History of Fingerprinting.

Science of fingerprint indentification has served all governments around the world for the past 100 years to provide correct ID of criminals. The first forensic organization established was the International Association of Identification in 1915. It remains the most commonly used forensic evidence worldwide. In Babylon, fingerprints were used on clay tablets for business transactions. Now days they use such things as fingerprint scanner's. The procedure for capturing a fingerprint using a sensor consists of rolling or touching with the finger onto a sensing area, which according to the physical principle in use (capacitive, optical, thermal, acoustic, etc.) captures the difference between valleys and ridges.

LINK: http://www.onin.com/fp/fphistory.html

Basic Types/ patterns of fingerprints.

If you examine the tips of your fingers with a magnifying glass, you will see that they are covered in little ridges of skin that make patterns. These patterns are formed on your fingers before you are born, and stay the way they are for your whole life. Nobody else in the world has a pattern like yours ... it's unique!

What chemicals to use on different types of surfaces.

Techniquies/Chemicals used to develop prints on nonabsorbent, porous, hard, and smooth surfaces.

1. To visualize fingerprints made on hard or non absorbent surfaces, the investigator typically applies a specialized fingerprint powder. Black powder which is composed of black carbon or charcoal is typically applied to white or light colored surfaces.

2. To visualize fingerprints on soft and porous surfaces , the crime scene investigator must use some kind of chemical treatment including: iodine fuming, ninhydrin, silver nitrate, and super glue fuming.

3. Florescent powders can be used to develop latent prints, these powders will florescence when viewed under ultraviolet light.

Types of Fingerprints: Patent, Plastic, & Latent.

Pantent Prints- are visable prints that occur when a foreign substance on the skin of the finger comes in contact with the smooth surface of another object. These prints leave a distinct ridge impression that is visable with the naked eye without any technology enhancement.



Plastic Prints- are visble, impressed prints that occur when a finger touches a soft, malleable surface concluding in an identation. Some surfaces that may contain this type of fingerprint are those that are freshly painted or coated, or those that contain wax, gum, blood, or any other substance that will soften when held and then retain the finger ridge impressions.

Latent Prints- are fingerprint impressions secreted in a surface or an object and are usually invisible to the naked eye. These prints are the result of presperation which is deprived from sweat pores found in the ridges of fingers. when fingers touch other body parts, moisture, oil and grease adhere to the ridges so that when the fingers touch an object, such as a lamp, a flim of these substances my be transferred to that obect. The impression left on the object leaves a distinct outline of the ridges of that finger.


LINK(S): http://www.buzzle.com/articles/identifying-fingerprint-patterns-types-of-fingerprints.html

http://ezinearticles.com/?Common-Types-of-Fingerprints&id=2592020

History of Handwriting.

The interest in handwriting as an indicator of personality has its origins far back in history. Over 2000 years ago, Aristotle noticed the correlation between handwriting and personality while the Chinese independently also made the observation that there was a connection between character and writing. However, only in 1622 that an Italian physician and professor of philosophy at the University of Bologna, published a book describing the analysis of character through the study of handwriting. Handwrinting has started over many years ago from a feathered pen to a mechanical pencil. Development has changed so differently over the years, that it's impacted the way it helps us learn. In schools now days teachers use expo markers on white boards to get the message across to students.

Twelve Basic Characteristics.

1. Line Quality

2. Spacing of Words and Letters

3. Ratio of Height, Width, and size of letters

4. Lifting Pen

5. Connecting Strokes

6. Strokes to begin and end

7.Unusual letter formation

8. Pen Pressure

9. Slant

10. Baseline Habits

11.Fantacy Wrinting Habits

12. Placement of Diacritics.

Inaccuracy in Handwriting Analysis.

Why do forensic investigators have trouble using handwriting analysis techniques?

There are a number of reasons that can interfere with ones use with handwriting analysis techniques. One is the type of writing instrument that one uses. Other items that should be taken into account when trying to compare writing samples are the document written on and the circumstance in which it was wrote.