chapter 4 solved: fingerprint analysis - developing prints 3:20 solved: fingerprint analysis -...

Chapter 4

Solved: Fingerprint Analysis - Developing Prints 3:20

Name 3 ways that fingerprints can be developed.

Kendall/Hunt Publishing Company2

http://investigation.discovery.com/videos/solved-fingerprint-analysis.html

http://investigation.discovery.com/videos/solved-fingerprint-analysis.html

Painting Time

Find the 6 differences between the two pictures.

Source: http://www.slylockfox.com/arcade/6diff/index.html

The answers are …

Answers: Tail feathers, hole in fence, ball, paint bucket, girl’s hair, ice cream cone

T. Trimpe 2006 http://sciencespot.net/

1. What is the name given to the study of fingerprints? A. Dactyloscopy B. Palynology C. Entomology D. Trichology

2. What causes fingerprints to be left behind when we touch things? A. Salt produced by our sweat glands C. Moisture in the atmosphereB. Natural oils in the skin D. Dust on the things we

touch3. Which of the following is NOT one of the 3 basic types of fingerprint patterns? A. Loops B. Whorls C. Arches D. Spirals

4. Which animal is said to have fingerprints virtually indistinguishable from those of human beings? A. Panda B. raccoon C. koala D. lemur

5. Who is generally recognized as being the first person to use fingerprints as a means of identification? A. Alphonse Bertillon C. Dr Henry FauldsB. Sir William Herschel D. Sir Edward Henry

1. What is the name given to the study of fingerprints? A. Dactyloscopy B. Palynology C. Entomology D. Trichology

2. What causes fingerprints to be left behind when we touch things? A. Salt produced by our sweat glands C. Moisture in the atmosphereB. Natural oils in the skin D. Dust on the things we

touch3. Which of the following is NOT one of the 3 basic types of fingerprint patterns? A. Loops B. Whorls C. Arches D. Spirals

4. Which animal is said to have fingerprints virtually indistinguishable from those of human beings? A. panda B. raccoon C. koala D. lemur

5. Who is generally recognized as being the first person to use fingerprints as a means of identification? A. Alphonse Bertillon C. Dr Henry Faulds

B. Sir William Herschel D. Sir Edward Henry

He was a government administrator in colonial India and began using fingerprints in July 1858 to identify illiterate prisoners and workers in India.

Fingerprints

T. Trimpe 2006 http://sciencespot.net/

1. At what age do humans acquire fingerprints? A. At three month's gestation C. At birthB. At six month’s gestation D. At three months of age

2. In forensics, criminologists use AFIS to search an online database for fingerprint matches. What does AFIS stand for?

A. Automated Footprint Identification SystemB. Actual Fingerprint Identification SystemC. Automated Fingerprint Identification SystemD. Auto Fingerprint Intelligence System

3. True or False: A fingerprint brush uses lion's mane hair.

A. They enable us to grasp objects. B. They provide insulation for the tissues under the skin.C. They help us to identify individual human beings.

4. What is the minimum number of matching points required to identify an unknown latent print in the United States? A.8 B. 16 C. 32 D. There is no minimum

5. What is the function of the ridges on our fingers which create fingerprints?

1. At what age do human beings acquire fingerprints? A. At three month's gestation C. At birthB. At six month’s gestation D. At three months of age

2. In forensics, criminologists use AFIS to search an online database for fingerprint matches. What does AFIS stand for?

A. Automated Footprint Identification SystemB. Actual Fingerprint Identification SystemC. Automated Fingerprint Identification SystemD. Auto Fingerprint Intelligence System

4. What is the function of the ridges on our fingers which create fingerprints? A. They enable us to grasp objects. B. They provide insulation for the tissues under the skin.C. They help us to identify individual human beings.

3. True or False: A fingerprint brush uses lion's mane hair.

5.. What is the minimum number of matching points required to identify an unknown latent print in the United States? A. 8 B. 16 C. 32 D. There is no minimum

Challenge Challenge

See if you can determine what the following magnified See if you can determine what the following magnified photos are. Number your paper to 5.photos are. Number your paper to 5.

http://www.youtube.com/watch?v=iOrlcPTxwVk

http://www.youtube.com/watch?v=noIz_NvotMw&feature=fvst

http://www.youtube.com/watch?v=bx_mQctz944

Chapter 4

The Answers: The Answers:

Types of Fingerprints Challenge

Chapter 4

What type of prints are What type of prints are these?these?

A.(r) B. C.

D.

Chapter 4

What type of prints are What type of prints are these?these?

A.(r) Plain whorl Radial loop B.

D. Tented arch

C. Double loop whorl

Chapter 4/

Crime 360 - Finding Fingerprints with Superglue? 1.00

Carefully listen to the video clip and be prepared to answer 5

questions at the end

http://www.youtube.com/watch?v=FkcSkADVMIM

http://www.youtube.com/watch?v=FkcSkADVMIM

Chapter 4 20

1. What is the name of the activator used during the process?A. Hot Prints B. Hot Stuff C. Hot Shot

2. During fuming the super glue heats up and attaches to _____ _____ in the fingerprint.A. Skin B. Amino Acids C. Valleys

3. The evidence is placed in a super glue _____ to develop the prints.A. Chamber B. Tube C. Slide

4. What color is the fingerprint after it develops?A. Red B. White C. Yellow

Watch the video and answer the questions at the end.

21

1. What is the name of the activator used during the process?A. Hot Prints B. Hot Stuff C. Hot Shot

2. During fuming the super glue heats up and attaches to _____ _____ in the fingerprint.A. Skin B. Amino Acids C. Valleys

3. The evidence is placed in a super glue _____ to develop the prints.A. Chamber B. Tube C. Slide

4. What color is the fingerprint after it develops?A. Red B. White C. Yellow

Fingerprint Processing Challenge

Chapter 4

What process of latent print What process of latent print development are these?development are these?

A. B.

C.

Chapter 4

What process of latent print What process of latent print development are these?development are these?

A. ninhydrinB. Iodine fuming

C. Cyanoacrylate – superglue fuming

Chapter 4:Chapter 4: FingerprintsFingerprints

“Fingerprints can not lie, but liars can make fingerprints.”

—Unknown

Chapter 4Kendall/Hunt Publishing Company

26

FingerprintsFingerprints

Why fingerprints are individual evidence.

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

How computers have made personal identification easier.

Students will learn:


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Students 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.

FingerprinFingerprintsts

The History of The History of FingerprintingFingerprinting


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TheThe Chinese Chinese

In the eighth century during China’s T’ang dynasty, Chinese used thumbprints to seal important documents and on business contracts.

There is no record of whether they were actually used for identification, and there was no systematic classification.


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Quntilian, the Roman LawyerQuntilian, the Roman Lawyer

Made use of a bloody handprint in a murder case in 1000 AD

A number of people throughout A number of people throughout history noted fingerprints and history noted fingerprints and

even commented on the even commented on the different ridge patterns.different ridge patterns.

However, the science of However, the science of dactyloscopydactyloscopy, the study , the study of fingerprints,(comes from the Greek word of fingerprints,(comes from the Greek word

daktulosdaktulos, meaning , meaning fingerfinger) really started in the 19) really started in the 19thth century in India with William Herschel.century in India with William Herschel.


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WilliamWilliam Herschel Herschel

Highly placed civil servant who decided to require Indians to add their fingerprint to contracts.

Later (1877) he introduced the use of fingerprints as a means of identifying prisoners.


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HenryHenry Faulds Faulds

In Japan, molded fingerprints in old pottery piqued the interest of Henry, a health missionary in Tokyo .

He published a scientific paper in 1880 about the possibility of using fingerprints to identify criminals.

Thought that fingerprints were unique. Could be used for classification Said fingerprints did not change over a lifetime. First to use fingerprints to solve a crime.


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PrisonersPrisoners

Identification has always been a problem for the criminal justice system.

Prisoners were often branded or tattooed or even had hands or fingers chopped off so they would be recognized as criminals.

This practice was generally abolished in the Western world in the early 1800’s.


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PhotographyPhotography

The advent of photography helped, but without a means of classification, the police records were soon overwhelmed with too many photographs to be useful.

They often employed men with “photographic” memories.


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AlphonseAlphonse Bertillon Bertillon

1881 Employed as a ledger clerk at the police

headquarters in Paris, suggested using 11 body measurements to identify habitual offenders.

Was accepted almost everywhere. The science of human measurements was called

anthropometry. This was initially the system that most police

departments used for personal identification.

Chapter 4

**AlphonseAlphonse Bertillon Bertillon (1853- (1853-1914)1914)

1879 First system of personal

identification. Wrote his first book on anthropometry.

Known as the father of personal identification

Began the development of anthropometry – a systematic procedure of taking a series of body measurements as a means of distinguishing one individual from another.

Was eventually replaced by fingerprinting in the early 1900’s.

Chapter 4


39

FrancisFrancis Galton Galton

1891 A British anthroplogist - Published two books in which he showed how to classify fingerprints using loops, whorls, and arches.

He showed that: 1. a person’s fingerprints stay the same from birth until

death. 2. no two fingerprints are identical 3. prints cannot be altered

And said it is possible to classify a very large number of prints.


40

Sir Edward Richard Sir Edward Richard HenryHenry

1897 – Inspector general of police in Bengal, India.

Simplified Galton’s classification system in India Established the Henry System of Classification

which replaced Bertillon’s system. England’s (FBI) Scotland Yard, adopted the

Henry System Henry System is used in most English speaking

countries.


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JuanJuan Vucetich Vucetich

1901 – Argentinean police official Set up a workable fingerprint classification

system based on Galton’s method Used in most Spanish speaking countries.


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Juan VucetichJuan Vucetich

1902 – a year later, Vucetich first officially identified a criminal using fingerprints.

In a small town in the province of Buenos Aires, Argentina, a woman named Francesca Rojas had murdered her two sons and blamed the attack on a neighbor.

Using Vucetich’s methods, police identified bloody fingerprints on a door post as Rojas’s, which led to her confession.


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Civil Service TestCivil Service Test

1902 – The New York Civil Service began the practice of fingerprinting everyone who took a civil service exam.


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LeavenworthLeavenworth PrisonPrison

1903 - The death of Bertillon’s anthropomorphic classification. . . . Mainly because . . .

A man named Will West arrived there to serve time. When convicted, he received an extra severe sentence

because he was a repeat offender. He protested the sentence, stating that he had never been

convicted before. As was done with all prisoners on admission, his Bertillon

measurements were taken and compared to existing files.


45

Will Will andand William William WestWest

Prison officials were astonished to find that another man who was serving a life term for murder had almost identical measurements, and even more amazing, his name was William West . . . And he looked almost the same as the new prisoner!

The two men’s fingerprints were taken and, of course, were quite different!

Chapter 4

a. Will West b. William Westa. Will West b. William West



47

1903 – The New York State prison system started fingerprinting all the inmates.

1904 – because of the William West case, Leavenworth Penitentiary also switched to fingerprinting as its primary means of personal identification.

1905 – the U.S. Army began using fingerprints , and the U.S. Department of Justice set up the Bureau of Criminal Identification in Washington D.C. to centralize and standardize the use of fingerprinting.


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1907 – The Navy began using fingerprints, and the Bureau of Criminal Identification was moved to Leavenworth Penitentiary.

1918 Edmond Locard recommended that 12 points of comparison be required to prove the identity of an individual.

1924 – the U.S. Congress established the FBI as the central repository for all fingerprint information. By 1946 it held 100 million fingerprint cards.


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IAFISIAFIS

2004 – The FBI crime lab identification section began using the Integrated Automated Fingerprint Identification System (IAFIS). It can search 47 million records in 5 minutes! Assuming good quality, IAFIS requires only one print for a

match! The final identification however, is always done by hand by a

forensic expert. The more than 250 million fingerprint cards already

collected are still kept on file. If piled on top of each other, these records would make 133 stacks

as high as the Empire State Building!


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Chapter 4

IAFISIAFIS

http://www.youtube.com/wat ch?v=ZKi1CKTRCQM&feature=related 6:37

http://www.youtube.com/watch?v=ZKi1CKTRCQM&feature=related


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Fundamental PrinciplesFundamental Principlesof Fingerprintsof Fingerprints

1. Fingerprints are unique. A fingerprint is an

individual characteristic.

2. Fingerprints do not change with age. A

fingerprint will remain unchanged during an

individual’s lifetime.

3. Fingerprints display patterns. Fingerprints

have general characteristic ridge patterns that

permit them to be systematically classified.

The Anatomy of a The Anatomy of a FingerprintFingerprint


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Human SkinHuman Skin

Human skin is the body’s first line of defense against invasion and infection.

The hills and valleys (ridges and grooves) you saw when examining your fingers with a magnifying glass make up the skin pattern that is yours alone.


56

Skin and PapillaeSkin and Papillae

Is made up an outer epidermal layer separated from the inner dermal part by the papillae.

The papillae form a boundary that determines the friction ridge structure of the epidermis.

The friction ridge pattern of a fingerprint is established by the dermal papillae.


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Identical Twins . . .Identical Twins . . .

Friction ridges as they are called, can also be found on your palms, feet, and lips.

Most amazing, the patterns made by the friction ridges are not genetically controlled, so even identical twins who have the same “DNA fingerprint” will have different fingerprints.


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unitedstreaming.com - Search Results: fingerprinting


62

Chemically or physically erasing the epidermal structure, as John Dillinger tried to do, causes only pain because the original print will soon grow back.


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JohnJohn DillingerDillinger

. . . Was as a notorious bank robber who tried to remove his fingerprints by using a corrosive acid.

Public Enemy Number One in the early 1930’s paid a doctor $5,000, plus $25 per day for room and board to “dissolve” his fingerprints and perform some minor surgery on his face.


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John DillingerJohn Dillinger

He had the outer layers of the skin (the epidermis) removed by acid and had plastic surgery performed on his face to conceal his identity.

The operation created lots of scar tissue that obscured the ridges in the centers of his fingers, but there were still plenty of minutiae for identification.

He was shot and killed on July 22, 1934, during the famous “lady in red” incident outside the Biograph Theater.


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““Lady in Red”Lady in Red”

The term lady in red derives from the incident in which the FBI was looking for Dillinger, and an informant, Ana Cumpanas (Sage) , stepped forward and said she would be going to the theater with him in the near future.

She wanted the cash reward offered for the capture of Dillinger and to be allowed to stay in the United States (she was scheduled for deportation back to Romania as an undesirable alien).


67

She was told to wear a bright red dress so that the agents waiting outside the theater could easily spot both her and her date, John Dillinger.

When she exited the theater, the agents attempted to arrest the man she was with, but he fled.

The agents shot and killed the man, but there was some question whether he was truly John Dillinger.


68

The fingerprints of the dead man were taken, and in spite of the presence of a tremendous amount of scar tissue, the FBI was able to match them to those of John Dillinger from fingerprint records taken earlier in his career.

Chapter 4

John Dillinger musical 5:45 John Dillinger and "Baby Face" Nelson Hu

nted by FBI 2:28

John Dillinger Died Here 1:59


Chapter 4

http://www.youtube.com/watch?v=noIz_NvotMw&feature=fvst John Dillinger 5:45 musical

http://www.youtube.com/watch?v=bx_mQctz944 John Dillinger and “Baby Face” Nelson Hunted by FBI 2:28

http://www.youtube.com/watch?v=iOrlcPTxwVk John Dillinger Died Here 1:59



71

Changes in Fingerprints????Changes in Fingerprints????

Certain professions can affect a fingerprint. For example:

The ridges of a concrete worker and plasterer can become rather indistinct over time because of the alkalinity of cement and gypsum can dissolve proteins.

Classification of Classification of FingerprintsFingerprints


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PatternsPatterns

All fingerprints can be classified into three basic patterns:

Loops Whorls Arches


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LoopLoop

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

Loops must have one delta. Have a core near the

center. The most common type

of fingerprint is the loop. Types

Radial—Opens toward the thumb – 5%

Ulnar—opens toward the “pinky” (little finger) – 60%


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


77

WhorlWhorl

Whorls have at least two deltas and a core.

Types Plain

A line between two deltas will bisect a circle – 20%

Central Pocket A line between two deltas will not

bisect a circle Double Loop

made of two loops. Accidental

An accidental is a pattern not covered by other categories


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ArchArch

Least common; simplest 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 - 4% Tented – 1%


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Frequency of Fingerprint PatternsFrequency of Fingerprint Patterns

Loops Whorls Arches

Ulnar Radial Plain Other Plain Tented

60% 5% 20% 10% 4% 1%


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Racial VariationsRacial Variations

There are racial variations in the distribution of the three patterns. People of African ancestry have more arches People of European background have many

loops Asians/Orientals have a higher frequency of

whorls.


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Other VariationsOther Variations

Certain patterns are more likely to be found on particular fingers; for example Forefingers have most of the radial loops.


83

Chapter 4

How to Roll FingerprintsHow to Roll Fingerprints

http://www.youtube.com/watch?v=d7N-4UNAzsw 4:31 How to roll fingerprintshttp://www.youtube.com/watch?v=d7N-4UNAzsw


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Sir Richard Edward HenrySir Richard Edward Henry

Developed a method of classifying fingerprints, later modified by the FBI, that allowed all sets of ten fingerprints in the world to be divided into 1,024 groups.

Secondary and even more complex classifications were created to allow for even more groups.

This is done so that when prints are submitted to the FBI for comparison, most of the millions of sets of prints on file can be weeded out so that only a few dozen sets have to compared by hand.


88

Primary ClassificationPrimary Classification

The Henry—FBI ClassificationEach finger is given a point value

It is based on the whorl pattern. It requires all ten fingerprints

right left


89

Primary ClassificationPrimary Classification

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

=

Complete Your Henry Complete Your Henry System ClassificationSystem Classification

Chapter 4

Fingerprint GamesFingerprint Games

Digital fingerprint puzzle

– sciencespot and tru tv - Forensic Files: Fingerprint Game on truTV.com

Match the fingerprints investigation discovery – sciencespot - Fingerprint Memory Games : Detective Games : Investigation Discovery

Match the fingerprints investigation discovery – sciencepost - Fingerprint Memory Games : Detective Games : Investigation Discovery

91

IndividualizationIndividualization

Ridge ClassificationRidge Classification


93

Individualization of FingerprintsIndividualization of Fingerprints

You have now classified fingerprints according to general patterns or groups, but to individualize them, you must use the fine structure of ridge characteristics or minutiae.


94


95


96


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Ridge CharacteristicsRidge Characteristics

Minutiae—characteristics of ridge patterns

Ridge ending Short ridge Dot or fragment -about as

long as it is wide Bifurcation – a single

friction ridge that splits into two ridges.

Double bifurcation Trifurcation Bridge Island Enclosure Spur


99


100


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Fingerprint MinutiaeFingerprint Minutiae


102


103


104


105


106


107

ComparisonComparison There are no legal

requirements in the United States on the number of points.. Generally, criminal courts will accept 8 to 12 points of similarity when comparing fingerprints for a match.

There are 150 – 200 minutiae in a properly rolled fingerprint.


108

How many ridge characteristics can you identify in this fingerprint?

Chapter 4 109

1

1 – Blow up your balloon about halfway and twist the end to keep the air from coming out. Do not tie it off!

2 – Use an ink pad to make a print with all of your fingers and label each one with a permanent marker. Write your name on the balloon as well.

3 – Blow up the balloon to full size and tie the end.

4 – Analyze the fingerprints to find several ridge structures that we have discussed. Use a highlighter to mark these structures on your “My Prints” worksheet.

Try It!

Think About It!

Which ridge structures were most common in your fingerprints?

Which ridge structures were most common in your group?

Were there any structures that were not found in any of the fingerprints?

Chapter 4

How to Compare Fingerprints: How to Compare Fingerprints: the basicsthe basics

http://www.youtube.com/watch?v=IrpTqKkgygA&feature=related 5:44

http://www.youtube.com/watch?v=IrpTqKkgygA&feature=related

Chapter 4

Digital Storytelling – Digital Storytelling – Fingerprints 7:58Fingerprints 7:58

http://www.youtube.com/watch?v=Ry8920R7bxs&feature=related

http://www.youtube.com/watch?v=Ry8920R7bxs&feature=related

fbi.gov fingerprint memory game

Types of PrintsTypes of Prints

PlasticPlastic

VisibleVisible

LatentLatent


113

1. 1. PlasticPlastic Prints - (etched) Prints - (etched)

Prints that are indented or molded Are made by pressing a finger against a

plastic-like material to form a negative impression of a fingerprint.

Paint, putty, soap, candle wax, gum on envelopes or stamps, a candy bar that has softened in ones hand.


114


115

2. Visible 2. Visible PrintsPrints

Prints that are easily seen. Left by a finger that has touched colored

material such as blood, paint, ink, grease, chalk, mud, or sometimes dust.


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3. 3. LatentLatent PrintsPrints

So called “invisible” prints that must be developed by chemical or physical means.

They result from deposits of perspiration and body oils.

A fingerprint on the skin could be an example of a latent print.


118

Visualizing Latent Visualizing Latent PrintsPrints


120

Sweat pores along the ridges release perspiration, which is 98 – 99 % water.

So, a fingerprint is composed mostly of water. It is estimated that a fingerprint initially may

weight 0.1 milligram, so after evaporation of the water, we have left about 1 microgram of residue.

This residue is made up of half salt and half complex organic compounds such as amino acids, lipids, vitamins, and additional body oils picked up on the finger by touching oily or hairy parts of the body.

This doesn’t leave much This doesn’t leave much for the investigator to for the investigator to

work with!work with!


122

Latent PrintsLatent 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—largely water with both inorganic (ammonia,

chlorides, metal ions, phosphates) and organic compounds (amino acids, lactic acids, urea, sugars). Most important for fingerprints.

ApocrineApocrine——secrete pheromones and other organic materials.

Sebaceous—secrete fatty or greasy substances.


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124

Developing Latent Developing Latent PrintsPrints

Developing a print requires substances that interact with secretions that cause 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.

Chapter 4

The first thing you want to do after The first thing you want to do after visualizing a fingerprint is to visualizing a fingerprint is to

photographphotograph it! it!


Physical MethodsPhysical Methods

Chapter 4

Latent prints can be developed Latent prints can be developed using using physicalphysical and and chemical chemical

methods.methods.


128

Dusting Dusting is a physical method of is a physical method of developing latent printsdeveloping latent prints

Dust with a fine powder. Most effective on hard,

nonabsorbent surfaces. Adhere to both water and fatty

deposits. Color is chosen to stand out against the

surface. The developed print can then be

“lifted” by means of clear sticky tape and collected for analysis.

Chapter 4

Developing Latent Prints with Developing Latent Prints with Magnetic PowderMagnetic Powder

http://www.youtube.com/watch?v=iomWm3_Qvhk&feature=related 2:46

http://www.youtube.com/watch?v=iomWm3_Qvhk&feature=related


Chemical MethodsChemical MethodsGenerally more effective for soft, porous Generally more effective for soft, porous surfaces such as paper, Styrofoam cups, surfaces such as paper, Styrofoam cups,

leather, metal, etc.leather, metal, etc.


131

Chemical Methods of Developing Chemical Methods of Developing Latent PrintsLatent Prints

Iodine fuming Ninhydrin Cyanoacrylate – also called “superglue

fuming” Silver nitrate – physical developer.

Should always be done last.


132

IodineIodine Fuming Fuming

Works best for prints on porous paper.

Iodine—fumes react with oils and fats to produce a temporary yellow brown reaction.

Iodine reacts with the fatty oils from the finger to form a visible but short lasting print.


133

Iodine FingerprintIodine Fingerprint

Chapter 4

Iodine Fuming ProcessingIodine Fuming Processing

Iodine Fuming 5:04



135

NinhydrinNinhydrin

Is most commonly used with paper and porous surfaces.

It reacts with amino acids left by the finger to make an orange to purple image.

Ex – matchbook


136

Ninhydrin FingerprintNinhydrin Fingerprint

Chapter 4

Ninhydrin Fingerprint Ninhydrin Fingerprint ProcessingProcessing

Ninhyrdin processing 8:02



138

CyanoacrylateCyanoacrylate

An interesting method of chemically developing fingerprints was discovered by accident in Japan in the late 1970’s.

Is now widely used for developing latent prints on nonporous surfaces such as metals, glass, adhesive tapes, and plastic articles

Crime 360: Superglue to find fingerprints?


139

CyanoacrylateCyanoacrylateFinding FingerprintsFinding Fingerprints

It involves evaporating superglue in an enclosed container.

The glue, a cyanoacrylate ester, reacts with print residues to make a white, permanent impression that can then be treated with powders or fluorescent dyes to make a sharper contrast and allow easier photography or lifting.

“super glue” fumes react with amino acids, fatty acids, proteins, water and other fingerprint constituents to form a hard, whitish deposit.


140

Cyanoacrylate Cyanoacrylate FingerprintsFingerprints

Chapter 4

Developing Prints with Developing Prints with Superglue Superglue

http://www.youtube.com/watch?v=R0e8WXkFA64&feature=related 5:25

http://www.youtube.com/watch?v=R0e8WXkFA64&feature=related

Crime 360: Superglue to find fingerprints? 1:00


142

Silver NitrateSilver Nitrate

Also called physical developer. Reacts with salt left from perspiration in a dried

print to form silver chloride, a material which turns gray when exposed to light.

It is then converted to dark silver oxide. This is the same process used in developing

photographs. This must be a last resort because it can wash

away traces of fatty oils and proteins.


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144

Often, the order of the steps in Often, the order of the steps in developing prints is important!developing prints is important!

When you have just one piece of evidence, first use tests that won’t harm that evidence.

You want to get as much information as possible, so you may have to perform several tests.


145

For example:For example:

To get the best image of latent fingerprints, you might first use iodine fuming; then you might try ninhydrin.

You would save the silver nitrate method until last because this procedure will wash away traces of fatty oils and proteins.

A fingerprint left at the A fingerprint left at the scene of a crime may last scene of a crime may last

for for years. . . years. . .


147

Lasers and Alterative Light Lasers and Alterative Light SourcesSources

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.


148

Other PrintsOther Prints

Ridge characteristics can be also found on footprints and palm prints.

Modern labs also utilize other evidences: A. Ears—shape, length and width

B. Voice—electronic pulses measured on a spectrograph

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

D. Shoes—can be compared and identified by type of shoe,

brand, size, year of purchase, and wear pattern.


149


Palm—friction ridges can be identified and may be used against suspects.


150


Footprints are taken at birth as a means of identification of infants.


151

CheloscopyCheloscopy

Lips—display several common patterns

Short vertical lines Short horizontal lines Crosshatching Branching grooves


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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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BiometricsBiometrics

Used today in conjunction with AFIS Use of some type of body metrics for the purpose of

identification. (The Bertillon system may actually have been the first biometry system.)

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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Chapter 4

Practice Makes PerfectPractice Makes Perfect

Fingerprints at the Crime Scene

Latent Print Concept Map fingerprints and identical twins fingerprint scanner replicating fingerprints



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More about PrintsMore about Prints

For additional information about prints and crime, check out Court TV’s Crime Library

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

chapter 4 solved: fingerprint analysis - developing prints 3:20 solved: fingerprint analysis -...

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