Ch 4 Fingerprint Outline
Dactyloscopy
The Study of Fingerprints
History from 1850 to 1900
_________________________—required Indians to put their fingerprints on contracts, and used fingerprints as a
means of identifying prisoners
_________________________—claimed that fingerprints did not change over time and that they could be classified
for identification
____________________—proposed body measurements as a means of identification; termed anthropometry
__________________________—developed a primary classification scheme based on loops, arches, and whorls
_________________________________—in collaboration with Galton, instituted a numerical classification system
______________________—developed a fingerprint classification system based on Galton’s that is used in
Spanish-speaking countries
Fundamental Principles of Fingerprints
A fingerprint is an _____________ characteristic.
A fingerprint remains ______________________ during an individual’s lifetime.
Fingerprints have general _________________________ that permit them to be systematically classified.
Ridge Characteristics
___________________—characteristics of ridge patterns
________________ ending
______________ or
short ridge
Bridge
Eye or _________________
Delta
Bifurcation or -_______________
Dot
Spur
Double _____________________________
Trifurcation
Arch
Simplest form; only ___________% of population has an arch. An arch has __________________ of the finger and
cross to the other side while ________________________. They _______________ have type lines, deltas, or cores.
Types
Plain
________________
Loop
_______________% of the population has loops. A loop must have _____________________________ from the
same side. Loops must have one ______________________________________.
Sometimes fingerprint can contain more than one loop.
Types
____________________—opens toward the thumb
_____________________—opens toward the “pinky” (little finger)
Whorl
______________________% of the population has whorls. A plain or central pocket whorl has at least
______________________________________. A double loop is made of ___________________. An
__________________ is a pattern not covered by other categories. Whorls have at least two
_______________________
Types
Plain
Central ________________
Double _________________
__________________
Loop
Whorl
Arch
Primary Classification
The Henry-FBI Classification System
Each finger is given a ________________________________________________
Assign the number of points for each finger that has a _______________________ 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.
There are no legal requirements in the United States on the number of ______________________ required for a
match. Generally, criminal courts will accept ______________________________________________________.
Latent Prints
Latent fingerprints are those that are not ______________________. These prints consist of the natural secretions of
human ____________________________________________________
Most secretions come from three glands:
__________________—secretes largely water, with both inorganic (ammonia, chlorides, metal ions,
phosphates) and organic (amino acids, lactic
acids, urea, sugars) compounds. Most important for
fingerprints.
____________________—secretes pheromones and other organic materials.
____________________________—secretes fatty or greasy substances.
Developing Latent Prints
Developing a print requires substances that interact with secretions, causing the
____________________________________. It may be necessary to attempt more than ______________________________, done in a particular order so as not to destroy the print.
_____________________________—adhere to both water and fatty deposits. Choose a color
to contrast with the background.
__________________________—fumes react with oils and fats to produce a
temporary yellow-brown color.
____________________________—reacts with amino acids to produce a purple color.
_____________________—reacts with chloride to form silver chloride, a
material that turns gray
when exposed to light.
__________________________—“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.
Other Prints
_____________—several common patterns
______________—electronic pulses measured on a spectrograph
____________________—size of foot and toes; friction ridges on the foot
______________—can be compared and identified by type of shoe, brand, size, year of purchase, and wear pattern
________________—friction ridges can be identified and may be used against suspects
_________________ are taken at birth as a means of identification of infants.
_________________—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.
The _______________________________ in the eye may be unique to individuals. They are used today for various
security purposes.
The ________________________________________________—a computer system for storing and retrieving
fingerprints
Established in the ______________________, AFIS enables law enforcement
officials to:
Search large files for a set of ____________________________
Compare a single print, usually a latent print developed from a ___________________________________
By the 1990s, most large jurisdictions had their own system in place. The problem: A person’s fingerprints may be
in one AFIS database _________________________________________________
______________________________—the FBI’s Integrated Automated Fingerprint Identification System, which is
a national database of all 10-print cards from _____________________________________________
Use of some type of body metrics for the purpose of identification. (The __________________ system may actually
have been the first biometry system.)
Used today in ________________________________
Examples include retinal or -_________________________________________________________.
Other functions for biometrics: can be used to control entry or access to computers
____________________________________________________________________________________________