Classification and Recognition of Fingerprints using Self ...
Classification of Fingerprints
description
Transcript of Classification of Fingerprints
Classification of
Fingerprints
AFIS Automated Fingerprint Identification System
Fingers are scanned to a screen where they can be enhanced and identified.
In 2007 the FBI had more than 55 million digital fingerprints of known criminals.
AFIS Criminal courts
consider 12 points a “match” for prints
Known Print on File
Unknown Print
Types of Prints1. Plastic (Molded) Print
3D print made as indentations in soft material
Examples : fresh paint, soap, candle wax
Types of Prints2. Visible Print
left by a finger that has touched colored material
Examples: blood, paint, ink, grease, mud
Types of Prints3. Latent Print
prints result from deposit of secretions from skin
invisible to the naked eye until developed
developed by chemical or physical means
Visualizing Latent Prints
Powders used on hard, nonabsorbent surfaces adhere to both water and fatty deposits choose a color to contrast with the
background
Visualizing Latent Prints
Iodine fumes react with oils and fats to produce a
temporary yellow-brown color works best developing fingerprints on paper
or cardboard
Visualizing Latent Prints
Ninhydrin fumes reacts with amino acids to produce a
purple color works best developing fingerprints on
porous surfaces such as paper, wood, cardboard
Visualizing Latent Prints
Cyanoacrylate “superglue” fumes react with
water and other fingerprint constituents to form a hard, whitish deposit.
works best on developing fingerprints on hard nonporous surfaces such as metals, glass, and plastic