Exam II

1. Exam II Chapters 16, 7, 13, 10 and 12, Labs 5, 6, 7/8

2. Chapter 16 Fingerprints1. What contributions did Henry Faulds, Francis Galton, Juan Vucetich and Edward Richard Henry each make to fingerprinting? • Henry Faulds- claimed that fingerprints did not change over time and that they could be classified for identification • Francis Galton- developed a primary classification scheme based on loops, arches and whorls • Juan Vucetich- developed a fingerprint classification based on Galton’s that is used in Spanish-speaking countries • Edward Richard Henry- in collaboration with Galton instituted a numerical classification system

3. 2. Why are fingerprints considered individual evidence and what is the foundation for their acceptance in court? • A fingerprint is an individual characteristic because no two have yet been found to possess identical ridge characteristics. • The foundation for their acceptance in court: - The probability that two fingerprints could match is low. - There are an estimated 64 billion different individual prints. • This is supported by the millions of individuals who have had prints taken over the past 90 years in the FBI central system-- no two have ever been found to be identical!

4. 3. What are fingerprints? • Fingerprints are a reproduction of friction skin ridges found on the palm of the fingers and thumbs. • Dermal papillae extend outward and determine the form and pattern of ridges on the surface. • Dermal papillae develop in the fetus and the ridge patterns remain unchanged throughout life except to enlarge during growth. Figure 16-3 Cross section of human skin.

5. 4. How does thin skin differ from thick, or friction, skin? How does epidermis differ from dermis? • Skin is composed of layers of cells: - thin skin has 4 layers - thick/friction skin has 5 layers • Epidermis is superficial (outside) to the dermis, which is deep (inside). Figure 16-3 Cross section of human skin.

6. 5. Be able to identify ridge characteristics, or minutiae, on a sample fingerprint.

7. 6. Be able to identify the general ridge patterns that allow fingerprints to be systematically classified: • A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta. • Types • radial loop- opens toward the thumb • ulnar loop- opens toward the “pinky” (little finger) Figure 16-5 Loop pattern.

8. A plain whorl or central pocket whorl has at least one ridge that makes a complete circuit. A double loop is made of two loops. An accidental is a pattern not covered by other categories. Whorls have at least two deltas and a core. Figure 16-6 Whorl patterns.

9. An arch has friction ridges that enter on one side of the finger and cross to the other side while rising upward in the middle. They do NOT have type lines, deltas, or cores. Figure 16-7 Arch patterns.

10. 7. Be able to calculate an individual’s primary classification numberwhen given the point values and equation. Assign the number of points for each finger that has a whorl and substitute into the equation: right left right right left left left index ring thumb middle little + 1 = right right right left left thumb middle little index ring +1

11. 8. What are latent prints? • Latent fingerprints are those that are not visible to the naked eye. These prints consist of the natural secretions of human skin and require development for them to become visible.

12. 9. What three glands provide the secretions for latent prints and how do they differ? • Eccrine- largely water with both inorganic (ammonia, chlorides, metal ions, phosphates) and organic compounds (amino acids, lactic acids, urea, sugars). Most important for fingerprints. • Apocrine- secrete pheromones and other organic materials. • Sebaceous- secrete fatty or greasy substances.

13. 10. Know some techniques for developing latent prints including powders, iodine, ninhydrin, silver nitrate, and cyanoacrylate. • Powders- adhere to both water and fatty deposits. • Iodine- fumes react with oils and fats to produce a temporary yellow brown reaction; can be fixed for at least several weeks with a 1% solution of starch in water • Ninhydrin- reacts with amino acids to produce a purple color. • Silver nitrate- reacts with chloride to form silver chloride, a material which turns gray when exposed to light • Cyanoacrylate- “super glue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit.

14. 11. What is sublimation? • sublimation- solid that turns into a vapor without passing through a liquid phase e.g. iodine crystals

15. 12. What other types of prints can be analyzed? • Ears- shape, length and width • Voice- electronic pulses measured on a spectrograph • Foot- size of foot and toes; friction ridges on the foot • Shoes- can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern • Lips- display several common patterns like short vertical or horizontal lines, crosshatching and branching grooves • Teeth- bite marks are unique and can be used to identify suspects. • Eye- the blood vessel patterns in the eye may be unique to individuals

16. 13. What is AFIS? How was it improved by IAFIS? • Automated Fingerprint Identification System (AFIS)- a computer system for storing and retrieving fingerprints that began in the 1970’s • By the 1990’s most large jurisdictions had their own systems in place. The problem: a person’s fingerprints may be in one AFIS but not in others. • IAFIS- the FBI’s Integrated Automated Fingerprint Identification system which is a national database of all 10-print cards from all over the country

17. 14. What are biometrics and how can they be used? • Use of some type of body metrics for the purpose of identification. (The Bertillon system may actually have been the first biometry system.) • Used today in conjunction with AFIS • Examples include retinal or iris patterns, voice recognition, hand geometry • Other functions for biometrics: can be used to control entry or access to computers or other structures, can identify a person for security purposes, can help prevent identity theft or control social services fraud.

18. Lab 5 Fingerprinting15. What are latent prints? What are inked prints? • Latent prints- not visible to the naked eye; must be developed to become visible • Inked prints- taken from an individual for identification purposes

19. 16. Why did running one of your thumbs or fingers down the side of your nose or through your hair help you make a latent print? • Pick up secretions from sebaceous glands as well as eccrine glands.

20. 17. How were latent prints developed with powder and lifted? • Dip a soft fingerprint brush into the carbon black or aluminum fingerprint powder. Then tap it against the top of the powder jar to shake off the excess powder. • With a circular, sweeping motion that barely touches the slide, brush across the surface until you see the fingerprint begin to appear. • Once you see the fingerprint, apply powder in a direction that follows the ridge flow. • When the print is clearly developed, stop brushing (or you may destroy the fingerprint)! • If necessary, carefully shake off any excess powder from the slide over the powder jar or trash can. • Unwind a piece of clear tape about 10 cm in length and place the free end of the tape at a point about 7 cm from the top of the print on the slide. Smooth the piece of tape over the print with your finger, moving slowly from the free end of the tape to a point about 1 cm past the print. • When the print is entirely covered with tape, pull the whole piece of tape straight up at once, carefully removing the tape and print from the slide. • Transfer the print to a clean white index card.

21. 18. What are the components of a fingerprint?

22. 19. How are ninhydrin, iodine, and super glue used to detect latent fingerprints? • ninhydrin- solution swabbed onto print; reacts with amino acids to produce a pink/purple color • iodine- print placed in fuming jar for 3-5 minutes; reacts with oils to produce yellow/brown color; then fixed in solution • super glue- print placed in fuming chamber for hours; polymerizes on secretions to produce white print

23. Chapter 7 The Microscope20. What are the differences between a simple microscope, a compound microscope, and a stereoscope or dissecting microscope? • simple microscope- one lens e.g. magnifying lens • compound microscope- 2 lenses that “compound” or magnify each other • stereoscope or dissecting microscope- no special slide preparation necessary

24. 21. Know the functions and be able to label the following parts of a compound light microscope: • eyepiece • the part of the microscope you look into • usually magnifies material being viewed by 10x • sometimes contains a pointer that can be seen as you look into the eyepiece • may also be called the ocular because it contains the ocular lens • may be monocular or binocular

25. body tube - connects eyepiece to nosepiece • nosepiece • part of microscope to which the objectives are attached • rotates to allow for the changing of objectives to increase or decrease magnification

26. objectives - scanning/low (4x) - medium (10x) - high (40x) - oil immersion (60x)

27. arm • a secure part of the microscope to hold on to when the microscope is being carried

28. stage - platform on which microscope slide rests • stage clip • mechanical stage/slide adjuster - used for adjusting the position of the slide for viewing

29. coarse adjustment/focus knob - controls large movements of the stage or nosepiece • fine adjustment/focus knob - controls more precise focusing under higher powered objectives

30. diaphragm - regulates the amount of light passing through the slide

31. illuminator - light source • base - provides support for microscope

32. 22. Be able to calculate the total magnification when given the magnification of the ocular lens and an objective lens. • Total Magnification = Magnification of Ocular lens (10x) x Magnification of Objective Lens

33. 23. What is the field of view and how does it change as magnification increases? • Field of View (FV) is the illuminated circle that you see when looking through the microscope. • As magnification increases, the size of the FV gets smaller.

34. 24. Be able to calculate the diameter of a field of view under a new objective when given the magnification and diameter of a field of view under another objective. • Step 1 Calculate the Increase in Magnification. New Objective Old Objective • Step 2 Divide the old FV by the increase in magnification calculated in Step 1. Old FV (microns) Increase in Mag

35. 25. What is a comparison microscope? • comparison microscope- uses two stages and sets of objectives connected by one body tube to one eyepiece

36. 26. What are electron microscopes? • electron microscopes- use electrons to illuminate a specimen instead of light - Scanning Electron Microscope (SEM) - Transmission Electron Microscope (TEM)

37. Chapter 13 Hairs, Fibers and Paint27. What is a hair follicle? • Hair grows from a hair follicle, extending from its root or bulb, and continuing into the shaft before terminating at the tip.

38. 28. What are the three layers of a hair and where are they located? • cuticle- outside covering formed by overlapping scales • cortex- thickest layer • medulla- inner row of cells

39. imbricate spinous coronal 29. What scale patterns are found in the cuticles of humans and animals? • imbricate- human, dog • spinous- rabbit • coronal- cat Figure 13-2 Scale patterns of various types of hair.

40. 30. In which part of the hair are pigment granules embedded? • cortex-embedded with pigment granules whose color, shape and distribution provide important features for comparison

41. 31. What patterns can be found in the medulla? • medulla-humans may have a continuous, an interrupted, a fragmented, a solid, or no medulla Figure 13-4 Medulla patterns for various types of hair.

42. 32. How do the medullary indexes differ between humans and animals? • The ratio of the diameter of the medulla relative to the diameter of the whole hair is called the medullary index (MI). - Human hair usually has an MI of 1/3 or less. - Animal hairs usually have an MI of ½ or more.

43. 33. What are the three phases of hair growth and how do they differ? • anagen- growth phase that may last up to 6 years; root is attached to the follicle giving it a flame-shaped appearance • catagen- hair continues to grow, but at a decreasing rate for 2-3 weeks; root takes on an elongated appearance • telogen- hair growth ends and hair is pushed out of the follicle over a 2-6 month period; root has a club-shaped appearance Figure 13-6 Hair roots in the anagen phase, catagenphase, and telogen phase.

44. 34. What part of the hair is best for DNA analysis? • The follicular tag, when attached to the root,allows for the best DNA analysis.

45. 35. How does nuclear DNA differ from mitochondrial DNA? • nuclear DNA- DNA present within the nucleus of a cell; inherited from both parents - obtained from follicular tags of hairs in the anagen or catagen phases • mitochondrial DNA- DNA present in organelles called mitochondria; only inherited from the mother - can be obtained from any hairs 1-2 cm in length

46. 36. How many hairs are needed for a representative sample of head hair? Of pubic hair? • The collection of 50 full-length hairs from all areas of the scalp will normally ensure a representative sampling of head hair. • A minimum collection of 24 full-length pubic hairs should cover the range of characteristics present in pubic hair.

47. 37. What is the difference between natural fibers and manufactured fibers? Be able to recognize examples of each. • Natural fibers- derived from animal or plant sources e.g. animal- wool, cashmere, fur plant- cotton Figure 13-8 Photomicrograph of cotton fiber. • Manufactured fibers- derived from either natural or synthetic polymers e.g. rayon (regenerated fiber), nylon (synthetic fibers) Table 13-1 Major Generic Fibers

48. 38. What is a monomer? What is a polymer? • monomer- subunit • polymer- chain of monomers • Figure 13-10 Starch and cellulose are natural carbohydrate polymers consisting of a large number of repeating units or monomers.

49. 39. When can fiber evidence be individual evidence? • If the analyst can fit pieces of fiber together at their torn edges, then the evidence becomes individual.

50. 40. How can class characteristics obtained from fibers aid in an investigation like the Wayne Williams’ case? • Fibers can be analyzed for characteristics such as color, cross- section, type and other features. Figure 13-13 A scanning electron photomicrograph of the cross section of a nylon fiber removed from a sheet used to transport the body of a murder victim. The fiber, associated with a carpet in Wayne Williams’s home, was manufactured in 1971 in relatively small quantities.