Crime Scene Forensics, LLC

Fingerprints

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BASIC FINGERPRINT PATTERNS:

There are three basic fingerprint patterns:

Click here for Glossary of Fingerprint Terms

Click here for a history of fingerprints

1. Loop Patterns:  

In a Loop pattern, the ridges will  flow in one side, recurve, (loop  

around) touch or pass through an imaginary line drawn from the  

delta to the core, and exit the pattern on the same side from which it

entered.

*A loop pattern has only one delta.

*There are two types of loop patterns:

1. Ulnar loop

2. Radial loop

*Loop patterns account for @ 70% of all fingerprints

2. Whorl Patterns:

A whorl pattern consists of a series of almost concentric circles.

* A whorl pattern has two deltas

*There are four types of whorl patterns:

1. Plain whorl,

2. Central Pocket Loop whorl,

3. Double Loop whorl,

4. Accidental whorl

*Whorl patterns account for @ 25% of fingerprints

3. Arch Patterns:

In an arch pattern, ridges flow in one side and flow out the

opposite side. There are no deltas in an arch pattern.

*There are two types of arch patterns:  

1. Plain arch,

2. Tented arch

Arch pattern account for @ 5% of all fingerprints

Type lines

-The two innermost ridges which start parallel, diverge, and             

    surround or tend to surround the pattern area.

-When there is a definite break in a type line, the ridge                     

    immediately outside of it is considered as its continuation.

Delta

-The point on a ridge at or in front of and nearest the center of the   

 divergence of the type lines.

-The delta area is located as a triangular area where the ridges       

 radiate outward in three directions.

CLASSIFICATION OF FINGERPRINTS

1. The sorting of fingerprints into file groups so that a file may be set upon on

the basis of fingerprints alone. Fingerprints are classified by general

shape, (arch, loop, or whorl) position within the finger, and relative size.

2. Classification of fingerprints provides for an orderly placing of fingerprint

cards in a file.

Two methods of classifying fingerprints:

1. Henry Classification

2. NCIC Classification

FINGERPRINTS ARE PERMANENT AND INDIVIDUALLY UNIQUE

1. •Fingerprints begin forming during the 12th week of gestation, and
   barring surgical or accidental removal of the finger itself, will remain
   permanent for the life of the individual until the body decomposes after
   death.
   

1. •No two fingerprints have ever been found to be alike. No two fingerprints
   on the same hand have ever been found to be alike.  Over 100 years of
   empirical testing and research has supported the uniqueness and
   permanence of friction ridge (fingerprint) arrangements. Modern DNA
   technology can not differentiate between mono zygotic (identical) twins.
   However each of the twenty fingerprints between those twins will be
   unique.
   

1. •Each fingerprint contains minutiae, or ridge characteristics. Fingerprints
   are identified to individuals by examining and comparing the ridge
   characteristics of two different impressions to determine if these
   characteristics occupy the same relative area and position, and if their
   unit relationship to each other matches.

To cite this website: Crime Scene Forensics, LLC, New York; www.crimescene-forensics.com