Fingerprinting

1. Fingerprinting Forensic Science

2. Forensic Science Fingerprinting

3. Is it a match? • You will be given 2 prints. • Compare the second print to this print. • Can you determine if it is a match?

5. Major patterns What are the distinguishing patterns of these fingerprints? How would you describe them?

6. Fundamental Principles of Fingerprints An individual characteristic. Unchanged during an individual’s lifetime. Characteristic ridge patterns

7. Why do we have fingerprints? • Provides better grip • Called dermal or friction ridges • ? Makes perspiration easier on a hairless surface • ? Improves sense of touch

8. Skin • Epidermis (outer skin) has 3 layers • Peridermal • Intermediate • Basal • Dermis (under layer) • Amorphous fiber • Basal Layer – new skin cells form

9. Prints form in the fetus • Forms between the 10th – 17th week • Determined for life • Basal layer – • Forms new skin cells • Grows faster than the upper layers and the dermis • Folds into interconnected ridges

10. Prints • Natural secretions - water, oils, salt • Dirt • Provide an impression on contacted surfaces • Also on toes, soles of the feet, palms Kendall/Hunt Publishing Company

11. Fingerprint formation

12. Important Terms • Dactyloscopy • Patent fingerprint • Plastic fingerprint • Latent fingerprint • Epidermal • Basal layer • Dermis • Arch • Loop • Whorl • Delta • Core • Minutia patterns

13. Resources • http://finger-prints.com/index.html • http://en.wikipedia.org/wiki/Fingerprint • http://www.crimemuseum.org/library/forensics/fingerprints.html • http://www.livestrong.com/article/287440-the-development-of-fingerprints-in-babies/

14. Major visual patterns Loops 65% population Arches 5% population Whorls 30% population

15. Classification of Fingerprints • Three basic patterns: • Loop • 65% • Whorls • 10-20% • Arches • 5% • Racial variations • African (more arches), European (more loops), Asians/Orientals (more whorls)

16. Loop • A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta. • Types • Radial—opens toward the thumb • Ulnar—opens toward the “pinky” (little finger) • Which type of loop is this, if it is on the right hand? Left hand? Delta

17. Whorl • Whorls have at least two deltas and a core. • Four Groups • Plain • Central Pocket • Double Loop • Accidental Plain Whorl

18. Whorl • Central Pocket

19. Whorl • Double loop

20. Whorl • Accidental

21. Arch • 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. Types • Plain • Tented

22. Identify each fingerprint pattern. ? A B Right Hand Left Hand C Right Hand E D Right Hand Left Hand

23. It’s time to makesome prints! Avoid Partial Prints GOOD PRINTGet as much of the top part of your finger as possible!

24. Henry-FBI Classification Developed by Edward Henry Allowed all sets of ten fingerprints in the world to be divided into 1024 groups Secondary and more complex classifications were created to allow for more groups

25. Primary Classification The Henry—FBI Classification Based on WHORLS Each finger is given a point value right left

26. Primary Classification right right left left left index ring thumb middle little + 1 = right right right left left thumb middle little index ring +1 That number is your primary classification number Assign the number of points for each finger that has a whorl and substitute into the equation:

27. Individualization • Henry-FBI Classification • Narrows into a group • Ridge Classification • Uses minutiae to individualize fingerprints • In U.S. there are no legal requirements for # of points • Criminal courts accept 8 to 12 points • 150-200 minutiae in a good rolled print

28. Fingerprint Minutiae Kendall/Hunt Publishing Company

29. Ridge Characteristics Minutiae—characteristics of ridge patterns • Ridge ending • Short ridge • Dot or fragment • Bifurcation • Double bifurcation • Trifurcation • Bridge • Island • Enclosure • Spur

31. Comparison Can you identify the points?

32. Fingerprint Minutiae

33. How are fingerprints analyzed? The Automated Fingerprint Identification System—a computer system for storing and retrieving fingerprints Established in the 1970s IAFIS—the FBI’s Integrated Automated Fingerprint Identification System, which is a national database of all 10-print cards from all over the country Kendall/Hunt Publishing Company

34. Latent Prints • Latent fingerprints • Hidden • Natural secretions of human skin • Require development for them to become visible • Most secretions come from glands: • 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.

35. Developing Latent Prints • Requires substances that interact with secretions • Attempt more than one technique, done in a particular order so as not to destroy the print

37. Iodine Fingerprint

38. Ninhydrin Fingerprint

39. Cyanoacrylate Fingerprints

40. Other Prints Lips—several common patterns 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

41. Other Prints Lips—display several common patterns • Short vertical lines • Short horizontal lines • Crosshatching • Branching grooves

42. Other Prints Palm—friction ridges can be identified and may be used against suspects Kendall/Hunt Publishing Company

43. Other Prints Footprints are taken at birth as a means of identification of infants. Kendall/Hunt Publishing Company

44. Other Prints A man has been convicted of suffocating an eldery woman on the basis of earprint evidence. The assailant was caught after police matched the inprint of his ear on the victim’s window. Police believe that the thief put his ear to the window to listen for signs of anyone home. Earprint catches murderer Kendall/Hunt Publishing Company

45. Other Prints, continued Teeth—bite marks are unique and can be used to identify suspects. These imprints were placed in gum and could be matched to crime scene evidence. Kendall/Hunt Publishing Company

46. Other Prints The blood vessel patterns in the eye may be unique to individuals. They are used today for various security purposes.

47. Which fingerprints are matches? Match the ones that are made by the same finger. In some cases, one print may appear two or three times.

48. Matching can be facilitated by digital enlarging and comparing cropped areas, or by enlarging with a photocopier and using a transparency overlay. A = G = S This one is interesting; there are three separate impressions of the same finger with some very unique features. B = no match C = no match D = no match E = T F = J H = R I = no match K = O L = no match M = P N = Q

49. Case Study: Madrid Bombings. Comparison of fingerprints Mayfield prints Prime suspect