The Three Dogmatic Principles Of Fingerprints

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Fingerprint is governed by three dogmatic principles which are recognized judicially by the different courts of the world: principle of constancy, principle of variation, and principle of infallibility.

Fingerprints are governed by three dogmatic principles which are recognized judicially by courts all over the world. These principles are based on facts.

What a Fingerprint is

Fingerprint is the impression made by the ridges on the inside of the first joint of the finger or thumb on any surface through the medium of sweats, inks or any ingredients capable of producing visibility. As a means of personal identification, its scope is embraced under the science of dactylography and its four allied subjects namely:

  • Dactyloscopy:  The study of the classification of fingerprint. It is derived from two Greek words, Dactylos which means a finger, and Skopein which means to examine.

Dactyloscopy is the procedure of personal identification based on the study and examination of the patterns that form arches, loops and whorls on the fingertips, the palms of the hands and the soles of the feet, as the method.

  • Poroscopy: The scientific examination or study of the sweat pores. It is the study of the configuration, size, and relative position of the pores in human skin, which are the external openings of the sebaceous and sweat glands. Together with dactyloscopy and palm print identification, it is used in Criminalistics for purposes of identification.

Poroscopy involves a comparative study of the pores visible in impressions left at the site of a crime and in the fingerprints of an identified person. It is performed when the impression left by the skin is not suitable for dactyloscopy.

  • Chiroscopy: The scientific examination or study of the palms of the hands. The palm of a hand is covered by minute ridges of skin called papillary or friction ridges separated by depressions known as furrows
  • Podoscopy:  The scientific examination or study of the soles of the feet. "A term coined by Wentworth and Wilder as a possible word, if ever needed, referring to the study of the soles."

Principles governing the study of fingerprints

1. The principle of constancy

A fingerprint will remain unchanged during an individual's lifetime.

The papillary ridges are immutable, perennial or individual from the beginning of the third month of the embryonic period until the decomposition sets in after death.

The ridges on the grasping surfaces of hands and on the soles of feet are present at birth and remain unchanged for life except for size as growth occurs. They may be obscured by deep tissue damage that causes scarring, like burns for example. However these scars may also be useful as points of identification.


2. The principle of variation

No two fingerprints of different persons or the neighboring finger of the same person have ever been found to be identical in all respects.

A fingerprint is an individual characteristic, and as of yet no two prints have been found to possess identical ridge characteristics.

“In the 90 years since fingerprinting was generally introduced, out of the millions of sets of prints that have been taken, no two individuals have been found to have the same fingerprints.”

Even identical twin brothers through fingerprint comparison can be identified as two different people as has been shown by an investigation in 1903 made upon two men who looked exactly alike per prison records of the U. S. Penitentiary at Leavenworth, Kansas

3. The principle of infallibility.

Forged fingerprints can be distinguished from genuine fingerprints.

    Genuine fingerprint                                   Forged fingerprint

1. Ridges are life-like                                   1. Ridges are sharp

2. The sweat pores dotting the                    2. Sweat pores dot the ridges

   ridges are well defined                                 and are noticeably absent

   and visible

"Of all the methods of identification, fingerprinting alone has proved to be both infallible and feasible. Its superiority over the older methods has been demonstrated time after time. To date, the fingerprints of no two individuals have been found to be identical." (J. E. Hoover)


1. Notes on Personal Identification by L. V. Balboa, 1987



1 comment

James R. Coffey
Posted on Nov 28, 2010