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Fingerprint readers take impressions of the friction ridges of the skin on the underside
of the tip of the fingers. Fingerprints are used to identify you and are unique
and different to everyone and do not change over time. Even identical twins who
share their DNA do not have the same fingerprints.
Police and Government agencies
have used these modes of identifying humans for many years but other agencies are
starting to use biometric fingerprint readers for identification in many different
applications.
Fingerprints are formed when the friction ridges of the skin come
in contact with a surface that is receptive to a print by using an agent to form
the print like perspiration, oil, ink, grease, etc. The agent is transferred to
the surface and leaves an impression which forms the fingerprint.
There are several
methods of biometric fingerprinting. A livescan devise basically reads or photographs
fingerprints by measuring the physical difference between ridges and valleys. The
procedure for capturing a fingerprint using a sensor consists of rolling or touching
with the finger onto a sensing area, capturing the difference between valleys and
ridges using a reader.
In order to “lift” latent prints it is necessary to use a developer like a powder or chemical reagent to develop or produce a high degree of visual contrast between ridge patterns and the surface on which it was left. There are many different types of chemicals used in developing fingerprints and choosing one depends on the agent used to make the fingerprint.
There are advances in the industry to form an SKP fingerprinting technique which is non-contact and does not require the use of developers, has the potential to allow fingerprints to be retrieved while still leaving intact any material that could subsequently be subjected to DNA analysis.
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