Hair. Name Period. Fill in the blanks and answer the following questions based on the powerpoint and your textbook.

Transcription

1 Hair Name Period Hair is important as trace evidence in criminal investigations. Chapter 3 in your textbook explains why we study hair, and how we study it. Your job is to become an expert on both! Fill in the blanks and answer the following questions based on the powerpoint and your textbook. 1. Hair as evidence: a) What characteristics make hair class evidence? b) What characteristics make hair individual evidence? c) When is hair considered secondary transfer? d) What characteristics of hair make it important evidence? 2. History of hair as evidence a) What famous case in history used hair as one piece of evidence for the conviction? In what year did this case take place? b) L Affaire Gouffe in 1889 made Goron famous because he was able to identify a body after it had decomposed for 4 months. What role did hair play in the identification?

2 c) In the year, Taylor and Stevenson wrote a forensic science text that included using hair in forensics investigations. What scientific instrument did they use to analyze hair? How did this instrument help investigators? d) In the year Balthazard and Lambert wrote a more comprehensive text on hair. What scientific instrument did they use to analyze hair? What new information did they add? e) In 1910 a murderer only after being confronted with hair evidence that had been found. f) A new scientific instrument was used in 1934 by to solve the murder of an 8- year old girl. The instrument was called a. Let s evaluate hair as evidence: 3. What are some possible limitations of hair as evidence? 4. What are some advantages of using hair as evidence? 5. What reasons might have prevented investigators from using hair in investigations before 1910?

3 6. What kinds of technology advances have made it possible for investigators to use hair as evidence? 7. What animals have hair? 8. Why do we have hair? What is its function? a. b. c. d. It is time to LOOK at hair. First, look at hair in skin; then examine parts of hair itself. 11. See the skin cross- section. Go to your lab table. Use the labels on the slips of paper to correctly label your diagram. Do not write in your packet until you are sure it is correct. 12. On the other diagram, label the medulla, cortex, and cuticle. 13. What is the purpose of the cortex? 14. What is the purpose of the cuticle? 15. Sketch a pencil below and label it as if it were a hair. This is an ANALOGY for hair.

4 14. This cuticle pattern is called. It is like. An example of an animal with this pattern is. 15. This cuticle pattern is called. It is like. An example of an animal with this pattern is. 16. This cuticle pattern is called. It is like. An example of an animal with this pattern is. 17. On your sketch above, draw an arrow that points to the non- growing end of the hair (away from the scalp). Why is this important to know? 18. Medulla Pattern Description Diagram One unbroken line of color Pigmented line broken at regular intervals Pigmented line unevenly spaced Pigmented area filling both the medulla and the cortex No separate pigmentation in the medulla 19. What four main shapes can be seen when looking at the cross- section of hair? a. c. b. d.

5 20. Where is coarse hair found on humans? 21. What determines the color of hair? 22. Why is it necessary to take 50 hairs as a sample from the head? Or 25 from the pubic area? 23. Make a table that lists the 6 types of human hair and its cross- sectional shape. 24. List the three stages of hair growth and what is happening during each stage. a. b. c. 25. How can one tell the difference between chemically bleached hair and sun- bleached hair? 26. Below is a bleached hair. How long ago was the hair bleached? (Use a ruler!) Show your work.

6 27. Hair characteristics are poorly defined and difficult to measure and yet it is often claimed in court that a certain hair is from a person with a certain racial background. What characteristics might be pointed out as proof of race? Give examples. 28. Think of one reason why over the next hundred years it will become even more difficult to distinguish races by hair type. 29. Fill in the T- chart below which compares human hair to other animal hair. Human Other Animals Pigmentation is denser toward the cuticle One color along the length Medullary index greater than 0.5 Cuticle is coronal in bats and rodents; spinous in cats, seals and mink 30. List five methods of collecting hair at a crime scene. a. b. c. d. e.

7 31. What is the difference between a macroscopic property and a microscopic property? Give examples of each. a. macroscopic- Examples: b. Microscopic- Examples: 32. What type of microscopy is used for each of the following? a. used to see the inside of the hair or the outside with much detail- b. used to provide contrast, good for translucent hair- c. detects presence of dyes or other treatments- 33. Both hair and urine can be analyzed for drugs. What is the advantage of testing the hair?