Fingerprints

Ridge Characteristics

"Minutiae" - Ridge endings, bifurcations, enclosures, and other ridge details; must match in to fingerprints to establish common origin

Loop

A class of fingerprints characterized by ridge lines that enter from one side of the pattern and curve around to exit from the same side of the pattern

Arch

A class of fingerprints characterized by ridge lines that enter the print from one side and flow to the other side

Whorl

A class of fingerprints that includes ridge patterns that are generally rounded or circular and have two deltas

Plastic Print

A fingerprint impressed on a soft surface

Latent Fingerprint

A fingerprint made by oils and/or perspiration; invisible to the naked eye

Visible Print

A fingerprint made when the finger deposits a visible material such as ink, dirk, or blood onto a surface

Physical Developer

A silver nitrate-based reagent formulated to develop latent fingerprints on porous surfaces

Anthropometry

A system of identifications of individuals by measurement of parts of the body, developed by Alphonse Bertillion

Iodine Fuming

A technique for visualizing latent fingerprints by exposing them to iodine vapors

Super Glue Fuming

A technique for visualizing latent fingerprints on nonporous surfaces by exposing then to cyanoacrylate vapors

Portrait Parle

A verbal description of a perpetrator s physical characteristics and dress provided by an eyewitness

List and describe three techniques for developing latent prints from porous surfaces

Iodine fuming, Ninhydrin, Physical developer

List the three General Ridge Patterns and what is the percent occurrence of each in the population?

Loops: 60% - 65% Arches: 5% Whorls: 30% - 35%

Have identical fingerprints been identified from two individuals?

No

Is there a requirement for the number of ridge characteristics that should be present to establish positive identification?

No - 8-16 suggested, but no scientific minimum can be established

Give three examples each for Nonporous and Porous surfaces

Nonporous: Glass, mirror, tile, painted wood Porous: Paper, cardboard, cloth

Where are the pores and sweat glands located on human skin?

Pores in a single row on each ridge; sweat glands in dermis, conected to pores by ducts

Fingerprints

Reproduction of friction skin ridges found on palm sides of fingers and thumbs; hills (ridges) and valleys (grooves)

What determines the individuality of fingerprints?

Ridge characteristics - Identity, number, relative location

Deltas

Ridge point at or nearest the type line divergence and located at or directly in front of the point of divergence (All loops must have one, whorls must have two)

Fluoresce

To emit visible light when exposed to light of a shorter wavelength

Ninhydrin

A chemical reagent used to develop latent fingerprints on porous materials by reacting with amino acids in perspiration

What role did William West and Will West play in the history of fingerprints in the United States?

1903, Fort Leavenworth prison, Two men could not be distinguished by body measurements or by photographs, Finger printing was the only way to distinguish them

What percent of the population has either loops or arches on all 10 fingers?

25%

Livescan

An inkless device that captures digital images of fingerprints and palm prints and electronically transmits them to AFIS

Cores

Approximate center of loop pattern

When are human fingerprints formed?

As a fetus

AFIS

Automated Fingerprint Identification System

What year did AFIS becomes fully operational?

Became available in 1970, Integrated AFIS (FBI) in 1999

Dermal Papillae

Boundary of cells separation epidermis and dermis; determines form and pattern of ridges on surface of skin

Digital Imaging of Fingerprints

Computer scans and digitally encodes fingerprints to be subject to high-speed computer processing; Automatic scanning devices convert image into digital minutiae and relative positions/orientations; each image becomes digital geometric pattern

How is the Primary Classification of a fingerprint determined?

Determination of presence/absence of a whorl; divide into 1,024 groups: R Index/R Thumb, R Ring/R Middle, L Thumb/R Little, L Middle/L Index, L Little/L Ring. Whorl = 16, 8, 4, 2, 1. Plus 1/1.

Type Lines

Diverging ridges surrounding pattern area of loop

List the three Fundamental Principles of Fingerprints

Fingerprint is an individual characteristic and no two have identical ridge characteristics; Fingerprints remain unchanged during an individual's lifetime; Fingerprints have general ridge patterns that permit them to be systematically classified

List and describe two techniques for developing latent prints from nonporous surfaces

Fingerprint powder, Superglue fuming