1. Fingerprints
“Fingerprints cannot lie, but liars can make fingerprints.” unknown

2. Why are fingerprints useful?
What is a fingerprint?
An imprint made by ridge patterns on the tip of a finger.
Also used to describe the characteristic pattern of DNA fragments.
Why are fingerprints useful?
Properties that make a fingerprint useful for ID:
It’s unique characteristic ridges which make them individual evidence.
It’s consistency over a person’s lifetime. It remains unchanged during an individual’s lifetime.
The systematic classification is used for fingertips based on their general characteristic ridge patterns.

3. Dactyloscopy The Study of Fingerprints
Chapter 4
Dactyloscopy The Study of Fingerprints
History from 1850 to 1900 William Herschel—required Indians to put their fingerprints on contracts, and used fingerprints as a means of identifying prisoners Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification Alphonse Bertillon—proposed body measurements as a means of identification; termed anthropometry Francis Galton—developed a primary classification scheme based on loops, arches, and whorls Edward Richard Henry—in collaboration with Galton, instituted a numerical classification system Juan Vucetich—developed a fingerprint classification system based on Galton’s that is used in Spanish-speaking countries
Kendall/Hunt

4. Collection and Classification of Prints
Chapter 4
Collection and Classification of Prints
Recording and classifying prints
Rolling inked prints
3 Basic patterns - Loops, whorls, arches
Ridge characteristics – Minutiae (very small)
Primary identification number
Lifting prints
Black, white, and fluorescent powder
Chemicals—ninhydrin, iodine, silver nitrate, cyanoacrylate
Other types of prints
Palm, lip, teeth, eye, ear, voice, shoeprints, and footprints
Kendall/Hunt

5. Ridge Characteristics
Chapter 4
Ridge Characteristics
Minutiae—characteristics of ridge patterns
Kendall/Hunt

6. Chapter 4
Fingerprint Minutiae
Kendall/Hunt

7. Basic Fingerprint Patterns
Chapter 4
Basic Fingerprint Patterns
LOOP
WHORL
ARCH
Kendall/Hunt

8. Chapter 4
Loop
A loop must have one or more ridges entering from one side, curving around and exiting from the same side. Loops must have one delta.
Most common type (65%) and more common in people of European background. Also, forefingers have most of the radial loops.
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?
Kendall/Hunt

9. Chapter 4
Whorl
A plain 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.
Found in 30% of population. People of Asian ancestry are more likely to have whorls.
Types
Plain
Central pocket
Double loop
Accidental
Kendall/Hunt

10. Arch Plain – gradual bump Tented – much higher, pinched arch
Chapter 4
Arch
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.
Least common type (5%) and more likely found in people of African ancestry.
Types
Plain – gradual bump
Tented – much higher, pinched arch
Kendall/Hunt

11. Four Types of Whorls Whorl: line drawn
from delta to delta intersect circle.
Double Whorl
Central Pocket: line drawn from delta to delta do not intersect circle.
Accidental: prints too irregular to fall into any group.

12. Primary Classification
Chapter 4
Primary Classification
The Henry-FBI Classification System
Each finger is given a point value.
**Fingerprints are given as a fraction. Identify
which fingers have whorls; each whorl has a number
based on which finger it is on.
Loops and arches are a “0”.
Right Right Left Left Left
index ring thumb middle little =
Right Right Right Left Left
thumb middle little index ring =
Example: Whorl on your left thumb and right middle finger.
= is your primary
= classification
right
left
Kendall/Hunt

13. Chapter 4
Comparison
There are no legal requirements in the United States on the number of points required for a match. Generally, criminal courts will accept 8 to 12 points of similarity.
Kendall/Hunt

14. Identify each fingerprint pattern? A B
Right Hand
Left Hand C
Right Hand E D
Right Hand
Left Hand 21 14

15. It’s time to make some prints!
Avoid Partial Prints
GOOD PRINT Get as much of the top part of your finger as possible! 15