1. FINGERPRINTS

2. 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.

3. Dactyloscopy is the study of fingerprint identification.
Ridgeology: The study of the uniqueness of friction ridge structures and their use for personal identification.1
minutiae points: points where
the ridge structure changes.

4. 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!

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

6. How many ridge characteristics can you identify in this fingerprint?

7. Fingerprint- An impression left on a surface by the ridges on a finger
Latent fingerprint-hidden finger prints made visible by treating with a powder.
Patent fingerprints-The transfer of a fingerprint pattern by blood, ink or another substance.
Plastic fingerprints- indentations left in soft material such as clay or wax.

8. 3 types of patterns
Arch- ridge pattern that originates from one side of the finger and leaves from the other (5%)
Whorl- fingerprint that resembles a bull’s-eye (30%)
Loop- Pattern flows inwards and returns to the area it started. (65%)

9. CHARACTERISTICS OF FINGERPRINTS

10. Core- the center of a loop or whorl
Delta- triangular shaped area near a loop
Ridge count- the number of ridges between the core and a delta on a finger print.

11. 5 Steps For Fingerprinting
Clean finger tips with alcohol
Individual stands in front at an arms length away
Roll the finger from one side of the nail to the other on the ink pad. Ink should cover up to the first joint of the finger
Place the finger on the appropriate space and gently roll the finger from one side of the nail to the other.
Make note of any deformations or missing fingers.

12. Ten card – form used to preserve a persons fingerprints.

13. Collecting Fingerprints

14. 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.

15. 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.

16. 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.

17. CHANGING FINGERPRINTS
There are several documented cases of people deliberately mutilating their fingerprints in an effort to avoid being identified from marks left on the surfaces they touch. Methods used have included burning the fingertips with acid, which John Dillinger tried, and surgical alteration.