Hair Analysis
Identification of species through
microscopy.
Collection of Hair
Specimen
Examination of the
Medulla
Patterns in Animal
Species
Examination of Scale Pattern
Human Hairs

Racial Determination
African
Asian
European
Hair Roots

Pulled
Forcibly Removed
Shed
Tip of the Shaft

Burned
Cut
Razored
Split
Identification of Hair
Differentiation between human
and animal hair
So --- How CAN we tell
human hair from animal
hair??
MEDULLA

The medulla is the core of a hair – it is,
however, not always present.
There are several types and patterns.

TYPES:

– Continuous—most animals
(seldom humans)
– Intermittent or interrupted
(mostly medulla with some gaps)—
human pubic hair, sometimes head hair
– Fragmented (mostly gaps
with some medulla)—mostly human hair
– Absent—human head hair only
Medula Patterns
Uniserial--small blocks in
a row
Vacuolated--uneven
pattern
Amorphous--without a specific pattern
Multiserial--several rows of blocks
Lattice--circular patterns
HAIR MEDULLA
Cat
Cow
Horse
Muskrat
Rabbit -- Multiserial
Rabbit -- Uniserial
Dog
Goat
Bat




Medulla: Present
Medullary Index: More than 1/2
Medulla Pattern: Vacuolated
Species: Goat





Medulla – present
Medullary Index – more than ½
Medulla Pattern – Vacuolated/amorphous
Root – Spade - shaped
Species: Dog




Medulla – present
Medullary index – more than ½
Medulla pattern – multiserial
Species -- Rabbit
Human or animal?





Medulla – present
Medullary Index – more than 1/2
Medulla pattern – uniserial
Root -- frayed
Species -- Cat

Now Take a look at some slides of
different kinds of hair, straight from the
FBI. Can you guess what hair is human
and what hair isn't?
1
2
3
4
5
6
Hair #1

No 1 is human head hair of
Caucasian origin. Caucasian
hairs come in the widest variety
of colors, can be of fine to
medium coarseness and are
generally straight or wavy. In
addition, the shafts vary from
round to oval in cross section.
Finally, color pigments are fine- to
medium-sized and are evenly
distributed throughout the shaft.
Hair # 2.

This is a deer hair. Unlike that of any other
animal, the root of deer hair has a wineglass shape: a narrow root that gradually
widens. In addition, the medulla, or inner
layer of cells, consists of spherical cells that
take up the whole width of the hair in a
repeating pattern of different shapes, such
as a hexagonal shape, depending on what
member of the deer family the subject
belongs to.
Hair #3

This is a human head hair of AfroCaribbean origin. Such hairs are generally
curly or kinky, and have a flattened cross
section. Larger than those of other racial
groups, its pigment particles are grouped in
clumps of different sizes and shapes and
may be so dense that they render the hair
opaque. Furthermore, the hair shaft may
vary — or seem to vary — in diameter
because of its flattened nature and the way
it settles on the microscope slide
Hair #4

This is a cat hair. Cat hair has fibrous
roots and its pigment particles do not
run down to the root. In addition, its
medulla, or inner layer of cells, is
thicker than that of dog hair.
Hair #5

This is a human head hair of Asian origin. Such
hair is generally coarse, straight and circular in
cross section. Its diameter is wider than the hair of
other racial groups, and the outer layer of the hair,
the cuticle, is usually significantly thicker. The
medulla, or inner layer of cells, is continuous and
wide. In addition, the hair shaft contains pigment
particles that are generally larger than those of
Caucasian hairs, and often appear to be grouped in
patchy areas. Finally, the hair may have a reddish
appearance, a product of its pigment.
Hair #6

This is a dog hair. Dog hair has
spade-like roots and its pigmentation
runs down throughout the shaft to the
root. Its medulla, or inner layer of
cells, is thinner, too, than that of cat
hair.
CUTICLE SCALES
Mosaic
Pectinate
Imbricate
Petal
Diamond Petal
Chevron
http://phs.psdr3.org/science/forensics/traceevidence.html
Human Cuticle
Cuticle Scales


HUMAN CUTICLE SCALES
DOG CUTICLE SCALES
"WEEKSTER"
ASK
DO OUR FINGERNAILS AND HAIR CONTINUE TO GROW AFTER WE
DIE?
Answer:

NO! The body will dehydrate soon after
death, shrinking as a result. The
fingernails and hair will appear to grow.
Just an optical illusion!!