Hair AnalysisHair AnalysisIdentification of species Identification of species through microscopy.through microscopy.

Collection of Hair Collection of Hair SpecimenSpecimen

Examination of the Examination of the MedullaMedulla

Patterns in Animal Patterns in Animal SpeciesSpecies

Examination of Scale Pattern

Human HairsHuman Hairs

Racial DeterminationRacial Determination

African Asian European

Hair RootsHair Roots

Pulled Forcibly Removed Shed

Tip of the ShaftTip of the Shaft

Burned Cut Razored Split

Identification of HairIdentification of HairDifferentiation between Differentiation between human and animal hairhuman and animal hair

So --- How CAN we tell So --- How CAN we tell human hair from animal human hair from animal hair??hair??

MEDULLAMEDULLA The medulla is the core of a hair – it is, The medulla is the core of a hair – it is,

however, not always present. however, not always present. There are several types and patterns.There are several types and patterns. TYPES:TYPES:

– Continuous—most animals Continuous—most animals (seldom humans)(seldom humans)– Intermittent or interrupted Intermittent or interrupted (mostly medulla with some gaps)— (mostly medulla with some gaps)— human pubic hair, sometimes head hair human pubic hair, sometimes head hair – Fragmented (mostly gaps Fragmented (mostly gaps with some medulla)—mostly human hairwith some medulla)—mostly human hair – Absent—human head hair onlyAbsent—human head hair only

Medula PatternsMedula PatternsUniserialUniserial--small blocks --small blocks

in a row in a row

VacuolatedVacuolated--uneven --uneven patternpattern

MultiserialMultiserial--several rows of blocks--several rows of blocks

LatticeLattice--circular patterns--circular patterns

AmorphousAmorphous--without a specific pattern--without a specific pattern

HAIR MEDULLA HAIR MEDULLA

Cat CowHorse

Muskrat

Rabbit -- UniserialRabbit -- Multiserial

Dog Goat Bat

Medulla: PresentMedulla: Present Medullary Index: More than 1/2Medullary Index: More than 1/2 Medulla Pattern: VacuolatedMedulla Pattern: Vacuolated Species: GoatSpecies: Goat

Medulla – presentMedulla – present Medullary Index – more than ½Medullary Index – more than ½ Medulla Pattern – Vacuolated/amorphousMedulla Pattern – Vacuolated/amorphous Root – Spade - shapedRoot – Spade - shaped Species: DogSpecies: Dog

Medulla – presentMedulla – present Medullary index – more than ½Medullary index – more than ½ Medulla pattern – multiserialMedulla pattern – multiserial Species -- RabbitSpecies -- Rabbit

Human or animal?Human or animal?

Medulla – presentMedulla – present Medullary Index – more than 1/2Medullary Index – more than 1/2 Medulla pattern – uniserialMedulla pattern – uniserial Root -- frayedRoot -- frayed Species -- CatSpecies -- Cat

Now Take a look at some slides of Now Take a look at some slides of different kinds of hair, straight from different kinds of hair, straight from the FBI. Can you guess what hair is the FBI. Can you guess what hair is human and what hair isn't? human and what hair isn't?

1

2

3

4

5

6

Hair #1Hair #1 No 1 is No 1 is human head hair of human head hair of

Caucasian originCaucasian origin. Caucasian . Caucasian hairs come in the widest variety hairs come in the widest variety of colors, can be of fine to of colors, can be of fine to medium coarseness and are medium coarseness and are generally straight or wavy. In generally straight or wavy. In addition, the shafts vary from addition, the shafts vary from round to oval in cross section. round to oval in cross section. Finally, color pigments are fine- Finally, color pigments are fine- to medium-sized and are evenly to medium-sized and are evenly distributed throughout the distributed throughout the shaft. shaft.

Hair # 2.Hair # 2. This is a This is a deer hairdeer hair. Unlike that of any . Unlike that of any

other animal, the root of deer hair has a other animal, the root of deer hair has a wine-glass shape: a narrow root that wine-glass shape: a narrow root that gradually widens. In addition, the gradually widens. In addition, the medulla, or inner layer of cells, consists of medulla, or inner layer of cells, consists of spherical cells that take up the whole spherical cells that take up the whole width of the hair in a repeating pattern of width of the hair in a repeating pattern of different shapes, such as a hexagonal different shapes, such as a hexagonal shape, depending on what member of the shape, depending on what member of the deer family the subject belongs to. deer family the subject belongs to.

Hair #3Hair #3

This is a This is a human head hair of Afro-human head hair of Afro-Caribbean originCaribbean origin. Such hairs are generally . Such hairs are generally curly or kinky, and have a flattened cross curly or kinky, and have a flattened cross section. Larger than those of other racial section. Larger than those of other racial groups, its pigment particles are grouped in groups, its pigment particles are grouped in clumps of different sizes and shapes and clumps of different sizes and shapes and may be so dense that they render the hair may be so dense that they render the hair opaque. Furthermore, the hair shaft may opaque. Furthermore, the hair shaft may vary — or seem to vary — in diameter vary — or seem to vary — in diameter because of its flattened nature and the way it because of its flattened nature and the way it settles on the microscope slide settles on the microscope slide

Hair #4Hair #4

This is a This is a cat haircat hair. Cat hair has fibrous . Cat hair has fibrous roots and its pigment particles do not roots and its pigment particles do not run down to the root. In addition, its run down to the root. In addition, its medulla, or inner layer of cells, is medulla, or inner layer of cells, is thicker than that of dog hair. thicker than that of dog hair.

Hair #5Hair #5

This is a This is a human head hair of Asian originhuman head hair of Asian origin. Such . Such hair is generally coarse, straight and circular in cross hair is generally coarse, straight and circular in cross section. Its diameter is wider than the hair of other section. Its diameter is wider than the hair of other racial groups, and the outer layer of the hair, the racial groups, and the outer layer of the hair, the cuticle, is usually significantly thicker. The medulla, or cuticle, is usually significantly thicker. The medulla, or inner layer of cells, is continuous and wide. In addition, inner layer of cells, is continuous and wide. In addition, the hair shaft contains pigment particles that are the hair shaft contains pigment particles that are generally larger than those of Caucasian hairs, and generally larger than those of Caucasian hairs, and often appear to be grouped in patchy areas. Finally, often appear to be grouped in patchy areas. Finally, the hair may have a reddish appearance, a product of the hair may have a reddish appearance, a product of its pigment.its pigment.

Hair #6Hair #6 This is a This is a dog hairdog hair. Dog hair has . Dog hair has

spade-like roots and its spade-like roots and its pigmentation runs down pigmentation runs down throughout the shaft to the root. throughout the shaft to the root. Its medulla, or inner layer of cells, Its medulla, or inner layer of cells, is thinner, too, than that of cat is thinner, too, than that of cat hair. hair.

CUTICLE SCALESCUTICLE SCALES

Mosaic Pectinate Imbricate Petal Diamond Petal Mosaic Pectinate Imbricate Petal Diamond Petal ChevronChevron

http://phs.psdr3.org/science/forensics/traceevidence.html

Human CuticleHuman Cuticle

Cuticle ScalesCuticle Scales

HUMAN CUTICLE SCALESHUMAN CUTICLE SCALES

DOG CUTICLE SCALESDOG CUTICLE SCALES

ASK "WEEKSTER" ASK "WEEKSTER"                                                                                                                                                                                                           

              

DO OUR FINGERNAILS AND HAIR CONTINUE TO GROW AFTER DO OUR FINGERNAILS AND HAIR CONTINUE TO GROW AFTER WE DIE?WE DIE?

Answer:Answer: NO! The body will dehydrate soon NO! The body will dehydrate soon

after death, shrinking as a result. The after death, shrinking as a result. The fingernails and hair will appear to fingernails and hair will appear to grow. Just an optical illusion!!grow. Just an optical illusion!!