Warm-Up September 23, 2014  Draw and label the following parts of the hair shaft: medulla, cortex and cuticle.

Objective  SWBAT differentiate between human and animal hair.

Agenda 1.DNA & Toxicology 2.Atlanta Child Murders Documentary 3.Human vs. Animal Hair 4.Microscopy 5.Exit Slip 1.DNA & Toxicology 2.Atlanta Child Murders Documentary 3.Human vs. Animal Hair 4.Microscopy 5.Exit Slip

Hair Analysis Lab Follow the directions and make sure that you draw the pictures and answer the questions on a separate sheet of paper.

DNA from Hair  Root  contains nuclear DNA  folicular tissue may be attached containing DNA  Shaft  contains abundant mitochondrial DNA, inherited only from the mother  typed by comparing relatives if no DNA from the body is available ($$$)

Collection of Hair  Questioned hairs must be accompanied by an adequate number of control samples.  from victim  from possible suspects  from others who may have deposited hair at the scene  Control Sample  50 full-length hairs from all areas of scalp  24 full-length pubic hairs

Hair Toxicology  Advantages:  Easy to collect and store  Is externally available  Can provide information on the individual’s history of drug use or of poisoning.  Collections must be taken from different locations on the body to get an accurate timeline.

Hair Toxicology  Napoleon died in exile in By analyzing his hair, some investigators suggest he was poisoned by the deliberate administration of arsenic; others suggest that it was vapors from the dyes in the wallpaper that did him in.

Atlanta Child Murders Documentary 9. Where were many of the bodies dumped? 10. What did forensic scientist Larry Peterson find at the autopsy of a body that was found? 11. Who did police suspect was the serial killer in February of 1981 based on a tip they received? 12. What test cleared members of the Klan? 13. What was being collected from the victims clothing? 14. What happened when the bodies started appearing in the river and how did that affect the amount of evidence? 15. What suggested the bridge stake outs? 16. What happened on the last night of the bridge stake outs? 17. What did police find when they searched William’s station wagon? 9. Where were many of the bodies dumped? 10. What did forensic scientist Larry Peterson find at the autopsy of a body that was found? 11. Who did police suspect was the serial killer in February of 1981 based on a tip they received? 12. What test cleared members of the Klan? 13. What was being collected from the victims clothing? 14. What happened when the bodies started appearing in the river and how did that affect the amount of evidence? 15. What suggested the bridge stake outs? 16. What happened on the last night of the bridge stake outs? 17. What did police find when they searched William’s station wagon?

Animal vs. Human Hair: Color  Human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft, whereas animal hairs may exhibit radical color changes in a short distance, called banding.

Human vs. Animal Hair: Medullary Index  The medulla, when present in human hairs, is generally less than one-third the overall diameter of the hair shaft.  The medulla in animal hairs is normally continuous or interrupted, and it generally occupies an area of greater than one-half the overall diameter of the hair shaft.  The medulla, when present in human hairs, is generally less than one-third the overall diameter of the hair shaft.  The medulla in animal hairs is normally continuous or interrupted, and it generally occupies an area of greater than one-half the overall diameter of the hair shaft.

 Human hair is imbricate (flattened)  Animal hair varies by species, but can be spinuous or coronal, as well as imbricate  Human hair is imbricate (flattened)  Animal hair varies by species, but can be spinuous or coronal, as well as imbricate Human vs. Animal Hair: Cuticle

Human vs. Animal Hair: Tip  Scissor cut or razor cut implies the hair has been “groomed”. Many animals are not groomed so if you see a scissor cut tip or a razor cut tip it might be a clue that the type of hair you are looking at did not come from an animal.

Human Hairs

Horse Hair

Dog Hair

Cat Hair

Mouse Hair

Rabbit Hair

Deer Hair

Cow Hair

Pig Hair

Special Conditions of Hair The following slides show the ends of several different species of hairs

Fallen Out Hairs

Natural Tip

Pulled Out-By the Root

Broken-Torn

Cut Hair

Can you identify the animal hairs shown? Think About It … (1)In which samples are we viewing the cuticle? How do they compare? (2) In which samples are we viewing the medulla? How do they compare? (3) What characteristics can be used to identify hair samples?

Types of Animal Hairs - Key ABCD EF G IH CatHorsePigHuman DeerDogRatRabbitHuman

Comparison Microscope  Allows the examiner to view the questioned and known hair together, side by side  Necessary to have an adequate number of known hairs that are representative of all its features when making a comparison  Allows the examiner to view the questioned and known hair together, side by side  Necessary to have an adequate number of known hairs that are representative of all its features when making a comparison

Issues with Microscopes  Subjective approach  Dependent on skills and integrity of the analyst  Subjective approach  Dependent on skills and integrity of the analyst

DNA Analysis  Study done on hair evidence of FBI between 1996 – 2000 and found that only 11% of hairs found a positive microscopic match  Now must hair evidence must be confirmed by DNA analysis  Study done on hair evidence of FBI between 1996 – 2000 and found that only 11% of hairs found a positive microscopic match  Now must hair evidence must be confirmed by DNA analysis

Homework  Chapter 10 Review Questions, #15-20 due Wednesday

Exit Slip September 23, Get out a mobile device or use one of the computers and go to m.socrative.com. You can also use one of the iPads that has the Socrative app. 2. When prompted, enter for the room number. QUESTION: What are characteristics used to determine the difference between human and animal hair? 1. Get out a mobile device or use one of the computers and go to m.socrative.com. You can also use one of the iPads that has the Socrative app. 2. When prompted, enter for the room number. QUESTION: What are characteristics used to determine the difference between human and animal hair?