jimtrue.com : school : CJT2240 : 2003-05-22: History, Definition Sheets, Loop, Typelines & Delta
Posted by Jim True on May 22, 2003 7:29 AM. Last Updated October 22, 2006 9:23 PM
Disclaimer for all material noted here is at the bottom of this web page.
HISTORY:
The West Case invalidated the Bertillon method; two inmates Will West and William West not related. Bertillon measurements were identical; fingerprints were not.
Fingerprints are first developed in the womb at the 12th week of gestation, last until the body totally decomposes.
Faulds - authored a paper on the practical use of fingerprints and the use of printer's ink to permanently record fingerprints.
Herschel - First used fingerprints on large scale.
Vucetich - Solved first known case using fingerprints
Henry - Henry Classification System in the English speaking world.
1902 New York City - First fingerprint brought to trial.
DEFINITION SHEETS:
On the soles of our feet and surface of our hands, we have friction skin. So we can grip and grab. Identifying characters on your hands and on your feet. Latent print identifies back to our friction skin.
Three types of patterns: LAW - Loops, Arches and Whorls
Two types of Loops - Ulnar and Radial Loop - runs towards the Ulnar bone in our arms towards the inside. Radial is towards the radial bone in the arm.
Two types of Arches - Plain and Tented Arches.
Whorls - Four kinds of Whorls. Something round. Plain, Central Pocket, Double Loop and Accidental. Accidental combination of several kinds of patterns.
60% of fingerprint patterns are Loops.
30% of fingerprint patterns are Arches.
11% are Whorls
Friction Ridge Skin on Soles of our Feet, Palms and fingers of our hands. In fingerprint work, the fingers have a sequence that we must follow.
NCIC - National Crime & Information Center
AMP - Amputated
MAB - Missing At Birth
AFIS System in Pinellas County - When booked into Pinellas County Jail (only Central Receiving in Pinellas County). Live image capture (rolled on piece of glass, looks like a rolled ink print). wizardry of fiber optics, sent to AFIS computer and searched through AFIS in Pinellas County.
8 x 8 Fingerprint Card, 10 Digits, 8" x 8"
3 Digits on Fingerprints, then the Palm
Pinellas had AFIS since 1984.
Henry and NCIC Classification Methods.
Pinellas AFIS connected to FBI in West Virginia.
In the past prior to AFIS, must have a suspect with fingerprint cards, or search the existing cards.
Plain Arches, simple arch
Tented Arches, upthrust or something that breaks or tented
Loops - Ulnar to the outside bone (toward right on right hand)
If you don't know the finger, you can only know it's a loop, not radial or ulnar.
Plain Whorls - simple circles
Central Pocket Whorls- circle within a circle
Double Loop Whorls - Two loops
Accidental Whorls - Typically have 3 deltas
THE LOOP PATTERN
Look for a river flowing into what looks like a lake formation. Ridges that start on one side curve and return to the same side.
A Loop is that type of pattern in which one or more ridges enter upon either side, recurve, touch or pass an imaginary line between the delta and the core and pass out or tend to pass out upon the same side the ridges entered.
Three Basic Requirements of a Loop:Sufficient recurve consists of the space between the shoulders of a loop free of any appendages which abut upon it at a right angle on the outside of the recurve.
Shoulders of a loop are the points at which the recurving ridge defintely turns inward or curves.
Appendage is an attachment or connection.
Appendage striking the outside of the recurve at a right angle will spoil that recurve.
Test for appendage. If you can trace around the recurve, and the appendage flows off smoothly, it does not spoil the recurve. When a recurve is spoiled, use the next recurve outside of it, if it is free of appendages.
An appendage may form a new loop.
Two focal points of a loop are the delta and core.
S - Spoiled, G - Good.
Fingerprints are subject to opinion. Allow 2 ridge counts different from instructor.
TYPELINES
TWO innermost ridges which start or go parallel, diverge and surround or tend to surround the pattern area.
Pattern area includes the core, delta and ridges are used in the classification of a loop.
Divergence - spreading apart of two ridges
Bifurcation - forking or dividing into two or more lines.
Arms of a Bifurcation on which the delta is located can never be used for typelines.
Angles can never be used for typelines. Angles Typelines would be outside that
DELTA
Delta is that point on a ridge at or nearest to the point of divergence of two typelines, and located at or directly in front of the point of divergence.
Delta Rules
Disclaimer: These are MY notes taken from classroom lectures while I'm in the classroom. While I'm perfectly happy to share my notes with my classmates and I know I take very good notes, you should still make every effort to attend the class and TAKE YOUR OWN NOTES. I will not transcribe everything the instructor says in the classroom, and I will NEVER post pre-exam reviews. My notes will not replace the value of actually attending class and taking your own class notes.I also cannot attest to their accuracy, other than they are what was provided in the lecture; you should not reference my notes as "expert opionion" by any means, and if you notice an error or omission, please do me the favor of e-mailing me with the correction and I will re-post my notes. End of Disclaimer.