Alphonse Bertillion
introduced using personal identification
Francis Galton
1892; developed identification system with fingerprints
William Herschel
fingerprints used in India to sign contracts
Henry Fauld
1880; suggested that skin ridge patterns could be important for identification of criminals
Fingerprints
are a reproduction of friction skin ridges found on the palm side of the fingers and thumbs
Basic principals
(1) no two fingers process identical ridge characteristics (2) fingerprint will remain unchanged during an individual's lifetime (3) fingerprints have general ridge patterns that permit them to be systematically classified
individuality of fingerprint
is not determined by its general shape or pattern but by the study of its ridge characteristics (minutiae)
Minutiae
ridge characteristics; the identity, number and relative location of the minutiae that imparts individuality to a fingerprint; there are as many as 150 on the average finger
Establishing positive identification
no valid basis exists for requiring a predetermined minimum number of friction ridge characters which must be present in two impressions in order to establish positive identification.
Court testimony of expert
must demonstrate a point by point comparison in order to prove the identity of an individual
epidermis
outer layer of the skin
dermis
inner layer of the skin
dermal papillae
layer of cells between the epidermis and dermis; is responsible for determining the form and pattern of the ridges on the surface of the skin
skin ridge
each one has pores leading to sweat glands; found on fingers, palms and soles; enlarge during growth but do no change; consists of hills (ridges) and valleys (grooves)
Three classes of general patterns
loop (60-65%), arches (30-35%) , and whorls (5-10%)
Loop
two focal points: core and delta; core=center; delta=area of pattern where there is triangulation (or dividing) of the ridges; must have one or more ridges entering from one side of the print, recurving, and exiting from the same side
ulnar loop
if loop opens toward the little finger
radial loop
if loop opens toward the thumb
Bifurcation
one ridge becomes two
latent fingerprint
made by the deposit of oils and/or sweat; invisible to the human eye; commonly called invisible fingerprints
People who tried to change prints
Dillinger used acid, Rosco used skin graft; neither worked
anthropometry
identification of a person with measurements of the parts of the body; the bone system is fixed from 20 years of age to death
Arches
divided into two groups: plain arches and tented arches; do not have type lines, deltas, or cores
Whorls
divided into four groups: plain, central pocket loop, double loop, and accidental; rounded or circular in shape, have two deltas;
Whorl-plain and central pocket loop
have at least one ridge that makes a complete circuit
Whorl-double loop
is made up of two loops combined into one fingerprint
Whorl-accidental
either contains two or more patterns, or is a pattern not covered by the other categories
Arches-plain arch
is formed by ridges entering from one side of the print, rising and falling, and exiting on the opposite side (like a wave)
Arches-tented arch
similar to plain arch except that instead of rising smoothly at the center, there is a sharp up thrust or spike; or the ridges meet at an angle that is less than 90 degrees
Classification
R index/R thumb; R ring/R middle; L thumb/R little; L middle/L index; L little/ L ring
Arch or loop=0
Whorl
1st pair=16
2nd pair=8
3rd pair=4
4th pair=2
5th pair=1
After values for all 10 fingers are obtained, they are totaled, and a 1 is added to both th
1/1 category
25% of the population, all their fingers have either loops or arches
removal of fingerprints for evidence
hard nonabsorbent surfaces: powder; porous surfaces: chemical
chemical methods for removal
iodine fuming, ninhydrin,physical developer; use iodine first, then ninhydrin, then physical develop
Super Glue fuming
develops latent prints on nonporous surfaces (metals, electrical tape, leather and plastic bags); development occurs when fumes from the glue adhere to the print usually producing a white latent print; is approximately 98-99% cyanoacrylate ester, a chemic
RUVIS reflected ultraviolet imaging system
aids in detecting latent prints without chemicals or powder; uses UV light
Iodine fuming
oldest method; involves heating iodine crystals that cause vapors (sublimation) which combine with latent prints to make them visible; iodine prints are not permanent and will fade, making it necessary to photograph the prints immediately;
Ninhydrin
method of choice for chemical; sprayed; reacts chemically with trace amounts of amino acids present in latent prints to produce a purple-blue color
physical developer
a silver nitrate based reagent used to develop prints when other chemical methods are ineffective; this method washes away any traces of protein from an objects surface
Light sources for fluorescence
lasers, quartz halogen, xenon arc or indium arc
AFIS
automated fingerprint identification system; match prints by comparing the position of bifurcations and ridge endings
Types of fingerprints
visible (formed by contact with colored material), plastic (ridge impressions left on soft material) latent (caused by sweat or oils from body)
livescan
an inkless device that captures the digital images of fingerprints and palm prints and electronically transmits the images to an AFIS
Sir Edward Richard Henry
1897; developed the fingerprint classification system still used in most English speaking countries
type lines
the pattern area of the loop is enclosed by two diverging ridges
Frequency Fourier Transform Analysis
is used to identify repetitive patterns such as lines or dots that interfere with the interpretation of a digitized fingerprint image