Ridge characteristics minutiae points Island Bifurication Enclosure Ridge

Ridge characteristics (minutiae points) Island Bifurication Enclosure Ridge ending Ridge crossing Short Ridge Delta A single fingerprint may have as many as 100 or more identification points that can be used for identification purposes

WARM UP 12/3 1. 2. 3. 4. 5. 6. What was the Bertillon Method? What are the 3 principles of fingerprints? Who do you think would be considered “the father of fingerprinting”? Name 3 problems with Bertillon Method. What are dermal papillae? What are the 3 different print types?

Common Types of Fingerprints Three main groups: LOOPS WHORLS ARCHES

Loops • 60 - 65% of fingerprints are loops • A loop must have one or more ridges entering from one side of the print, curving & exiting from the same side • Loops have 1 delta

Whorls • About 30% - 35% of fingerprints are whorls • Whorl patterns must have at least two deltas

Types of Whorls 4 groups of whorls: 1. Plain 2. Central Pocket 3. Double Loop 4. Accidental

Plain Whorl • Inner area of pattern forms circles

Central Pocket Whorl • Circular pattern is off-centered

Double Loop Whorls • Looks like a sideways “S”

Accidental Whorl • Doesn’t fit any of the other types

There is a long history in India and China of the use of fingerprints as indications or attributes or character traits. Folk lore from both India and China have traditions of reading certain attributes or abilities from fingerprints. Before we become amused at the tendency to find significance in the counted number of prints, we note that such an approach is often used in scientific studies of the searching for meaningful relationships of fingerprints as genetic and/or chronic health markers. So while the conclusions drawn in Chinese and Hindu folk ways may be quaint, their methods of analysis still persist.

Chinese folk fingerprint formula(21) One whorl indicates poverty Two whorls indicate riches Three and four whorls good aspect to open a pawnshop Five whorls for a mediator Six whorls for a thief; Seven whorls very bad, indicates catastrophes; Eight whorls and you will eat chaff; Nine whorls with a loop and there will be no work for you to do, and plenty of food till old age;

HINDU: When the loop is found on: One finger, the subject is happy; But on two Fingers, it is not a favorable sign; and On three fingers it is a bad sign; When found only on four fingers it is not a good omen; and when found on five fingers it is not auspicious; But it is a sign of prowess if found on six fingers; and When placed on seven fingers live in kingly comfort; While on eight fingers one is as noble as a king; and On nine fingers one must live like a king;

Arches • About 5% of all fingerprints • There are no deltas Two types of arches 1. plain arch 2. tented arch

Plain Arch lines come in one side of the print and exit the other side

Tented Arch • Like a plain arch but it rises at a steep angle

Primary Classification (Henry System) Determined on the presence or absence of the whorl pattern Presence of a whorl pattern is given a numerical value that depends on the finger on which it occurs • other patterns are given a value of zero 25% population is 1/1 OR no whorls on any fingers

FORMULA: R. index + R. ring + L. thumb + L. middle + L. little +1 R. thumb + R. middle + R. little + L. index + (16/0) (8/0) (4/0) (2/0) L. ring + 1 (1/0) +1

10 Fingerprint Classification Good for having all prints on file Can narrow down fast if all prints were found at the scene FBI system of having all prints in categories

Crime Scene Fingerprints • Fingerprints found at a crime scene are often incomplete or less than perfect • An inked (known) print is compared to a latent (unknown) print • Ridge characteristics must be of the same shape & type, occupying the same relative position • Must be an adequate # of indistinguishable features with no unexplainable differences to be used in court – at least 12 characteristics (though no set number by law)