Chapter 6 Fingerprints By the end f this chapter yu will be able t: Discuss the histry f fingerprinting Describe the characteristics f fingerprints and fingerprinting minutiae Explain when and hw fingerprints frm Describe hw fingerprints can be left n bjects Identify the basic types f fingerprints Describe hw criminals attempt t alter their fingerprints 1 All Rights Reserved Suth-Western / Cengage Learning 2012, 2009 Frensic Science: Fundamentals & Investigatins, Chapter 6
Chapter 6 Fingerprints By the end f this chapter yu will be able t: Determine the reliability f fingerprints as a means f identificatin Describe the Integrated Autmated Fingerprint Identificatin System (IFAIS) Explain hw fingerprint evidence is cllected Describe the latest identificatin technlgies Determine if a fingerprint matches a fingerprint n recrd Use the prcess f lifting a latent print 2 Frensic Science: Fundamentals & Investigatins, Chapter 6
Histrical Develpment 1. 3rd century B.C. in China ldest knwn dcuments 2. Ancient Babyln (1792-1750 B.C.) fingerprints pressed int clay tablets marked cntracts 3. 1684 Dr. Nehemiah s paper describes the patterns n human hands, including the presence f ridges 4. 1788 Jhann Mayer nted that the arrangement f skin ridges is never duplicated in tw persns 3 Frensic Science: Fundamentals & Investigatins, Chapter 6
Histrical Develpment 5. 1823 Jan Evangelist Purkyn describes nine fingerprint patterns 6. 1856 Sir William Herschel (right) began the cllectin f fingerprints and nted they were nt altered by age 7. 1883 Alphnse Bertilln created a way t identify criminals that were repeat ffenders 4 Frensic Science: Fundamentals & Investigatins, Chapter 6
Histrical Develpment 8. 1888 Sir Francis Galtn (r) and Sir Edmund Richard Henry develped the fingerprint classificatin system still used in the US 9. 1891 Iván (Juan) Vucetich cllected all ten fingerprint impressins and nted measurements 10. 1896 Sir Henry, with tw clleagues, created a system that divided fingerprints int grups. All ten fingerprints are imprinted n a card (called a ten card) alng with ther ntatins 5 Frensic Science: Fundamentals & Investigatins, Chapter 6
The West Stry Will West arrived t serve prisn sentence at Levenwrth in 1903. ID persnnel insisted that he had been there befre. After Bertilln measurements taken, fficials fund file f William West, whse measurements were virtually identically t Will West. William West was still in prisn serving time fr murder. Even their phts were identical
Example f a Ten Card 7 Frensic Science: Fundamentals & Investigatins, Chapter 6
What Are Fingerprints? All fingers, tes, feet, and palms are cvered in small ridges Ridges help us grip bjects Ridges are arranged in cnnected units called dermal, r frictin, ridges Fingers accumulate natural secretins and dirt Fingers leave create prints n bjects we tuch 8 Frensic Science: Fundamentals & Investigatins, Chapter 6
Structure f Skin 9 Frensic Science: Fundamentals & Investigatins, Chapter 6
Frmatin f Fingerprints Skin cnsists f: Inner layer dermis Outer layer epidermis Basal layer in between Basal layer grws faster than the layers abve and belw it Basal layer cllapses and flds t frm intricate shapes Fingerprints begin frming near the 10 th week f pregnancy 10 Frensic Science: Fundamentals & Investigatins, Chapter 6
Arund week 10 f develpment vlar pads f a fetus stp grwing but the hand cntinues t grw. Over the next few weeks, the vlar pad is absrbed back int the hand. During this critical stage, the first signs f ridges begin t appear n the skin f the vlar pads. 11 Frensic Science: Fundamentals & Investigatins, Chapter 6
Develpment f Fingerprints 12 Frensic Science: Fundamentals & Investigatins, Chapter 6
Summary Vlar pads enlarging at different times with embrynic hand grwth prvides stress t the layers f skin. Pssibly a genetic factr that determines primary template. Stress + Genetics = Fingerprints 13 Frensic Science: Fundamentals & Investigatins, Chapter 6
Fundamental Principles f Fingerprints A fingerprint is an individual characteristic. A fingerprint will remain unchanged during an individual s lifetime. Fingerprints have general characteristic ridge patterns that permit them t be systematically classified. 14 Frensic Science: Fundamentals & Investigatins, Chapter 6
Characteristics f Fingerprints There are 3 general fingerprint distinctins: ARCH Abut 5% WHORL Abut 30% f the ppulatin LOOP Abut 65% 15 Frensic Science: Fundamentals & Investigatins, Chapter 6
Characteristics f Fingerprints Frensic examiners lk fr Cre (the center f a whrl r lp) Deltas (triangular regins near a lp) Ridge cunt Cunting frm the cre t the edge f the delta Distinguishes ne fingerprint frm anther 16 Frensic Science: Fundamentals & Investigatins, Chapter 6
Characteristics f Fingerprints Basic patterns can be further divided: Arch patterns: 4% plain 1% tented Whrl patterns: 2% central pcket 4% duble lp 0.01% accidental Even twins have unique fingerprints 17 Frensic Science: Fundamentals & Investigatins, Chapter 6
Lp In the Lp pattern there are tw fcal pints: the Cre, r the center f the lp, and the delta. The Delta is the area f the pattern where there is a triangulatin r a dividing f the ridges. When recrding fingerprints, the delta and the area between the delta and the cre must be cmpletely recrded. 18 A Lp must have 2 characteristics r it is nt a Lp! Frensic Science: Fundamentals & Investigatins, Chapter 6
Lp In a lp pattern, the ridges enter frm either side, re-curve and pass ut r tend t pass ut the same side they entered. 19 Frensic Science: Fundamentals & Investigatins, Chapter 6
Lp 20 Frensic Science: Fundamentals & Investigatins, Chapter 6
Whrl A Whrl pattern will have tw r mre deltas. Fr a whrl pattern, all deltas and the areas between them must be recrded.
Whrl Ridges frm a circular pattern cmpletely arund a central pint r shrt line. Typically tw deltas will be nticed belw and t the utside f the whrl.
Whrl
Arch The arch pattern is the nly pattern withut a "delta" r triangular pattern made f ridges frming a triangle arund a pint.
Arch In an arch pattern the ridges enter frm ne side, make a rise in the center and exit generally n the ppsite side.
Characteristics f Fingerprints 26 Frensic Science: Fundamentals & Investigatins, Chapter 6
Characteristics f Fingerprints 27 Frensic Science: Fundamentals & Investigatins, Chapter 6
28 Frensic Science: Fundamentals & Investigatins, Chapter 6
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L L L L L R R R R R Pinky Ring Middle Index Thumb Thumb Index Middle Ring Pinky Finger Numb er 10 9 8 7 6 1 2 3 4 5 Value (if Whrl) 1 1 2 2 4 16 16 8 8 4
Henry Classificatin System Frmula: 1+(Sum f whrled, EVEN finger value) = Primary Gruping Rati 1+(Sum f whrled, ODD finger value ex. An individual has a fingerprint recrd with a LWAALALWLA pattern series (the series begins with Finger 1, the right thumb and ending with Finger 10, the left pinky), the crrespnding classificatin rati wuld be 19:1 L L L L L R R R R R Pinky Ring Middle Index Thumb Thumb Index Middle Ring Pinky
Finger Number 10 9 8 7 6 1 2 3 4 5 Value (if Whrl) Pattern Type 1 1 2 2 4 16 16 8 8 4 Arch Lp Whrl Lp Arch Lp Whrl Arch Arch Lp Finger Value 0 0 2 0 0 0 16 0 0 0 ex 1+(Sum f Even Finger value) = 1+16+2 = 19 1+(Sum f Odd Finger value) 1+(0) 1 r 19:1
Fingers 1 1 2 2 4 16 16 8 8 4 40 40