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Fingerprint Analysis
Bud & Patti Bertino
Fingerprints Formation
• Skin produce secretions oil, salts
• Dirt combines with secretions
• Secretions stick to unique ridge
patterns on skin
Did You Know?
• Fingerprints are unique
• Form before birth in dermal papillae
• Never change
• Return after scarring or burning
History of
Fingerprinting
• B.C. Chinese first used fingerprints
• 1886 fingerprints for ID purposes
• 1891 first ‘10 card’
• 1902 first murder solved using
fingerprints
1891
University @ Lyon
Ferroprussinate was
used as the developer.
Source: Evidence
Technology, Nov-Dec 2007
First handprint
• 1905 U.S. Army uses fingerprints
• 1946 100 Millionth 10 card
• 1975 FBI introduces AFISAutomated
Fingerprint
Identification
System
• 2007 Department of Homeland Security has 63 million records
Types of Fingerprints
• Patent or Visible on smooth surfaces
• Latent or invisible
• Plastic: prints found in soft materials
such as soap
A famous set of prints
John
Dillinger
Making your ‘10 Card’
Who’s fingerprint?
Source: www.virtualsciencefair.org
Human
Chimp
Koala
Latent Fingerprints
• Treated with powders or chemicals
enhance ridge pattern
• Ninhydrin
• Super glue
• Iodine
How are latent prints obtained?
• Iodine fuming
• Ninhydrin
• Super glue
• Super glue
+NaOH
treatment
• Toxic & over-develops
• Toxic & fades in two
days
• Toxic
• Toxic
Method Effect
Fingerprints and Gloves
• Prints can be formed through surgical
gloves
• Prints left on the inside of gloves can be
lifted
Fingerprint Pattern Types
L(oops) A(rches) W(horls)
Loop 65% Core
Delta
One delta only
Loops
Two types:
Pinky side – ulnar
Thumb side - radial
Plain Arch
4 percentTented Arch
1 percent
Whorl Patterns
• Whorls occur in 30% of fingerprint patterns
PLAIN 24% CENTRAL POCKET 2%
Two deltas
Whorl Patterns
DOUBLE LOOP 4% ACCIDENTAL .01%
Fingerprint Patterns
• F.B.I recognizes eight basic
patterns
• Ten basic details within the
patterns (minutiae)
• 12 identical points were
necessary for a match
Balloon Thumbprint
Minutiae patterns
Ridge Minutiae
Identify some ridge patterns
Minutiae
Ending ridges
Bifurcations
Dots
Islands
Identify Minutiae patterns
CSI vs. The Real World
• AFIS (Automated Fingerprint Identification System) can search back 99 years
• Lack of standardization
• AFIS searches for a biometric pattern not a fingerprint! It matches chosen minutia patterns.
Source: The Forensics Teacher - Summer 2008
• Criminal, civilians, stock
brokers, civil servants, military
personnel, teachers, security
guards, etc., are included but
systems are not always linked.
• Latent database and cold cases
How Does AFIS Work?Fingerprint images are
scanned and digitized
Minutiae are coded
Minutiae are searched by
computerized matchers
Search candidates are
produced side-by-side on a
computer screen
Candidates are examined
Evidence Technology, 2012
Ten Card Print Crime Scene Print
Algorithm using MinutiaeReplaces point ID Uses computers
Faster More accurate
Fingerprint formed in soot.
Evidence Technology Magazine May-June 2008
What’s new?
Lift fingerprints from
Pills Feathers
Source: Evidence Technology Magazine Nov-Dec 07
Even from cadavers
Source: Evidence Technology Magazine Nov-Dec 07
Evidence Technology Magazine
September-October 2008, p30
Fingertips in
I.D. Enhancer Solution
Casting made of fingerprints in
silicone-rubber
A Match!
Orange fluorescent
powder viewed with
special camera filter
Electrical tape
both sides
Source: Evidence Technology Magazine Nov-Dec 07
Mobile cyanoacrylate fuming
Source: Evidence Technology Magazine Nov-Dec 07
Identity Recognition
• Fingerprints
• Facial recognition – within 10
years
• Iris scan – are no two alike?
To be determined and cannot
be used in court (as yet)
Matrix
scanners
Biometric Devices
Kiplinger Newsletter 11/12
Finger scanners
Free NIJ online sourcebook
Notice the scar
Fingerprints!
They’ll get you every time.