Unit 5: Hair

Objective: SWBAT identify forensic evidence found in hair samples.

Do Now: What forensic evidence can be determined from hair?

Hair is the most frequently found piece of trace evidence.

What is trace evidence?

Objective: SWBAT identify forensic evidence found in hair samples.

Usually Class evidence unless:DNA in root is found = individual Sometimes mtDNA testing can be done (still class evidence but more narrowed)

Objective: SWBAT identify forensic evidence found in hair samples.

From hair one can determine:

Human vs animal?

Race (sometimes)

Location of hair on body (head, leg...)

Was hair was forcibly removed ?

Was hair treated with chemicals?

Were drugs/ toxins ingested?

Individualized if root is present (DNA)

Things hair can’t determine:• Age (except infant hair)• Gender (unless DNA in root)

Objective: SWBAT identify forensic evidence found in hair samples.

Complete Strands of evidence reading on hair with questions

Objective: SWBAT identify forensic evidence found in hair samples.

Questions on “Strands of

Hair” ArticleWhat is the basic technique of hair analysis?

Is visible hair analysis as reliable as fingerprints?

Generally, how else can hair be analyzed?

How do substances in the blood get into the hair?

What other techniques are used for hair analysis?

Drug use can be detected up to a _________________________.

What must be present for DNA analysis?

What other type of DNA can be located? Give 2 examples.

How does the Department of Defense use this testing?

What are the drawbacks to mDNA testing?

Objective: SWBAT identify forensic evidence found in hair samples.

Do Now: Is Hair analysis as reliable as fingerprints?

Hair is composed of three principal parts (sketch in your notes):

Cuticle

Cortex Medulla

Objective: SWBAT identify forensic evidence found in hair samples.

Objective: SWBAT identify forensic evidence found in hair samples.

The cuticle is the outside covering made of overlapping scales.

Scales point down towards tip (older part) of hair.

Objective: SWBAT identify forensic evidence found in hair samples.

3 Basic Patterns of Cuticle

Objective: SWBAT identify forensic evidence found in hair samples.

Non- Human Cuticle Structure

Cuticle Structure: Coronal

Scales stacked like paper cups

Ex. Bat Hair

Objective: SWBAT identify forensic evidence found in hair samples.

Cuticle Structure: Spinous

Scales shaped like petals

Ex. Rabbit Hair

Objective: SWBAT identify forensic evidence found in hair samples.

Human Cuticle Structure

Cuticle Structure: Imbricate

Scales flattened and close together

Objective: SWBAT identify forensic evidence found in hair samples.

Using the Microscope

Complete Activity: observing the cuticle

Objective: SWBAT identify forensic evidence found in hair samples.

Do Now: What type of cuticle is present in human hair?

Objective: SWBAT identify forensic evidence found in hair samples.

Complete Wayne Williams Case study

Objective: SWBAT identify forensic evidence found in hair samples.

Do Now: What is the most common piece of evidence found at a crime scene?

Objective: SWBAT identify forensic evidence found in hair samples.

Medulla3 types in Humans: 1. Continuous2. Interrupted3. Fragmented/Absent

Objective: SWBAT identify forensic evidence found in hair samples.

Medulla: ContinuousFormed as a solid center line

Objective: SWBAT identify forensic evidence found in hair samples.

Medulla: InterruptedMedulla is seen as individual cells or fragments in repeating intervals

Objective: SWBAT identify forensic evidence found in hair samples.

Medulla: Fragmented/ Absent

Fragmented: few parts visible

Absent: no medulla visible

Objective: SWBAT identify forensic evidence found in hair samples.

Animal Vs. Human

The medullary Index is the ratio of diameter of medulla to the overall diameter of the hair

Medullary index:Humans < 1/3Animal > 1/2

Objective: SWBAT identify forensic evidence found in hair samples.

Complete activities: observing the medulla

Closure: what is the medullary index?

Objective: SWBAT identify forensic evidence found in

hair samples.

Do Now: How fast does your hair grow? Approximately how many inches a month?

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Naturally Shed Hair

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Forcible Removal of Hair

Objective: SWBAT identify forensic evidence found in hair samples.

Burned Hair

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Toxicology

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Grows approximately 0.5 inches (1.3cm) per month

1cm 2cm 3cm 4cm

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Objective: SWBAT determine the condition of hair and generate an

idea on how it was lost.

Closure:

Complete case study on central park jogger

Complete hair assessment lab