Introduction Introduction to to

FingerprintinFingerprintinggBy:By:

Steve ChristiansenSteve Christiansen

Why are prints Why are prints important?important?

Tells us who the person Tells us who the person is (or is not)is (or is not)

Who committed the Who committed the crimecrime

Keeps criminal historyKeeps criminal history

Why so many copies?Why so many copies?

Arresting agencyArresting agency County agencyCounty agency StateState FBIFBI

Brief History of Brief History of FingerprintingFingerprinting

Bertillian System (1883)Bertillian System (1883)– Relied on a detailed description of the Relied on a detailed description of the

subject and body measurements.subject and body measurements.– AKA: AnthropometryAKA: Anthropometry

Chinese used fingerprints to sign Chinese used fingerprints to sign documents 3,000 years agodocuments 3,000 years ago

18921892– Galton published classic textbook “Finger Galton published classic textbook “Finger

Prints”Prints”

History of FingerprintingHistory of Fingerprinting

18971897– Classification system designed by Sir Classification system designed by Sir

Edward HenryEdward Henry 19241924

– Merger of Bureau of Investigations Merger of Bureau of Investigations and Leavenworth Prison formed and Leavenworth Prison formed nucleus of ID section of FBI.nucleus of ID section of FBI.

Fundamental Principle of Fundamental Principle of FingerprintsFingerprints

1 A fingerprint is an individual A fingerprint is an individual characteristic.characteristic.

2 No two fingers have ever been found to No two fingers have ever been found to be alike.be alike.

3 A fingerprint will remain unchanged A fingerprint will remain unchanged during an individual’s lifetime.during an individual’s lifetime.

4 Fingerprints have general ridge patterns Fingerprints have general ridge patterns that permit them to be systematically that permit them to be systematically classified.classified.

Live ScanLive Scan

In use at a California facility

Fingers Cut by Fingers Cut by RazorbladeRazorblade

Common Common Fingerprinting Fingerprinting

ProblemsProblems

What do you do if suspect What do you do if suspect has dry hands?has dry hands?

Have them apply lotion.Have them apply lotion.

What do you do for sweaty What do you do for sweaty hands?hands?

Wash hands in cold water and dry Wash hands in cold water and dry thoroughly.thoroughly.

Additional Fingerprinting Additional Fingerprinting ProblemsProblems

Ink on officer’s Ink on officer’s handhand– Always wear Always wear

glovesgloves The correct sizeThe correct size

Amount of inkAmount of ink Placement of Placement of

inkink

Amount of Amount of pressure pressure

Direction of rollDirection of roll– Thumbs-inThumbs-in– Fingers-outFingers-out

Drunk/drugged Drunk/drugged suspectssuspects

Direction of RollDirection of Roll ThumbThumb

– Toward the Toward the center of center of the the subject’s subject’s body.body.

FingerFinger– Away from Away from

the center the center of the of the subject’s subject’s body.body.

To roll the best To roll the best prints:prints:

Roll finger “nail to nail”Roll finger “nail to nail” or or “cuticle to cuticle” “cuticle to cuticle”

Steady even pressureSteady even pressure Grasp each finger at the base Grasp each finger at the base andand tip tip YouYou control the suspect’s finger, arm, control the suspect’s finger, arm,

and body.and body. Clean ink board frequently; if not, Clean ink board frequently; if not,

proper prints will not be taken.proper prints will not be taken.

ADDITIONAL HINTSADDITIONAL HINTS

If fingers are bent or crooked, take best If fingers are bent or crooked, take best prints possible using a spoon.prints possible using a spoon.

Place print in the center of the box, Place print in the center of the box, straight up and down (not tilted).straight up and down (not tilted).

Take footprints if suspect has no hands.Take footprints if suspect has no hands. Forearm should be horizontal to table.Forearm should be horizontal to table. Always try and take palm prints!Always try and take palm prints! Pats or simultaneous impression are Pats or simultaneous impression are

always needed; if not, AFIS will reject card.always needed; if not, AFIS will reject card.

DemonstrationDemonstration Fingerprint DemoFingerprint Demo

– Any volunteers?Any volunteers?

Palm DemoPalm Demo– Any volunteers?Any volunteers?

CoreCore The The

approximatapproximate center of e center of the the fingerprint fingerprint pattern.pattern.

DeltaDelta A point on A point on

the the fingerprint fingerprint where it where it splits and splits and forms a “Y”-forms a “Y”-type type formation.formation.

Types of Types of fingerprintsfingerprints

ArchArchLoopLoopWhorlWhorl

ArchArch A plain arch is that A plain arch is that

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

LoopLoop A loop is that type of A loop is that type of

pattern in which one pattern in which one or more ridges enter or more ridges enter upon either side, upon either side, recurve, touch, or recurve, touch, or pass an imaginary pass an imaginary line between delta line between delta and core and pass and core and pass out upon the same out upon the same side the edges side the edges entered.entered.

WhorlWhorl A central pocket loop A central pocket loop

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

AFISAFIS Automated Automated

Fingerprint Fingerprint Identification Identification System, a large System, a large mainframe mainframe computer used computer used to store and to store and search search fingerprints.fingerprints.

Latent Scan Center

How does AFIS read and How does AFIS read and process printsprocess prints

Scans cardScans card– Starts at coreStarts at core– Places dots where lines endPlaces dots where lines end– Creates spider web connecting the Creates spider web connecting the

dotsdots– Comparisons are made of spider websComparisons are made of spider webs– Prints out matchesPrints out matches– Verified by techniciansVerified by technicians

Have a great Have a great day!!!day!!!

Questions???Questions???