200 likes | 808 Views
The Basics. A fingerprint is an impression of the friction ridges of all or any part of the finger.A friction ridge is a raised portion of the epidermis on the palm and fingers or sole and toes skin, consisting of one or more connected ridge units of friction ridge skin.These ridges are sometimes
E N D
1. Fingerprint Patterns
You be the detective!
2. The Basics A fingerprint is an impression of the friction ridges of all or any part of the finger.
A friction ridge is a raised portion of the epidermis on the palm and fingers or sole and toes skin, consisting of one or more connected ridge units of friction ridge skin.
These ridges are sometimes known as "dermal ridges" or "dermal papillae".
3. Print Facts Fingerprints may be deposited in natural secretions from the glands present in friction ridge skin (secretions consisting primarily of water)
They may be made by ink or other contaminants transferred from the peaks of friction skin ridges to a relatively smooth surface such as a fingerprint card.
4. Reliability of fingerprinting as an identification method Fingerprints collected at a crime scene, or on items of evidence from a crime, can be used in forensic science to identify suspects, victims and other persons who touched a surface.
No two fingerprints have ever been found identical in many billions of human and automated computer comparisons.
Fingerprints are the very basis for criminal history foundation at every police agency.
5. Fingerprints old school? Is claimed to outperform DNA and all other human identification systems to identify more murderers, rapists and other serious offenders (fingerprints are said to solve ten times more unknown suspect cases than DNA in most jurisdictions).
6. Print History The discovery of fingerprints has been widely attributed to a 19th century scientist named Francis Galton.
An ancient Chinese custom includes using the fingerprint to sign legal documents .
7. Galton's proposal that "no two fingerprints are identical" changed the world of forensic science forever.
In order for fingerprinting to be useful in forensic identification, a method of sorting and classifying them would be necessary.
8. Fingerprint Locks In the 2000s, electronic fingerprint readers were introduced for security applications such as identification of computer users (log-in authentication).
However, early devices have been discovered to be vulnerable to quite simple methods of deception, such as fake fingerprints cast in gels.
In 2006, fingerprint sensors gained popularity in the notebook PC market. Built-in sensors in ThinkPads, and others also double as motion detectors for document scrolling, like the scroll wheel.
9. Types of Prints Fingerprint impressions fall into three basic types: latent, visible, and the plastic (molded), prints.
Latent print = invisible to the eye.
Latent prints are formed by sweat
Even the swiftest of criminals find it difficult to escape without leaving behind the trace of a single fingerprint.
10. Types of Prints Continued Fingers stained with blood or ink found can form visible prints.
Plastic prints are quite easy to read because they make an impression on a soft surface such as soap, putty, or wax.
11. LOOPS Loops constitute between 60 and 70 per cent of the patterns
One or more of the ridges enters on either side of the impression, recurves, touches or crosses the line of the glass running from the delta to the core
12. RADIAL/ULNAR LOOPS Depends on the way the loop travels
Obviously to make the distinction between these two types of loops you have to know on which hand they appear
13. WHORLS Any fingerprint pattern which contains 2 or more delta's will be a whorl pattern.
14. Types of Whorls
15. CENTRAL POCKET WHORLS Notice the inner area of the pattern, that is the area which tends to form a circle?
16. DOUBLE LOOP WHORLS Looks like a ying yang symbol in the centre of the whorl
17. ARCHES Arches represent only about 5 per cent of the fingerprint patterns encountered. In arch patterns, the ridges run from one side to the other of the pattern, making no backward turn. There is ordinarily no delta.
18. COMPOSITES Composites include patterns in which combinations of the tented arch, loop and whorl are found in the same print, also patterns where the majority of ridges are loops and a few ridges at the centre or side are whorls. These are subdivided into central pocket loops, double loops and accidentals.
19. Superhero Thumbprints At the back of the lab there are ink pads and worksheets.
You are to ink both your right and left thumbs and then put them in the appropriate boxes.
Put a star beside any deltas
that you see
Identify the pattern of your
thumbprint.
Pass into Ms. Clarke and get an
exit card to complete by the end
of class.