appears at one as a dark red
discolouration. A deep bruise may take several hours to
one or two days to appear. Therefore, a second
examination should be carried out two days later.
CLASSIFICATION BY CAUSATIVE FACTORS - BRUISE
Time Condition
At first Red
Few hours to 3 days Blue
4th day Bluish black to brown
5 to 6 days Greenish
7 to 12 days Yellowish
Two weeks Normal

13. MEDICO-LEGAL IMPORTANCE
• A bruise is a simple injury, but the contusion of the heart may cause
death. multiple contusions may cause death from shock and internal
haemorrhage. A contusion may contain 20 to 30 ml. of blood or more.
– Patterned bruises may connect the Victim and the object or weapon.
– The age of the injury can be determined.
– The degree of violence may be determined from their extent.
– In the case of a fall, sand, dust or mud may be found on the body.
– The manner of injury may be known from its distribution (similar to abrasions).
CLASSIFICATION BY CAUSATIVE FACTORS - BRUISE