Forensic Fingerprint Analysis

1. Forensic Fingerprint Analysis

2. History of Fingerprints 1788 - Johann Mayer noted that the arrangement of skin ridges is never duplicated in two persons. He was probably the first scientist to recognize this fact. 1880 – Henry Fauld working in Japan publishes fingerprint identify after case where print was left on whitewashed wall Rejected for Bertillon system for 20 years then adopted 1892 – Francis Galton assigned fingerprints into 3 types Loops, Whorls, and Arches

3. 3 Fundamental Principles of Fingerprints • A fingerprint is an individual characteristic. No 2 people have been found to have identical ridge characteristic 1 x 1020 chance of 2 people having identical ridge characteristics That’s 1 in 100,000,000,000,000,000,000!

4. A fingerprint remains unchanged during an individual’s lifetime - each print is composed of valleys and ridges - The ridges are believed to help with grip - Each ridge has multiple sweat pores that lead to sweat glands

5. People have tried to change their prints • John Dillinger (public enemy #1)

8. Fingerprints have general ridge patterns that permit them to be systematically classified

9. Loop Whorl Arch Fingerprint Classes There are 3 specific classes for all fingerprints based upon their visual pattern: arches, loops, and whorls. Each group is divided into smaller groups

10. Arches, Loops, Whorls

11. Directions 1st – Roll the “pad” portion of your thumb over the ink pad from the left side of your thumb to the right. You do not have to push down really hard! 2nd – Roll the “pad” portion of your thumb from the left side of your thumb to the right in the correct box on your paper to make a thumbprint. 3rd – Continue this process to make a fingerprint of all ten fingers on the “Data Table A” worksheet. 4th –Use your notes and a magnifying lens to help you figure out what type of pattern is found in each of your fingerprints. Label each one with the pattern’s name.

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

13. Fingerprint Analysis How do our fingerprint patterns compare to the expected averages?

14. Table C

15. Let’s determine the rate of occurrence for our fingerprint patterns ... How do our results compare to the averages? 60% - Loops 35% - Whorls 5 % - Arches __% - Loops __% - Whorls __% - Arches Write a paragraph on your worksheet that summarizes our results.

16. Let’s determine the rate of occurrence to compare males vs. females. Which pattern is most common pattern among the males in this class? Which is most common pattern among the females? How do the averages for each sex compare to the expected averages?

17. Characteristics of Fingerprints • Forensic examiners look for the presence of core and deltas. • The core is the center of a loop or whorl • The delta is a triangular region where ridges change directions • A ridge count is another characteristic used to distinguish one fingerprint from another. • Draw an imaginary line from the center of the core to the edge of the delta

18. Characteristics of Fingerprints • Forensic examiners look for the presence of a core (the center of a whorl or loop) and deltas (triangular regions near a loop). • A ridge count is another characteristic that distinguishes one fingerprint from another. The count is made from the center of the core to the edge of the delta. Forensic Science: Fundamentals & Investigations, Chapter 6

19. ADD TO NOTES Interesting Info Fingerprint Factoid: 60% of people have loops, 35% have whorls, and 5% have arches Did you know? Dactyloscopy is the study of fingerprint identification. Police investigators are experts in collecting “dactyl grams”, otherwise known as fingerprints.

20. Spike or “tent” Plain Arch Ridges enter on one side and exit on the other side. Tented Arches Similar to the plain arch, but has a spike in the center. Arches Arches are the simplest type of fingerprints Formed by ridges that enter on one side of the print and exit on the other. No deltas are present.

21. Loops Loops must have one or more ridges that enter and leave on the same side. Have one delta These patterns are named for their positions related to the radius and ulna bones. Delta

22. To characterize a fingerprint as a radial or ulnar loop, one must know from which hand it came. Ulnar loop Radial loop

23. Radial Loop Loop opens toward right or the ulna bone. (toward Pinkie finger) Ulnar Loop Loop opens toward the left or the radial bone. (thumb) NOTE: On the left hand, a loop that opens to the left would be an ulnar loop, while one that opens to the right would be a radial loop.

24. Whorls Whorls have at least one ridge that makes (or tends to make) a complete circuit. (4 types) Have at least two deltas. If a print has more than two deltas, it is most likely an accidental. Central Pocket Whorl Plain Whorl Draw a line between the two deltas in the plain and central pocket whorls. If some of the curved ridges touch the line, it is a plain whorl. 2)If none of the center core touches the line, it is a central pocket whorl.

25. Double Loop Whorl Accidental Whorl Double loop whorls are made up of any two loops combined into one print. Accidental whorls contain two or more patterns (not including the plain arch), or does not clearly fall under any of the other categories. Delta Delta Whorls – Part 2

26. Accidental Whorl Double Loop Whorl Central Whorl Plain Whorl

27. Double loop Whorl Identify each fingerprint pattern. ? PLAIN WHORL A B Right Hand Left Hand PLAIN ARCH TENTED ARCH C Right Hand E D ULNAR LOOP Right Hand Left Hand

28. Classification of Prints • 1st system: Henry system but could only handle 100,000 prints • Today IAFIS has over 66 million (66,000,000) sets of prints • Today use FBI system, very similar to Henry system • All prints will fit in 1 of 1,024 different groups

29. FBI System • Pair up fingers in 5 fractions: • R. IndexR. RingL. ThumbL. MiddleL. Little+1 R. Thumb R. Middle R. Little L. Index L. Ring +1 • Now look for presence of a whorl • If on the first pair = 16 • If on 2nd pair = 8 • 3rd pair = 4 • 4th pair = 2 • 5 pair = 1 • Add up 1 to numerator and denominator and all together

30. Example of FBI system • If whorls were found on right index, right middle fingers • 16 + 0 + 0 + 0 + 0 + 1 0 + 8 + 0 + 0 + 0 + 1 * 25% of population has a 1:1 ratio 17/9 =

31. As we have learned in our first lesson, a fingerprint is made of a series of ridges and valleys on the surface of the finger. The uniqueness of a fingerprint can be determined by the pattern of ridges and valleys Did you know? The koala is one of the few mammals (other than primates) that has fingerprints. In fact, koala fingerprints are remarkably similar to human fingerprints; even with an electron microscope, it can be quite difficult to distinguish between the two. Ridgeology: The study of the uniqueness of friction ridge structures and their use for personal identification.1

32. Automated Fingerprint Identification System (AFIS) AFIS is a computerized system capable of reading, classifying, matching, and storing fingerprints for criminal justice agencies. Quality latent fingerprints are entered into the AFIS for a search for possible matches against the state maintained databases for fingerprint records to help establish the identity of unknown deceased persons or suspects in a criminal case. http://www.fdle.state.fl.us/CrimeLab/images/fingerrint%20comparison%20for%20afis.jpg Fingerprint Identification When minutiae on two different prints match, these are called points of similarity or points of identification. At this point there is no international standard for the number of points of identification required for a match between two fingerprints. However, the United Kingdom requires a minimum sixteen points while Australia requires twelve.

33. AFIS CLOSE UP Automated Fingerprint Identification System : A network that scans crime scene fingerprints and compares them with millions of prints collected by law enforcement agencies around the world.

34. Livescan • Don’t use ink much anymore, but scan directly into the computer

35. Island Dot Bifurcation Ridge ending Minutiae • Each individual has unique fingerprints. A fingerprint is defined by the uniqueness of the local ridge characteristics and their relationships. • Minutiae points (aka Galton’s details) are the local ridge characteristics. • Identification points consist of bifurcations, ending ridges, dots, ridges and islands. • A single rolled fingerprint may have as many as 100 or more identification points that can be used in order to identify the individual.

36. Ridge Characteristics Use these characteristics as points of identification when comparing fingerprint samples. The more points you can find in common, the better the match!

37. Minutiae Patterns www.fbi.gov

38. Minutiae Patterns www.fbi.gov

39. Crossover Core Bifurcation (fork) Ridge ending Scar Island Delta Pore Ridge Characteristics EXAMPLE

40. http://www.dkfz.de/tbi/projects/bmcv/images/iu_it246_04s_fingerprint1.jpghttp://www.dkfz.de/tbi/projects/bmcv/images/iu_it246_04s_fingerprint1.jpg How many ridge characteristics can you identify in this fingerprint?

41. Try It! 1 – Blow up your balloon about halfway and twist the end to keep the air from coming out. Do not tie it off! 2 – Use an ink pad to make a print with all of your fingers and label each one with a permanent marker. Write your name on the balloon as well. 3 – Blow up the balloon to full size and tie the end. 4 – Analyze the fingerprints to find several ridge structures that we have discussed. Use a highlighter to mark these structures on your “My Prints” worksheet. Think About It! Which ridge structures were most common in your fingerprints? Which ridge structures were most common in your group? Were there any structures that were not found in any of the fingerprints? Balloon Fingerprint Activity: http://www.msichicago.org/fileadmin/Education/learninglabs/lab_downloads/fingerprint_analysis.pdf

42. 3 types of prints • Visible prints • Prints seen with naked eye in oil (blood, paint, grease, ink) • Plastic Prints • Print impression left on putty, wax, soap, or dust

43. Did you know? Camel hair is the most common animal hair used to make fingerprint brushes. Now many brushes (like the one above) are made out of fiberglass. Latent prints are impressions left by friction ridge skin on a surface, such as a tool handle, glass, door, etc. that are invisible to the naked eye. Prints may be collected by revealing them with a dusting of black fingerprint powder.

45. Powdering Techniques • Always wear gloves • Hold brush lightly between index finger and thumb • Apply powder with tips of strands of brush • Brush WITH the grain of the ridges • Use fiberglass brushes for graphite powder

46. Magnetic powder can also be used to reveal latent prints. This type of powder works better on shiny surfaces or plastic baggies or containers. Some investigators use fluorescent powder and UV lights to help them find latent prints on multi-colored or dark surfaces. RUVIS Reflected Ultraviolet Imaging System The cyanoacrylate fuming method (often called the super glue method) is a procedure that is used to develop latent fingerprints on a variety of objects. Ninhydrin is a chemical that bonds with the amino acids in fingerprints and will produce a blue or purple color. It is used to lift prints from surfaces such as paper and cardboard. Top Left: http://www.stapletonandassociates.com/images/MagPowder.jpg Bottom Left: http://www.ok.gov/osbi/images/ninhydrin%20print.jpg Bottom Right: http://www.forensicsrus.com/images/SupergluePrint.jpg

47. Iodine Fuming • Iodine sublimes and sticks to oils • Silver Nitrate • Sticks to salt in perspiration. Good for porous surfaces or have even been wet at one time

48. IF MORE THAN ONE METHOD IS USED... • If more than one method is used to develop prints, the order in which the techniques are used is important. The following order should be used to develop fingerprints: • This is the procedure used for optimal visualization because Iodine fuming is not permanent. • If Ninhydrin fails, silver nitrate can be used but it will wash away all the fatty oils and proteins from the surface. • Superglue fuming, if used, must be used last. (1) Iodine fuming (2) Ninhydrin (3) Silver nitrate (4) Superglue fuming

49. Preservation of Prints • Always take a digital picture of print • If small enough object, wrap in cellophane to preserve print • Or use piece of adhesive (scotch tape) and then stick to contracting piece of cardboard (mounting card)

50. Photographing Prints • Photograph latent print life size 1:1 • If not 1:1 – fill the frame • Use macro lens • Include identification tag with scale • Maintain photo log