Name:____________________ Hour:_____Hair and Fiber Analysis Notes

Part One: Hair Analysis

Characteristics of Hair:• Hair is produce by ________ within the skin called _____________________.• It becomes non-living as it reaches the ______________________.• Hair extends from the ________ (bulb) embedded in the ____________, and continues into a

_____________ and terminates at the end.• The ____________ is the part most observed by _____________________.• It is made of three layers: ________________, _______________, _________________

The Cuticle• The cuticle varies in:

• Its scales- how many there are per __________, how much they ________, their overall _________, and how much they protrude from the ____________

• Its ___________, and • Whether or not it contains ___________• Characteristics of the cuticle may be important in distinguishing

between hairs of different _____________ but are often not useful in distinguishing between different ______________

Cuticle Patterns- Coronal (crown-like)• Scales appear like ________________.• Example: Mouse Hair

Cuticle Patterns- Spinous• Spinous (petal like)- ____________ shaped scales, often protrude from the shaft• Example: Cat hair, rabbit hair

Cuticle Pattern- Imbricate• Imbricate- ____________, ____________ scales• Example: human, dog, horse

________– central core (may be absent)

_______– protein-rich structure around the medulla that contains pigment

______– outer coating composed of overlapping scales

The Cortex•The area between the _______________________________•Varies in: Thickness, Texture, and Color•There can be air spaces (_________________) and solid spheres (_____________) in the cortex• The cortex gives hair its ________________•Distribution of the cortex is perhaps the most important component in determining from which ____________ a ___________ hair may have come• Microscopic examinations can also reveal the condition and shape of the root and tip

The Medulla•A collection of cells that appear to be the ___________________ of the hair• Human Medulla: Usually occupies 1/3 or less of the ______________

• ____________________: Occupies 1/2 or MORE of the hair diameter• Medulla Classifications:

• _________________: small sections of irregular size• ________________________________: longer segments with spaces• _________________: no breaks in the medulla• __________________: no medulla present

• Medulla shape: varies from ___________ to ___________

Special Hair Conditions• Dyed hair: often present in _______________ as well as

throughout the _____________• Bleached hair: removes the ________________ from the hair • Cut Hair:

• Hair grows approximately _____________ per month• When looking at ________________________, a forensic

scientist can see if it has recently been cut (no split ends)

Forensic Analysis• Hair is _____________ and labeled for its _______________• Collected with: Tweezers, Vacuum Sweepers, or Lifting Tape• Samples from _________________ and _________________ are taken by:

• Combing and collecting loose hair• Pulling root hairs (has the _____________ ______________) from various parts of the body

• Hair can determine:• __________• If the hair fell out or was ___________ removed• Poison and ____________

• Hair is ________________ evidence. It cannot determine the ______________• Exception: if the follicle is attached, ___________ can identify the person

Part Two: Fiber Analysis

• Fiber is often the _____________________________________ found at a crime scene• In _______________________, fiber often plays an important role• Fiber is often found:

• Caught in screens or on __________________• Around _____________________• On cars involved in a ________________• Transferred during a _________________

• It is collected in the same manner as hair• Collection is _________________________• Most analysis is done ___________________• Fiber has less parts than hair but is still as _______________• Things to look at:

• Color• _____________• Shape/pattern• _____________• Cross-section• ___________________________

• Physical matching- used when larger pieces are avaiable and can be physically matched by ________________________________

• Micro-chemical tests- chemical reactions are used to determine the ______________________• Micro-chemical tests ____________________________• Tests include:

• ____________________________• Density• Ash Formation• Tensile Strength• ____________________

• Types of Fiber: _______________ and ________________• Natural Fibers

• _________________ in whole from ________________________ sources

• Examples:• Wool• Cotton• Silk

• Man-Made Fibers• _______________________- fibers made totally from man made materials

• Examples: Nylon, ________________, and acryllic• _______________________- chemically altered natural materials

• Example: Rayon

Cotton Wool

Nylon

Rayon

Hair Part Identification:

1. Label the following hair samples with the three parts of hair (cortex, cuticle, and medulla)

2. Label each of the following hair samples by the types of cuticle they have (total: 10):

3. Label each of the following medullas as Continuous, Fragmented, Discontinuous, or Absent. When possible, also label which type of medulla is present (lattice, unilateral, etc):