Fingerprints. Chapter 4 Fingerprints 2 Kendall/Hunt Publishing Company 2 Chinese records from the 221-206 BC included details about using handprints

Fingerprints

Chapter 4

FingerprintsFingerprints

2Kendall/Hunt Publishing Company

2

Chinese records from the 221-206 BC included details about using handprints as evidence during burglary investigations.

Chinese clay seals bearing friction ridges

History of Fingerprints

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You will be able to:Define the three basic properties that allow

individual identification by fingerprints.

Obtain an inked, readable fingerprint for each finger.

Recognize the general ridge patterns (loops, whorls, and arches).

Identify friction ridge characteristics and compare two fingerprints with at least ten points of identification.

Explain the differences among latent, plastic, and visible fingerprints.

Develop latent prints (make them visible) using physical and chemical methods.

Objectives, continued

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You will understand:

Why fingerprints are individual evidence.

Why there may be no fingerprint evidence at a crime scene.

How computers have made personal

identification easier.

Objectives

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Fundamental Principles of Fingerprints

What is a fingerprint?

An imprint made by the ridge patterns on

the tip or last joint of a person’s finger.What is the purpose of ridge patterns?

Provides a better grip

Makes perspiration easier on hairless surface

Improves the sense of touch (heightened sensitivity)

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Properties that make fingerprints useful for identification

A fingerprint is an individual because it has unique characteristic ridges.

A fingerprint remains unchanged during an individual’s lifetime.

Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.

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Anatomy of fingerprints

Fingerprints consist of ridges and grooves

Fingerprints are unique because the patterns made by friction ridges are not genetically controlled.

Any attempts to chemically or physically erase the epidermal layer of fingerprints will only result in pain because the original layer will soon grow back.

Initially fingerprints consist mostly of water, but after evaporation what is left behind is made up of salt and organic matter such as amino acids, lipids and vitamins.

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Dactyloscopy: The Study of Fingerprints

History from 1850 to 1900 William Herschel—required Indians to put their fingerprints

on contracts, and used fingerprints as a means of identifying prisoners

Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification. He was the first person to use fingerprints to solve a crime

Alphonse Bertillon—proposed body measurements as a means of identification; termed anthropometry

Francis Galton—developed a primary classification scheme based on loops, arches, and whorls. He showed that a person’s fingerprint remained the same from birth until death, no two fingerprints are the same, and that fingerprints cannot be altered.

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History from 1850 to 1900

Edward Richard Henry—in collaboration with Galton, instituted a numerical classification system

Juan Vucetich—developed a fingerprint file (database) based on Galton’s system

Mark Twain (Samuel L Clemens) In Mark Twain's book, "Life on the Mississippi", a murderer

was identified by the use of fingerprint identification. In a later book, "Pudd'n Head Wilson", there was a dramatic court trial on fingerprint identification.

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History from 1850 to 1900 1863 - Coulier

Professor Paul-Jean Coulier, published his observations that (latent) fingerprints can be developed on paper by iodine fuming

explains how to preserve (fix) such developed impressions and mentions the potential for identifying suspects' fingerprints by use of a magnifying glass.

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Recording and classifying prints

Recording-Rolling inked prints

classification-Loops, whorls, arches, ridge

characteristics

Henry Classification- Primary identification number

Lifting prints

Black, white, and fluorescent powder

Chemicals—ninhydrin, iodine, silver nitrate, cyanoacrylate

Other types of prints

Palm, lip, teeth, eye, ear, voice, shoeprints, and footprints

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Ridge Characteristics

Minutiae—characteristics of ridge patterns

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Fingerprint Minutiae

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Arch Least common and simplest

type of fingerprint. An arch has friction ridges that

enter on one side of the finger and cross to the other side while rising upward in the middle.

They do NOT have type lines, deltas, or cores.

Types

Plain

Tented

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Loop A loop must have one or more ridges

entering and exiting from the same side. Loops must have one delta (triangular area). Loops also have a core near the center of

the pattern

Types

Radial—opens toward the thumb

Ulnar—opens toward the “pinky” (little finger)

Which type of loop is this, if it is on the right hand? Left hand?

Without knowing which hand made the print one cannot determine if it is ulnar or radial (ulnar loops are more common)

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Whorl

Whorls have at least two deltas and a core

A plain or central pocket whorl has at least one ridge that makes a complete circuit.

A double loop is made of two loops. An accidental is a pattern not covered

by other categories..

TypesPlain

Central pocket

Double loop

Accidental

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Types of Whorl

Plain

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Types of Whorl

Plain

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Primary Classification

The Henry-FBI Classification System

Each finger is given a point value.

right left

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Primary Classification, continued

Assign the number of points for each finger that has a whorl and substitute into the equation:

right right left left left index ring thumb middle little + 1

right right right left left thumb middle little index ring + 1

That number is your primary classification number.

=

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Comparison

Dactyloscopy: The Study of

Fingerprints

There are no legal

requirements in the

United States on the

number of points required

for a match.

Generally, criminal courts

will accept 8 to 12 points

of similarity.

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Latent Prints

Latent fingerprints are those that are not visible to the naked eye. These prints consist of the natural secretions of human skin and require development for them to become visible.

Most secretions come from three glands:

Eccrine—secretes largely water, with both inorganic (ammonia, chlorides, metal ions, phosphates) and organic (amino acids, lactic acids, urea, sugars) compounds. Most important for fingerprints.

Apocrine—secretes pheromones and other organic materials.

Sebaceous—secretes fatty or greasy substances.

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Developing Latent Prints

Developing a print requires substances that interact with secretions, causing the print to stand out against its background. It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print.

Powders—adhere to both water and fatty deposits. Choose a color

to contrast with the background.

Iodine—fumes react with oils and fats to produce a

temporary yellow-brown color.

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Developing Latent Prints, continued

Ninhydrin—reacts with amino acids to produce a purple color.

Silver nitrate—reacts with chloride to form silver chloride, a material that turns gray when exposed to light.

Cyanoacrylate—“superglue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit..

In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. These were first used by the FBI in 1978. Since lasers can damage the retina of the eye, special precautions must be taken.

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Iodine Fingerprint

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Ninhydrin Fingerprint

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Cyanoacrylate Fingerprints

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Other Prints

Lips—several common patterns

Voice—electronic pulses measured on a spectrograph

Foot—size of foot and toes; friction ridges on the foot

Shoes—can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern

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Other Prints, continued

Palm—friction ridges can be

identified and may be used

against suspects

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Footprints are taken at birth

as a means of identification of

infants.

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A man has been convicted of suffocating an eldery woman on the basis of earprint evidence. The assailant was caught after police matched the inprint of his ear on the victim’s window. Police believe that the thief put his ear to the window to listen for signs of anyone home.

Earprint catches murderer

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Teeth—bite marks are unique and

can be used to identify suspects.

These imprints were placed in gum

and could be matched to crime

scene evidence.

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The blood vessel patterns in

the eye may be unique to

individuals. They are used

today for various security

purposes.

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AFIS

The Automated Fingerprint Identification System—a computer system for storing and retrieving fingerprints

Established in the 1970s, AFIS enables law enforcement officials to:

Search large files for a set of prints taken from an individual

Compare a single print, usually a latent print developed from a crime scene

By the 1990s, most large jurisdictions had their own system in place. The problem: A person’s fingerprints may be in one AFIS database but not in others.

IAFIS—the FBI’s Integrated Automated Fingerprint Identification System, which is a national database of all 10-print cards from all over the country

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Biometrics

Use of some type of body metrics for the purpose of identification. (The Bertillon system may actually have been the first biometry system.)

Used today in conjunction with AFIS.

Examples include retinal or iris patterns, voice recognition, hand geometry.

Other functions for biometrics: can be used to control entry or access to computers or other structures; can identify a person for security purposes; can help prevent identity theft or control social services fraud.

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More about Prints

For additional information about prints and crime, check out truTV’s Crime Library:

www.crimelibrary.com/criminal_mind/forensics/fingerprints/1.html

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History from 1850 to 1900 William Herschel—required Indians to put their fingerprints

on contracts, and used fingerprints as a means of identifying prisoners

Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification. He was the first person to use fingerprints to solve a crime

Alphonse Bertillon—proposed body measurements as a means of identification; termed anthropometry

Francis Galton—developed a primary classification scheme based on loops, arches, and whorls. He showed that a person’s fingerprint remained the same from birth until death, no two fingerprints are the same, and that fingerprints cannot be altered.

Chapter 4



43


History from 1850 to 1900

Edward Richard Henry—in collaboration with Galton, instituted a numerical classification system

Juan Vucetich—developed a fingerprint file (database) based on Galton’s system

Mark Twain (Samuel L Clemens) In Mark Twain's book, "Life on the Mississippi", a murderer

was identified by the use of fingerprint identification. In a later book, "Pudd'n Head Wilson", there was a dramatic court trial on fingerprint identification.

Chapter 4



44


History from 1850 to 1900 1863 - Coulier

Professor Paul-Jean Coulier, published his observations that (latent) fingerprints can be developed on paper by iodine fuming

explains how to preserve (fix) such developed impressions and mentions the potential for identifying suspects' fingerprints by use of a magnifying glass.

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45

Ridge Characteristics

Minutiae—characteristics of ridge patterns

Ridge endingIsland or short ridgeBridgeEye or enclosureDeltaBifurcation or fork DotSpurDouble bifurcationTrifurcation

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Identify each fingerprint type

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Pre-lab questions

What did law enforcement officials rely in the early 1800’s in order to identify known criminals?

What pieces of data did Bertillion use in order to create a unique classification/identification for an individual?

Which incident rendered the Bertillion system of classification as an unreliable means of uniquely identifying an individual?

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Pre-lab questions

What allows fingerprints to be a more reliable method of identifying a criminal?

What are some other parts of the body that can make distinctive marks that can be used to identify a criminal?


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Post –lab questions Was your data identical to any one else’ in the

class? Based on your lab result, would you consider

this a reliable method to conclusive identify a criminal? Explain your answer

What are two advantages of using this method? What are two disadvantages of using this

method?


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BSO response questions

1. Which layer of skin would you have to cut through to permanently alter your fingerprint?

2. fingerprints that are visible to the naked eyes are known as ___________prints, while those that are hidden are known as ______ prints.

3. What method would be required to process a visible print that was left behind by greasy fingers?

4. Give the name of a famous bank robber who attempted to alter his fingerprints.


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5. What is the criteria for determining the order of the method used to process latent prints?

6. How would you determine what type of powder works best for a given surface?

7. In the case with the check fraud, how was the fingerprint examiner able to identify that the fingerprint being used was a fake?


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8. Print A (top image) would be classified as:

A.Latent B. patent C. plastic

9. Print B would be classified as:

A.Latent B: Patent C. Plastic

Please give a explanation for answer choice.


Documents

Fingerprints. Chapter 4 Fingerprints 2 Kendall/Hunt Publishing Company 2 Chinese records from the 221-206 BC included details about using handprints