Chapter 4
Fingerprints
Fundamental Principles of Fingerprinting
*A fingerprint is an _________________________
*Fingerprints will remain _______________________ during an individual’s lifetime.
*Fingerprints have general characteristic _________________________ that permit
them to be systematically classified.
History of Fingerprints
*________________________ is the study of fingerprints
*Early Contributions:
1. __________________________ (1877)—required Indians to put their
fingerprints on contracts: also used them to identify ________________.
2. __________________________(1880)--claimed that fingerprints do not
change over time and could be classified for identification: used an ink and
transfer method to record prints.
3. ___________________________(1881)—proposed body measurements as a
means of identification (___________________________)
4. ___________________________(1891)—developed a classification scheme
based on __________________________________: also showed that not two
prints are alike and that they cannot be altered
5. ___________________________(1897)—worked with Galton to institute a
numerical classification system which is currently used in English-speaking
countries.
6. __________________________(1901)—developed a similar classification
system for Spanish-speaking countries
*The ____________________________________________ was formed in 1924.
Currently, The FBI has ______________________ sets of fingerprint records
Anatomy of Fingerprints
*The ridges and grooves of fingerprints are known as ____________________________
1. ____________________________________
2. Also found on ________________________________
3. Not genetically controlled, so even identical twins will have _______________
fingerprints.
4. The friction ridge on the epidermis is determined by a lower layer known as
the ____________________. Chemically or physically altering the epidermis
only causes pain—the original print will soon grow back.
5. Fingerprint residue is made up of ___________________________________
_________________________. Residue of most prints is about 1 microgram.
Classification of Fingerprints
*All fingerprints can be classified into three basic patterns:
1. _________________ (65%)
2. _________________(20%)
3. _________________ (least common)
*Loops—must have ______________________________ entering and exiting from the
____________________. Must have one _____________ (triangular area) and a
___________
Two Types:
_______________--opens toward the thumb
_______________--opens toward the pinky
Right Hand
______________________
_____________________
*Whorls: subdivided into 4 groups: __________________________________________
____________________________________. A 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 the other categories. Whorls have at least
____________________ and a ____________.
*Arch (least common and simplest pattern): Have no ___________________________.
All ridges enter one side and ____________________________.
Two types: _____________ and __________________
Primary Classification
*In the Henry-FBI Classification (Developed by ________________________) each finger
is given a ______________________________
*Assign the number of points for each finger that has a _______________ and
substitute into the equation then add “1” to the numerator and denominator.
*Use the chart below to calculate primary classification numbers of fingerprints:
Right index
16
Right thumb
16
Right ring
8
Right middle
8
Left thumb
4
Right little
4
Left middle
2
Left index
2
Left little
1
Left ring
1
+1 =
+1
*The primary classification number is used to _______________________________
*All sets of ten fingerprints can be divided into _______________
*The ___________________ of loops, whorls and arches present in the general
population has been determined.
*The chart below shows the frequency of fingerprint patterns in the general population:
Loops
Ulnar
60%
Whorls
Radial
5%
Plain
20%
Arches
Other
10%
Plain
4%
Tented
1%
Ridge Classification
*After primary classification, scientists must then use the fine structure of ridge
characteristics called
____________________ to individualize them.
*Ten different patterns are used:
*There are no legal requirements in the United States on the number of points.
Generally, criminal courts will accept ___________________________________
Types of Prints
*Three main types:
1. ______________________ (indented or molded)
2. ______________________ (touched colored material)
3. ______________________ (invisible to naked eye—must be developed to see)
Latent Prints (left behind from the natural secretion from human skin)
*Most secretions come from three glands:
1. __________________--largely water and both inorganic and organic
compounds. Most important for fingerprints.
2. __________________--secrete pheromones and other organic materials
3. __________________--secrete fatty or greasy substances
Developing Latent Prints (Several Methods Used)
*____________________--adhere to both water and fatty deposits. They can be used
on hard, nonporous surfaces. Choose a color to _______________________________.
Prints can then be “ ____________” with sticky tape.
*Chemicals—used to visualize prints on porous surfaces, such as ___________________
1. _________________--fumes react with oils and fats to produce a ___________
yellow-brown reaction.
2. _________________--reacts with amino acids to produce a _______________
3. ______________________--reacts with salt from sweat to form silver chloride:
turns gray when exposed to light
4. ______________________--“Super glue” fumes react with water and residue
to form a hard, whitish deposit. Can be used on metals, glass, and plastics.
*The order of the tests should be done with the least damaging test first.
*In modern labs, _________________________________ are used to view latent prints.
First used by FBI in ____________. Special precautions needed to protect eyes.
AFIS
*The __________________________________________________ is a computer system
for storing and retrieving fingerprints.
*Began in the early ___________ to:
1. Search large files for __________________________ taken from an individual
2. Compare a single print developed from a ___________________________
*By the __________, a person’s fingerprints may be in one AFIS but not in others,
creating problems.
*Problems were lessened when the FBI created ___________ (Integrated Automated
Fingerprint Identification System): a national database of all 10 print cards from all
over the country.
Other Prints
*______________--shape, length and width
*______________--electronic pulses measured on a spectrograph
*______________--size of foot and toes; friction ridges on the foot
*______________--type of shoe, brand, size, year of purchase, and wear pattern
*______________--friction ridges can be identified
*_____________________--used to identify infants
*______________--display several common patterns:____________________________
_________________________________________________________
*______________--bite marks are unique
*_______________________________--may be unique. Often used for security purposes.
Biometrics
*Biometrics is the used of some type of _____________________ for identification.
*Used in conjunction with AFIS
*Examples: _____________________________________________________________
*Can also be used to _______________________________ to computers or other
structures; can identify a person for ____________________________; can help
prevent identify theft or control ____________________________________.