1. Chapter 4
Fingerprints
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2. Lesson 1 – Fingerprints at the Crime Scene
Chapter 4
Lesson 1 – Fingerprints at the Crime Scene
Lesson Essential Questions:
How are fingerprints used as evidence in crime scenes?
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3. According to criminal investigators, fingerprints follow 3 fundamental principles:
A fingerprint is an individual characteristic; no two people have been found with the exact same fingerprint pattern.
A fingerprint pattern will remain unchanged for the life of an individual; however, the print itself may change due to permanent scars and skin diseases.
Fingerprints have general characteristic ridge patterns that allow them to be systematically identified.

4. 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
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5. Kendall/Hunt Publishing Company
Friction ridges (ridges and valleys) are present on the outer layer of our skin that make up our fingerprint. – Not due to genetics.
Outer epidermal layer separated from an inner dermal layer separated by papillae
The papillae form a boundary that determines the friction ridge.
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6. Fundamental Principles of Fingerprints
Chapter 4
Fundamental Principles of Fingerprints
A fingerprint is an individual characteristic.
A fingerprint remains unchanged during an individual’s lifetime.
Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.
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7. Kendall/Hunt Publishing Company
Using Fingerprints at a Crime Scene Video Fingerprints inside the Lab
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8. Kendall/Hunt Publishing Company
Lesson 2 – Classifying Fingerprints
Essential Questions:
How are fingerprints classified?
What are the basic differences in fingerprints?
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9. Kendall/Hunt Publishing Company
All fingerprints can be classified into 3 basic patterns:
Loops
Whorls
Arches
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10. Kendall/Hunt Publishing Company
Chapter 4
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?
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11. Kendall/Hunt Publishing Company
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.
Types
Plain
Central pocket
Double loop
Accidental
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12. Kendall/Hunt Publishing Company
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.
Types
Plain
Tented
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13. Primary Classification
Chapter 4
Primary Classification
The Henry-FBI Classification System
Each finger is given a point value. If your finger has a whorl pattern it is given a number.
right
left
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14. Primary Classification, continued
Chapter 4
Primary Classification, continued
Using your fingerprint sheet, assign the number of points for each finger that has a whorl and substitute into the equation:
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.
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15. Kendall/Hunt Publishing Company
Switch cards with others in the class and determine their types of fingerprints and classification numbers.
Fingerprint Factoid:
60% of people have loops, 35% have whorls,
and 5% have arches
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16. Kendall/Hunt Publishing Company
Ridge Classification
You have classified fingerprints according to general patterns.
Ridge Classification uses individual ridge characteristics or minutiae.
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17. Ridgeology: The study of the uniqueness of friction ridge structures and their use for personal identification.1 
The uniqueness of a fingerprint can be determined by the pattern of ridges and valleys as well as the minutiae points, which are points where the ridge structure changes.
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.
Did you know?
1Introduction to Basic Ridgeology by David Ashbaugh, May Image from

18. Ridge Characteristics
Chapter 4
Ridge Characteristics
Minutiae—characteristics of ridge patterns
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19. Kendall/Hunt Publishing Company
Chapter 4
Fingerprint Minutiae
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20. Kendall/Hunt Publishing Company
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.
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21. How many ridge characteristics can you identify in this fingerprint?

22. Kendall/Hunt Publishing Company
Lesson 3 – Fingerprinting Techniques:
1. What techniques are used to compare fingerprints?
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23. Latent prints are impressions left by friction ridge skin on a surface, such as a tool handle, glass, door, etc.
Prints may be collected by revealing them with a dusting of black powder and then lifted with a piece of clear tape.
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.

24. In modern labs, lasers can be used.
Some investigators use fluorescent powder and UV lights to help them find latent prints on multi-colored or dark surfaces.
Magnetic powder can also be used to reveal latent prints. This type of powder works better on shiny surfaces or plastic baggies or containers.
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.
In modern labs, lasers can be used.
Bottom Left:

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Chapter 4
AFIS
The Automated Fingerprint Identification System—a computer system for storing and retrieving fingerprints
Established in the 1970s, AFIS enables law enforcement officials to:
Search large files for a set of prints taken from an individual
Compare a single print, usually a latent print developed from a crime scene
By the 1990s, most large jurisdictions had their own system in place. The problem: A person’s fingerprints may be in one AFIS database but not in others.
IAFIS—the FBI’s Integrated Automated Fingerprint Identification System, which is a national database of all 10-print cards from all over the country
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26. Kendall/Hunt Publishing Company
Chapter 4
Biometrics
Use of some type of body metrics for the purpose of identification. (The Bertillon system may actually have been the first biometry system.)
Used today in conjunction with AFIS.
Examples include retinal or iris patterns, voice recognition, hand geometry.
Other functions for biometrics: can be used to control entry or access to computers or other structures; can identify a person for security purposes; can help prevent identity theft or control social services fraud.
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27. Kendall/Hunt Publishing Company
Chapter 4
Iodine Fingerprint
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28. Ninhydrin Fingerprint
Chapter 4
Ninhydrin Fingerprint
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29. Cyanoacrylate Fingerprints
Chapter 4
Cyanoacrylate Fingerprints
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30. Kendall/Hunt Publishing Company
Chapter 4
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
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31. Other Prints, continued
Chapter 4
Other Prints, continued
Palm—friction ridges can be identified and may be used against suspects
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32. Other Prints, continued
Chapter 4
Other Prints, continued
Footprints are taken at birth as a means of identification of infants.
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33. Other Prints, continued
Chapter 4
Other Prints, continued
Earprint catches murderer
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.
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34. Other Prints, continued
Chapter 4
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.
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35. Other Prints, continued
Chapter 4
Other Prints, continued
The blood vessel patterns in the eye may be unique to individuals. They are used today for various security purposes.
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36. Kendall/Hunt Publishing Company
Chapter 4
More about Prints
For additional information about prints and crime, check out truTV’s Crime Library:
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