Introduction
Over the years there has been a rise in crimes around societies. This has posed a very big problem for the law enforcement agencies and the judicial system. One way of combating this upsurge has been the employment of fingerprint identification technology. Employment of this method started at the beginning of the 20th century with New York law enforcement personnel being among the first ones. Every person on the face of the planet has a unique fingerprint pattern and no person has the same print even identical twins (Schmalleger, 2004, p. 700).
The advantage of using fingerprints to identify individuals lies in two major characteristics of fingerprints namely: fingerprints do not change during a person’s lifetime and the ridge pattern of fingerprints makes it easy to systematically classify individuals. This has caused a revolution in forensic investigations making it easy for forensic experts to solve cases and identify the culprits. The forensic team has also been able to document and store crucial fingerprints information of criminals which helps to trace criminal activities (Bolle & Ratha, 2009, p. 320).
Types and Patterns of prints
Fingerprint Types
There are distinct groups of fingerprints which can be classified as plastic fingerprints, fingerprints with foreign materials on them, and latent fingerprints. Plastic fingerprints are those that occur when a person touches or presses on plastic-made objects in ways that leave a negative impression. These types of prints will be found mostly on newly painted materials; gum on envelopes and stamps, wax-based products, and also on substances that are handheld and can melt or softened such as chocolate.
Latent fingerprints are prints that are left as a result of grease, sweat, or dirt being deposited on the item touched. This leaves the imprint from every element in the friction ridge outline at the finger’s tip (Woytowicz & Tilstone, 2004). Although the term latent means hidden it is used in the forensic world to refer to accidental impressions that are left by friction ridge skin after touching a surface, regardless of the print being visible or not at the time they are deposited. Latent prints will mostly show a small part of the finger’s fingerprint and will be mostly distorted or mucky. This makes this type of print hard to successfully make comparisons than detailed fingerprints that may be collected (Christophe, 2004, p. 126).
They can be further classified into exemplary prints and patent prints. Exemplar prints are also referred to as known as known prints. They are used to refer to fingerprints that are collected from individuals, whether for enrolment purposes in a system or when a person is arrested by the authority. In criminal arrests, exemplary prints are collected from each finger. Exemplary prints are usually collected and used live scan or by making imprints on paper cards after a finger has had ink rolled on it. Patent prints are those prints that can be seen by the naked human eye. They are caused by the transfer of foreign materials from a finger to a surface or object. Good examples of these prints are impressions that may arise from flour or clay use. Having the prints made visible, they are only photographed and do not require any enhancements or lifting like other types of prints. The best thing about these patent prints is that they can be left on the items or surfaces by materials such as dirt, blood, or paint (Schmalleger, 2004, p. 700).
Different Methods Used To Develop And Preserve Prints Fingerprints
Prints that are visible due to the presence of foreign material are developed by just photographing. They may also be obtained by lifting using a print lifting tape. If the prints are lying on a small item then the whole object will be taken in as evidence. Latent prints have to be developed by use of special equipment where they are made visible and then preserved. The methods used to process fingerprints on a surface are by use of powdering or treating with chemicals. The prints that need dusting to develop are supposed to be photographed before being lifted. The prints found in dust are just photographed and subsequently lifted (Bolle & Ratha, 2009, p. 352).
Powdering Method
Fingerprints powers come in different colors but black and white are mostly used. In choosing a color, choose the one that gives the best contrast. To preserve a print by use of powder, the first thing to do is check for the print that needs to be developed. The trick to developing clear latent prints is careful brushing.
Chemical Method
This method is applied in the lab where trained personnel use chemical mixtures to develop the prints. These persons are trained in the use of methods that are approved by the government for handling highly toxic chemicals. This method is used in the development of prints from paper products.
Obtaining fingerprints from people
The prints taken from people for identification should be clear and visible. The print should be free of smudges and should be collected on all fingers. Ink should be rolled on the hand and each finger pressed on a paper to create a good impression of the fingerprint. These impressions are then later stored for future reference and use.
Lifting And Preservation Of Fingerprints
After the print is visible a photograph should be taken and then the print lifted. The method of lifting patent prints involves the use of rubber filters and in other times use of a special transparent lifting tape. The most efficient item to use is the rubber filters. This is more so in taking prints from rough planes or edges.
Automated Fingerprint Identification System (AFIS)
The Integrated Automated Fingerprint Identification System (IAFIS) is a governmental collection of national’s fingerprints and criminal records that help local and federal personnel in their work. This system helps law enforcement agencies to apprehend and profile criminals. IAFIS provides an automated capability to search for fingerprints of persons. The system can also be used in searching for criminals’ or suspects’ images and related information to various cases. It also has information on persons who have previously served in the military or are the federal government’s employees. Information in IAFIS is voluntarily provided by the local, state, and federal agencies on law enforcement. IAFIS is the largest of its kind in the world and has records of more than 66 million individuals in the criminal file.
In the criminal database, there is also fingerprint information of more than 73,000 known and suspected people with terrorist connections. IAFIS was started on July 28, 1999, and before this time processing of criminal fingerprints was largely done manually. This was not only time-consuming but was to an extent grossly ineffective. The FBI has been mandated for a long time to be the national storehouse for fingerprint and criminal records information since 1924. It has remained as the custodian of this information and IAFIS is one of the systems developed to enhance productivity and improve the efficiency of the law enforcement agencies (Schmalleger, 2004, p. 645).
References
Bolle, R. & Ratha, K. N. (2009). Automatic fingerprint recognition systems. London: Springer Publishers.
Christophe, C. (2004). Fingerprints and other ridge skin impressions. Boca Raton: CRC
Schmalleger, F. (2004). Criminal justice today: an introductory text for the twenty-first century. Upper Saddle River: Prentice Hall
Woytowicz, C., & Tilstone, J. W. (2004). Introduction to Criminalistics: The Foundation of Forensic Science. Burlington: Elsevier Academic Press.