Fingerprinting 101 – What’s worth Knowing
First, it’s necessary to clear up a bit of nomenclature confusion. Fingerprinting is the recording of the pattern of loops and whorls, typically on a standard FD258 (civilian, non-criminal) card. This is accomplished with either ink or a scanning device. “Fingerprint Kits” on Ebay are most often fingerprint “lifting” kits, essentially very fine powders that are applied to the fingerprint and a “copy” taken (lifted with tape, etc.), physically or they can be photographed.

I choose to not do fingerprint lifting as it would require me to prepare a written report and probably be called to testify in a courtroom. Yecch. Also, such activity is usually done by a Police professional – trained for the task. However, I do a lot of fingerprinting. New York State does not offer a fingerprint license; if they did I would have it. My authority to establish positive ID on the cards comes from being a Notary. I fingerprint people for FBI background checks, various licenses, and many immigration related purposes. There is no “oath” nor is there a need to be able to converse with the applicant, however, a translator is often helpful.

Back to the nuts and bolts. First, there is the “Live Scan” machine. Essentially a scanner hooked to a PC that communicates to a specific destination. All this must be prearranged and “type accepted” by the receiving party. A Live Scan setup is target centric and is generally not able to transmit (over telephone lines) to multiple destinations. This makes sense when many applicants go to a single place, which transmits to a single place. The more common and flexible fingerprinting is done with ink. Ink can be either embedded into a ceramic pad, similar to a common ink pad; or spread on a glass or metal plate with a roller. The latter is more time consuming but gives greater control to the fingerprint technician.

The FD258 fingerprint card is a bit narrower than a standard 8.5 inch wide sheet of paper. Of course the card holders are designed for the card to fit with no wiggle. Therefore a downloaded and printed image of the FD258 card does not fit a standard cardholder. It is possible to fold the edges and create an imprecise fit of the sheet of paper card image. Unfortunately, most computer paper is really not suitable for accepting standard fingerprint ink properly. Bottom line: printouts of the fingerprint card image should be avoided. Much better is to maintain a stock of FD258s. A common variation is the FINRA (used by the brokerage industry) cards. They are the exact same FD258 with the addition of preprinted barcoding, required by FINRA.

Proper finger preparation is essential. I have seen fingerprinting done without even having the applicant wash their hands! Access to hand washing facilities (soap and very warm water) is essential. Once the hands are washed the applicant should touch nothing, not even their ringing cell phone (I have had mixed results with this request!). Next, a mild solution of pepper extract (an “irritant”) is applied to the fingertips to raise the “friction ridges”. The friction ridges are ever so slightly “higher” than the underlying finger flesh; it is the ridges that form the fingerprint. This solution requires a second hand washing to remove prior to applying the ink.

It is critical that the minimum amount of ink be applied, lest the ink pass the friction ridges and collect in the “valleys” between the ridges. Perhaps the most common mistake is over inking. Using the traditional ink and roller allows greater control of ink application compared to the ceramic pad. If the layer of ink on the glass or metal plate is exactly correct; it’s impossible to transfer too much to the fingertip. With the ceramic pad the transfer of ink is directly proportional to the pressure exerted, and the risk of over inking is greater.
There is also a psychological aspect to fingerprinting. Many clients have two issues. Some don’t like to be physically manipulated; a necessity to take the fingerprint impressions. Always use a blank sheet of paper to check how the ink layer reacts to their fingertips. The test prints are good for explaining the procedure on a spare card while demonstrating the procedure. Emphasize that you must be in control and not be “assisted” – your subject must not press down or actively turn their finger. You must, when completed; check their ID and match to the name they printed and signed on the card. Lastly, you sign and date each card; or, if it does not meet the standard of clarity and completeness – break out another card and start over; it must be perfect.

Tweets:
(1) is the recording of the pattern of loops and whorls, typically on a standard FD258 (civilian, non-criminal) card
(2) Proper finger preparation is essential for fingerprinting. Wash each finger one by one!