Fingerprinting

history of fingerprinting:
The first use of the fingerprints as useful record keeping was in India by Sir William Hershel. In 1856, William used fingerprints on contracts as personal identification. He believed that this method was more binding due to the fact that this was personal contact on record. This became a trend for him and after a while found that the fingerprints were actually unique and a very good source of identification.

Sir Francis Galton made the first fingerprinting classification system in his book Fingerprints, in 1888. In his book, he concluded that fingerprints could actually be a use of personal identification.

By 1946, the FBI maintained about 100 million fingerprint cards which were later split into either civil or criminal files. These cards can be sorted through with the AFIS technology and are used to identify and catch criminals.

procedures for lifting prints:

Gather a zephyr brush, graphite powder, magnifying glass, and tape. Dip the zephyr brush into the beaker of graphite powder and get rid of excess on the brush. Brush the powder over the object. Find a print with magnifying glass. Place tape over the print and put it on a piece of paper.

ways to take prints:

non absorbing surfaces: when you are taking fingerprints from non absorbing surfaces like glass and tile, you can use powders and super glue to reveal the print and then make a copy of it.

porous surfaces: for developing a print on porous surfaces such as those on some papers, you can heat the paper to get a fluorescent glow of the print.

hard surfaces: to develop a print that is left on a hard surface like a murder weapon, tools, or any hard material touches by the criminal in a hurry, you can put an ultraviolet light to magnify the pattern.

smooth surfaces: smooth surfaces, such as glass, can be developed through the use of powder to reveal it.

types of prints:

Latent fingerprints: latent fingerprints can be left on any surface at a crime scene. These fingerprints are hard to see but can be revealed by using certain types of powders and lights.

Plastic fingerprints: plastic fingerprints can be found on plastic of other smooth surfaces and can be easily seen by the naked eye. They are produced by leaving ridges as the finger touches the surface.

Patent fingerprints: patent fingerprints are made when foreign materials such as ink, dirt, and blood are transferred from the finger to a surface. These prints are visible to the naked eye and are usually have their picture taken.

Handwriting

history of handwriting:
Before people could write, tribes and other cultures passed on stories and culture through pictographs that were usually written on rock walls. One of the earliest established systems of writing was the ancient Egyptians system of hieroglyphics around 2800 B.C. which used symbols as different words/letters of their alphabet. The Roman Empire acquired the 23 letter alphabet from Greece, it became popular and spread throughout Europe, northern Africa, and the Persian gulf. By 700 AD, king Charlemagne got a monk to make a standard lettering practice and the system of lower and uppercase was made.

inacuracy in handwriting analysis:
A problem with handwriting analysis is that they cannot be scientifically measured and won’t always be accepted in court cases. Another problem investigators have a problem with is that the writing could be disguised by the criminal so that he is not caught. A criminal could also have written something in cursive because they don’t write in it usually (or visa versa) so that the scientists can’t match it to anything.

twelve basic characteristics for comparing handwriting

Experts usually examine the following characteristics when examining handwriting samples:
1. Line quality: Do the letters flow or are they written with very intent strokes?
2. Spacing of words and letters: What is the average space between words and letters?
3. Ratio of height, width, and size of letters: Are the letters consistent in height, width, and size?
4. Lifting pen: Does the author lift his or her pen to stop writing a word and start a new word?
5. Connecting strokes: How are capital letters connected to lower-case letters?
6. Strokes to begin and end: Where does the letter begin and end on a page?
7. Unusual letter formation: Are any letters written with unusual slants or angles? Are some letters printed rather than in cursive?
8. Pen pressure: How much pen pressure is applied on upward and downward strokes?
9. Slant: Do letters slant to the left or right? If slant is pronounced, a protractor may be used to determine the degree.
10. Baseline habits: Does the author write on the line or does the writing go above or below the line?
11. Fancy writing habits; Are there any unusual curls or loops or unique styles?
12. Placement of diacritics: How does the author cross the t's or dot the i's?

Hair Analyisis

hair structure:

hair is composed mainly of keratin and contains a cuticle, medulla, and cortex. the cuticle is the layer on the outside edges of the hair, the medulla the middle(usually a dark line) of the hair, and the cortex is everything in between. hair also contains certain characteristics depending on the type of person. the lengths, straightness, thickness, color, shape, line in the middle, and texture all rely of either race or gender. for instance, an Asian hair is typically dark brown with an even darker brown stripe down the middle while a white male may have more of a teal color with a brown stripe in the middle.

hair transfer:

hair is a very good way of catching a criminal by linking the hairs/ fibers found on his/ her shirt that match those of which a murdered victim or missing person was wearing. the transfer of hair could result from a struggle that the criminal got into with the victim and hair was left on their clothes. another place where hair evidence can be found is in the home/ car of the suspect where the victim might have been. this can also work vice-versa by seeing if there was anyone making contact with or at the house/ in the car of the victim around the time of the crime.

blood types:

There are four different types of blood that a person can posses. these are type: A, B, AB, and O. these are all determined by four elements that they either posses or dont and can determine the individuals blood type. blood is also a great key piece of evidence because it contains the persons DNA and because every ones DNA is unique to that individual, it is easy to track someone through it.