Significance of Fingerprint Evidence in a Criminal Investigation
However, even today fingerprint evidence remains very much in use in criminal cases and investigations. Criminal lawyers, consequently, devote great amount of time in challenging the utilization and introduction of such evidence.
The widely known principle that no two people can have the exact same fingerprints does certainly not have scientific validity. But it is still treated as highly reliable evidence and it very accessible to juries. No specialized knowledge is needed to understand something so basic that each individual's fingers include a contour map of whorls and ridges that's entirely unique.
How are Fingerprints Matched
In a criminal case, fingerprint evidence is dependant on two fundamental principles. The first is that the swirled skin the finger tips of a human being does not change over his or her lifetime. The second principle is that no two individuals can have an identical γραφειο ιδιωτικων ερευνω pattern of friction ridges. Even siblings and twins have different fingerprints.
Law enforcement officers take advantage of fingerprints to spot defendants by making a comparison between the prints already existing in the police files and the prints available at the scene of crime. Police records include fingerprints of millions of people, and it is not really a record only of known criminals.
Fingerprints can be recorded each time a person is arrested, or each time a person uses up a sensitive job assignment. Matching of fingerprint involves matching several points that are common between the 2 sets of prints.
Fingerprinting experts have a disagreement over the minimum amount of points required to match in order to declare an ideal match. Some experts may opine that only 12 points are sufficient to declare a match, although some other experts may insisting on matching as much as 20 points before declaring an ideal match.
How are Fingerprints Found?
One of many challenges commonly faced by the officers investigating a criminal case is to locate good fingerprints at the scene of crime. Several rows of sweat pores are included in the friction ridges in the hands. Hands typically have sweat that's combined with dirt in addition to natural body oils, and this leaves fingerprints on even surfaces.
Crime investigators take advantage of certain chemicals and powders to really make the prints visible. How clear the fingerprints are in this situation will largely be determined by the quality and smoothness of the outer lining from where they're lifted.
New and advanced computer-based fingerprint enhancement techniques are available nowadays to develop a complete pattern of fingerprints where only some fragments of prints are available.
A Defensive Strategy
Laser technology can be used to spot the prints that are barely visible on the surface. With the help of latest technologies, fingerprint experts are increasingly able to recoup identifiable fingerprints from the majority of the surfaces. However, the prevailing technologies are unable to determine age a particular set of fingerprints.
Therefore, defense attorneys may sometimes argue that the defendant's prints available at the scene of the crime belonged to an interval before the occurrence of the crime. For example, the defendant could have left those prints at the scene of the crime several days prior when he or she was over there watching a film or a football game.
