This document discusses the anatomy and forensic importance of hair. It describes how hair can be used to identify characteristics like species, sex, and body part. Hair injuries like cuts, stretches, and damage from assaults can also provide information. Barr bodies are discussed as a feature to distinguish male and female hair. The document also covers scars, their appearance based on wound type, and how their age can be estimated. Methods for analyzing hair samples are outlined, including distinguishing human vs animal hair and identifying evidence of crimes.
1. Anatomy of Hair is of forensic importance.
Identification either animal – human – sex – part of
the body i.e. beard, moustaches axilliary, Pubic and
scalp hair, Chest Hair.
Injuries to Hair: clean cut – stretched – sexual assaults
– Barr bodies (70% Female & 7 % Male from the route
bulb of Hair)
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2.
3. A scars or a cicatrix is a fibrous tissue covered by epithelium, formed as a result
of healing process of wound or injury when there has been a breach of
continuity in the tissues. It has no hair follicles or sweat glands but it is slightly
vascular, owing to presence of a few capillaries.
Characters of Scars:- it generally resembles the shape of wound i.e.
1. In incised wound, it is linear and straight.
2. If wound has healed by granution, after suppuration then scar is
wider and thicker in.
3. If incised wound is on loose skin as axilla, scrotum, etc. Scar will
be irregular and may be smaller than original wound.
4. Extensive burns leave large irregular, keloidal scars
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4. 6) Bullet wound, scar of entrance would is smaller than that of exit
and is irregular and surrounded by grains of powder if fired
from closed range
Disappearance of Scars:-
Those involving in whole thickness of skin are permanent.
Those involving only epidermis or cuticle of skin may disappear in course of
few months.
Age of Scars:-
The approximate age of a scar can be estimated from the following sequence
of its ageing process i.e.
Vascular to a vascular (2 weeks to 2 months).
Tender to non Tender (2 months to 6 months) and
Soft to tough (more than 6 months)
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5. The points to be considered in the examination of
hair are:
1) The nature that is, if the material is hair or some other
fiber.
2)If it is hair, its source, whether human or animal .
3)If human, the race, age, sex , and special features of
identification.
4) Evidence in relation to suspected crime.
5)In case of dead bodies, the time since death, if possible.
6. Hair, both human and animal, consists of three zones,
1) Cuticle
2)Cortex
3)Medulla
7. Cuticle :
is the outer zone
consists of non- pigmented scales of keratin
and forms a certain pattern.
Cortex:
Is the middle zone of varying thickness.
It consists of longitudinally arranged
elongated cells without nuclei, and a varying
amount of pigment, which gives hair its
colour
8. Medulla :
Is the inner zone
It is known as medullary canal or the central
shaft.
It contains a considerable amount of pigment
in animals and shows a characteristic pattern.
Medullary Index: is the ratio of the diameter
of the medulla to the diameter of the shaft.
9. In human hair, only the cortex is pigmented; the
medulla is narrow, absent, or fragmented. The root has
the appearance similar to that of shaft except that it is
enlarged in the form of bulb or knob.
Fibers are devoid of cuticle and many fibers especially
the synthetic ones, are quite homogenous.
10. S.No Structures Human Hair Animal Hair
1 Texture Fine & thin Coarse & thick
2 Cuticle Scales are small, flattened,
serrated, and surround the
shaft completely
Scales are large, Polyhedral ,
wavy, and do not surround the
shaft completely
3 Medulla Narrow. May be absent,
fragmented, or discontinuous
Broad, Always present and
continuous
4 Cortex Thick, 4-10 times as broad as
medulla
Thin, Rarely more than twice the
breadth of medulla
5 Medullary Index Less than 0.3 More than 0.5
6 Pigment More towards the periphery of
the cortex.
Uniform, peripheral or central
7 Preciptin Test
with intact root
Specific for human Specific for animals
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12. Hair can resist putrefaction & hence forms an
important means to establish identity even in
putrefied bodies.
Hair also lasts longer & thus constitutes good trace
evidence in criminal investigations.
Hair and poisoning : Chronic arsenic poisoning –
arsenic may be deposited in the hair & chemical
examination shows the presence of it
13. INJURY ON HAIR TYPES OF WEAPON /
INJURY
Cut end is clean – it is fresh &
cut end turns round after few
days
Sharp edge weapon
Cut end is crushed / ragged out Blunt weapon
Bulb is distorted, irregular &
swollen if seen fresh.
Forcibly plucked out hair
Bulb atrophic small & shrunken
up with smooth surface
Naturally shed hair.
14. SINGED HAIR:
The singed hairs are grossly – swollen,
blackish in colour, fragile , twisted & curly,
carbon particles deposited on its surface.
It gives a peculiar odor due to burning of
keratin.
Tip of hair is swollen & resembles the root.
Microscopically singed hair is wider than
normal.
15. TYPE OF STAIN MEDICOLEGAL INFORMATION
Mud stains Struggle
Seminal Stains Rape / Sexual offences
Blood stains Injury
Salivary stains Asphyxial Death
Carbon particles Stain Fire arm injury / burns
Presence of Dyes Concealing natural colour.
16. Identifying the weapon / Vehicles of crime : Hair found on the
suspected weapon or vehicle must be always compared with
sample hair (from victim) to identify & confirm the weapon
producing injury or vehicle causing accident.
In rape / other sexual offences: Pubic hairs of the victim may
be matted with blood and semen. Proper examination may
show presence of pubic hair of assailant on victim and vice
versa.
In bestiality – animal hair may be found on human being &
vice versa.
17. Scalp hair are long, soft, tapering, rounded or oval in cross
section
Pubic hair are short, curly, oval in cross section
Eye brows are stiff, tapering, triangular in cross section
Moustaches are short, thick, triangular in cross section
18. In an intact body, it is not difficult but in mutilated
bodies the stature is determined with the help of
following data:
1. Length of arm+30cm for clavicle + 4 cm for sternum.
This will roughly give the stature.
2. Pubic symphysis normally forms the centre of the body
after 25 years of age; STATURE=length from vertex or
heel up to upper border of pubic symphysis x 2
19. 3. Stature can be assessed by measurement of long
bones:
A. Humerus represents 20% of stature
B. Femur represents 27% of stature
C. Tibia represents 22% of stature
D. Spine represents 35% of stature
20. 1. Humerus 5.3
2. Radius. 6.3
3. Ulna 6.0
4. Femur 3.6
5. Tibia 4.2
6. Fibula 4.4
7. Clavicle 11.2
e.g. If one femur is found and its length is 20” 20x3.6=72” or
6 feet (72÷12)=6” 6 feet + 1 inch=6’. 1” is exact height of the
person.
1” is added for soft tissues of scalp and sole.
21. 5. Length = tip of middle finger to other with arms
extended
6. Length of forearm = 5/19th of stature
7. Length from sternal notch to pubic symphysis = 1/3rd
of stature
8. Length of skull = 1/8th of statement
9. Vertical diameter from top of head to tip of chin =
1/7th of stature