II: Development, Identification, and Presentation of Fingerprints
Table of Contents:
Known/Direct/Inked Fingerprints: Processing Techniques for Unknown/Latent Fingerprints
Whether the method of taking inked prints is manual or through the use of a live scan, the process of obtaining good quality prints is basically the same. Taking a good quality fingerprint from a known source that can be used at a later time for a variety of purposes, from searching to individualization, is the ultimate goal. The terms known, direct, and inked are considered synonymous. Simply stated, these are prints taken from a known source. The clarity of the prints should be sufficient to allow for the comparison process to be conducted. These prints may also be known as tenprint cards.
I. Equipment required for taking known fingerprints (Figure 5.1)
A. Inking Plate: Hard, rigid, scratch-resistant surface; glass, metal, or scratch-resistant plastic
Figure 5.1 Manual fingerprint equipment.
Figure 5.2 Manual fingerprint methodology.
B. Cardholder: Used to hold the card flat and maintain an appropriate surface for registering required fingerprint information.
C. Printer’s Ink: Required to provide the necessary transfer medium to obtain proper finger and/or palm prints. Printer’s ink is used due to its quick-drying properties, ease of use, and permanence.
Figure 5.3 Manual fingerprint technique (rolling prints).
Figure 5.4 Manual fingerprint technique (rolling prints).
D. Roller: Preferably 6 inches long by 2 inches in diameter. Used to provide a uniform layer of ink onto the inking plate. The ink film must be sufficient to provide a transfer medium, but not too much to prevent proper inking of fingerprints.
E. Fingerprint Card: Standard 8x8 inch identification card
Figure 5.5 Manual fingerprints (flat impressions).
Figure 5.6 Manual (flat impression).
A. Inking the plate
III. Taking the fingerprints (Figures 5.2 through 5.6)
A. The subject should stand in front of and at the forearm’s length from the inking plate.
B. The person taking the prints should stand slightly to the left of the subject when printing the right hand, and slightly to the right when printing the left hand.
C. The side of the bulb of the finger is placed on the inking plate and the finger is rolled to the other side until it is entirely covered with ink. The entire bulb should be covered with ink from the tip to below the first joint.
Recording fingerprints with coroner’s spoon.
D. The subject should be cautioned to relax and refrain from trying to help the operator. Oddly enough, the more the subject tries to help, usually the worse the prints will be.
1. Advise the subject to relax and “look at some distant object.”
E. Rolled impressions (Figures 5.2 through 5.6)
a. The fingers should be rolled away from the center of the body.
b. The thumbs should be rolled toward the center of the body.
F. Plain impressions (simultaneously lay down four fingers on each hand; Figure 5.6)
1. All fingers should be inked at the same time and pressed onto the card simultaneously. If all four fingers will not fit in the box, then print three fingers and place the fourth on the rear of the card, making note of this on the face of the card.
a. Before inking the subject, advise the subject to extend their four fingers and hold in that position. Be careful, as some subjects may have a bow to their fingers. If that is the case, advise subjects they are extending too tightly.
2. The thumbs are then inked individually and taken separately. Remember to press down; do not roll the thumbs.
G. Taking of palm prints
IV. Problems in taking fingerprints
A. Mechanical operation:
1. Poor impressions are usually caused by
a. Poor, thin ink
b. Failure to clean the inking apparatus and finger prior to printing
i. Alcohol or other commercial preparation may be used.
ii. Perspiring fingers should be wiped dry (perspiring fingers will cause smeared fingerprints).
c. Failure to completely roll the fingers fully from one side to the other and to ink the whole area from tip to below the first joint
d. Using too much ink
e. Insufficient inking
f. Allowing the fingers to slope or twist resulting in smears and blurs (Note: One of the biggest challenges is to take proper control of the subject being printed.)
B. Temporary disabilities
a. Try using a small amount of ink
b. Might also try using softening agents (oils/creams)
4. Excessive perspiration
a. Wash hands or wipe with alcohol.
5. Young children with small ridges. As children get older, the ridges become more pronounced and recording becomes much easier. Generally, children younger than three years old will not leave good prints.
C. Permanent disabilities
1. Lack of fingers
a. Note on the card: “Missing at birth.”
b. Note on the card: “Amputated on_.”
c. If part of the first joint is present, print it.
d. If all fingers are missing, print the feet.
2. Crippled or deformed fingers and hands.
a. If fingers are so deformed that they are touching the palm permanently, note on the card.
b. In other cases, use spatula, small holder, or curved holder (coroner’s spoon).
c. For fingers of elderly individuals with faint ridges, use a very small amount of ink.
D. Deformed fingers
Figure 5.7 Automated fingerprint equipment (live scan).
Note: Where fingerprints on the rolled impressions are not of sufficient clarity to read or to be scanned into a database, those fingers may use a “Tab Over.” The tab over is an adhesive-backed, square tab that may be used to do a reprint of the finger in question. The tab over is placed in the square of the fingerprint to be retaken. There is a caution that must be advised: no more than two tab
Figure 5.8 Automated fingerprint equipment (live scan).
Figure 5.9 Live scan fingerprints.
Figure 5.10 Live scan palm prints.
overs may be used on a card or that card will be rejected by the FBI or other agency that will be registering or searching that card in a database.
Live Scan (Figures 5.7 through 5.10)
Live scan prints are basically taken in the same manner as manual fingerprints. However, slightly different protocols must be followed to ensure the quality of the known fingerprint.
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. With live scans, after a specified number of uses, depending on the system, the system must be checked or recalibrated for accuracy. The printer that is used with the system must also be checked for accuracy to ensure that a quality product is generated. The live scan system automatically records the prints, so the need for extreme accuracy is paramount. Live scan, as the name implies, displays an image on a monitor to the fingerprint operator to register for printing. The main difference between obtaining a live scan print and a manual print is that the live scan print cannot be rolled in the same manner as an inked print. The reader on the live scan system is flat, and therefore the print operator must place the finger on the reader and apply pressure to spread the bulb of the finger onto the reader. Too much pressure and the print becomes smeared. Too little pressure and the entire print will not be captured on the reader. An advantage of the live scan system is that 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. The flat impressions at the bottom of the card are taken in the same fashion as in the manual method. Four fingers are simultaneously taken, then the thumbs. Live scan is considered to be more efficient than the manual method. From personal experience, the author can state that the live scan system is not as messy as the manual method. Both systems share the same challenges and issues when it comes to poor-quality prints and the reasons for obtaining them. As with everything in life, both systems have their advantages and disadvantages. That topic is material for a different discussion.