Prepared by:

Rene Vincent B. Tad-o

Instructor
Structure of Hair and Their variations
Phases in the Examination of Hair
Textile Fiber and the Structure
Methods of Fiber
Examination
Collection, Preservation, and Transit of
Specimen
 the principle was described by Dr. Edmond Locard, director of the
crime laboratory in Lyon, France (ca.1910 and 1940)

‘It states that with contact between two items, there

will be an exchange of microscopic material’
‘The more violent the contact, the more likely the
transfer will occur.’
 Linking a suspect to the crime scene or
Locard Exchange Principle linking a victim to a suspect is the essence
of solving crimes.

- defined by James Osterburg, along with

the New York City crime laboratory

Victim Car It signifies that some connection or

association has been established between
Paint crime scene and criminal.
Headlight
glass
Blood
Hair
Cloth fibers
1. All of the hair in the questioned specimens should be submitted but
do not mix hairs at different places.
2. In vicious assault and murder cases, obtain the clothing of the victim
from the hospital or morgue to avoid the lost of evidence by careless
handling and to prevent the clothing from being destroyed.
3. Representative samples of hair from the victim as well as the suspect
should be obtained of possible. To be a representative head hair
samples from a particular individual it should consist of at least a
dozen hairs from different areas of the scalp and preferably full-
length hair.
4. Don’t mix known samples of hair from different parts of the body.
5. The hairs should be placed in a folded paper or in a white envelope,
but the corners of the envelope should be sealed with scotch tape.
6. Do not secure the hair samples to a piece of paper with scotch tape
because that will damage the hair.
7. All foreign fibrous debris should be removed from the submitted
specimen.
8. Fragmentary hairs or underdeveloped hairs are not suitable for
examination.
9. Areas on an object containing hairs should be protected with
cellophane or paper taped over the area before wrapping the object
from transmittal to laboratory.
 Is it hair?
Is it human hair?
What area of the body is it from?
What is the person’s ancestry?
Is there damage, disease, treatment?
Is it suitable for comparison?
Structure of Hair and Their variations
 slender threadlike outgrowth
from the follicles of the skin
 occur everywhere (except
the palm/sole)
 consists of dead, cornified
cells with keratin and
melanin
 its width is not always the
same along its length
*Function: provides skin protection,
provides warmth
Real hair – generally
long and stiff
Fuzz hair – generally
short, fine at times
curly and wooly
shaft

1. HAIR FOLLICLE
• tube/sac like structure that surrounds
the root and strand of a hair
• promotes hair growth
• contains active cells and blood vessels
• extend from the surface of the skin into
the dermis
• Lower part is made up of:

a. hair bulb – contains follicular papilla

(active reproductive portion of the hair)
b. suprabulbar region made up of root
sheath
2. HAIR SHAFT
• fiber that extends outside the skin
• it contains no DNA (nDNA)

Parts:
A. CUTICLE (outer layer)
• adhered tightly to the cortex cells in an
overlapping manner (layer of scales)
B. CORTEX (middle layer)
• comprise the bulk of the shaft
• contains pigment granules (melanin)
C. MEDULLA or CORE (center layer)
• contain pigment granules or
unpigmented
 Cortical Fusi
are irregular-shaped airspaces of
varying sizes

Ovoid body
large (larger than pigment
granules), solid structures that
are spherical to oval in shape
Pigment granules
small, dark, and solid
structures that are
granular in appearance
and considerably
smaller than cortical fusi Human hair
Dog hair
The duration of the phases changes based on the location of the hair and also
personal nutritional and hormonal status and age.
I. ANAGEN PHASE
• the active growth phase (active mitotic activity)
• follicle enlarges and takes the original shape
• hair fiber is produced

*Almost 85–90% of all scalp hairs are in

anagen.

**Hair shaft synthesis and pigmentation

only take place in anagen.
 I. ANAGEN PHASE

moves up to become part of the hair shaft

dead cells are filled with a fibrous protein called keratin

(keratinization)

cells undergo maturation

process
(denucleation)

new hair cells formed at the hair bulb

II. CATAGEN PHASE

• mitotic activity of the matrix cells is

diminished
• the proximal of the hair shaft is
keratinized and forms the club hair
• the distal part of the follicle is involuted
by apoptosis
III. TELOGEN PHASE (Resting)
• the duration between the completion of follicular
regression and the onset of the next anagen
phase

• the follicle remains in this stage until the hair

germ is responsive to anagen initiating signals
from the dermal papilla will lead to the initiation of
anagen
*It is not unusual for human telogen
*Approximately 10–15% of all hair is in hairs to be retained from more than
telogen stage. one follicular cycle.
 EXOGEN STAGE (Shedding
Phases)

• shedding phase
• an active process and independent of
telogen and anagen
• on average, humans shed approximately
100 head hairs per day

*During the telogen stage, the hair shaft is transformed to club hair
and finally shed.
 ANAGEN PHASE CATAGEN PHASE TELOGEN PHASE

*hair plucked prior to *the hair root exhibits *hair root is hardened,
maturation is soft, has the bulbous shape with has a bulbous shape,
a distorted a tag attached and has little or no
appearance, and may follicular tissue
have tissue adhering
to it
 Visual Confirmatory DNA
Examination Assay/Test Profiling
 Before performing the examination, note of any foreign material on the hair and
should be identified in sufficient quantity. Hair should be cleaned with a mixture of
equal parts of alcohol or ether.
1. Hair color

*Melanin *Red hair is thought to

– the brownish-black pigment in the hair, skin, etc. be due to iron.
- differs on the amount (black and brown)

2. Length by actual measurement

3. Character of the hair – whether stiff, wiry or soft

4. Width breadth
5. Character of the hair tip if present
7. condition of root or base or bulb of hair
*Root of hair pulled forcibly
have a portion of the sheath clinging to the
root
root is shaped like a bulb

*Root of hair that has fallen naturally

there is bulb formation at the root end (clean
appearance with nothing adhering to it) sometimes
root is dry and small called follicular
tag
 Visual Confirmatory DNA
Examination Test Profiling

Microscopic test
• Animal or human?
• Race
• Region of the body
• Damage/disease
• Suitability for comparison

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 • Cuticle structure
• Medullary structure
• Medullary index
 *cuticular scales always point from the proximal or root end of the hair to the distal or tip
end of the hair
1. Coronal or crown-like
 characterizes hairs of very fine diameter,
and that resemble a stack of paper cups
 common in rodents and bats, and rare in
human hairs
2. Spinous or petal-like
 more or less triangular-shaped scales
 found in the hairs of seals, cats, etc.
 never found in human hairs

3. Imbricate or flattened
 overlapping scales with narrow margins
 Found in human hairs and in other
animals
 AMORPHOUS UNISERIAL MULTISERIAL
(medulla appears as a solid (medulla appears as a single (medulla appears as two or
line or row of disc-shaped, square, or more rows of disc- shaped,
irregular/fragmented) rectangular compartments) square, or rectangular
compartments)

i.e. HUMAN HAIR, DOG i.e. CAT and RABBIT i.e. RABBIT
 AMORPHOUS LATTICE Cellular OR
(medulla appears as a solid (medulla appears as a wide
VACUOLATED
line or band that is composed of many
irregular/fragmented) small, circle-shaped,
(medulla appears as a wide band
that is composed of randomly-
compartments)
shaped, “bubbly”, compartments)

most common in animals

i.e. HUMAN HAIR, DOG i.e. DEER i.e. FOX, DOG, CAT
is the relationship between the diameter of the medulla and the diameter of the
whole hair which is expressed in fraction

Microscope with micrometer

eyepiece
Medullary Index < 0.5 or 0 Medullary Index = 0.5 Medullary Index > 0.5

i.e. cows, horse

i.e. almost all animal hair

i.e. Human and certain

monkey hair
 HUMAN ANIMAL
Medullary index is less than 0.5 Medullary index is 0.5 or more
Medulla may not be present Medulla is always present
Scale patterns is fine and each Scale is coarse and overlaps
one overlaps the other more less than ½
than 4/5
Pigment granules are fine Pigment granules are coarse
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1. Scalp hair
 they are more mature than any other kind of
human hair
 long with moderate shaft diameter and diameter
variation
 medulla absent to continuous and relatively
narrow when compared to its structure in hairs
from other body areas
 often with cut or split tips
 may show artificial treatment, solar bleaching, or
mechanical damage, such as, caused by
backcombing
 soft texture (pliable)
2. Beard or mustache
hair
 coarse, curved, very stiff and
irregular or often triangular in
cross section
 medulla very broad and
continuous, may be doubled
3. Hairs from eyebrows,
eyelid, nose, and ear
 Short stubby and have wide
medulla
 Eyebrow and eyelashes are
usually very short and has a
sharp tip
4. Chest hairs
 Shaft diameter moderate and
variable.
 Tip long and fine, arclike.
 Stiff texture.
5. Limb hairs
 similar trunk hairs but
usually are not so long or
so coarse and usually
contain less pigment
 Medulla is discontinuous to
trace with a granular
appearance
 Tips usually are tapered (due to
wear)
6. Axillary hair
 Are fairly long with unevenly
distributed pigment
 Frequently has bleached
appearance
 Looks like pubic hair but the ends
are sharper and the hair is not so
curly
 Less wiry than pubic hair
7. Pubic Hair
- More wiry; similar to axillary hairs but
are coarser and do not appear
bleached
- Shaft diameter coarse with wide
variations and buckling
- Medulla relatively broad and usually
continuous when present
- Tip usually tapered, rounded, or
abraded
back

Body parts Male Female

Neck 0.115 0.163
Forehead 0.132 0.148
Eyebrows 0.236 0.233
Eyelashes 0.095 0.146
Beard 0.26 -
Genitals 0.153 0.114
Armpits 0.102 0.179
CAUCASOID /
CAUCASIAN) / EUROPEAN
ANCESTRY
l. Appearance: generally straight or wavy
2. Hair contains very fine to coarse
pigment and more evenly distributed
than is found in Negro or Mongolian
2. Pigment granules sparse to
moderately dense with fairly even
distribution.
3. Oval cross-sectional shape.
NEGROID / AFRICAN
ANCESTRY
1. Appearance: kinky, curly, or oiled
2. Shaft diameter moderate to fine with
considerable variation.
2. Pigment granules densely distributed
(hair shaft may be opaque) and
arranged in prominent clumps.
3. Shaft with prominent twist and curl.
4. Flattened cross-sectional shape.
1. Appearance: straight
2. Shaft diameter coarse and usually
with little or no variation.
3. Pigment granules densely
distributed and often arranged in
large patchy clumps or streaks.
4. Prominent medulla (broad and
continuous).
5. Cuticle thick.
6. Round cross-sectional shape.

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DYED HAIRS
 possess an unnatural cast or
color
 the cuticle will take on the
color of the dye
Healthy cuticle layer Hair color and Cuticle can get damaged
shows smooth relaxers have by chemical processes,
scales are tightly chemicals overexposure to sunlight
and firmly attached specifically designed (UV), too much heat from a
to the inner cortex. to raise the hair’s dryer, abusive brushing
cuticle and reach the and combing, over-
hair’s cortex and
manipulate it.
chlorinated swimming pool
water, etc.
 Scissor cut produces a Razor cut is angular and
sheared or square-cut end. very straight or clean
 Burned or singed hairs are charred Broken hairs exhibit a square
and brittle and exhibit round tip with elongated fragments
vacuoles at the point of burning.

*evidence of singed hair

has value in arson and
firearm cases
 CRUSHED HAIR
- will exhibit a
widening
INSECT of the hair shaft
MARKS and the cortical
cells may appear
ruptured and
separated
 changes in the appearance of hair
 serve to further individualize the hair specimen

PILI ANNULATI
- autosomal-dominant
hair disorder
- characterized has a
pattern of light and dark
banding
TRICHORRHEXIS NODOSA
• is a common hair problem in which
thickened or weak points (nodes) along
the hair shaft could cause the hair to
break off easily

Causes:
• can be an inherited condition

• triggered by things such as blow-drying,

ironing the hair, over-brushing, perming,
or excessive chemical use

• caused by an underlying disorder such

as hypothyroidism, iron deficiency etc.
 MONILETHRIX
- is a rare inherited
disorder characterized
by sparse, dry, and/or
brittle hair that often
breaks before reaching
more than a few inches
in length
- hair shaft resembles a
string of evenly-spaced
beads
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 • Damaged
• Too short
• Too light in color
• Fragmented
• Extreme
treatment
 Suitable hairs may be compared with
suitable known hair samples of the same
type

- Head to head
- Pubic to pubic
Use a comparison microscope
• Two microscopes optically joined
• Two samples side-by-side
simultaneously
• Use all characteristics available

known
hair

questioned
hair
 Visual Confirmatory DNA
Examination Assay/Test Profiling

Microscopic test
• Animal or human?
• Race
• Region of the body
• Damage/disease
• Suitability for comparison
 Unknown Human Hair
With follicular tag or Root with follicular tag (Telogen) Root without
root sheath follicular tag
• Nuclear DNA
(nDNA)
*individual evidence

Hair shaft only

• Mitochondrial
DNA (mtDNA)
suitable for nuclear not suitable for nuclear
*class evidence
DNA DNA analysis
*PURPOSEFUL SAMPLING FROM THE SUSPECT FOR
**mtDNA analysis is usually only performed on
DNA PROFILING – do not take hair shaft
hair or other evidence when there is no other
probative physical evidence available in an
investigation.
 MICROSCOPIC EXAMINATION
1. The hairs from the questioned source exhibit the same microscopic
characteristics as the hairs in a known hair sample and can be
associated to the source of the known hairs.

2. The hairs from the questioned source are microscopically

dissimilar to the hairs in a known hair sample and cannot be
associated with the source of the known hairs
3. The questioned hairs exhibit both similarities and slight
differences to hairs found in a known hair sample, and no
conclusion can be reached whether they could have originated
from the known source.
When forensic experts do find shared characteristics
between the known and unknown hair, a statement
such as the following may be added to their report:
“Hair comparisons are not a basis for absolute
personal identification. It should be noted, however,
that because it is unusual to find hairs from two
different individuals that exhibit the same microscopic
characteristics, a microscopic association or match is
the basis for a strong association.”
https://www.news-medical.net/life-sciences/Hair-Analysis-in-Forensic-Science.aspx