BASICS OF FINGERPRINTING FINGERPRINT CHARACTERSMINUTIAE PLAIN AND ROLLED

BASICS OF FINGERPRINTING • FINGERPRINT CHARACTERS/MINUTIAE • PLAIN AND ROLLED FINGERPRINTS.

FINGERPRINT CHARACTERS • Ridge characteristics or Galton details may take the following forms. • Spur/hook • Trifurcation • Bifurcation • Divergence • Rod enclosed in recurving • Enclosure or island • Dot • Short ridge • Long ridge • Ending ridge

Prints in database Known Prints Unknown Prints Direct Inked Latent Fingerprints

KNOWN PRINTS • These are prints taken from a known source. • Ultimate goal is to obtain good quality fingerprint from a known source so that it can be used for a variety of purposes, from searching to individualization. • The terms known, direct, and inked are considered synonymous. • The quality of these prints should be of sufficient clarity to allow for the comparison process to be conducted. These prints may also be known as ten print cards. • Can taken by manual method (Inked)or direct.

MANUAL METHOD (INKED) : EQUIPMENT Inking Plate : Should be hard, rigid and must have scratch resistant surface Printer’s Ink : Acts as a transfer medium. Dries quickly, easy to use and permanent. Roller : 6 X 2 in, provides uniform layer of ink on plate Fingerprint card : 8 X 8 inch identification card Cardholder : to hold the card flat to obtain proper surface Coroner’s spoon

Inking Plate Roller Cardholder Ink Fingerprint Card

MANUAL METHOD: PROCESS • Plate inked by using a roller. Film should be almost transparent Preparation. Taking Prints • Finger is rolled on inking plate from one side to another. • Fingers should be pressed lightly on card and roll from side to side (cuticle to cuticle; finger : rolled away and thumb : rolled toward the center of the body). These are known as rolled impressions. • For plain impressions: fingers should be inked at the same time and pressed onto the card simultaneously.

Fingers are rolled on inked slab Fingers are rolled on fingerprint card All four fingers are dabbed with ink on plate Fingers are rolled from awkward to easy position All the fingers are pressed simultaneously on FP card

Using Coroner’s Spoon for taking fingerprints

ROLLED IMPRESSIONS AND PLAIN IMPRESSIONS • Rolled fingerprints impressions are the ten individually-taken fingerprint images rolled from nail to nail. • These are of larger size and contain more minutiae. • Plain fingerprints impressions are taken simultaneously without rolling. These are referred to as plain, slap, or flat impressions. • The individual’s right and left four fingers should be captured first, followed by the two thumbs (4 -4 -2 method). Instituting this finger capture method ensures the highest level of fingerprint sequence accuracy. • are used to verify the sequence and accuracy of the rolled impressions and are less affected by distortion and have clearer ridge structure.

PROBLEMS IN TAKING FINGERPRINTS MECHANICAL OPERATION: Poor impressions are usually caused by • TEMPORARY DISABILITIES: • Poor, thin ink / Insufficient inking • Fresh cuts or wounds • Failure to clean the inking apparatus and finger prior to printing • Bandaged finger or fingers • Occupational issues: Bricklayers, carpenters, dishwashers • • Alcohol or other commercial preparation may be used. • Perspiring fingers should be wiped dry (perspiring fingers will cause smeared fingerprints). • Failure to completely roll the fingers fully from one side to the other • Use of too much ink • Allowing the fingers to slope or twist resulting in smears and blurs. (One of the biggest challenges is to take proper control of the subject being printed. ) • • Try using a small amount of ink. • Might also try using softening agents (oils/creams). Excessive perspiration • Wash hands or wipe with alcohol. • PERMANENT DISABILITIES • DEFORMED FINGERS

DIRECT PRINTS • Direct prints are taken by the means of live scanner. • With the manual method, proper inking of the prints is accomplished by ensuring the equipment is clean and in order. Live scans must adhere to the same basic principles. • Live scan displays an image on a monitor to the fingerprint operator to register for printing. • Advantage : • If the operator does not like the print that was registered, that print can be eliminated and retaken before permanent registration onto the fingerprint card. • Live scan system is not as messy as the manual method.

Finger being rolled on reader Automated Fingerprint Equipment (live scan) Live Scan palm prints Fingerprints in live scan

REFERENCES • Fingerprints : Analysis and Understanding , Mark Hawthorne.