How to Take Fingerprints

1. Using a brush and some white powder (in our case baking soda) dab a small amount over the actual fingerprint. (assuming it is a dark surface)
2. Carefully spread the white powder over the fingerprint. Be careful! If you are too rough you could smear the fingerprint.
3. Using some tape, tape over and take off the fingerprint from the surface.
4. Tape the fingerprint to a black sheet and analyze it.

Patterns of Fingerprints

There are three main fingerprint patterns: arches, loops and whorls.


Arches are found in about 5% of all fingerprints. The ridges travel across the fingertip without looping, only curling slightly.

About 60%-70% of fingerprints are loops. The ridges enters on either side of the fingertip, and loop, followed by more ridges to be surrounded by that loop.

                                                              

25%-35% percent of fingerprints are whorls. In a whorl, some of the ridges make a turn through at least one circuit.

                                                                   

Techniques and Chemicals used for Developing Fingerprints

There are several techniques to develop fingerprints:

The traditional or most common technique of fingerprinting is taking impressions of a person's hand with the help of ink. Pressing fingers covered in ink, on to a paper is the way of obtaining fingerprints.

                                                      

Rosa Parks being fingerprinted (1955)

For the digital scanning method, a sensitive touch-pad is used to capture the fingerprints of a person or a suspect in this method. The impression of fingerprint recorded on the touch-pad is then compared with thousands of impressions with the help of software or stored in the system.

For the lifting method, oil from hands which are left behind are captured by means of powders made from resinous polymers. To make a distinct fingerprint, dark-colored powders are used on light surfaces and vice versa. In order to put the fingerprints on porous materials, chemicals such as Ninhydrins are used. The super glue chamber is used to place object taken from the site of crime. The glue present in these chambers adhere to the fingerprints and thereby makes them visible.

The laser technique is one of the most useful for capturing fingerprints. In this fingerprinting technology, the fingerprints from many different surfaces can be lifted by using of laser.

Types of Fingerprints

There are three main types of fingerprints:

Patent prints are visible prints that occur when an outside substance located on the skin of a finger comes touches the smooth surface of another object. These prints leave a defined ridge impression that is visible without a microscope. The "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.

"Blood on his hands"

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. These prints require no enhancement in order to be viewed, because they are easily seen.

Latent prints are prints that are buried within a surface/object. Normally you cannot see them with your eye alone. They are the result of sweat that builds up from sweat pores in the ridges of the fingers. Also, when you touch other parts of your body, the oil from those regions attaches to the ridges of the fingers, which may transfer when you touch a table or a lamp. These fingerprints have to be enhanced.

History of Fingeprinting

Fingerprinting has been around for more than 3,000 years. The first documented fingerprints date back to ancient Babylon. There, fingerprints were used for business transactions. Fingerprints were also used on clay seals in China as well in Persia by different government officials.

        

    The development of fingerprinting to what it is today started in the late 1700’s when Marcello Malpighi, a professor at the University of Bologna observed a difference of spirals, ridges and loops in fingerprints. However, Malpighi did not acknowledge fingerprinting as a means of identification. One of the first discoveries of fingerprints being used as a means of identification was by Paul-Jean Coulier in 1863. Coulier explained that latent fingerprints could be developed on paper by using iodine fuming which may preserve developed impressions. Using iodine fuming gives an investigator the chance to identify a suspect’s by using a magnifying glass.

                                                            

Marcello Malpighi

  The first criminal fingerprint was made in 1892 by Juan Vucetich. He used fingerprinting as a means to identify a murderer by the name of Francis Rojas, who murdered her two sons and then proceeded to cut her own throat in order to make it look like someone else did it. However, her bloody fingerprint was found on the door which proved her as the murderer.

Five years later in 1897 Azizul Haque and Hem Chandra Bose will become the two Indian fingerprint experts that develop the Henry System, a system used to identify fingerprints, named for their supervisor, Edward Richard Henry.



Edward Richard Henry

            In 1903 The New York State Prison system began using fingerprints in the U.S. for criminals. In 1905, 1907 and 1908 the Army, Navy and Marines adopt fingerprints, respectively.

        

    In 1908 Edmond Locard identified that if 12 points (Galton's Details) were the same between two fingerprints, the two fingerprints would be identical.

                                                          

Edmond Locard

In 1924, an act of U.S. Congress created the Identification Division of the FBI. The IACP's National Bureau of Criminal Identification and the US Justice Department's Bureau of Criminal Identification merged to form the nucleus of the FBI fingerprint files. By 1946, the FBI had processed 100 million fingerprint cards in manually maintained files; and by 1971, 200 million cards. With the introduction of automated fingerprint identification system (AFIS) technology, the files were split into computerized criminal files.