Dactyloscopy
the study of fingerprints
Sir Francis Galton
established the idea of individuality and permanence of fingerprints; In 1892, published a book, "Fingerprints" which established the first means of fingerprint classification; In the book Galton also identified characteristics (minutia) of fingerprints w
Juan Vucetich
an Argentinian police officer, researched the science of fingerprints, corresponded with Galton, then devised his own system of fingerprint classification; his system is used throughout Spanish speaking countries
Sir Edward Henry
devised a workable classification system independently of Vucetich and implemented it in India in 1897;In 1901, Henry was appointed Assistant Commissioner of Police at New Scotland Yard and began to introduce his fingerprint system into that institution;
Thomas Jennings
The first person convicted in the US on fingerprint evidence. He was tried and convicted of murder in Chicago, 1910.
Fundamental Principles of Fingerprints
a fingerprint is an indvidual characteristic
a fingerprint will remain unchanged during an individual's lifetime
fingerprints have general chacteristics
A fingerprint will remain unchanged during an individual's lifetime.
Called friction ridges
Formed by
Minutia
lines of the fingerprint
Ridge Characteristics
Ridge ending
Short ridge
Dot or fragment
Bifurcation
Double bifurcation
Trifurcation
Bridge
Island
Enclosure
Spur
arch
An 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 deltas
Types
1 tented
2 plain
loop
A loop must have one or more ridges entering and exiting from the same side it began.
Loops must have one delta and one core
Types
Radial --opens toward the thumb
Ulnar --opens toward the "pinky" (little finger)
whorl
A plain or central pocket whorl have at least one ridge that makes a complete circuit. A double loop is made of two loops and an accidental is not covered by other categories.
A whorl has: 2 deltas
Types
1. plain
2. Central pocket
3. double
4. accidental
AFIS: Automated Fingerprint Identification System
Uses automated scanning devices that convert the image of a fingerprint into digital minutiae that contain data showing ridges at their points of termination (ridge endings) and the branching of ridges into two ridges (bifurcations
Visible Prints
Made by fingers touching a surface after the ridges have been in contact with a colored material such as blood, paint, grease, or ink.
plastic prints
Ridge impressions left on a soft material such as putty, wax, soap, or dust
latent prints
not visible to the naked eye. These prints consist only of the natural secretions of human skin and require treatment to cause them to become visible.
Most secretions come from three glands:
Eccrine�largely water with both inorganic and organic compounds
lifting latent prints
Powders--adhere to both water and fatty deposits. Choose a color to contrast the background.
Iodine--fumes react with oils and fats to produce a temporary yellow brown reaction. Iodine crystals sublime (go directly from solid to vapor).
Ninhydrin--reacts
lip prints
Lips--display one of five common patterns
Short vertical lines
Long vertical lines
Rectangular lines that may crisscross
Diamond
Branching
palm prints
Palm--lines can be identified and may be used against suspects
foot prints
Foot Prints are taken at birth as a means of identification for infants
bite marks
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
biometrics
Use of some type of body metrics for the purpose of identification