Forensics test 2

Skin structures

Epidermis, dermis, hypodermis, hair shaft, hair follicle, sweat pore, sweat gland, oil gland, nerve, blood vessels

Classes of fingerprints

Loops 65%, whorls 35%, arches 5%

loop percentage

65

whorl percentage

35

arch percentage

5

Fundamental principles of fingerprints

Unique, never change, ridge characteristics for classification

Origin of fingerprints

Multifactorial trait: DNA and environment, formed at 10

Types of evidence prints

Latent (hidden), plastic (3

Latent print

hidden

Plastic

3d/molded print

patent

visible print

Silver nitrate (pourous) is used for

Wood/styrofoam

Silver nitrate interacts with

salt

silver nitrate produces

red/black fingerprint

ninhydrin (pourous) is used for

paper

ninhydrin interacts with

amino acids

ninhydrin produces

permanent purple fingerprint

iodine fuming (pourous) used for

cardboard

iodine fuming (pourous) interacts with

carbohydrates

iodine fuming (pourous) technique

purple starch solution

fingerprint poweder/magnetic power(Non pourous)used for

non pourous surfaces

fingerprint poweder/magnetic power(Non pourous) sticks to

oils and sweat

Super glue (non pourous) used for

plastic, metal glass

super glue (non pouous) interacts with

amino acids

super glue (non porous) produces a

white print

Documentation of all prints

Photograph, document, and lift

IAFIS

Integrated Automated Fingerprint Identification System

Correct technique for rolling inked prints

Uncomfortable to comfortable

Sir William Herschel

Had workers sign contracts with handprints

Sir Edward Henry

Developed the Henry system based on presence/absence of whorls

Dactylogram

Scientific name for a fingerprint

Legal Minimum Number of Minutiae

No legal minimum number of minutiae required for a match in court, but usually 12

Average Minutiae Count

Approximately 150 minutiae in each fingerprint

Genes (DNA) and Class Patterns

Genes (DNA) code for class patterns in fingerprints

Basal Layer of Epidermis

Fingerprints are formed in the basal layer of the epidermis

Livescan

Digital machine used to take fingerprints

Marcello Malphighi

First to describe loops, whorls, and arches in fingerprints

Thomas Jennings

First person convicted by fingerprint evidence in the US

Juan Vucetich

Policeman who abolished anthropometry in favor of fingerprints in Argentina; first to do so

The West Brothers

Will and William West, both prisoners at Leavenworth; had different fingerprints despite similar body measurements

Bertillon

Developed anthropometry and introduced the concept of 'mug shots'