Definitions
o Injury: Any harm, whatever illegally, caused to any
person in body, mind, reputation or property (Sec.11.18)
o History of assault incompatible with injuries
o Multiple shallow, non-penetrating cuts or fingernail
abrasions
o Uniform in shape, linear or slightly curved course of
lesions
o Grouped and/or parallel and/or criss-cross
arrangement
o Location is easily reachable--usually on the left side
(non-dominant side)
o Avoidance of pain sensitive regions of the body
o Absence of defense injuries
o No damage to clothes or inconsistent damagei. Suicide: Signs indicative of suicide:
o Location: Accessible areas o Tentative/hesitation
(precordial region-- wounds: Concomitant,
most common site) shallow stabs with
o Direction: Descending, similar direction
backwards and to o Combination with trial
the right cuts (mostly on the
o Depth: Variable, mostly arms/wrists)
superficial and one enters o Exposure/undressing
the heart/pericardium of stab region
o Extensive traces of blood o Absence of defense
on the hands of the victim injuries
Death is due to hemopericardium if heart is involved,
but cardiac tamponade can occur (accumulation >
150 ml of blood is fatal). o Stabs are most often located on the thorax and the
neck. o Stab wound of the chest may have any direction,
but the most common direction is at an angle from
left to right and from above downwards. o The absence of weapon at the scene of incident
suggests homicide as the assailant usually does
not leave the weapon at the scene of death. o The number of stabs shows a correlation with
gender of the perpetrator. In homicide committed
by female perpetrators, the victims had fewer stab
wounds on an average than in homicides
committed by male perpetrators. The term 'overkill' refers to the infliction of massive
injuries by a perpetrator by exceeding the extent necessary
to kill the victim. Personal conflict between the
perpetrator and the victim, history of sex or drugs are
associated factors. iii. Accident: Rare. It is caused by falling against any
projecting sharp objects, like glass or nails. o Physical activity following fatal stab wound: Whether a victim
after receiving fatal stab can perform any physical activity,
like running away from the assailant or shouting for
help depends on the organs injured, extent of the injury,
the amount and rapidity of blood lost. When bleeding is
profuse, physical activity is limited and with slow
bleeding, the victim may be able to run a few meters
from the assailant. - After stab injuries to the heart, the ability to act is
maintained at least for a short period of time. - In lesion of the abdominal aorta, the ability to act
may be maintained over prolonged periods of time,
whereas in injuries of the thoracic aorta, incapacitation
generally occurs within seconds. - Injuries of the lungs or abdominal organs do not lead
to immediate incapacitation. o The amount of blood loss necessary to cause death is
variable from seconds to hours and depends on the rate
of bleeding, amount of blood loss, nature of the injury
and body's physiological response. - Arterial hemorrhages from major vessels may lead to
death relatively fast. A loss of1 litre of blood from
a major vessel may be fatal. - Sudden blood loss causes interference with activity
when it exceeds 20-25% of the total blood supply. A
person can lose over a third of his blood volume before
progressing to irreversible hemorrhagic shock. 180
Fundamentals of Forensic Medicine and Toxicology
- A person who is elderly or frail has little reserve to
withstand blood loss may succumb quickly. The sudden evisceration of the internal
organs causes immediate decrease of intra-abdominal
pressure and cardiac return resulting in collapse and
death. Defense Wounds
Defense wounds are wounds of the extremities which
result from the immediate and instinctive reaction of
the victim to ward off an attack. They are usually classified into two types (Fig. 11.16):
i. Active defense injuries: They are seen when the
victim tries to seize the weapon and the injuries
are sustained on grasping the weapon.Some features of suicidal wounds are:
a. Fatal wounds are present over limited accessible
areas of the body, such as front of neck, groin,
Injuries 175
Table 11.4: Dating of incised wound
Duration Gross findings Microscopic findings
Fresh Red with clotted blood Capillary dilatation, margination and emigration of
neutrophils, reactive changes in tissue histiocytes
12 h Margins red, swollen and adherent with blood and lymph
Reactive changes in fibroblast, monocytes in exudates
24 h Continuous layer of endothelial cells cover the surface with a scab of dried clot Endothelium begins to grow at edges, vascular buds
begin to form
2-3 days __ Vascularized granulation tissue formation (fibroblasts)
4-6 days __ Formation of new fibrils
7 days Scar formation Scar formation
Differentiation 11.4: Suicidal and homicidal cut-throat wounds
S.No.Scalp
lacerations occur due to the tissues being crushed
between the skull and some hard object.16
Incised-looking lacerated wounds: When the skin
is closely applied to the bone and the subcutaneous
tissue is scanty, blunt force may produce a wound
which by linear splitting of the tissues resembles
an incised wound.17
Sites: Scalp, forehead, eye brows, zygoma, iliac
crest, lower jaw, perineum and shin.18
ii. Stretch lacerations: Result from a heavy forceful
frictional impact of blunt forces exercising localized
'pressure with pull'.Factors Influencing the Bruise
i. Type of tissue/site involved
o Soft, lax and vascular tissues, such as face, scrotum
and eyelids develop large bruises even with little
force.10
o In tissues which are strongly supported, contain
firm fibrous tissue and are covered by thick dermis,
e.g. abdomen, back, scalp, palms and soles, even a
moderate violence may produce only a small
bruise.11.17: Typical defense wound in a victim
with a sharp edged weapon
Defense wounds are absent if the victim is:
o Unconscious
o Taken by surprise
o Attacked from behind
o Under the influence of alcohol/drugs
Therapeutic or Diagnostic Wounds
These are produced by medical personnel during the
treatment of the patient, e.g. surgical wounds on the
chest and abdomen for insertion of tubes for drainage,
laparotomy incisions, cutdowns on antecubital fossa or
wrists, tracheotomy and thoracotomy incisions.ii. Graze abrasion (sliding/scrape/grinding abrasion)
o Grazes are caused by horizontal or tangential
friction between the skin and the hard rough
surface.1 They show uneven, longitudinal parallel
lines, which indicate the direction in which the
force was applied (epidermis being heaped up at
the opposite end) (Fig.Accidental
iv. Defense wounds
v. Fabricated or self-inflicted wounds
Based on Time of Infliction
i. Antemortem--recent or old
ii. Postmortem
Abrasion
Definition: Removal of the superficial epithelial layer
of the skin, usually the epidermis, by friction against
rough surface.v. Natural diseases: Prominent bruising following
minor trauma is seen in persons suffering from
atherosclerosis, purpura hemorrhagica, leukemia,
hemophilia, scurvy, bleeding diathesis, vitamin K
and prothrombin deficiency, and in phosphorus
poisoning.Avulsion or grinding compression: Produced by
force (shearing force) delivered at an oblique or
tangential angle to detach (tear off) a portion of
traumatized skin surface or viscus (tissue/organ)
from their attachment (Fig.Characteristics (Fig 11.7)
o Margins: Ragged, irregular and uneven; may show
tearing of the extremities at angles diverging from
the main laceration, the so-called 'shallow tails'; pieces
of tissue are attached in between called tissue tags or
bridges.o 'Bruise' implies that the lesion is observed through
the overlying intact skin as bluish purple
discoloration and swelling of the involved area, while
a 'contusion' is a bruise within an organ or tissues,
such as muscles, liver or mesentery.Injuries 173
Table 11.3: Healing of a lacerated wound
iv. If located where skin stretches or is wrinkled, e.g.
over joints, repeated and continued oozing of tissue
fluids and blood may cause irritation, pain and
dysfunction. iv. Imprint abrasion (impact/contact/patterned
abrasion): It is caused when the force is applied
perpendicular to the skin, the cuticle gets crushed
at the point of impact and bears the imprint of the
object causing it.
Duration Features
Fresh Bright red, oozing of serum and some blood.o Hemorrhage: Less, because the arteries are crushed
and torn across irregularly; they retract and blood
clots readily, except in the scalp where the temporal
arteries bleed freely as they are firmly bound and
unable to contract.b. Hesitation cuts/marks or tentative cuts or trial
wound: These cuts are multiple, small and
superficial often involving only the skin and are
seen at the beginning of the incised wound,
presumably hesitating while gaining courage to
make a final decisive cut.22
c. A person who commits suicide exposes his body
by opening his clothes and then inflicts the
wounds. Such injuries, when dry, become firm, even though
no true 'scab' is present.3-5
o Friction burn: An extensive, superficial, reddened
excoriated area with little or no linear mark, occurs
when the skin is covered by clothing (element of
thermal damage is present).The slight movement
directed inwards results in crushing the superficial
layers of the cuticle and bruising underneath, e.g.
nooses or ligatures in hanging and strangulation.o Pattern abrasion is a variation of pressure
abrasion.6
o When a person is knocked down by car, pattern of
the radiator grill, headlamp rim or tyre-tread mark
may be seen on the skin.7 Imprint of bicycle chain,
serrated knife are other examples.iv. Decubitus/pressure ulcers (bed sores): These are due
to pressure necrosis of the skin in a bedridden
caused by prolonged compression of soft tissue
between bony prominence and external surface.It is red at first, then becomes
Fresh Red (oxygenated blood)
Few hours to 3 days Blue (deoxyhemoglobin)11
4-5 days Bluish black to brown (hemosiderin)12
5-6 days Green (biliverdin)13
7-12 days Yellow (bilirubin)
2 weeks Normal
yellow and finally disappears.14 Similar changes are
seen in meningeal hemorrhages owing to O2
supplied from CSF.Lacerated Wound
Definition: Laceration is tearing or splitting of skin,
mucous membranes, muscles or internal organs caused
by either a shearing or a crushing force and produced
by application of a blunt force to a broad area of the
body.Wounds caused by sharp edged and pointed weapons are of four
types:
o Incised wound o Chop wound
o Stab wound o Therapeutic/diagnostic wound
Incised Wound (Cut/Slash/Slice)
Definition: Incision is a clean cut wound through the
tissues (usually the skin and subcutaneous tissues
including blood vessels), caused by a sharp-edged
instrument, which is more long than deep.o Teeth bite marks are included in this category,
though they may produce contusion or laceration,
depending upon the force applied.8
o UV light may be used to visualize the pattern
injuries not apparent with visible light.Differential Diagnosis
i. Postmortem insect bites of the skin caused by ants
or cockroaches produce dry, pale brown lesions
with irregular margins and are arranged in a linear
pattern.Bruise/Contusion
Definition: Bruise is the extravasation of blood in the
subcutaneous/subepithelial tissues due to rupture of
blood vessels, usually capillaries as a result of blunt
force injury or pressure.o Direction: When a knife penetrates at an angle, the
wound will have a beveled margin on one side with
undermining (undercut) on the other, so that subcu-
taneous tissue is visible, indicating the direction from
which the knife entered (Fig.o Shape: It is slit-shaped with two acute angles or gape
open depending on their location and their
orientation, with regard to the cleavage lines of
Langer (Figs 11.13 to 11.15).o The pattern of arrangement of the dense network of
intimately intermingled dermal collagen and elastic fibres
is called the cleavage direction or lines of cleavage of the
skin and their linear representation on the skin are called
Langer's lines (Fig.- Imprint abrasion becomes more defined when
injured cuticle dries up and becomes brownish
and parchmentized, in contrast with the
surrounding uninjured skin surface.Injuries 169
ii. Subcutaneous bruise: It is situated in subcutaneous
tissue, often in the fatty layer and the edges are
blurred.This is called flaying and most
frequently occurs on the legs.19
o Amputation injuries are a type of avulsion injury
in which an entire extremity or portion thereof is
severed from the body.Characteristics
o Margins: Edges of the wound are clean cut, usually
no abrasion or bruising of the margins, but in full
penetration of the blade, a patterned abrasion or
bruising may be produced by the hilt-guard striking
the skin.o Hara-Kiri (seppuku): It is an unusual type of suicide
connected with Japanese Samurai warriors in which the
victim with a short sword inflicts a single large abdominal
stab wound into the left side, drawing the blade across
to the right side and then turning it upwards producing
an L-shaped cut.Thermal injuries
Due to application of heat
a. General effects (may not cause any visible injury),
e.g. heat cramps and heat stroke
b. Effects of local application, e.g. burns and scalds
Due to application of cold
a. General effects, e.g. hypothermia
b. Local effects, e.g. frost bite and trench foot
Fig.Miscellaneous injuries
i. Electrical injury
ii. Radiation injury: Due to X-ray, UV radiation, radio-
active substances
iii.Lightning injury
iv. Blast injury
Based on Severity of Injury (Legally)
i. Simple
ii. Grievous, which may or may not be dangerous
Based on Nature of Injuries (Medico-legally)
i. Suicidal
ii. Homicidal
iii.o Hemosiderin is a granular brown iron-storage complex
composed of ferric oxide, commonly found in macrophages
and derived from breakdown of hemoglobin.Long, thin objects, like pipes or sticks produces
linear or elongated lacerations, while objects with
a flat surface produce irregular, ragged or Y-shaped
lacerations. 174
Fundamentals of Forensic Medicine and Toxicology
o Skin flap which overhangs the cut margin (avulsion
cases) can indicate the direction of force applied.o Concealed punctured wounds: These are punctured
wounds caused on concealed parts of body, such as
nostrils, fontanelles, inner canthus of eyes, axilla,
vagina, rectum and the nape of the neck.o Skin tension and Langer's lines may transform round
skin defects into slit-like wound resembling stabs
wounds; round-out genuine stab wounds and
artefactually lengthen stab wounds.Abrasions over the cornea may cause corneal
opacity which may restrict vision permanently,
amounting to grievous hurt (Sec.ii. Age: Children and elderly bruise more easily
because of softer tissue and delicate skin in the
former, and loss of subcutaneous supportive tissue
and cardiovascular changes in the latter.o Grey Turner's sign: Ecchymosis seen over flank or side
of abdomen, occurring due to extensive retroperitoneal
hemorrhage.o Cullen's sign: Bluish-black discoloration of the
periumbilical skin due to extensive retroperitoneal or
intraabdominal hemorrhage.iv. Suction or biting on the sides of the neck or the
breasts during love making/sexual intercourse
produces elliptical patterned bruises.11.5: Formation of 'tram-line contusion'
Deep tissue and organ contusion
o Internal organs can also get contused; contusion of
the brain may cause confusion, coma and death.However, methods
used to date a bruise are:
i. Histology (only in postmortem situation)
ii. Color changes (visual examination)
iii.On incision Blood is seen in blood vessels which can be easily washed away, subcutaneous tissues are pale Extravasation of blood into the surrounding
tissues, cannot be washed by water,
subcutaneous tissues are deep reddish-black
8.iv. Tears: Tearing of skin and subcutaneous tissue can
occur from localized impact by or against some
hard, irregular object like car door handle, radiator
mascot or from blows with broken glass bottles.11.6: Avulsed lacerated wound
Duration Gross findings
Fresh Bleeding or fresh clot is attached;
margins are red, swollen and tender.o Beveling: Laceration caused by a blow directed
tangentially or at an angle will produce undermining
of the tissue on one side (indicates the direction of
blow) and abrasion and beveling on the other
(direction from which the blow was coming). Gaping is more,
if the underlying elastic fibres in the skin (Langer's
lines) have been cut transversely or obliquely and is
less when cut longitudinally (Fig.e. Most people have a vague knowledge of the
anatomy and do not know where to cut a major
176
Fundamentals of Forensic Medicine and Toxicology
blood vessel and may cut their forearms
vertically, rather than horizontally.v. Stabs produced with a broken bottle appear as
clusters of wounds of different sizes, shapes and
depths with irregular margins.Injuries are
usually located on the palms, the flexor sides of
the fingers and the interdigital spaces, more
common in the web between the base of the thumb
and index finger (Fig.By soldiers and prisoners to escape difficult task
iv. Suicidal gestures, attempted suicide
v. For the purpose of insurance frauds
Diagnosis: The diagnosis can be done by careful history
taking and examination of injuries (Box 11.1).Chemical injuries
i. Irritation: Due to application of weak acids, alkalis,
plant or animal extracts
ii. Corrosion: Due to application of strong acids or
alkalis
4.2-24 h Exudation dries to form a reddish scab,
comprising of blood, lymph and epithelial
cells.Bite may tear or crush, resulting in two U-shaped
marks, corresponding to the upper and lower anterior six
teeth (canine to canine) and separated by an open space
of about 2.5-4 cm, which can be contused from teeth
pressure.Most commonly found at mucocutaneous
junctions--around the eyelids, nose, mouth, ears,
axilla, groins and genitalia.ii. Excoriation of skin by excreta and diaper rash may
be misinterpreted as abrasions.ii. Hysterical women may produce abrasions over
accessible areas, like the front of forearm or over
the face, to fabricate charge of assault.iv. Person collapsing due to a heart attack may fall
forward and receive abrasions on the forehead,
nose and cheek, but there will be no injuries on
the upper limbs.o Gunshot wounds: Contact entry wounds (may have sight
marks) and shotgun wounds (e.g. wad marks) may
produce distinct patterned injuries.Classification
Bruise is classified into three types depending on its
situation:
i. Intradermal bruise: Bruise lies in the immediate
subepidermal layer.vi. Gravity shifting of blood (ectopic/migratory bruise):
It is responsible for the appearance of bruises at a
site other than the site of injury, e.g. black eyes.Mechanism: The weapon sinks into the skin on
impact, so that the edges drag the skin downwards
and the traction tears the marginal blood vessels.11.4: Patterned bruise
170
Fundamentals of Forensic Medicine and Toxicology
Table 11.2: Age of bruise
Duration Color
Fig.Dating/Age of Bruise
Consistent, reliable microscopic dating is not possible
and color changes in resolution of a contusion is not
always a reliable indicator of its age.o The extravasation of blood is followed by an
inflammatory reaction that causes vasodilation and
attracts macrophages which breaks down
hemoglobin to biliverdin.o Bruises may be fabricated by applying juices of
marking nut or calotropis to incriminate others, or
in defense of a crime.o Surgical removal of cornea can result in hemorrhage
into the eyelids, identical with antemortem trauma.Microscopically Blood cells are found within the blood vessels and there is no evidence of inflammation
Blood cells are found outside the blood
vessels, evidence of inflammation present
172
Fundamentals of Forensic Medicine and Toxicology
iii.vi. Bruises found in 'soft' sites in a child such as cheeks
or trunk and multiple bruises in various stages of
healing suggest abuse.o Depth of wound: Shows bridges of irregularly torn
fibrous tissue, blood vessels and nerves across the
interior of the wound.o Soiling of wound: Mud, wood splinters, sand, glass
fragments, paint material of the vehicle involved, hair
or fibres may get embedded in the wound and are of
great medico-legal importance.Antemortem lacerations show bruising of margins, vital
reaction, eversion and gaping of margins.Pulmonary/systemic fat embolism may occur due
to crushing of subcutaneous tissue.o Beveled cuts: If the blade of the weapon enters
obliquely, tissues will be visible at one margin and
Fig.11.9: Incised wound due to oblique strike
other margin will be undermined; if the blade is
nearly horizontal a flap wound is caused (Fig.Edges Usually ragged due to overlapping of multiple superficial incisions
Sharp and clean cut, beveling may be seen
6.v. Self-mutilation: Sometimes, injuries may be caused
by an individual with a mental disorder as a form
of self-mutilation or by one who deliberately harms
oneself for motives of gain.o Margins are sharp, and may show abrasion, bruising
and some laceration with severe injury to the
underlying organs.Medico-legal Importance
o Most of the injuries are homicidal and usually
inflicted on the exposed portions of the body, like
head, face, neck, shoulders and extremities.11.10: Determining the relative position
of the assailant from a chop wound
o Few are accidental due to machinery, like propeller
injuries. Stab Wound
Definition: Wound produced from penetration with
long narrow instruments having pointed (sometimes
blunt) ends into the depths of the body.Less often, injuries are
caused by pieces of glass (broken-off bottle necks),
scissors, dagger, screwdrivers, pens, ice picks or
forks.o Resistance offered by the tissues and organs: Apart from bone
and calcified cartilage, the skin is most resistant to knife
penetration.- A stab wound which runs parallel to the cleavage
lines will remain slit-shaped and narrow, and the
dimensions of the blade will be represented with
considerable accuracy.i. If a single-edged weapon is used, the surface
wound will be triangular or wedge-shaped and
one angle of the wound will be sharp the other
rounded, blunt or squared off.Injuries 179
ii. Homicide
o Most deaths from stab wounds are homicidal,
especially if found in an inaccessible area, such as
back (most common mode of homicide in UK).They
are located on the extensor or ulnar surfaces of
forearms, wrists, knuckles and the back of the
hands.In medico-legal practice, the terms wound
and injury are synonymous, but strictly wound will
include any lesion, external or internal, caused by
violence, with or without breach of continuity of skin.Lacerated wound
iv. Incised wound
v. Stab wound
vi. Firearm wound
vii.o Most common type of abrasion and commonly seen
in road traffic accidents.2 Particles of glass, gravel
or dirt may be embedded in such wounds.Epithelium grows and
covers defect under the scab (epithelial
regeneration).o It tends to be focal and is commonly seen over
bony prominences, where a thin layer of skin
covers the bone.Healing process May be evident Not seen
Note: Abrasions produced slightly before or after death cannot be differentiated even by microscopic examination.Medico-legal importance: Connect a particular weapon or
object to an injury, which may allow a perpetrator to be
linked to the crime and/or enable better understanding of
the events surrounding a death.o Chronic alcoholics with cirrhosis and individuals
taking aspirin, bruise easily. Blood will track along the fascial planes (or
between muscle layers) along the path of least
resistance and may appear where the tissue layers
become superficial.When the impact is
released, the blood flows back into the injured
marginal zones and leaks into tissues (Fig.A woven, spiral or plaited ligature may produce a
patterned bruise.Calorimetry
iv. Spectrophotometry
o Bruises heal by destruction and removal of
extravasated blood.Drugs, such as steroids may change
the rate of bruise dispersion, and interventions, such
as ice packs or heat treatment may add to variability.Medico-legal Importance
o It is advisable that a medical officer should re-
examine the patient after 24 h, as by this time the
bruises are clearly visible.o To confirm at postmortem examination, deep
incisions are made at suspected sites, which show
ecchymosis (Diff.If the blunt force produces extensive bruising and
laceration of deeper tissue, it is called crush injury.Types
i. Split lacerations: Occur when soft tissues are
sandwiched between a hard unyielding deeper
structure and the agent applying the force.Overstretching of the skin and
subcutaneous tissues may cause lacerations with
flapping of the skin which may indicate the
direction of application of force.Medico-legal Importance
o The type of laceration may indicate the cause of
injury and shape of blunt weapon, e.g.
i. Blunt round end (hammer) may cause a stellate
laceration.An
accidental type of injury results from an attacker
striking the victim's incisor teeth with his knuckles
(metacarpophalangeal joint is usually involved). They may be inverted, if a thin layer
of muscle fibres is adherent to the skin as in the
scrotum (due to the attached dartos muscle to the
skin).Vessels As head is thrown back, carotid artery escapes injury Jugular vein and carotid artery are likely to be
cut
14.o Presence of an incised wound on the skin with an
underlying comminuted fracture or deep groove in
the bone indicates wounds caused by such weapons.ii. Perforating wound (through and through
punctured around): Weapon after entering into one
side of the body will come out through the other
side, producing two wounds:
o Wound of entry: Through which the weapon enters
the body.- It is not safe to find out the depth of a stab wound
by introducing a probe because it may disturb a
loose clot and may lead to fatal hemorrhage.ii. If a double-edged weapon is used, the wound will
be elliptical or slit-like and both angles will be
sharp or pointed.iv. A pointed square weapon may produce a cross-
shaped injury, each of the four edges tearing their
way through the tissues (stellate shaped).vi. A screwdriver will produce a slit-like stab wound
with squared ends and abraded margins.11.1)
i. Abrasion
ii. Bruise or contusion
iii. 11.3).11.3). 11.4). 11.5).11.6).11.8).11.8).11.9). 12.22). 11.10). 11.12).11.15). 11.17).11.18).