characteristics of ridge patterns
Black, white and fluorescent powder Chemicals—ninhydrin, iodine, silver nitrate, cyanoacrylate
The Henry—FBI Classification
Each finger is given a point value
rt( from pinky to thumb):
4,8,8,16,16
lf (from thumb to pinky):
4,2,2,1,1
Latent 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.
reacts with amino acids to produce a purple
color.
Ridge ending
Short ridge
Dot or fragment
Bifurcation
Double bifurcation
Trifurcation
Bridge
Island
Enclosure
Spur
+ drawings
A fingerprint is an individual
characteristic. A fingerprint will remain unchanged
during an individual’s lifetime. Fingerprints have general characteristic
ridge patterns that permit them to be systematically classified.
Eccrine—largely water with both inorganic
(ammonia, chlorides, metal ions, phosphates) and
organic compounds (amino acids, lactic acids, urea,
sugars). Most important for fingerprints.
Apocrine—secrete pheromones and other organic
materials.
Sebaceous—secrete fatty or greasy substances.
Study for Fingerprints:
William Herschel—required Indians to put their fingerprints
on contracts, and also 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 anthropometry Francis Galton—developed a primary classification scheme
based on loops, arches and whorls. Edward Richard Henry—in collaboration with Galton instituted a numerical classification system Juan Vucetich—developed a fingerprint classification based on Galton’s that is used in Spanish-speaking countries
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 type lines, deltas,
or cores.
Types-Plain Tented