1. Fingerprinting
Dr. Walker

2. Background Where do fingerprints come from?
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Background
Where do fingerprints come from?
The friction ridge pattern is determined in the womb (before birth) by the dermal papillae, cells between the surface and lower layers of the skin.
The papillae are roughly 2 mm below the surface and form a “negative” of the fingerprint. Cutting into the papillae leaves a scar, but does not change the print.

3. Background How do fingerprints occur?
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Background
How do fingerprints occur?
Friction ridge skin that deposits oil, perspiration, dirt on object touched
Fingerprints are 99% water
Cold hands or recently washed hands leave practically NO secretion

4. Background What makes fingerprints useful? All fingerprints are unique
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Background
What makes fingerprints useful?
All fingerprints are unique
Fingerprints cannot be changed.
Fingerprints display patterns that allow them to be classified.

5. Can’t be changed? Only instances of changing fingerprints are:
injuries or surgery causing deep scarring
diseases such as leprosy damaging the formative layers of friction ridge skin
Can’t cut deep enough to fully remove skin for fingerprinting

6. History 1880 – Henry Faulds 1888 – Sir Francis Galton
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History
1880 – Henry Faulds
Discussed fingerprints as a means of personal identification, and the use of printers ink as a method for obtaining such fingerprints.
Credited with the first fingerprint identification of a greasy fingerprint left on an alcohol bottle.
1888 – Sir Francis Galton 
Published his book, "Fingerprints", establishing the individuality and permanence of fingerprints. His book included the first classification system for fingerprints.

7. History 1896 - Sir Edward Richard Henry 1918 – Edmund Locard
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History
Sir Edward Richard Henry
Developed the print classification system that would later be used in Europe and North America.
1918 – Edmund Locard
12 point match
Locard wrote that if 12 points were the same between two fingerprints, it would suffice as a positive identification.  This is the most common standard for print matches today

8. Databases IAFIS UIAI – India FBI’s database
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Databases
IAFIS
FBI’s database
60 million prints contained (to date)
Collected since 1924, automated since 1974
UIAI – India
Current database, known as AADHAAR, has over 200 million prints
Hopes to have 600 million by 2014

9. Who Gets Fingerprinted?
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Who Gets Fingerprinted?
Criminals fingerprints
Federal job applicantsemployees
Military
Aliens (aka non-residents)
Anyone else who wants them on record

10. Features of Fingerprints
From left:
Arch
Loop
Whorl – circular pattern within print
These are the basic features

11. Features of Fingerprints
Tented Arch
Distinct angles within arch
Twinned Loop
Distinct loops going in two separate directions
Central Pocket Loop
Whorl within a loop

12. Features of Fingerprints
Lateral pocket loop
Distinct loops in two different directions
Composite
Multiple distinct features
Accidental
Multiple features, pattern within patterns

13. Types of Fingerprint Evidence
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Types of Fingerprint Evidence
Latent
Small amounts of grease, sweat, and dirt on surface of skin
Patent (aka contaminated)
Dirty finger (dust, blood, ink, oil)
Plastic
Left in paint, wax, chocolate, dust, etc. Leaves a NEGATIVE impression of friction ridge

14. Fingerprinting Reagents
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Fingerprinting Reagents
Reagent
Reacts With
Used On?
Resulting Color
Iodine
Porous or non-porous
Ninhydrin
Porous
Silver Nitrate
Cyanoacrylate
Non-porous

15. Fingerprinting Reagents
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Fingerprinting Reagents
Reagent
Reacts With
Used On?
Resulting Color
Iodine
Adheres to sebaceous (fatty) material
Porous or non-porous
Yellow to Brown
Ninhydrin
Reacts with amino acids
Porous
Ninhydrin (purple)
Silver Nitrate
Reacts with salts
Brown or black
Cyanoacrylate
Polymerizes materials in print – used for preservation
Non-porous
White (can be enhanced)

16. Fingerprinting Reagents
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Fingerprinting Reagents
Reagent
Reacts With
Used On?
Resulting Color
Regular Powder
Non-porous and
porous.
Depends on exact powder and surface
Amido black
Bloodstained
specimens.
Blue - black
Luminol
Chemical reaction
with hematin.
Presumptive test for
blood.
Titanium Dioxide
Use on plastic,
electrical & duct tape

17. Fingerprinting Reagents
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Fingerprinting Reagents
Reagent
Reacts With
Used On?
Resulting Color
Regular Powder
Adheres to
moisture and lipid
components.
Non-porous and
porous.
Depends on exact powder and surface
Amido black
Chemical reaction
with protein in blood.
Bloodstained
specimens.
Blue - black
Luminol
with hematin.
Presumptive test for
blood.
Luminescence (view with fluorescent light)
Titanium Dioxide
Use on plastic,
electrical & duct tape
White

18. Collection Procedure Photograph all prints prior to collection!!
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Collection Procedure
Photograph all prints prior to collection!!
Use cellophane tape over prints
Prevent air pockets
Smooth gently over print with finger. Slowly remove from surface
Apply tape to fingerprint backing card that has been filled out BEFOREHAND.
Use appropriate color of backing card

19. Sources http://onin.com/fp/fphistory.html