History of Fingerprinting
 

Being taken many centuries ago, although they weren't nearly as sophisticated as they are today. The ancient Babylonians pressed the tips of their fingertips into clay to record business transactions. The Chinese used ink-on-paper finger impressions for business and to help identify their children.

However, fingerprints weren't used as a method for identifying criminals until the 19th century. In 1858, an Englishman named Sir William Herschel was working as the Chief Magistrate of the Hooghly district in Jungipoor, India. In order to reduce fraud, he had the residents record their fingerprints when signing business documents.

A few years later, Scottish doctor Henry Faulds was working in Japan when he discovered fingerprints left by artists on ancient pieces of clay. This finding inspired him to begin investigating fingerprints. In 1880, Faulds wrote to his cousin, the famed naturalist Charles Darwin, and asked for help with developing a fingerprint classification system. Darwin declined, but forwarded the letter to his cousin, Sir Francis Galton

 Types of Finger prints

·     PATENT PRINTS - are 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 leave a distinct ridge impression that is visible with the naked eye without technological enhancement of any kind. The tried and true "blood on his hands" evidence is an example of patent prints recovered from a crime scene or scene of interest to investigators. These foreign substances contain dust particles which adhere to the ridges of the fingers and are easily identifiable when left on an object.

·    PLASTIC PRINTS - are visible, impressed prints that occur when a finger touches a soft, malleable surface resulting in an indentation. Some surfaces that may contain this type of fingerprint are those that are freshly painted or coated, or those that contain wax, gum, blood or any other substance that will soften when hand held and then retain the finger ridge impressions. These prints require no enhancement in order to be viewed, because they are impressed onto an object and are easily observable

·    LATENT PRINTS - are fingerprint impressions secreted in a surface or an object and are usually invisible to the naked eye. These prints are the result of perspiration which is derived from sweat pores found in the ridges of fingers. When fingers touch other body parts, moisture, oil and grease adhere to the ridges so that when the fingers touch an object, such as a lamp, a film of these substances may be transferred to that object. The impression left on the object leaves a distinct outline of the ridges of that finger. These fingerprints must be enhanced upon collection and, because they serve as a means of identifying the source of the print, they have proven to be extremely valuable over the years in the identification of its source.

Techniques/Chemicals

Prints on hard and nonabsorbent surfaces (such as mirror, tile, glass, and painted wood) are developed with the application of powder. While soft and porous surfaces (such as cloth, paper, and cardboard) are made visible by the treatment of a chemical. The powder of choice is the one that shows the best contrast with the surface being examined. Experienced examiners find that black and gray powders are satisfactory for most latent print work. Chemicals are also used to visualize latent prints. The oldest method is iodine fuming which is based on the fact that iodine has the property to sublime. Another chemical used is silver nitrate, which after being applied is developed with the exposure of ultraviolet light. This event is made possible because of the chemical reaction between sodium chloride (salt, left by perspiration after evaporation) and silver nitrate which forms the colorless silver chloride. After a 3% solution is brushed onto the evidential object and exposed to ultraviolet light, a silver print will be shown as a reddish-brown or black color.

Basic shapes/patterns of fingerprints.

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

• Double loop whorls 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.

Procedures for collecting/lifting prints

• Marking of Latent Fingerprint Evidence

All such evidence should be marked in some distinctive manner, such as is the case with any other type of physical evidence. Precautions should be taken, when marking evidence, not to damage or destroy potential latent fingerprints. Lifted, developed laten should also be marked or sealed in marked envelopes. Photograph-developed latent with and without identifying markings and scale.

• Preservation of Fingerprint Evidence

The primary precaution in all cases is the prevention of adding fingerprints to evidence, or of destroying those already present.

Most fingerprints submitted will be on paper, glass, metal, or other smooth surfaced objects. When articles containing latent must be picked up, touch as little as possible, and then only in areas least likely to contain identifiable latent, such as rough surfaces. While gloves or handkerchiefs may be used to pick up such exhibits, any unnecessary contact should be avoided. Although using a cloth to pick up exhibits prevents leaving additional prints on the articles, the cloth will frequently wipe off or smear any prints originally present, unless great care is taken. Large articles containing latents such as glass, metal articles, and firearms should be placed on wood or heavy cardboard and fastened down with string to prevent shifting and contact with other objects in transit. Where such evidence is to be examined frequently, a pegboard should be obtained on which wooden pegs can be moved as desired to support exhibits and keep them from moving. Bottles and glasses may be placed vertically on a board and placed in the bottom of a box. The base of the bottle or glass can be surrounded with nails to hold it in place, and the top can be either inserted through a hole in a piece of cardboard or held in position with a wooden board nailed to the container's lid. Papers and documents containing latent prints should be placed individually in a cellophane or manila envelope. Such a container can be sandwiched between two sheets of stiff cardboard, wrapped, and placed in a box for mailing.


Reflection

For fingerprinting when in end up using ink or glass to take down our fingerprint. we had to practice first with ink so we wouldn't smudge our prints. it toook me many times befor getting down without smudging my pritns. To use glass we had to use powder to find our prints to take down. Fingerprinting seems easy on TV but in real life it takes a lot of of skill to find fingerprints for evidence.