1. Monday September 12 th, 2016 Announcements  Chapter 3 Review Due Today  Thursday is Parent/Teacher Conferences  Friday is a half day Agenda  Start Chapter 4 Hair and Fibers  Grab a notetaker from the silver bin “Judge a man by his questions rather than his answers” – Voltaire Happy National Chocolate Milkshake Day Fun Fact: In Colorado it’s illegal to throw missiles at cars

2. Chapter 4: The Study of Hair, Fibers, and Textiles Part 1: Hair

3.  Hair is considered Class evidence  Class Evidence: material that connects an individual or thing to a class of people who share a certain type of characteristic  Physical characteristics of hair can offer clues to the broad racial background of an individual  Chemical test can provide a history of toxins or drug use Introduction

4.  When the hair follicle is present DNA evidence can be obtained  Results of the DNA analysis is considered individual evidence  Individual Evidence: evidence that identifies a particular person or thing Introduction

5.  1883: Alfred Swaine Taylor and Thomas Stevenson wrote about using hair in forensic investigations  1910: Victor Balthazard and Marcelle Lambert published a comprehensive study of hair  Included numerous microscopic studies of hairs most from animals  1934: Dr. Sydney Smith analyzed hairs side by side using a comparison microscope  Helped solve the murder of an 8 year old girl  Today: standard procedures of hair analysis include microscopic examination and DNA analysis History of Hair Analysis

6.  Regulates body temperature  Not as much in humans as it does in animals  Decreases friction  Protects against sunlight  Acts as a sense organ  Humans are born with about 5 million hair follicles  Only 2% is found on the head Function of Hair

7.  Human hair consists of a follicle and a shaft  Shaft: the visible portion of the hair  Composed of keratin (a protein)  Follicle: sheath of cells and connective tissue that surrounds the root of the hair  Root: part of the hair which can be tested for DNA The Structure of Human Hair

8.  Hair shaft is made up of 3 layers:  Inner medulla  Forensic investigators classify hair into 5 different groups depending on the appearance of the medulla  Cortex  Contains most of the pigment granules  Outer cuticle The Structure of Human Hair Cuticle of human hair with overlapping scales

9. Medulla PatternDescriptionDiagram ContinuousOne unbroken line of color Interrupted (Intermittent) Pigmented line broken at regular intervals Fragmented or Segmented Pigmented line unevenly spaced SolidPigmented area filling both the medulla and the cortex NoneNo separate pigment in the medulla

10. 1.3 parts of the hair shaft 2.Material that connects an individual to a class of people 3.2 standard procedures used today for hair analysis 4.Evidence that identifies a particular person or thing 5.Medulla pattern that is broken at regular intervals 6.Part of the hair which contains DNA

11.  Human hair varies from person to person,  Hair can vary in shape, length, diameter, texture and color  Those attributes can all be used for identification or exclusion in forensic investigations  Because inconsistencies occur within each body region; 50 hairs are usually collected from a suspect’s or victim’s head Types of Hair

12.  Forensic scientist distinguish 6 types of hair on the human body  Head hair: circular or elliptical shape in a cross section  Eyebrows and eyelashes: circular but have tapering ends  Beard and mustache hair: thick and triangular  Underarm hair  Body hair: triangular or oval depending on whether the body region is regularly shaved  Pubic hair: oval or triangular Hair From Different Parts of The Body

14.  Hair develops through 3 stages 1.Anagen Stage  80-90% of all human hair is in the Anagen stage  Last approximately 1000 days 2.Catagen Stage  Hair stops growing and the follicle recedes 3.Telogen Stage  Hair follicle is dormant and hair is easily lost The Life Cycle of Hair

15.  Hair examiners have identified key physical characteristics associated with hair of different racial groups  Characteristics are generalities, might not apply to individuals of a certain race Ethnic or Ancestral Differences

16. RaceAppearancePigment Granules Cross Section Other EuropeanGenerally straight or wavy Small and evenly distributed Oval or round of moderate diameter with minimal variation Color: blonde, red, brown, or black AsianStraightDensely distributed Round with larger diameter Shaft is coarse and straight; Thick cuticle; Continuous medulla AfricanKinky, curly, coiled; shaft may be buckled Densely distributed, clumped, may differ in size and shape Flattened with moderate to small diameter and considerable variation

17. 1.Type of hair that is circular and has tapering ends 2.Hair stage when the hair stops growing 3.Some attributes of hair which investigators use in their investigations 4.Hair type which is thick and triangular 5.Hair stage which last about 1000 days 6.Cross section of this type of hair will vary on if the area is regularly shaved Check For Understand 2

18.  Animal hair and human hair have several differences  Pattern of pigmentation  Animal pigmentation is denser, found in solid masses  Human hair is usually one color; animal hairs can change color abruptly in a banded pattern  Cuticle type  Human cuticle scales are called imbricate and they are flat and narrow Animal Hair and Human Hair

19.  Medullary index  Medullary Index: ratio of the diameter of the medulla to the diameter of the entire hair  Animals: medullary index.5 or greater  Human: medullary index.33 or less Animal hair and Human Hair

20.  Hair is studied macroscopically and microscopically  Macroscopically  Length  Color  Curliness  Microscopically  Pattern of the medulla  Pigmentation of the cortex  Types of scales on the cuticle Microscopy

21.  Breaking down the keratin, releases substances and toxins in the hair  Provides evidence of poisoning or drug use  Testing different parts of the hair can establish a timeline for when exposure to poison or toxins occurred  N eutron Activation Analysis (NAA): can identify up to 14 elements in a single 2 cm long strand of hair  Hair shaft analysis only provides class evidence Testing For Substances In The Hair Shaft

22.  If hair is forcibly removed it may contain the hair follicle  Blood and tissue on the follicle can be tested  Blood proteins can identify the blood type  DNA analysis can be performed  DNA analysis provides individual evidence Testing For Substances In The Hair Follicle

23. 1.Characteristics studied macroscopically 2.The name of human hair cuticles 3.The 3 ways animal and human hair differ 4.Ratio of the diameter of the medulla to the diameter of the entire hair 5.DNA analysis can be performed if you have the …….. 6.The hair shaft provides this type of evidence Check For Understand 3