Introduction to Fingerprinting

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 • Bertillian System (1883) • Relied on a detailed description of the subject and body measurements. • AKA: Anthropometry • 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 fingers 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. 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. Ink on officer’s hand Always wear gloves The correct size Amount of ink Placement of ink Amount of pressure Direction of roll Thumbs-in Fingers-out Drunk/drugged suspects Additional Fingerprinting Problems

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

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. Demonstration • Fingerprint Demo • Any volunteers? • Palm Demo • Any volunteers?

17. Core • The approximate center of the fingerprint pattern.

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

19. Types of fingerprints • Arch • Loop • Whorl

20. 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.

21. 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.

22. 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.

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

24. 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

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