Ch. 14 FingerprintsCh. 14 Fingerprints

History of FingerprintingHistory of Fingerprinting

The first system of personal The first system of personal identification used in criminal identification used in criminal investigations was investigations was anthropometry.anthropometry.

AnthropometryAnthropometry – developed in 1883 – developed in 1883 by Alphonse Bertillonby Alphonse Bertillon

System of precise body System of precise body measurementsmeasurements

History of FingerprintingHistory of Fingerprinting

History of FingerprintingHistory of Fingerprinting

1892 – Francis Galton – published the 1892 – Francis Galton – published the textbook, textbook, Finger Prints.Finger Prints.*impetus for police agencies to adopt *impetus for police agencies to adopt

fingerprinting as a means of identificationfingerprinting as a means of identification 1891 – Dr Juan Vucetich-developed a 1891 – Dr Juan Vucetich-developed a

classification system still used in many classification system still used in many Spanish speaking countriesSpanish speaking countries

1897 – Sir Edward Richard Henry –1897 – Sir Edward Richard Henry –proposed a classification system used proposed a classification system used today in most Engish-speaking countriestoday in most Engish-speaking countries

History of FingerprintingHistory of Fingerprinting

1901 - Fingerprints were first used 1901 - Fingerprints were first used for identification in the US by the for identification in the US by the New York City Civil Service New York City Civil Service Commission.Commission.

1924 – Fingerprint records were 1924 – Fingerprint records were consolidated into one system by the consolidated into one system by the FBIFBI

Principles of FingerprintsPrinciples of Fingerprints

Fingerprints are a reproduction of friction skin Fingerprints are a reproduction of friction skin ridges found on the palm side of the fingers and ridges found on the palm side of the fingers and thumbs. thumbs.

The basic principles underlying the use of The basic principles underlying the use of fingerprints in criminal investigations are that:fingerprints in criminal investigations are that:

1.1. a fingerprint is an individual characteristic a fingerprint is an individual characteristic because no two fingers have yet been found to because no two fingers have yet been found to possess identical ridge characteristics; possess identical ridge characteristics;

2.2. a fingerprint will remain unchanged during a fingerprint will remain unchanged during an individual’s lifetime; and an individual’s lifetime; and

3.3. fingerprints have general ridge patterns fingerprints have general ridge patterns that permit them to be systematically classified.that permit them to be systematically classified.

First PrincipleFirst Principle

The individuality of The individuality of a fingerprint is a fingerprint is determined by determined by careful study of careful study of ridge ridge characteristics.characteristics.

Ridge Ridge characteristics:characteristics:

Ridge endings, Ridge endings, bifurcations, bifurcations, enclosures and enclosures and other ridge details.other ridge details.

Second PrincipleSecond Principle

Fingerprints are a reproduction of Fingerprints are a reproduction of friction skin ridges found on the palm friction skin ridges found on the palm side of fingers and thumbs.side of fingers and thumbs.

Latent fingerprint-Latent fingerprint-made by the made by the deposit of oils and/or sweat; invisible deposit of oils and/or sweat; invisible to the naked eye.to the naked eye.

A fingerprint remains unchanged A fingerprint remains unchanged during an individual’s lifetime.during an individual’s lifetime.

Second PrincipleSecond Principle

Third PrincipleThird Principle

Fingerprints have general ridge Fingerprints have general ridge patterns that permits them to be patterns that permits them to be systematically classifiedsystematically classified

Fingerprints are classified as:Fingerprints are classified as:1.1. LoopsLoops

2.2. WhorlsWhorls

3.3. ArchesArches

LoopsLoops

LoopsLoops Ridge lines enter Ridge lines enter

from one side and from one side and curve around to exit curve around to exit from the same sidefrom the same side

60-65% of 60-65% of populationpopulation

Radial loops open Radial loops open towards thumbtowards thumb

Ulnar loops open Ulnar loops open toward pinkytoward pinky

Have one deltaHave one delta

WhorlsWhorls

Rounded or circular Rounded or circular ridge patternridge pattern

30-35% of 30-35% of populationpopulation

Two deltasTwo deltas

ArchesArches

Ridge lines enter from one side of print and Ridge lines enter from one side of print and exit out the otherexit out the other

5% of population5% of population

Identify each fingerprint pattern.Identify each fingerprint pattern.

Right Hand

Left Hand

Left Hand

Right Hand

Right Hand

Primary ClassificationPrimary Classification First, fingers are paired up, placing one finger in the First, fingers are paired up, placing one finger in the

numerator of a fraction and the other in the denominator.numerator of a fraction and the other in the denominator. The presence or absence of the whorl pattern is the basis The presence or absence of the whorl pattern is the basis

for the determination of the primary classification.for the determination of the primary classification. If a whorl pattern is found on any finger of the first pair, it If a whorl pattern is found on any finger of the first pair, it

is assigned a value of 16; on the second pair, an 8; on the is assigned a value of 16; on the second pair, an 8; on the third pair, a 4; on the second pair, a 2; and on the last third pair, a 4; on the second pair, a 2; and on the last pair, a 1. pair, a 1.

Any finger having a loop or arch is assigned a 0. Any finger having a loop or arch is assigned a 0.

R. Index R. Index R. Ring R. Ring L. ThumbL. Thumb L. MiddleL. Middle L. LittleL. Little

R. Thumb R. Middle R. Little L. Index L. RingR. Thumb R. Middle R. Little L. Index L. Ring

Primary ClassificationPrimary Classification After values for all 10 fingers are obtained, After values for all 10 fingers are obtained,

they are totaled, and a 1 is added to both the they are totaled, and a 1 is added to both the numerator and denominator. The fraction thus numerator and denominator. The fraction thus obtained is the primary classification obtained is the primary classification

As an example: If the right index finger and right As an example: If the right index finger and right middle finger are whorls and the rest are loops middle finger are whorls and the rest are loops the classification is:the classification is:

16 + 0 + 0 + 0 + 0 + 1 16 + 0 + 0 + 0 + 0 + 1 = = 1717 0 + 8 + 0 + 0 + 0 + 1 90 + 8 + 0 + 0 + 0 + 1 9

This system allows for 1024 classification This system allows for 1024 classification groupsgroups

Automated Fingerprint Identification Automated Fingerprint Identification SystemsSystems

1999- FBI initiated the IAFIS 1999- FBI initiated the IAFIS database which linked state AFIS database which linked state AFIS systems to the FBI databasesystems to the FBI database

Many AFIS systems exist at the city, Many AFIS systems exist at the city, county, and local government levelcounty, and local government level

AFISAFIS Scanning devices digitally encode Scanning devices digitally encode

fingerprints bases on the presence and fingerprints bases on the presence and location of ridge endings and bifurcationslocation of ridge endings and bifurcations

A fingerprint can be rapidly scanned and A fingerprint can be rapidly scanned and compared with thousands of prints per compared with thousands of prints per second.second.

A search produces a list of possible A search produces a list of possible matches.matches.

The ultimate verification of a prints identity The ultimate verification of a prints identity is made by a finger print expert.is made by a finger print expert.

AFISAFIS

Before AFISBefore AFIS police were limited to police were limited to comparing crime-scene fingerprints comparing crime-scene fingerprints to known suspectsto known suspects

After After police can use crime-scene police can use crime-scene fingerprints to generate a list of fingerprints to generate a list of suspects.suspects.

AFISAFIS

There are two major disadvantages of using There are two major disadvantages of using AFIS systems:AFIS systems:

1.1. Sometimes a latent print does not make Sometimes a latent print does not make a hit on AFIS because of the poor quality a hit on AFIS because of the poor quality of the file print.of the file print.

2.2. Many different AFIS systems operate at Many different AFIS systems operate at various levels of government using various levels of government using different software systems which different software systems which prevents them form communicating with prevents them form communicating with each other.each other.

Methods of Detecting FingerprintsMethods of Detecting Fingerprints

Three types of FingerprintsThree types of Fingerprints

1.1. Visible printsVisible prints – made when the finger – made when the finger deposits a visible material such as ink, dirt, deposits a visible material such as ink, dirt, or blood on a surfaceor blood on a surface

2.2. Plastic printsPlastic prints – a fingerprint impressed in a – a fingerprint impressed in a soft surface such as wax, soap, clay, etc.soft surface such as wax, soap, clay, etc.

3.3. Latent printsLatent prints – caused by the transfer of – caused by the transfer of perspiration or oils to the surface of an perspiration or oils to the surface of an object; usually invisible to the investigator.object; usually invisible to the investigator.

Locating FingerprintsLocating Fingerprints

Some prints can be visibly identifiedSome prints can be visibly identified Powders or chemicals can be used Powders or chemicals can be used

depending on the surface.depending on the surface. RUVIS – uses ultraviolet light to RUVIS – uses ultraviolet light to

identify the location of prints on a identify the location of prints on a surface.surface.

YouTube - Solved- Fingerprint Analysis

Locating FingerprintsLocating Fingerprints

Developing Latent PrintsDeveloping Latent Prints

On hard On hard surfaces:surfaces: PowderPowder

Grey or blackGrey or black FlorescentFlorescent MagneticMagnetic

SuperglueSuperglue

On soft On soft surfaces:surfaces: Iodine fumingIodine fuming

Nonpermanent Nonpermanent visualizationvisualization

NinhydrinNinhydrin Reacts with proteinsReacts with proteins

AgNOAgNO33

Reacts with saltReacts with salt

Fingerprint PowdersFingerprint Powders Used on smooth, non-Used on smooth, non-

porous materials.porous materials. The area is lightly and The area is lightly and

carefully dusted with carefully dusted with powders of various powders of various colors, chosen based on colors, chosen based on contrast with the contrast with the surface.surface.

The dust is lifted with The dust is lifted with tape and set against a tape and set against a contrasting background.contrasting background.

The print is preserved The print is preserved via photography.via photography.

YouTube - Developing Latent Fingerprints

Iodine FumingIodine Fuming

Suspect material is Suspect material is placed in an placed in an enclosed cabinet enclosed cabinet along with iodine along with iodine crystals.crystals.

The crystals are The crystals are heated, and will heated, and will sublimate (turn into sublimate (turn into a gas vapor).a gas vapor).

The vapors cause The vapors cause the prints to the prints to visualize.visualize.

Chemical TreatmentChemical Treatment Ninhydrin - this chemical is Ninhydrin - this chemical is

sprayed onto a porous sprayed onto a porous surface via an aerosol can. surface via an aerosol can. Prints begin to visualize an Prints begin to visualize an hour or two after hour or two after application, although the application, although the process can be accelerated process can be accelerated through heating the print.through heating the print.

Silver nitrate- silver nitrate Silver nitrate- silver nitrate is sprayed onto the porous is sprayed onto the porous surface and left to dry. Then surface and left to dry. Then it is exposed to ultraviolet it is exposed to ultraviolet light to visualize the prints.light to visualize the prints.

Super Glue FumingSuper Glue Fuming Used mainly on non-Used mainly on non-

porous materials.porous materials. Superglue is placed on Superglue is placed on

cotton and treated with cotton and treated with sodium hydroxide.sodium hydroxide.

Fumes can also be Fumes can also be created by heating the created by heating the glue.glue.

The fumes and the The fumes and the object are contained in a object are contained in a closed chamber for up closed chamber for up to six hours. to six hours.

The fumes adhere to the The fumes adhere to the print, visualizing it.print, visualizing it.

YouTube - Developing Fingerprints with Super Glue

Prints taken from a plastic bag and developed using super glue fuming

Other techniquesOther techniques

Laser light – causes substances Laser light – causes substances found in perspiration to fluoresce.found in perspiration to fluoresce.

Chemicals can be added to Chemicals can be added to fingerprints which fluoresce in the fingerprints which fluoresce in the presence of laser lightpresence of laser light

Other techniques have been Other techniques have been developed which allow chemicals developed which allow chemicals added to prints to fluoresce with added to prints to fluoresce with alternative sources of light.alternative sources of light.

Preservation of Developed PrintsPreservation of Developed Prints Developed prints can be Developed prints can be

photographed with a photographed with a specially designed specially designed camera.camera.

After photographs are After photographs are taken:taken:

1.1. The object containing The object containing the fingerprint can be the fingerprint can be transported to a crime transported to a crime lablab

2.2. The print can be “lifted” The print can be “lifted” using various types of using various types of adhesive tape.adhesive tape.

Digital Imaging of FingerprintsDigital Imaging of Fingerprints