FINGERPRINTING ANALYSIS

Prehistoric Fingerprinting• Ancient Babylonians

• Ancient China

History of Fingerprinting• 1858 – Sir William Herschel

– An English Chief Magistrate in India–

History of Fingerprinting• 1880 - Henry Faulds

–

– Published an article in “Nature” saying fingerprints could be used for identification

– Wrote to his cousin, Charles Darwin, asking for help with developing a classification system

– Darwin forwarded the letter to his cousin, Sir Francis Galton

History of Fingerprints• 1880 Henry Faulds

–

Henry Faulds (1843-1930) 1882 Gilbert Thompson

History of Fingerprinting• 1883 – Alphonse Bertillon

_______________________________________________________________________________________________________________________________________

• Body height• Length of middle finger• Length of left foot• Length of outstretched reach of both arms• Width of head• Length of head

History of Fingerprinting• 1892 – Sir Francis Galton

– Published textbook ________________________• Outlined a fingerprint identification system• Suggested __________________________________• Assigned three pattern types

– _____________ _______________ ________________

• Demonstrated two fundamental principles underlying fingerprint identification system

– ___________________

– ___________________

History of Fingerprints• Uniqueness

– Galton calculated that there was a possible existence of ___________________different fingerprints

– No two fingerprints have yet been found that are identical

– Even identical twins have different fingerprints

• Permanence–

History of Fingerprinting

• 1891 – Juan Vucetich– Developed a ____________________________________– Used in most Spanish-speaking countries– Made one of 1st criminal fingerprint identifications

• 1897 – Sir Edward Richard Henry– Developed another searchable filing system– Adopted by _____________________________________

History of FingerprintingIn 1903, Will West thought he was fooling the

system at Leavenworth Penitentiary by stating that he was not already in the system at the Penitentiary for a previous crime.

The clerk decided to look up his Bertillon number anyway.

What was found was another man serving a life sentence for murder, already imprisoned in the Penitentiary, named William West

This flaw in the system would have never been noticed, had Will West not lied when entering the Penitentiary for a second time in 1903

Will West William West

History of Fingerprinting

• 1904 – World’s Fair • 1924 –

What are Fingerprints?

• ______________________________________________________________________________________

• Also found on palms, toes, and soles of feet• Designed for firmer grasp and to prevent slippage

What are Fingerprints?

• Human skin is composed of layers– Epidermis = __________________– Dermis = ____________________– Dermal papillae = _________________________

• Determines pattern of ridges on skin’s surface• Develop in fetus and enlarge during growth

Dermal papillae separating the two layers of dermis

Ridge Characteristics• Minutiae

– ____________ in a ________________– ___________________________and _____________________ imparts individuality to a fingerprint

– Used to make a ____________________comparison by expert fingerprint examiners

Three Fundamental Principles of Fingerprinting

1. A fingerprint is an ____________________________ characteristic because no two fingers have yet been found to possess identical ridge characteristics (______________________)

2. A fingerprint will remain _____________________ during an individual’s lifetime; and

3. Fingerprints have general ___________________that permit them to be systematically classified.

Rid

ge C

hara

cter

istic

s Ridge Characteristics

Ridge Characteristics• A fingerprint may contain up to

________________________________________________________________

• Crime scene prints usually have only a ___________ number of ridges that are actually recoverable

• To make a match an examiner has to determine that two prints have the same ridge characteristics in the same location to one another

• Around ___________________points of similarity are needed to determine a match

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Comparison There are

________________________________________________in the United States on the number of points required for a match. Generally, criminal courts will accept _____________________________________points of similarity.

2nd Principle: ________________________________________________________________A positive identification of John Dillinger from his fingerprints, even though he had mutilated them

Ridge Patterns

• Three classes– __________________

• 60-65% of all fingerprints– __________________

• 30-35% of all fingerprints– __________________

• 5% of all fingerprints

3rd Principle:Fingerprints have general ridge patterns that permit them to be systematically classified.

All fingerprints are divided into three classes on the basis of their general pattern:

loops, arches and whorls (_______________).

Loops

• One or more ridges enters from one side of the print, re-curves, and exits from the same side– Ulnar loop: ______________________________– Radial loop: _____________________________

Right Hand Ulnar Loop

Right Hand Radial Loop

Loops

• All loops must have ________________ surrounded by type lines and a core

Core

Type lines

Delta

Ulnar vs. Radial LoopMake sure you indicate what hand

you are fingerprinting

Whorls

• Ridges are generally circular• All whorl patterns have type lines and

_______________________________deltas

Whorls

• 4 distinct groups– _____________________

• At least 1 ridge makes a complete circuit

• Imaginary line between deltas touches spiral ridge

– _____________________• At least 1 ridge makes a complete

circuit• Imaginary line between deltas

does not touch spiral ridge– _____________________

• Made of 2 loops combined together

– _____________________• Contains 2 or more patterns or

doesn’t fit anywhere else

Arches

• Ridge __________ from ____________side of the print, rises in the center and ____________ on the other side

• ____________________have – Type lines– Deltas– Cores

Arches

• 2 Distinct groups– ___________________

• Ridges rise in the center in a wave-like pattern– _____________________

• Ridges rise in the center with a sharp spike

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Primary Classification

The Henry-FBI Classification SystemEach 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.

=

FBI System of Classification

• Modification of the Henry system• Pair up fingersR. Index R. Ring L. Thumb L. Middle L. LittleR. Thumb R. Middle R. Little L. Index L. Ring• Based on presence or absence or whorl pattern

– 1st pair: 16 points– 2nd pair: 8 points– 3rd pair: 4 points– 4th pair: 2 points– 5th pair: 1 point

FBI System of Classification

• Total the values• Add 1 to the numerator and denominator• Fraction is what you use to classify the prints• Provides examiner with list of candidates in

system to look at more closely• Can help narrow down suspect list• Final identification of an individual is based

on comparison of minutia by examiner • Only useful when a full set of prints are

available

Automated Fingerprint Identification Systems (AFIS)

• Prints are scanned and encoded by computers• ____________________________position and

orientation of minutia for each print• Produces a list of file prints with the closest correlation

to a question print for the examiner to compare• __________________________________known

suspects in each case

Methods of Detecting Fingerprints

• 3 kinds of crime scene prints– __________________________

– __________________________

– __________________________

Latent Prints

• Each skin ridge contains a single row of pores – openings for ducts of sweat glands– Tops of fingerprint ridges get covered with

_____________________– When a finger touches an item, sweat and oil are

deposited onto the surface– This leaves an _____________________ of the finger’s

ridge pattern (fingerprint)– _____________________ to the eye

Visible and Plastic Prints

• Visible prints– Made by ________________________________________________________

______ touching a surface• Plastic prints

– Made when a finger by_____________________

___________________________________________________________________

Methods of Detecting Fingerprints• Method used depends on surface type print is

located on– Hard nonabsorbent surfaces

• Examples:_____________________________• _____________or _________________treatment

– Soft and porous surfaces• Examples: ________________________• Chemical treatment

– _____________________– _____________________– _____________________– Super Glue treatment

Methods of Detecting Fingerprints

• Powders– _______________________________________

_______________________________________– Applied with camel hair or fiberglass brush– Select color powder with best contrast– Magnetic Sensitive Powders

• No bristles means less chance of destroying print

• Useful on leather and rough plastics– ______________________ Powders

• Fluoresce under UV light• Useful on confusing or multi-colored

backgrounds

Methods of Detecting Fingerprints• Iodine Fuming

– _______________________________________• Sublimation = physical change from the solid directly to

the gaseous state– Suspect material is placed in an enclosed chamber

filled with iodine vapors

– Iodine vapors react with _____________________in print to form a ________________deposit

– ________________________• Photograph developed print• Fix developed print with 1%

starch solution

Methods of Detecting Fingerprints• Ninhydrin

– Ninhydrin powder is mixed with acetone or ethanol to form a spray

– Reacts with _____________________present in perspiration to form a purple deposit known as ____________________________________

Prints can develop within 1-2 hours but can take up to 10 days

– Development of prints is ________________________________

– Very sensitive• Used to get prints off paper as old as

15 years

– b

Methods of Detecting Fingerprints• Physical Developer

– Silver-nitrate based liquid reagent– ____________________________________________

____________________________________________– Reacts with sodium chloride in fingerprint residue

to produces a dark grey deposit

– Destroys _________________________________________________________________________________

Methods of Detecting Fingerprints

• Super Glue Fuming– Heating superglue forms

_________________________________fumes– Suspect material is placed in an

enclosed chamber filled with cyanoacrylate fumes

– Fumes ________________________________________________________________________________________________

– Developed prints may be dusted with powders

Methods of Detection Review

Powders Iodine Ninhydrine Physical Developer Super Glue

What Reacts With

Perspiration and oil Fats Amino

AcidsSodium Chloride Fats

Surface Nonporous Porous Porous PorousPorous and

Nonporous

Notes Not permanent

Very sensitive

Use Last OR Use if item

was wet

Preservation of Developed Prints

• Prints must be permanently preserved for: – future comparison – possible use in court as evidence

• Steps to preservation– Photograph prints– Small objects: cover with cellophane– Large objects: lift prints with tape and secure

to cardboard backing