Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. What are Fingerprints? If a finger touches a surface, perspiration and oils from the body are transferred onto the surface, leaving an impression of the finger’s friction ridge patterns. Fingerprints may contain traces of any material found in perspiration including DNA and chemicals such as nicotine.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. What are Fingerprints? Friction ridges are found on skin in the following regions: –Palms of hands –Palmar aspect (palm-side) of fingers –Soles of feet –Solar aspect (sole-side) of toes They exist to give firmer grip and resistance to slippage. The number of ridges and their shape is largely determined by genes.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Skin Surface Outer surface layer of skin is the epidermis. The inner layer of skin is the dermis. Between these two are the dermal papillae. The papillary pattern determines the form and pattern of the friction ridges on skin surface.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Skin Surface Each skin ridge is populated by a single row of pores that are openings for ducts leading from the sweat glands. Perspiration is released and deposited on the surface of the skin through these pores.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Fingerprints are Unique Dermatoglyphics is the study of fingerprints. No two fingers have yet been found to have identical ridge characteristics (minutiae). Ridge pattern remains unchanged throughout life.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Fingerprints do not Change Friction ridge pattern of skin develops in utero (before birth) due to uneven stresses in the different layers of the developing skin. Identical (monozygous) twins –have the same DNA. –have different fingerprints.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Intentionally Altering Fingerprints Very difficult to do, but there has never been a lack of trying. –Bank robber John Dillinger attempted to burn off his fingerprints with corrosive acid. They grew back. –Illegal immigrants and criminals sometimes undergo finger print plastic surgery. They can still be identified by palm prints and DNA. To change the pattern requires obliteration of the dermal papillae (1- 2 mm deep). Attempts to destroy the pattern can backfire and cause more unique details!

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Types of Fingerprint Patterns There are 3 basic fingerprint patterns –loops (60-65% of population) –whorls (30-35%) –arches (5%)

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Loops Have ridges entering from one side of the print, turning, and leaving from the same side. The pattern area of the loop is surrounded by two diverging ridges known as type lines. The approximate center is called the core. The ridge point nearest the type line divergence is known as the delta (capital greek letter Δ).

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Loops 65% of the population have loops. All loops must have one delta. If the loop opens toward the little finger then it is a ulnar loop. If the loop opens towards the thumb then it is a radial loop.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Arches In an arch, ridges enter from one side of the print and exit on the opposite side.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Arches Arches are divided into two distinct groups: –plain arches –tetrarches or tented arches The tetrarch consists of an upthrusted ridge in the center of the arch.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Whorls All whorl patterns must have a core and at least two deltas

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Special Loops The double loop is made up of two loops combined into one fingerprint. The pocked loop has a small circle at the core.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Other Patterns An accidental pattern contains two or more patterns, but not the plain arch, and is not covered by other categories. It may consist of a combination loop and plain whorl or loop and tented arch.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Types of Prints Latent: hidden or invisible –Made by natural body secretions of the hands and fingers (perspiration & grease) –Requires dusting or other method to make visible Patent: visible to the naked eye –Blood, ink, dirt, glass Plastic: a 3-D fingerprint –Wet paint; Soft material like clay

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Impressions and Prints Impression - 3-D –in soft surface; often visible Print - 2-D –transfer of skin perspiration, oils, etc; usually latent

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Fingerprint Points The individuality of a fingerprint is determined by a careful study of its ridge characteristics (minutiae points). Specific traits found in friction ridges are used to establish an identification The average finger has between 75 and 175 points of identification.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Types of Points

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Matching Points For two points to match they must be at the same location on the fingerprint be the same type. 16 matching characteristics have been suggested to establish the uniqueness of a print.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Powder Techniques Used on non-absorbent surfaces Tipped or very softly brushed on Various Types –Black powder (carbon) –Grey powder (Aluminum dust) –Fluorescent Powder (seen in UV light)

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Chemical Techniques Iodine Fuming - for latent prints Ninhydrin - latent prints on paper & porous surfaces Silver Nitrate - for porous surfaces Super Glue Fuming - Non-porous surfaces

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting In 1892, two boys were brutally murdered in the village of Necochea, in Argentina.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Suspicion fell on a man named Velasquez, a suitor of the children's mother, Francisca Rojas. But even after torture, the police could not get him to confess.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting But even after torture, the police could not get him to confess.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Investigators found a bloody fingerprint at the crime scene and contacted Juan Vucetich, who was developing a system of fingerprint identification for police use.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Vucetich compared the bloody fingerprint with those of Rojas.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting They did not match.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Vucetich compared the fingerprint to those of Rojas. Francisca Rojas had denied touching the bloody bodies….

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting …but the fingerprint matched one of hers.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Confronted with the evidence, she confessed.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting Confronted with the evidence, she confessed.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Story Time - Juan Vucetich and the origins of forensic fingerprinting The first successful use of fingerprint identification in a murder investigation.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Classification Systems The most prominent system in the late 19tyh cent. was the Henry System created by Sir Edward Richard Henry. The Henry System is still included as part of many electronic systems and taught by the FBI.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System Prints are classified by broad characteristics. All 10 fingers are put into groups of 2 with numerical weights assigned to each group

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number Value if whorl is present

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System If a whorl is present the value is recorded for that fingerprint. If a whorl does not exist then zero is recorded for that fingerprint

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number Value if whorl is present Example No 0 Yes 16 No 0 Yes 8 No 0 No 0 Yes 2 No 0 No 0 Yes 1

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System Next, the Henry Classification Formula is used to find the grouping ratio. The grouping ratio is a unique identifier for categorizing the particular type of fingerprint that the person has.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System The Henry Classification Formula is: The grouping ratio cannot be simplified. For example, 32/32 and 1/1 are both unique ratios.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Henry Classification System R Thumb R Index R Middle R Ring R Pinky L Thumb L Index L Middle L Ring L Pinky Number Value if whorl is present Example No 0 Yes 16 No 0 Yes 8 No 0 No 0 Yes 2 No 0 No 0 Yes 1

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. IAFIS Integrated Automated Fingerprint Identification system (IAFIS) is used by the FBI to store digital prints. It is the largest biometric database in the world, containing records for more than 100 million people. The automated process generates a “hit” list of possible matches then checked by expert

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. What is included in IAFIS? Each record may include: –Criminal history –Fingerprints –Mug shots –Scars and tattoos –Physical characteristics height, weight, aliases, hair and eye color, race

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Who submits data to IAFIS? The system includes: –civil fingerprints; Individuals in the U.S. military; people employed by the federal government. Employment background checks and some firearms purchases also provide information to the system.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Other Forms of Biometrics Eye Scans - both retina and the iris have unique characteristics Retinal scan - they are used in most high security facilities but are too expensive to be widespread Iris Identification Systems - these are used in prisons and increasingly in airports

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Other Forms of Biometrics Ear Scans –Ears are unique in size shape and structure –a camera creates an image of an ear that is then analyzed.

Copyright © 2013 Crosscutting Concepts, LLC. All Rights Reserved. Other Forms of Biometrics Voice Fingerprints –frequency, intensity, and other measurements are analyzed to determine whether the tape is authentic –Not as definitive as fingerprints or DNA but they do provide supporting evidence DNA Fingerprints –we all have unique DNA –it can be found in your blood, skin, hair etc. –it gets isolated, amplified and transferred via radioactive probes and "fingerprinted"

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