Types of Fingerprints

Latent Fingerprint: a fingerprint made by deposits of oils and/or perspiration, not usually visible to the human eye. Various technologies, including lasers, can be used to identify latent prints.

www.rcs.k12.tn.us/HipHop/forensics-terms.doc


http://sciencefair.math.iit.edu/projects/fingerprints/fingerprint1.jpg

Direct fingerprints: obvious to the human eye and are caused by a transfer of foreign material on the finger, onto a surface. Because they are already visible they need no enhancement they are usually photographed instead of being lifted in the same manner as latent prints (i.e blood prints)


http://thumbs.dreamstime.com/thumb_39/11382857244e1rUJ.jpg




Plastic Fingerprints: occurs when the finger touches or presses against a plastic material in such a way that a negative impression of the friction ridge is produced. These types of prints are generally found in places like a newly painted object, wax from candles or sealants, in the gum on envelopes and stamps, on substances that melt easily or soften when they are held in the hand. An example of this would be chocolate.

http://technologyinterface.nmsu.edu/summer97/security/finger.html






https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiWTY3ojaqD5DV1yi-dTLDOzqX55anyOD38z1ehvnisA6ECoGM8uAOZSV6C1SbaCHMkj-h_M9OFLQlABSxP3vku0vAtkDsruHjEuigWAW5UA-cA5vq9GVqAbKy7nXxG2pgcr1XA4cNBZaL0/s1600/Ancient+Fingerprints.jpg

Fingerprints

The International Association for Identification was created in 1915 just for fingerprint analysis. In early years, fingerprints can be found on artifacts such as clay pots. There are fingerprints on many different historical artifacts and other means of identification as well (some of these will be discussed later in the blog). Since no fingerprint is exactly alike, fingerprinting is a good tool to use in the identification of a criminal or someone else.

Timeline of Fingerprints

1686: The history of fingerprinting doesn't have a clear cut beginning but one of the first recorded fingerprint discussions was in 1686

1858: Sir William J. Herschel took the first documented fingerprints in India

1901: Fingerprinting was officially introduced for use for criminal identification in England and Wales

September 10th 1984: The accidental discovery of DNA Fingerprinting
2001: A History of Fingerprinting. And Criminal Identification. By Simon A. Cole

FINGERPRINTS

After all the fingerprint discoveries, experiments, and conversations; Illinois finally began electronic capture of fingerprints in1992. I looked back to find something further back in history to relate to fingerprints. In the Late BC, Nova Scotia prehistoric picture writing of hand are found with ridges in them. Also, in the 8th century AD Chinese documents refer to business contracts when fingerprints are impressed on them. As I looked through the historical facts, there were many really old things that I would never had otherwise wanted to look up.

Identification

Fingerprint Pattern Type

Lifting Prints

Ways of Lifting Fingerprints:

There are a variety of colors of powder you can use depending on which one shows the best contrast to where the fingerprint is. Most examiners with experience find that the black or gray powder is the best to use. The black is composed of charcoal and works best with light colored surfaces. Then the gray is composed mainly of aluminum dust and it is used on dark color surfaces. The gray powder can also be used on mirror or metal surfaces because these will photograph black. Flouresencent powder can also be used on latent prints. The powder will make the print light up or flouresce under ultraviolet light. Another method is with iodine fuming. However when the process stops the print begins to fade.

Lifting prints off surfaces can be done with clear tape that you liie on the print. You don't push down on it. If you do then it will smudge the print. Another way, and mind you much simpler is to take a picture. Once you have the print where you can see it you can take a picture (make sure your photographer has a steady hand). If possible I'd advise to take a picture first and then lift the print very carefully.

HaNdWrItInG aNaLySiS

HANDWRITING ANALYSIS:

Handwriting Analysis

We had to write the fake ransom note and then in a group of three...

each of us tried to copy the person to the right of ours handwriting...

then the other person in the group had to trace the writer's handwriting.

By having us to try to forge someone else's handwriting it showed how different handwriting is for each one of us, Even though we learned the same cursive and regular handwriting we each have our own different style of handwritng. Some of us write just plain print, others write plain cursive, and others write a combination of print and cursive. Even then, some write long y's short y's wide cursive l's and the dot on i's is sometimes to the right.

After the handwriting was copied and traced to the best of the copier and tracer's ability we had to identify certian things or characteristics would be a better word for it. These characteristics are on the next post.

Twelve Basic Characteristics for Comparing Handwriting

Experts usually examine the following characteristics when examing 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 slany 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?

Joseph John Doe Handwriting Activity

After we practiced with forging each other's handwriting then we each wrote a fake check out and wripped it to shreds. Then we put the torn up check in an envelope with a number on it. We handed them in and then were handed back out other's checks. Then we had to tape/put them back together and figure out who wrote the check from another handwriting activity sheet we did.

Trouble using handwriting analysis techniques

why do forensic investigators have trouble using handwriting analysis techniques?

There are a number of reasons that can halt 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.

Verbal to Writing

At the basis of handwriting is communication. It used to be that they would pass on tales by stories from generation to generation. As the world continued on, they started using pictures.

Sumerian cuneiform developed around 3000 BC, then developed the Egyptian hieroglyphs around 2800 BC. Writing allows cultures to record the different events that happen in their everyday lives. Around 1500 BC the ancient Phoenician Alphabet developed. This alphabet consisted of 22 phonetically-based symbols. After awhile as time continued on, Christianity had more influence and Bibles were distributed as fast as they could right them by hand. Another style of writing was Celtic. This involved writing the letters with 1-inch square guides. These were known as uncials. After some time passed the first typewriter in the US was developed after the Civil War by Christopher Sholes. Johannes Gutenburg created the printing press in 1440 (moveable type). Since then the printing press has developed further so that we are able to print papers considerably faster.

Sumerian Cuneiform:

Egyptian hieroglyphs:

hAiR aNd FiBeR aNaLySiS

History of Hair and Fiber Analysis: Lab

Hairs consist primarily of the protein keratin. Hair can be defined as slender threadlike outgrowths from the skin (in more scientific terms, hair is a protein that grows out of the hair follicles of the skin). There are three parts of hair: cortex, medulla, and the cuticle. The cortex is the outside, the medulla is the very middle, and the cuticles the rest of the inside. In class, we completed a lab where we had to look at a series of hairs under microscopes and draw them.
Fibers are elongated* substances capable of being spun into yarn.
Hair analysis can tell us much more than some people may think. In a video we watched in class, a man died from thallium poisoning. At first the death was thought of as accidental. Since there was thallium at the man's workplace the authorities thought he must have accidentally injested it. However, after a drawn out investigation a different scientist came to the case. He examined some of the man's hair and made a chart that showed the different dates when the man was poisoned. Also, as the authorities examined every possible lead they found that the man's tea thermos had thallium in it. The authorities interrogated the man's wife and uncovered that she poisoned her own husband to get his money. The man was given a last dose of thallium that was huge in the very hospital that he died on his death bed. She just walked in and stayed with him and was alone and gave him thallium in his tea.

*Elongated: drawn out, stretched

Techniques of Identification of Hair/Fiber: Lab

Microscope: Place hair on wet glass slide with forceps. Cover with clear protector so the hair or fiber stays in place. Observe slide and draw. By looking at different hairs or fibers under microscopes, you can compare the slides and decide whether they are the same or not.

There are color tests that can be used for fibers but the fibers need to be stripped of their colors before the test. This is because fibers are usually dyed.

Hair : During the lab we did in class, we had to observe seven different known hair samples and we had to compare and find out which one was the closest to the unknown hair sample.

Major Blood Types

A- Anti B Antibodies- A anitgens
B- Anti A Antibodies- B antigens
AB- no antibodies- A and B antigens
O- Anti A and B Antibodies- no antigens

*antigens = any substance that causes an immune response in the body
*antibodies = produced by antigens, produces an immune response in body

there's...
A+ and A-
B+ and B-
AB+ and AB-
O+ and O-

the difference between the positive and negative is that the positive as the RhD antigen

Ability of Blood Mixing and Transfusions

Blood transfusions have been used for multiple circumstances. Some use blood transfusions to make up for blood lost during surgery or massive blood loss in tramas. Some people require frequent blood transfusions. People who suffer from hemopilia or sickle-cell disease may require frequent blood transfusions.

Blood Type Lab Findings

Suspect List...Who did it?

Reported Theft...Can you find the thief?

CSI Lab

We were called in the investigate a reported theft. We had eight suspects, and with the evidence that was collected narrowed it down to three suspects: Mike Kelly, Ralph Johnson, and Jenny Cho.

Evidence:
1- Possibly Mike Kelly's hair (could be Jenny's)
2- Ralph Johnson's handwriting on note "I have your diamond ring"
3-Ralph Johnson's hair
4- Type A Blood Antigens
5- Mr. Kelly's fingerprint: Ulnar Loop
6- Mr. Kelly's empty wallet
7- Shoe Print

INCIDENT:
Ralph Johnson and Jenny Cho are married. They devised a plan to defraud Mike Kelly. Jenny moved in with Mike. Mike fell in love with Jenny and was going to propose to her. This was just the right time for Ralph and Jenny to inact their plan. Ralph stole Jenny's diamond ring and wrote the "I stole your diamond ring" note. Ralph came over to Mike's house to talk to Jenny when Mike wasn't home. Mike walked in on them talking and overheard part of their plan. When they realized that Mike had overheard them, they knew their plan would no longer work as smoothly as they wished. Afraid of going to jail, Ralph overpowered Mike and took his wallet. He threw the wallet to Jenny who quickly emptied it. While Jenny emptied the wallet, Mike fought with Ralph leaving some of Ralph's blood and hair behind. When the wallet was empty, Jenny and Ralph fled leaving Mike behind.