Three fundamental principals of Fingerprints Individual characteristic Will remain unchanged during the individuals lifetime Have general characteristic ridge patterns that permit systematic classification ID: 343494
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Fingerprints and Minutiae
. Slide2
Three fundamental principals of Fingerprints
Individual characteristicWill remain unchanged during the individual’s lifetimeHave general characteristic ridge patterns that permit systematic classificationSlide3
History
Alphonse Bertillon started the identification process with his Anthropometry measurements in 1881Francis Galton then upon studying fingerprints and Bertillon's method perfected the fingerprint system and published books in1892 and later Edward Henry simplified his system
In 1901 Juan Vucetich set up a workable system refining Galton's system and it was used in Spanish speaking countries. He was the first to officially identify a criminal using the fingerprint systemSlide4
3 TYPES OF FINGER PRINTS
Latent – prints are not visible until developed made by oils and chemicals this type can be found on any evidence including skin.Visible –visible to naked eye—left by a finger that has touched material such as blood , paint etc.Plastic or Physical--- Made in soft material such as putty, paint, soap etc.Slide5
3 MAJOR PATTERNS OF FINGERPRINTS
3 main Patterns consisting of: Arches – least commonLoops –most common-two sub groups …radial & ulnar
Whorls- 4 sub groups--- plain whorl- central pocket whorl- double loop whorl- accidental whorlApproximately five percent of all fingerprints are Arches, 30% are Whorls and 65% are Loops.Slide6
METHODS OF OBTAINING PRINTS
Some of the most common techniques of finding and lifting prints include:Dusting with carbon – dusting with white or black powder to cover print( most common) can be used with glass, solids plastics etc. Super glue fuming – developed in 1970s--leaves white impression
Ninhydrin – reacts/amino acids in fingerprint and leaves purple image used on matchbooks, newspaper etc.Silver nitrate- reacts with NACL left from perspiration in the fingerprintLaser technology – laser imagesSlide7
INFOFingerprints can last for years
Loop most commonFingerprints composed of salt, oil, & amino acids Latent fingerprints can be left anywhere including skinPrints can also be found in feet and palms even other parts of the bodySlide8
ArchSlide9
ArchThe
Arch pattern has no delta or core; but, it too, must be fully recorded so that its individual characteristics can be readily distinguished. Simplest of all fingerprintsSlide10
Tented archSlide11
Whorl Slide12
Whorl A
Whorl pattern will have two or more deltas. For a whorl pattern, all deltas and the areas between them must be recorded. Subdivided into 4 groups—plain whorl, central pocket loop whorl, double loop whorl, and accidental whorlSlide13
Loop Slide14
Loop
In the Loop pattern there are two focal points: the Core
, or the center of the loop, and the delta. The Delta is the area of the pattern where there is a triangulation or a dividing of the ridges. Most common type
When recording fingerprints, the delta and the area between the delta and the core must be completely recorded
Two types of loop:
Ulnar loop
– opens toward the little finger and the
Radial loop
– opens toward the thumbSlide15
Minutiae
Different ridge characteristics in the finger printsSlide16
Ridge Ending
Ridge ending
a single ridge ending within
a
friction ridge structureSlide17
Ridge characteristics/Bifurcation
Bifurcation
The point at which one friction ridge divides into two friction ridgesSlide18
Enclosure or eye ridge
A single friction ridge that bifurcates and
rejoins after a short course and continues as a single friction
ridge Slide19
Island or short ridge
a single friction ridge that
only travels a short distance before termination
Slide20
Crossover ridge
One ridge crosses
Over another ridge Will look like an xSlide21
Dot ridge
Small dot by itself in the middle of two or more ridges Slide22
Spur ridge
The spur has a single short ridge that looks like a hook that comes off of a longer ridge.µSlide23
Triple bifurcation ridge
Similar to the bifurcation except it has three ridges coming of the main ridge looks sort of like a forkSlide24
Bridge
Two ridge points are joined together by a short ridge ≠Slide25
Other Characteristics
Scaring…..Slide26
Points used for identification
No legal requirements in the USA for the number of points that must match before deciding that a print matchesCriminal courts will generally accept 8-12 points.Apx 150- 200 minutiae in properly rolled fingerprint.Slide27
Match the pointsSlide28
Are they fool proof?
Fingerprints cannot lie however analysis and identification are subject to error.Example: Madrid bombings on March 11, 2004 coordinated train bombings in Madrid Spain killed 191 people ( 911 days after 9/11)Bag found with fingerprints identifying Brandon Mayfield, an Organ lawyer..he was held for two weeks while investigated and it turned out after a more thorough analysis the prints were not an exact match…..FBI acknowledged “serious error” in the identification and apologized. Mayfield was not satisfied and sued the U.S.
gov and settled for 2 million dollars.Slide29
AFISAutomated Fingerprint Identification System
FBI system that stores all fingerprints taken –over 200 million prints on file with FBILinked to countries around the world Decreases the ability of criminals to flee the country or to commit murders in several different places.