CRIM 409: FORENSIC CRIM 409: FORENSIC SCIENCESCIENCE

CRIM 409: FORENSIC CRIM 409: FORENSIC SCIENCESCIENCE

LECTURE EIGHT: HAIR EXAMINATIONS LECTURE EIGHT: HAIR EXAMINATIONS

Why Is Hair Good Why Is Hair Good Evidence?Evidence?

• AbundantAbundant - average person has - average person has >100,000 hair follicles on their head >100,000 hair follicles on their head alonealone

• Easily Easily transfertransfer - average person loses - average person loses 100 hairs per day100 hairs per day

• Considerable Considerable variabilityvariability - comparing - comparing body area alone, human hair can be body area alone, human hair can be from the head, pubic, anal, eye, nose, from the head, pubic, anal, eye, nose, ear, underarm, leg, arm, chest, trunk, ear, underarm, leg, arm, chest, trunk, or beard area, not including the fine or beard area, not including the fine hair covering the entire body except on hair covering the entire body except on a person’s palms and solesa person’s palms and soles

• DurableDurable - hairs have been recovered - hairs have been recovered from mummies dating back 2,000 yearsfrom mummies dating back 2,000 years

HairHair

What crimes are hairs involved in?What crimes are hairs involved in?

• Hairs are shed from peopleHairs are shed from people• Can link person to crime sceneCan link person to crime scene• Animal hair may also link person Animal hair may also link person

to crime sceneto crime scene

IntroductionIntroduction

Human hair frequently found at Human hair frequently found at scene of violent crimes scene of violent crimes

Provides link between criminal and Provides link between criminal and crimecrime

From hair one can determine:From hair one can determine: human human v.v. animal source animal source race (sometimes)race (sometimes) origin from bodyorigin from body Whether hair was forcibly removedWhether hair was forcibly removed If hair has been treated with chemicalsIf hair has been treated with chemicals If drugs have been ingestedIf drugs have been ingested

Hair EvidenceHair Evidence

• Found in many crimes, submitted to Found in many crimes, submitted to the laboratory. the laboratory. – Can include homicides, hit and runs, Can include homicides, hit and runs,

sexual assaults, kidnappings, sexual assaults, kidnappings, burglaries, etc.burglaries, etc.

SuspeSuspectct

ObjecObjectt

SceneScene

VictiVictimm

Hair ShaftHair ShaftComposed of:Composed of:

CuticleCuticle——outside outside covering, made of covering, made of overlapping scalesoverlapping scales

CortexCortex——inner layer inner layer made of keratin and made of keratin and imbedded with imbedded with pigment; also pigment; also contains air sacs contains air sacs called cortical fusicalled cortical fusi

MedullaMedulla——inside inside layer running down layer running down center of cortexcenter of cortex

HairHair

How is hair analyzed?How is hair analyzed?

Look at class characteristics Look at class characteristics (microscope):(microscope):

• ColorColor• Medulla, Cortex, CuticleMedulla, Cortex, Cuticle

The CuticleThe Cuticle

…………outermost layer of hair which is outermost layer of hair which is covered with scales. Scales point toward covered with scales. Scales point toward tip of the hair. Scales differ between tip of the hair. Scales differ between species of animals and are named based species of animals and are named based on their appearanceon their appearance

The three basic patterns are:The three basic patterns are:

CoronalCoronal SpinousSpinous ImbricateImbricate

Animal HairsAnimal Hairs

Coronal scale pattern is found in hairs of Coronal scale pattern is found in hairs of very fine diameter. Coronal scales are very fine diameter. Coronal scales are commonly found in the hairs of small commonly found in the hairs of small rodents and batsrodents and bats

Animal HairsAnimal Hairs

Spinous or petal-like scales are Spinous or petal-like scales are triangular in shape and protrude from triangular in shape and protrude from hair shaft. Found on hairs of seals, hair shaft. Found on hairs of seals, cats, and some other animals. They are cats, and some other animals. They are never found in human hairsnever found in human hairs

Animal HairsAnimal Hairs

Imbricate or flattened-scale type Imbricate or flattened-scale type consists of overlapping scales with consists of overlapping scales with narrow margins. Commonly found in narrow margins. Commonly found in human hairs and many animal hairshuman hairs and many animal hairs

The CortexThe Cortex

………………gives hair its shape and colorgives hair its shape and color

Contains:Contains:

MelaninMelanin——pigment granulespigment granules

Hair ColorHair Color

Dyed HairDyed Hair

The MedullaThe Medulla

…… …… is the hair core that is not is the hair core that is not always visible. The medulla comes always visible. The medulla comes in different types and patternsin different types and patterns

Types:Types: Intermittent or interruptedIntermittent or interrupted FragmentedFragmented ContinuousContinuous AbsentAbsent——not visible!not visible!

Medulla StructureMedulla Structure

Hair ShapeHair Shape

Can be straight, curly or kinky Can be straight, curly or kinky depending on the cross-section, depending on the cross-section, which may be round, oval or flat:which may be round, oval or flat:

Round(Straight)

Oval(Curly)

Flat (kinky)

Cross Section

Hair Growth CycleHair Growth Cycle

Hair GrowthHair Growth

TerminologyTerminology AnagenAnagen——hair that is actively growing; lasting up to 5 hair that is actively growing; lasting up to 5

yearsyears

CatagenCatagen——hair is not growing; a resting phasehair is not growing; a resting phase

TelogenTelogen——hair that is dying and ready to fall out; lasting hair that is dying and ready to fall out; lasting two to six monthstwo to six months

LengthLength——about 0.5 mm per day or 1 about 0.5 mm per day or 1 centimeter per month; approximately one centimeter per month; approximately one half inch per monthhalf inch per month

The RootThe Root

Human roots look different based Human roots look different based on whether they have been forcibly on whether they have been forcibly removed or if they are telogen hairs removed or if they are telogen hairs and have fallen outand have fallen out

Root StructureRoot Structure

Hair ComparisonHair Comparison

ColorColor LengthLength DiameterDiameter Distribution, shape Distribution, shape

and color intensity and color intensity of pigment granulesof pigment granules Dyed hair has color Dyed hair has color

in cuticle and cortexin cuticle and cortex Bleaching removes Bleaching removes

pigment and gives a pigment and gives a yellow tintyellow tint

Scale types Scale types Presence or Presence or

absence of absence of medulla medulla

Medullary Medullary patternpattern

Medullary indexMedullary index

DNA from HairDNA from Hair

The root contains nuclear DNA. If The root contains nuclear DNA. If the hair has been forcibly the hair has been forcibly removed, some folicular tissue removed, some folicular tissue may be attached containing DNA. may be attached containing DNA.

The hair shaft contains abundant The hair shaft contains abundant mitochondrial DNA, inherited only mitochondrial DNA, inherited only from the mother. It can be typed from the mother. It can be typed by comparing relatives if no DNA by comparing relatives if no DNA from the body is available. from the body is available.

Collection of HairCollection of Hair

Questioned hairs must be Questioned hairs must be accompanied by an adequate number accompanied by an adequate number of control samples.of control samples. from victimfrom victim from possible suspectsfrom possible suspects from others who may have deposited hair from others who may have deposited hair

at the sceneat the scene

Control SampleControl Sample 50 full-length hairs from all areas of scalp50 full-length hairs from all areas of scalp 25 full-length pubic hairs25 full-length pubic hairs

Hair ToxicologyHair Toxicology

Advantages:Advantages: Easy to collect and storeEasy to collect and store Is externally availableIs externally available Can provide information on the Can provide information on the

individual’s history of drug use or of individual’s history of drug use or of poisoning.poisoning.

Collections must be taken from Collections must be taken from different locations on the body to different locations on the body to get accurate timelineget accurate timeline

Hair ToxicologyHair Toxicology

Napoleon died in exile in Napoleon died in exile in 1821. By analyzing his 1821. By analyzing his hair, some investigators hair, some investigators suggest he was poisoned suggest he was poisoned by the deliberate by the deliberate administration of administration of arsenic; others suggest arsenic; others suggest that the cause is that the cause is attributed to vapors attributed to vapors from dyes in the from dyes in the wallpaperwallpaper

Summary of Potential Summary of Potential ResultsResults

A qualified hair examiner can provide the following A qualified hair examiner can provide the following informationinformation

from a hair examination and comparison:from a hair examination and comparison:

1. Whether there is hair(s) recovered from item(s) 1. Whether there is hair(s) recovered from item(s) submitted. submitted.

2. Racial origin of hair (Caucasian-type, Negroid-type, 2. Racial origin of hair (Caucasian-type, Negroid-type, Mongoloid-type)Mongoloid-type)

3. Area of body that hair came from (head, pubic, body)3. Area of body that hair came from (head, pubic, body)4. Whether hair has been artificially treated4. Whether hair has been artificially treated6. Whether there has been damage to the hair 6. Whether there has been damage to the hair 7. Whether there are similarities and/or differences 7. Whether there are similarities and/or differences

between the questioned hair and known sample.between the questioned hair and known sample.

*How much information an examiner can provide depends *How much information an examiner can provide depends upon suitability of hair.upon suitability of hair.

Hair Examination Hair Examination ConclusionsConclusions

A hair examiner can conclude the following:A hair examiner can conclude the following:• 1. Questioned hair exhibits similar 1. Questioned hair exhibits similar

characteristics (no significant differences are characteristics (no significant differences are present) to known sample. Thus, source of present) to known sample. Thus, source of known sample cannot be excluded as being known sample cannot be excluded as being source of questioned hair.source of questioned hair.

• 2. Questioned hair exhibits dissimilar 2. Questioned hair exhibits dissimilar characteristics to the known sample. Thus, the characteristics to the known sample. Thus, the source of known sample can be excluded as source of known sample can be excluded as being source of questioned hair. being source of questioned hair.

• 3. Questioned hair exhibits both similarities and 3. Questioned hair exhibits both similarities and differences to known sample. Thus, no differences to known sample. Thus, no conclusion can be reached conclusion can be reached

• 4. Known hairs insufficient or unsuitable for 4. Known hairs insufficient or unsuitable for comparison purposes.comparison purposes.

• 5. Questioned hair(s) insufficient or unsuitable 5. Questioned hair(s) insufficient or unsuitable for comparison purposes.for comparison purposes.

Postmortem Root BandingPostmortem Root Banding