Fingerprints Recording and classifying prints Rolling inked prints Loops, whorls, arches, ridge characteristics Primary identification number Lifting.

FingerprintsRecording and classifying prints

• Rolling inked prints• Loops, whorls, arches, ridge

characteristics• 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

Fundamental Principles of Fingerprints1. A fingerprint is an individual

characteristic.

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

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

When do fingerprints form?

• Ridges form in early embryonic development (3rd or 4th month)

• remain constant throughout life.

What determines fingerprint pattern and minutiae?

1. DNA: Genes

2. Environmental forces: pressures within the womb and contact with the amniotic fluid

What do the genes control?1. The tissue underlying

the first few layers of skin is controlled by genes.

2. This tissue forms a unique pattern in the skin layer – Dermal Papillae

3. Environment has more to do with fingerprints than genes!!

John Dillinger – couldn’t change fingerprints with acid

Can only be altered by deep scarring of dermal layer (2-3mm).

History of Fingerprinting

1. Used in Ancient China as far back as 3 thousand years ago to sign documents.

2. William Herschel (1858)• India - English civil

servant required natives to sign

• contracts with the imprint of right hand

3. Henry Fauld (1870’s)• Became the first person to

solve a crime using fingerprints.

• Matched the fingerprints found on a cup at a robbery in Tokyo with those of a servant.

• First to suggest fingerprinting as the primary means of identification.

4.Francis Galton (1892)• Fingerprints do not

change as you age• No two are exactly the

same. • Odds of two

fingerprints being the same were 1 in 64 billion.

• Published 1st book on Fingerprinting

• Coined terms: loops, arches, and whorls.

5. Sir Edward Henry (1897)• Developed a System to file

fingerprints

Fingerprinting in the US

1. NY was the 1st state to use fingerprints – 1901

2. Became the official system of criminal identification in the U.S. in 1924 at the formation of the F.B.I.

3. US vs. Mitchell (1999)• Challenged the

individuality of fingerprints

• Court ruled Human friction ridges are unique & permanent

Famous CasesPeter Griffiths –

•killed a 3 year old.

•Mass fingerprinting was done to find the killer.

Dactyloscopy: The study of Fingerprints

History from 1850 to 19001. William Herschel—required Indians to put their fingerprints on

contracts, and used fingerprints as a means of identifying prisoners

2. Henry Faulds—claimed that fingerprints did not change over time and that they could be classified for identification

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

4. Francis Galton—developed a primary classification scheme based on loops, arches, and whorls

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

6. Juan Vucetich—developed a fingerprint classification system based on Galton’s that is used in Spanish-speaking countries

Fingerprinting

• Height – Fingerprinting surface should be 39 inches from floor

• Clean fingers with alcohol swab

• The individual should stand to the right and rear of the person taking the fingerprints in front of the card

Fingerprinting Procedure1. Thumbs rolled toward the center of the

body

2. Fingers rolled away from the center of the body.

3. Roll each finger in the correct space taking care to lift each finger up and away after rolling, to avoid smudging.

Rolled impressions• The upper ten impressions are taken

individually

Rolling Prints

4. Flat Impressions - Taken simultaneously without rolling, at a 45o angle and then the thumbs.

What can go wrong?

Ridge Characteristics

Minutiae - characteristics of ridge pattern• Ridge ending• Island or short ridge• Bridge• Eye or enclosure• Delta• Bifurcation or fork • Dot• Spur• Double bifurcation• Trifurcation

Ridge Characteristics

Crossover

Core

Bifurcation (fork)

Ridge ending

Island

Delta

Pore

Scar

Furcations

1. Bifurcation

2. Trifurcation

3. Double bifurcation

1. Opposed bifurcation

Endings

1. Ridge Ending

1. Opposed Bifurcation Ridge Ending

Hook, Dot, Island, & Lake

1. Island (Short Ridge)

2. Dot

3. Lake (enclosure)

1. Hook

Bridge & Ridge Crossings

1. Bridge

1. Ridge Crossing

Fingerprint Minutiae

Arch

1. 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.

2. Types

• Plain

• Tented

Loop

1. A loop must have one or more ridges entering and exiting from the same side. Loops must have one delta.

2. Types

• Radial—opens toward the thumb

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

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

Whorl

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

2. A double loop is made of two loops. An accidental is a pattern not covered by other categories.

3. Whorls have at least two deltas and a core.

4. Types• Plain• Central pocket• Double loop• Accidental

Loop Whorl Arch

Percentages in the Population

• Loop – 65%• Whorls – 30%-35%• Arches – 5%

Core

1. Top of the innermost recurving ridge.

2. Center of the pattern

Type Lines

• Diverging ridges that go above & below the loop

Delta

• The point of divergence of the type lines

Loop Pattern

1. One or more ridges entering and exiting from the same side it began.

2. Must have one delta.

Types of Loops1. Radial--opens towards thumb

2. Ulnar--opens towards pinky

Whorl

1. Have type lines and a minimum of 2 deltas

2. Types– Plain

– Central Pocket

– Double Loop

– Accidental

Plain & Central Pocket loop• Both have at least one ridge that makes a

complete circuit (spiral).

PLAIN - Line drawn between the two deltas touches a spiral ridge

CENTRAL POCKET LOOP - Line drawn between the two deltas doesn’t touch a spiral ridge

Double loop1. Two loops combined

2. s-shaped

Accidental

• Has 2 or more patterns (not including the plain arch)

Arches

1. Ridges enter on one side and cross to the other side while rising upward in the middle.

2. No type lines, deltas, or cores.

Types

Plain

Tented sharp center rise

What is the fingerprint pattern?

Plain arch Tented arch Plain whorl Loop (r or u)

Which Loop is it?

ulnar radial

The Henry System (1899)

1. Classification system using all 10 fingers. Based on identifying the patterns of each finger.

2. 1,024 labels are created.

3. Still used today.

4.The fingerprint record is filed under its label

5.To locate a record, only 1 / 1,024th of the entire collection must be examined

Step 1: Determine which fingers have whorls

right left

Step 2: Each finger is given a point value

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

_________________________________ = ______

That number is your primary classification number.

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

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

Step 3: Set up a ratio

Example 1

2. right 4. right 6. left 8. left 10. left index ring thumb ring little

16 8 4 2 1

16 8 4 2 1

1. right 3. right 5. right 7. left 9. left thumb middle little index little

+ 1

1

A suspect has whorls on her right index, left ring and right little fingers.

What is her Henry classification number?

What is the ratio if all 10 fingers have whorls?

2. right 4. right 6. left 8. left 10. left index ring thumb ring little

16 8 4 2 1

16 8 4 2 1

1. right 3. right 5. right 7. left 9. left thumb middle little index little

32/32

+ 1

1

What is the ratio if no fingers have whorls?

2. right 4. right 6. left 8. left 10. left index ring thumb middle little

16 8 4 2 1

16 8 4 2 1

1. right 3. right 5. right 7. left 9. left thumb middle little index ring

1/1

25% of the population

+ 1

1

Comparison of Prints

1. There are no legal

requirements in the

United States on the

number of points

required for a match.

2. Generally, criminal

courts will accept 8 to

12 points of similarity.

Latent Prints1. 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

2. 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.

Developing Latent Prints1. 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.

2. 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.

3. Powders—adhere to both water and fatty deposits. Choose a color to contrast with background.

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

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

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

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

Other ways of locating Latent Prints

1. RUVIS - Reflected UV Imaging System

2. UV light is used to locate latent prints

3. Chemicals can also be used

Developing fingerprints using powders

1. Used on hard, non porous surfaces

2. Glass, mirror, metals, painted wood, tile, your desk, etc…

3. Adhere (stick) to water and fatty deposits in prints. • Use black (charcoal) for light surfaces

• Use gray (aluminum) for dark surfaces

4. Magnetic Powder - special “brush” won’t smudge print (leather, rough plastic). Works better on shiny surfaces or plastic baggies or containers.

5. Fluorescent Powder - print glows with UV light

Developing Fingerprints Using Iodine

1. Heating iodine crystal causes sublimation (Liquid to Gas)

2. Fumes react with oils on skin

3. Temporary yellow brown print

4. To last longer spray with starch to set iodine.

5. Photograph after the treatment – permanent record.

6. Use on porous surface

Developing Fingerprints using Silver nitrate – Physical developer

1. Amino acids react with chlorides to form silver chloride (gray when exposed to light)

2. Develops prints not developed by other chemicals, even wet or documents over 2000 years old

Developing Fingerprints using Ninhydrin

1. Reacts with amino acids in sweat to produce a purple print.

2. Reaction takes 1 to 2 hrs or more on weaker prints.

3. Heat speeds it up.

4. Used on paper as old as 15 years old

5. Preferred method by scientist

Developing Fingerprints using Cyanoacrylate “super glue”1. For non-porous materials such

as metals, electrical tape, leather, plastic bags

2. Heat glue: vapors react with fingerprint constituents to form a hard, whitish print.

New Advances in Fingerprinting

1. DFO- (1,8-diazafluoren-9-one) instead of ninhydrin. 2.5 times more latent print exposure.

2. Dye Combinations - RAM, RAY, MRM 10 used with Super Glue fuming

Laser Techniques1. In modern labs and

criminal investigations, lasers and alternative light sources are used to view latent fingerprints.

2. It was first used by the FBI in 1978.

3. Since lasers can damage the retina of the eye, special precautions must be taken and a filter used.

Other Prints1. Lips—several common patterns

2. Voice—electronic pulses measured on a spectrograph

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

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

5. Palm—friction

ridges can be

identified and may

be used against

suspects

6. Footprints are

taken at birth as a

means of

identification of

infants.

7. Ear-print• A man has been convicted of

suffocating an elderly woman on the basis of ear-print evidence.

• The assailant was caught after police matched the imprint 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.

8. 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.

9. Blood vessel patterns

• Blood vessel patterns

in the eye may be

unique to individuals.

• They are used today for

various security

purposes.

AFIS1. The Automated Fingerprint Identification System—a computer system for

storing and retrieving fingerprints

2. 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

3. 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.

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

Biometrics

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

2. Used today in conjunction with AFIS.

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

4. 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.