Characteristics of Physical Evidence Types
Introduction to Forensics
In these next few paragraphs I will list and explain the three fingerprint ridge patterns and what are the three types of fingerprints investigators may find at crime scenes. And I will also describe I.A.F.I.S. include Live scan technology and the procedure Live scan has replaced. Hopefully after reading you will have a better understanding of the topics.
Fingerprints are supposed to be the most important proof against any crime as they are unique to each person and cannot be matched with other people. The Crime Information Bureau is an agency of the Division of Law Enforcement Services falling ...view middle of the document...
The arch fingerprint patterns come in four main types: plain arches, radial arches, tented arches and ulnar arches. Plain arches show an even flow of ridges running across from one side to the other end of the pattern. The radial arches ridges are arranged in the form of slope which runs towards the thumb and do not have any re-curving ridges or delta. Tented arches are seen with an up thrust angle or even couple of basic characteristics resembling the loop. The ulnar arches have ridges sloping in the direction of little finger, but have one delta and are without any re-curving ridges.
Around 60 to 70% fingerprint patterns belong to this type – Loops. In this pattern you can see one or even couple of ridges entering both the sides of the impression, re-curving, touching or crossing the line which runs from the delta to core and is seen terminating in the direction from where the ridges start. One of the remarkable characteristics of this type of fingerprint pattern is that each loop pattern displays one core, one delta and one ridge count. The loops are further divided as radial loops and Ulnar loops. Radial loops show a pattern running in the direction toward the thumb i.e. radius. It is named after radius which is a bone placed in the forearms joining hand on similar side as thumb. Ulnar loops are placed on the same side that of the little finger and its pattern flows in the direction of ulna or the little finger.
These types of fingerprint patterns are seen in around 25 to 35% of patterns. The fingerprint patterns with one or two deltas are considered as a whorl pattern. It is further divided in four whorl patterns. Plain whorls show one or two ridges which appear like making a full circuit with the two deltas and if an imaginary line is drawn between them, you get one re-curving ridge at least touching the inner area or cutting it. Central pocket loop whorls comprise of minimum one re-curving ridge or sometimes an obstruction placed at right angles with the line of the flow, having two deltas. When an imaginary line is drawn between them it does not cut or touch any re-curving ridge. The complete circuit of Central pocket loop can be oval, spiral, circular or of any circular variant version. The double loop whorls comprise of two separate and exclusive loops and also have two independent shoulders for every core. It also consists of one or couple of ridges and two deltas which together complete its circuit. Accidental whorls display two types of patterns. The only exception is plain arch. It has two or even more deltas.
There are three distinct types of fingerprint impressions that can be recovered from a crime scene or a scene of interest for investigators looking for some clues as to a missing person, or for other identification purposes. One of those is patent prints. Patent prints are visible prints that occur when a foreign substance on the skin of a finger comes in contact with the smooth surface of another object. These prints...