1. Introduction to Fingerprinting
By:
Steve Christiansen

2. Why are prints important?
Tells us who the person is (or is not)
Who committed the crime
Keeps criminal history

3. Why so many copies?
Arresting agency
County agency
State
FBI

4. Brief History of Fingerprinting
Chinese used fingerprints to sign documents 3,000 years ago
1892
Galton published classic textbook “Finger Prints”

5. History of Fingerprinting
1897
Classification system designed by Sir Edward Henry
1924
Merger of Bureau of Investigations and Leavenworth Prison formed nucleus of ID section of FBI.

6. Fundamental Principle of Fingerprints
A fingerprint is an individual characteristic.
No two fingerprints have ever been found to be alike.
A fingerprint will remain unchanged during an individual’s lifetime.
Fingerprints have general ridge patterns that permit them to be systematically classified.

7. In use at a California facility
Live Scan
In use at a California facility

8. Fingers Cut by Razorblade

9. Common Fingerprinting Problems

10. What do you do if suspect has dry hands?
Have them apply lotion.

11. What do you do for sweaty hands?
Wash hands in cold water and dry thoroughly.

12. Additional Fingerprinting Problems
Ink on officer’s hand
Always wear gloves
The correct size
Amount of ink
Placement of ink
Amount of pressure
Drunk/drugged suspects

13. Direction of Roll Thumb-IN Finger-OUT
Toward the center of the subject’s body.
Finger-OUT
Away from the center of the subject’s body.

14. To roll the best prints:
Roll finger “nail to nail” or “cuticle to cuticle”
Steady even pressure
Grasp each finger at the base and tip
You control the suspect’s finger, arm, and body.
Clean ink board frequently; if not, proper prints will not be taken.

15. ADDITIONAL HINTS
If fingers are bent or crooked, take best prints possible using a spoon.
Place print in the center of the box, straight up and down (not tilted).
Take footprints if suspect has no hands.
Forearm should be horizontal to table.
Always try and take palm prints!
Pats or simultaneous impression are always needed; if not, AFIS will reject card.

16. Core
The approximate center of the fingerprint pattern.

17. Delta
A point on the fingerprint where it splits and forms a “Y”-type formation.

18. Types of fingerprints
Arch
Loop
Whorl

19. Arch
A plain arch is that type of pattern in which the ridges enter upon one side, make a rise or wave in the center, and flow or tend to flow out upon the opposite side. A plain arch cannot have a looping ridge, an up-thrust, or a recurve.

20. Loop
A loop is that type of pattern in which one or more ridges enter upon either side, recurve, touch, or pass an imaginary line between delta and core and pass out upon the same side the edges entered.

21. Whorl
A central pocket loop whorl consists of at least one re-curving ridge, or an obstruction at right angle to the line of flow, with two deltas, between which, when an imaginary line is drawn, no re-curving ridge within the inner pattern area is cut or touched.

22. AFIS
Automated Fingerprint Identification System, a large mainframe computer used to store and search fingerprints.
Latent Scan Center

23. How does AFIS read and process prints
Scans card
Starts at core
Places dots where lines end
Creates spider web connecting the dots
Comparisons are made of spider webs
Prints out matches
Verified by technicians

24. Have a great day!!! Questions???