Fingerprints

arch

fingerprint pattern in which the ridge pattern originates from one side of the print and leaves from the other side

core

a center of a loop or whorl

delta

triangular ridge pattern with ridges that go in different directions above and below a triangle

fingerprint

an impression left on any surface that consists of patterns made by the ridges on a finger

latent fingerprint

hidden fingerprint made visible through the use of powders or other techniques

loop

fingerprint pattern in which the ridge pattern flows inward and returns in the direction of the origin

minutiae

the combination of details in the shapes and positions of ridges in fingerprints that make each unique; also called ridge characteristics

patent fingerprint

visible fingerprint that happens when fingers with blood, ink, or some other substance on them touch a surface and transfer

plastic fingerprint

three-dimensional fingerprint made in soft material such as clay, soap, or putty

ten card

form used to record and preserve a person's fingerprints

whorl

fingerprint pattern that resembles a bulls-eye

exemplar

known sample from a suspect or victim used for comparison

dactylography/dactyloscopy

study of fingerprints for identification purposes

basal

layer of skin that grows quickly during fetal development that forms fingerprints

eccrine

sweat glands found on hands and feet that produce residue left behind by fingerprints

ridge count

distance between the core and delta, measured by counting intersecting lines

ninhydrin

chemical used to show latent prints on paper

silver nitrate

chemical used to show latent prints on wood and styrofoam

iodine fuming

process used to show latent prints on paper, cardboard and unpainted surfaces

cyanoacrylate vapor

process used to show latent prints on plastic, glass, metals and other household items

identification

when there are 12+ minutiae in common between the exemplar and the print being investigated

inconclusive

when there are some matching minutiae in common between the exemplar and the print being investigated, but not enough to make an identification

exclusion

when you have no matching minutiae in common or the wrong print type between the investigated print and the exemplar