A fingerprint can be defined as an impression of the whorls on the inner surface of a finger that is used by investigators, usually the police, in identifying a person. It is also a distinctive mark found on the end joint of the fingers that is unique and unambiguously identifies a character. With this in mind, fingerprint evidence is not as high profile as other crime solving methods e.g. DNA but it is still used in criminal cases to track down and apprehend suspected perpetrators. It bases its principle on the fact that no two people born in this world have the same fingerprints. While this principle cannot be one hundred percent scientifically validated, fingerprintevidence has generally been considered to be highly reliable especially when it comes to testifying in court.
In the beginning, only highly learned specialists used to deal with fingerprints. Nowadays, you don’t need a Doctorate or even attendance to scientific lectures on genetics to comprehend how fingerprint impressions are used in solving crime.
Evidence gathered from fingerprints is manipulated with two principles in mind; a person’s fingers contain a contour map of whorls and ridges that are unique and a person’s friction ridge patterns i.e. the swirled skin on their fingertips, is not altered in their entire lifetimes regardless of how much friction their hands encounter.
Crime scene investigators use fingerprints by comparing prints found in crime scenes to the ones in their database. A database can contain a collection of millions of fingerprints in file. Unlike in the past where fingerprints were only taken of people who were to be convicted or booked by the police, today there are several reasons as to why fingerprints are taken. In certain occupations, the employees’ prints are taken before they can commence work. It is also not uncommon for some parents to insist that their children prints be taken to help in identifying their young should they be abducted or kidnapped.
Like I mentioned earlier, this method has its own hiccups. It is not uncommon for experts to disagree on how many “points in common” are required between two sets of prints before a match is declared. Some specialists insist on twelve while others cannot work with less than twenty. The common points in prints are determined by the way the prints are found and collected. To get a clearer view of this a deeper understanding of fingerprint collection is required.
When it comes to prints and their visibility, the surface from which they are lifted plays a very crucial role. Another factor is the biology of the human being in question. Because friction ridges have rows of sweat pores that are mixed with sweat, oils and other body fluids to make impressions on smooth surfaces; experts use mild chemicals and powders to make them visible. Technology has also played a very significant role when it comes to prints. With the aid of computers and other enhancement techniques, it is now possible to extract a complete pattern of fingerprints from very little fragments. Laser technology can also read what used to be considered invisible fingerprint markings thus making print retrieval from most surfaces to be much easier.
The only shortcoming of using fingerprints is that it is almost impossible to determine the age of a given set of prints. This has led to many suspected perpetrators arguing that they left their prints at the said crime scenes at a different period other than the one when the crime is said to have occurred.