Fingerprinting

History



Chinese deed signed with fingerprint



     Fingerprinting has been around for thousands of years, the oldest dating to circa 2000 BC when building the pyramids! About 3rd century BC, the Chinese recognized the individual aspects of fingerprints. Fingerprints were put on every legal document, which could later be used in court litigation proceedings. Over two thousand years  later in Persia, documents were again signed by fingerprints.

    Advances in fingerprinting didn't take too many leaps until the years surrounding 1858. William J. Hershal was an English administrator who was the first to document the application of fingerprints when he made a construction builder, by the name of Rajyadhar Konai, put a print of his palm and fingers on an official business transaction form since Mr. Konai could not write. Hershal was also the first to systematically record the fingerprints of inmates at jails.

    At about the same time, Scottish doctor Henry Faulds was making his own strides in the field of fingerprinting. While woking at a hospital in Tokyo, Japan about 1874, Faulds kept records of fingerprints and concluded that fingerprints were unchangeable. He also discovered that fingerprints were best created for wile with printer's ink on a smooth board. In addition, Faulds was credited for the fist identification of a fingerprint when he successfully lifted a print from a bottle of whiskey. Fingerprinting became a part of the American society in 1882, when a surveyor in New Mexico by the name of Gilber Thompson put his prints on a survey to prevent forgery. ten years later in Argentina, fingerprints were first used in crimesolving when Police Commodore Juan Vucetich took prints off a door which led to the capture of a murderer. In 1924, Congress gave the Federal Bureau of Investigation (F.B.I.) the authority to establish an Identification Division. This centralized all fingerprinting files and made it much easier to identify repeat criminals and missing persons.

An exapmle of a patent print
is dirty fingerprints on a glass,
such as those shown here.

Types

Patent Prints: visible prints that occur when a foreign substance on the skin of a finger comes in contact with the smooth surface of another object. These prints are visible without the aid of technology or any way to enhance them.

"Booking" is when general information of an offender
is put into the police database. Part of the booking
process includes taking exemplar fingerprints.

Exemplar Prints: Prints taken directly from a person.

There are many methods used to reveal invisible latent prints.

Latent Prints: Prints that are invisible to the naked eye. 

Techniques/Chemicals used to Expose Fingerprints

Laser luminescence: Involves the illumination of fingerprints due to fluorescing particles picked up during everyday life from paints, inks and oil.  It can be used on painted walls, metals, plastic and rubber, cloth and wood.

This diagram shows how laser luminescence works in a simple form.

Fingerprint reqovered using
metal evaporation.

  Metal evaporation- The fingerprint is developed by first evaporating a thin layer of gold onto the specimen, followed by a layer of cadmium which fills in the print and provides a contrast

Ninhydrin test kit

  Ninhydrin test - Indantrione hydrate reacts with the amino acids in the fingerprint, giving a visible deposit.  Also not suitable for fabrics or rough surfaces.

The collection of iodine vapor is called iodine
fuming. Fingerprints are sealed in a container
with iodine crystals. The vapor released by the
crystals adhears to the oils of the fingerprint,
making it visible.

Iodine vapor: Can be used to develop fingerprints on fabrics and rough surfaces.  Iodine vapour alone is useful only for prints up to 24 hours old, however a mixture of the vapor and steam allows this method to be effective for up to two months.

Acinetobacter Calciacatieus

Bacteria: Certain bacteria, for example acinetobacter calciacatieus, can be used to develop prints on valuable oil paintings, without harming the painting in the process.  The bacteria in a nutrient gel are pasted onto the surface of the painting, making the print visible as they multiply.  The gel can then simply be wiped off, leaving the painting unaffected.

TyphoonTrio+ variable mode imager,
a machine used to perform
autoradiography.

Autoradiography - Radioactive atoms are incorporated into the fingerprint by placing the piece of fabric into a container containing radioactive gases, such as iodine or sulphur dioxide, at a humidity of less than 50%.  The fabric is then put into contact with photographic film, and the radioactive atoms cause a picture to become clear.

Basic types/patterns of Prints

Basic fingerprint patterns. Specific variations look slightly different from the
ones shown here.

 

 Arches:

Plain: have an even flow of ridges from one side to the other of the pattern, no “significant up thrusts” and the ridges enter on one side of the impression, and flow out the other with a rise or wave in the center.

Radial: slope towards the thumb, have one delta and no re-curving ridges.

Ulnar: ridges slope towards the little finger, have one delta and no re-curving ridges.

Tented: have an angle, an up thrust, or two of the three basic characteristics of the loop.

Loops:

Radial: named after the radius, a bone in the forearm that joins the hand on the same side as the thumb. The flow of the pattern in radial loops runs in the direction of the radius (toward the thumb).

Ulnar: named after the ulna, a bone in the forearm. The ulna is on the same side as the little finger and the flow of the pattern in a ulnar loop runs in the direction of the ulna (toward the little finger).

Whorls:

Plain: consist of one or more ridges which make or tend to make a complete circuit with two deltas, between which an imaginary line is drawn and at least one re-curving ridge within the inner pattern area is cut or touched.

Central Pocket: consist of at least one re-curving ridge or an obstruction at right angles to the line of flow, with two deltas, between which when an imaginary line is drawn, no re-curving ridge within the pattern area is cut or touched.

Double Loop: consist of two separate and distinct loop formations with two separate and distinct shoulders for each core, two deltas and one or more ridges which make, a complete circuit

Accidental: consist of two different types of patterns with the exception of the plain arch, have two or more deltas or a pattern which possess some of the requirements for two or more different types or a pattern which conforms to none of the definitions.