fingerprints photos from kendall hunt publishing content from chapter 4 in forensic science for high...
TRANSCRIPT
Fingerprints
Photos from Kendall Hunt Publishing
Content from Chapter 4 in Forensic Science for High School Students
and numerous other sources
EQ: How has technology changed the methods and techniques in fingerprinting 2Chapter 4
FingerprintsChapter 4
Bertillon SignalmentIn the late 1800’s Alphonse Bertillon’s method
of identification became popular. With photos people could now be ID’d Method required many instruments and took
much training to be accurate Inaccuracy was major issue
Measurements: standing height, wing span, trunk sitting, head length & width, each ear, left foot, left middle finger, & left forearm
EQ: How has technology changed the methods and techniques in fingerprinting 3Chapter 4
FingerprintsChapter 4
DactyloscopyThe Study of FingerprintsHistoryWilliam Herschel—required Indians to put their fingerprints on contracts,
and used fingerprints as a means of identifying prisoners Henry Faulds—claimed that fingerprints did not change over time and
that they could be classified for identification Alphonse Bertillon—proposed body measurements as a means of
identification; termed anthropometryFrancis Galton— published Finger Prints in 1892 after extensive
research-identified anatomy-methods of recording-pattern types: loops, arches, and whorls-estimated 64 billion possibilities-theorized 3 principles
EQ: How has technology changed the methods and techniques in fingerprinting 4Chapter 4
FingerprintsChapter 4
DactyloscopyThe Study of FingerprintsHistory Edward Richard Henry—in collaboration with Galton, instituted a
numerical classification system
Juan Vucetich—developed a fingerprint classification system based on Galton’s that is used in Spanish-speaking countries
1924-US consolidates Bureau of Investigation files with Leavenworth Prison files as FBI formed
Today the FBI has the largest collection of prints in the world with 700,000,000 individuals
EQ: How has technology changed the methods and techniques in fingerprinting 5Chapter 4
FingerprintsChapter 4
Fundamental Principles of Fingerprints1. A fingerprint is an individual
characteristic.
2. A fingerprint remains unchanged during an individual’s lifetime.
3. Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.
EQ: How has technology changed the methods and techniques in fingerprinting 6Chapter 4
FingerprintsChapter 4
1. A fingerprint is an individual characteristic.
Minutiae-ridge characteristics -150 individual minutiae per finger-Most prints are partial- 8 to 12 are needed for match
Ridge Counts - # of ridges between Delta and core-only in loop prints
A balloon will help you see it
EQ: How has technology changed the methods and techniques in fingerprinting 7Chapter 4
FingerprintsChapter 4
Minutiae
EQ: How has technology changed the methods and techniques in fingerprinting 8Chapter 4
FingerprintsChapter 4
Fingerprint Minutiae
EQ: How has technology changed the methods and techniques in fingerprinting 9Chapter 4
FingerprintsChapter 4
2. Fingerprints remain unchanged
The dermal papillae develops as fetus, except growth, it never changes
Impossible to obliterate, even scars would provide unique prints
Primates have prints
EQ: How has technology changed the methods and techniques in fingerprinting 10Chapter 4
FingerprintsChapter 4
3. Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.LAW :Loops: 60%
Ulnar Radial
Arches: 6%TentedPlain
Whorls: 34%PlainCentral PocketDouble LoopAccidental
EQ: How has technology changed the methods and techniques in fingerprinting 11Chapter 4
FingerprintsChapter 4
Loop – Looks like a LAKEA loop must have one or more ridges
entering and exiting from the same side. Loops must have one delta.
Types
Radial—opens toward the thumb
“Right On!”
Ulnar—opens toward the “pinky” (little finger)
“Under”
Which type of loop is this, if it is on the right hand? Left hand?
EQ: How has technology changed the methods and techniques in fingerprinting 12Chapter 4
FingerprintsChapter 4
ArchAn arch has friction ridges that
enter on one side of the finger and cross to the other side while rising upward in the middle. They do NOT have type lines, deltas, or cores.
Types
Plain – Bike rider won’t blow out a tire
Tented – spike in the road
EQ: How has technology changed the methods and techniques in fingerprinting 13Chapter 4
FingerprintsChapter 4
WhorlA plain or central pocket whorl has at
least one ridge that makes a complete circuit. A double loop is made of two loops. An accidental is a pattern not covered by other categories. Whorls have at least two deltas and a core.
TypesPlain
Central pocket
Double loop
Accidental
EQ: How has technology changed the methods and techniques in fingerprinting 14Chapter 4
FingerprintsChapter 4
Plain WhorlArrow through the delta –
must cross at least one circle
Deltas are more symmetrical
EQ: How has technology changed the methods and techniques in fingerprinting 15Chapter 4
FingerprintsChapter 4
Central Pocket Loop Whorl1 Circle, 2 Deltas and
arrow does not cross a circle
Delta is usually off balance
EQ: How has technology changed the methods and techniques in fingerprinting 16Chapter 4
FingerprintsChapter 4
Double Loop Whorl2 loops inside 2
deltasLooks like a wave or
Yin/Yang
EQ: How has technology changed the methods and techniques in fingerprinting 17Chapter 4
FingerprintsChapter 4
Accidental Whorl3 deltas or
combination of tented & loop arch
Basically a mess
EQ: How has technology changed the methods and techniques in fingerprinting 18Chapter 4
FingerprintsChapter 4
LOOP WHORL ARCH
EQ: How has technology changed the methods and techniques in fingerprinting 19Chapter 4
FingerprintsChapter 4
Primary ClassificationThe Henry-FBI Classification System
Each finger is given a point value.
right left
EQ: How has technology changed the methods and techniques in fingerprinting 20Chapter 4
FingerprintsChapter 4
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.
=
EQ: How has technology changed the methods and techniques in fingerprinting 21Chapter 4
FingerprintsChapter 4
Comparison There are no legal
requirements in the United
States on the number of
points required for a match.
Generally, criminal courts will
accept 8 to 12 points of
similarity.
EQ: How has technology changed the methods and techniques in fingerprinting 22Chapter 4
FingerprintsChapter 4
Latent PrintsLatent fingerprints are those that are not visible to the naked eye.
These prints consist of the natural secretions of human skin and require development for them to become visible.
Most secretions come from three glands:
Eccrine—secretes largely water, with both inorganic (ammonia, chlorides, metal ions, phosphates) and organic (amino acids, lactic acids, urea, sugars) compounds. Most important for fingerprints.
Apocrine—secretes pheromones and other organic materials.
Sebaceous—secretes fatty or greasy substances.
EQ: How has technology changed the methods and techniques in fingerprinting 23Chapter 4
FingerprintsChapter 4
Developing Latent PrintsDeveloping a print requires substances that interact with secretions,
causing the print to stand out against its background. It may be necessary to attempt more than one technique, done in a particular order so as not to destroy the print.
Powders—adhere to both water and fatty deposits. Choose a color
to contrast with the background.
Iodine—fumes react with oils and fats to produce a
temporary yellow-brown color.
EQ: How has technology changed the methods and techniques in fingerprinting 24Chapter 4
FingerprintsChapter 4
Developing Latent Prints, continued
Ninhydrin—reacts with amino acids to produce a purple color.
Silver nitrate—reacts with chloride to form silver chloride, a material that turns gray when exposed to light.
Cyanoacrylate—“superglue” fumes react with water and other fingerprint constituents to form a hard, whitish deposit..
In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. These were first used by the FBI in 1978. Since lasers can damage the retina of the eye, special precautions must be taken.
EQ: How has technology changed the methods and techniques in fingerprinting 25Chapter 4
FingerprintsChapter 4
Iodine Fingerprint
EQ: How has technology changed the methods and techniques in fingerprinting 26Chapter 4
FingerprintsChapter 4
Ninhydrin Fingerprint
EQ: How has technology changed the methods and techniques in fingerprinting 27Chapter 4
FingerprintsChapter 4
Cyanoacrylate Fingerprints
EQ: How has technology changed the methods and techniques in fingerprinting 28Chapter 4
FingerprintsChapter 4
Other PrintsLips—several common patterns
Voice—electronic pulses measured on a spectrograph
Foot—size of foot and toes; friction ridges on the foot
Shoes—can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern
EQ: How has technology changed the methods and techniques in fingerprinting 29Chapter 4
FingerprintsChapter 4
Other Prints, continued
Palm—friction ridges can be
identified and may be used
against suspects
EQ: How has technology changed the methods and techniques in fingerprinting 30Chapter 4
FingerprintsChapter 4
Other Prints, continued
Footprints are taken at birth
as a means of identification of
infants.
EQ: How has technology changed the methods and techniques in fingerprinting 31Chapter 4
FingerprintsChapter 4
Other Prints, continued
A man has been convicted of suffocating an eldery woman on the basis of earprint evidence. The assailant was caught after police matched the inprint of his ear on the victim’s window. Police believe that the thief put his ear to the window to listen for signs of anyone home.
Earprint catches murderer
EQ: How has technology changed the methods and techniques in fingerprinting 32Chapter 4
FingerprintsChapter 4
Other Prints, continued
Teeth—bite marks are unique and
can be used to identify suspects.
These imprints were placed in gum
and could be matched to crime
scene evidence.
EQ: How has technology changed the methods and techniques in fingerprinting 33Chapter 4
FingerprintsChapter 4
Other Prints, continuedThe blood vessel patterns in
the eye may be unique to
individuals. They are used
today for various security
purposes.
EQ: How has technology changed the methods and techniques in fingerprinting 34Chapter 4
FingerprintsChapter 4
AFISThe Automated Fingerprint Identification System—a computer system for
storing and retrieving fingerprints
Established in the 1970s, AFIS enables law enforcement officials to:
Search large files for a set of prints taken from an individual
Compare a single print, usually a latent print developed from a crime scene
By the 1990s, most large jurisdictions had their own system in place. The problem: A person’s fingerprints may be in one AFIS database but not in others.
IAFIS—the FBI’s Integrated Automated Fingerprint Identification System, which is a national database of all 10-print cards from all over the country
EQ: How has technology changed the methods and techniques in fingerprinting 35Chapter 4
FingerprintsChapter 4
BiometricsUse of some type of body metrics for the purpose of identification.
(The Bertillon system may actually have been the first biometry system.)
Used today in conjunction with AFIS.
Examples include retinal or iris patterns, voice recognition, hand geometry.
Other functions for biometrics: can be used to control entry or access to computers or other structures; can identify a person for security purposes; can help prevent identity theft or control social services fraud.
EQ: How has technology changed the methods and techniques in fingerprinting 36Chapter 4
FingerprintsChapter 4
Developing Prints - basicsA little powder goes a long way!
Gentle! You can obliterate prints
Applying powder is the “art” of the job – some swirl others up/down & side to side
Lift best print first
EQ: How has technology changed the methods and techniques in fingerprinting 37Chapter 4
FingerprintsChapter 4
Rolling Finger PrintsMedia Sheet: How to Take Prints
Video goes quickly so pay attention
Completed worksheet serves as your lab instruction guide
EQ: How has technology changed the methods and techniques in fingerprinting 38Chapter 4
FingerprintsChapter 4
Rolling Finger PrintsReminders:
A little ink goes a long way
Nail edge to nail edge!
Don’t change pressure or course
Have person RELAX!
Hands lower than inking surface