Criminalistics Fingerprints

Loop

A fingerprint pattern where ridge lines enter from one side and exit from the same side; contains one delta.

Arch

The least common fingerprint pattern; ridge lines enter from one side and flow out the other.

Whorl

A fingerprint pattern that is generally rounded or circular and contains at least two deltas.

Francis Galton

Published the book "Finger Prints" in 1892 and proposed the three pattern types.

Alphonse Bertillon

Developed the first systematic attempt at personal identification using anthropometry (body measurements).

Individual Characteristic

The First Principle of Fingerprints: no two fingers have yet been found to possess identical ridge characteristics.

Remain Unchanged

The Second Principle: a fingerprint stays the same during an individual's lifetime.

Classified

The Third Principle: fingerprints have general ridge patterns that permit them to be systematically ________.

1999

The year AFIS (Automated Fingerprint Identification System) became operational.

Porous

Surfaces that absorb liquids

Non-porous

Surfaces that do not absorb liquids

Plastic Print

A fingerprint impressed into a soft surface like putty

150

The average number of individual ridge characteristics on a single fingerprint.

8 to 16

The minimum number of ridge characteristics necessary to establish a match in court.

Latent Fingerprint

An invisible print made by the deposit of body oils or perspiration.

John Dillinger

A notorious criminal who tried to destroy his fingerprints using corrosive acid.

Ninhydrin

A chemical reagent used to develop latent prints on porous materials by reacting with amino acids.

Super Glue Fuming

A technique using cyanoacrylate vapors to visualize prints on non-porous surfaces.

Black Powder

Fingerprint powder used on evidence with a light-colored background.

Gray Powder

Fingerprint powder used on dark or reflective surfaces.

1924

The year the Bureau of Investigation and Leavenworth merged to form the FBI.

Photographing

The very first step that must be taken before any fingerprint development process.