Fingerprints and Minutiae

1. Fingerprints and Minutiae .

2. Three fundamental principals of Fingerprints • Individual characteristic • Will remain unchanged during the individual’s lifetime • Have general characteristic ridge patterns that permit systematic classification

3. History • Alphonse Bertillon started the identification process with his Anthropometry measurements in 1881 • Francis Galton then upon studying fingerprints and Bertillon's method perfected the fingerprint system and published books in1892 and later Edward Henry simplified his system • In 1901 Juan Vucetich set up a workable system refining Galton's system and it was used in Spanish speaking countries. He was the first to officially identify a criminal using the fingerprint system

4. 3 TYPES OF FINGER PRINTS • Latent – prints are not visible until developed made by oils and chemicals this type can be found on any evidence including skin. • Visible –visible to naked eye—left by a finger that has touched material such as blood , paint etc. • Plastic or Physical--- Made in soft material such as putty, paint, soap etc.

5. 3 MAJOR PATTERNS OF FINGERPRINTS • 3 main Patterns consisting of: • Arches – least common • Loops –most common-two sub groups …radial & ulnar • Whorls- 4 sub groups--- plain whorl- central pocket whorl- double loop whorl- accidental whorl • Approximately five percent of all fingerprints are Arches, 30% are Whorls and 65% are Loops.

6. METHODS OF OBTAINING PRINTS • Some of the most common techniques of finding and lifting prints include: • Dusting with carbon – dusting with white or black powder to cover print( most common) can be used with glass, solids plastics etc. • Super glue fuming – developed in 1970s--leaves white impression • Ninhydrin – reacts/amino acids in fingerprint and leaves purple image used on matchbooks, newspaper etc. • Silver nitrate- reacts with NACL left from perspiration in the fingerprint • Laser technology – laser images

7. INFO • Fingerprints can last for years • Loop most common • Fingerprints composed of salt, oil, & amino acids • Latent fingerprints can be left anywhere including skin • Prints can also be found in feet and palms even other parts of the body

8. Arch

9. Arch • The Arch pattern has no delta or core; but, it too, must be fully recorded so that its individual characteristics can be readily distinguished. • Simplest of all fingerprints

10. Tented arch

11. Whorl

12. Whorl • A Whorl pattern will have two or more deltas. For a whorl pattern, all deltas and the areas between them must be recorded. • Subdivided into 4 groups—plain whorl, central pocket loop whorl, double loop whorl, and accidental whorl

13. Loop

14. Loop • In the Loop pattern there are two focal points: • the Core, or the center of the loop, and the delta. • The Delta is the area of the pattern where there is a triangulation or a dividing of the ridges. • Most common type • When recording fingerprints, the delta and the area between the delta and the core must be completely recorded • Two types of loop: Ulnar loop – opens toward the little finger and the Radial loop – opens toward the thumb

15. Minutiae • Different ridge characteristics in the finger prints

16. Ridge Ending • Ridge ending a single ridge ending within a friction ridge structure

17. Ridge characteristics/Bifurcation • Bifurcation The point at which one friction ridge divides into two friction ridges

18. Enclosure or eye ridge A single friction ridge that bifurcates and rejoins after a short course and continues as a single friction ridge

19. Island or short ridge a single friction ridge that only travels a short distance before termination

20. Crossover ridge One ridge crosses Over another ridge Will look like an x

21. Dot ridge Small dot by itself in the middle of two or more ridges

22. Spur ridge • The spur has a single short ridge that looks like a hook that comes off of a longer ridge. • µ

23. Triple bifurcation ridge • Similar to the bifurcation except it has three ridges coming of the main ridge looks sort of like a fork

24. Bridge • Two ridge points are joined together by a short ridge • ≠

25. Other Characteristics Scaring…..

26. Points used for identification • No legal requirements in the USA for the number of points that must match before deciding that a print matches • Criminal courts will generally accept 8-12 points. • Apx 150- 200 minutiae in properly rolled fingerprint.

27. Match the points

28. Are they fool proof? • Fingerprints cannot lie however analysis and identification are subject to error. • Example: Madrid bombings on March 11, 2004 coordinated train bombings in Madrid Spain killed 191 people ( 911 days after 9/11) • Bag found with fingerprints identifying Brandon Mayfield, an Organ lawyer..he was held for two weeks while investigated and it turned out after a more thorough analysis the prints were not an exact match…..FBI acknowledged “serious error” in the identification and apologized. Mayfield was not satisfied and sued the U.S. gov and settled for 2 million dollars.

29. AFIS • Automated Fingerprint Identification System • FBI system that stores all fingerprints taken –over 200 million prints on file with FBI • Linked to countries around the world • Decreases the ability of criminals to flee the country or to commit murders in several different places.