INTRODUCTION TO FINGERPRINTS
A special kind of friction skin is covered on the palmer surface of the hands, fingers and the sole of the feet including toes. The skin is covered with minute ridges which are raised lines. The nature designed the ridges and furrows in-between two ridges on the hands and feet to prevent in slipping, grasping and locomotion.
According to Professor Haris Wilder and Mr Burt Wentworth, the ridges are formed by the fusion of epidermal units in the rows of minute, round or oval structures each having a sweat pore in its centre. Dr. A Kollmann who specially studied the embryological development of the ridges says that the ridges are formed through the lateral pressure between nascent structures. The ridges are first discernible in the fourth month of the foetal life and are fully formed by the sixth.
PRINCIPLES OF FINGERPRINTS
Sir Francis Galton, who is also regarded as the father of fingerprints propounded two basic principles on which the fingerprints have been accepted as the foremost scientific method for personal identification.
The papillary ridges present on the friction skin of fingers, palm and sole have two main principles due to which the fingerprints have been accepted as the most reliable source of Identification. They are:-
1) PERMANENCY OR PERSISTENCY
The design made by the papillary ridges fully formed in the sixth month of the foetal life remains permanent for the life of an individual without any change in their design, and
2) INDIVIDUALITY OR UNIQUENESS
Every finger impression is unique due to the formation of ridges and arrangement of the ridge characteristics there-in. This gives an individual identification to each finger.
According to some of the pioneers in the fingerprint, the non-changing quality of the fingerprint pattern and the arrangement of ridge characteristics, is also regarded as the third principle of fingerprints.