Monday, September 14, 2009
Crime Scene
Gather information with evidence: -Fix note and take picture. -Examine and catalogue hair and fiber samples. -Identify blood. -Observe dead body & footprint.2. Identify what happened on this crime scene.
Data
Ripped note
“You’ll never catch Me!!”
Hair sample 1 (light brown)
Perhaps white male. Suspected to be from Mike Kelly.
Hair sample 2 (brown)
Darker than the other sample. Looks like African-American hair.
Blood sample
Type AB
Footprint
Size 10
Fiber 1
White-gray; woven in a plastic tube.
Fiber 2
White-gray; woven wave-like shred.
Corpse
Female; face beaten; possible Koolaidria Jones.
Mike Kelly and Koolaidria Jones are suspected to have been involved.Mike Kelly was convicted and charged with murder.
Conclusion
Here is a synopsis of the story: “Mike Kelly hires Koolaidria Jones in a prostitution and drug deal. She insults him, causing him to strike her multiple times across the face with a tennis racket. Though she fought back, she was not able to significantly harm Mike Kelly; she only managed to rip out part of what was left of his hair. His bleeding scalp was the source of his blood at the crime scene.
Sunday, September 13, 2009
Sunday, August 23, 2009
The History of Fingerprinting
Lifting Prints
- When a fingerprint is suspected to be in an area, lightly dust the spot with white talc powder, then blow on it softly in order to remove excess powder. This action should also reveal where powder is stuck in the ridges of a fingerprint.
- With a soft brush, brush around the fingerprint until it is relativly isolated from other powdered sections and easily visible.
- Take clear tape and carefully place it onto the revealed print. When you pull the tape back, talc powder should outline the fingerprint on the tape.
- Press tape gently onto a black card. Now the fingerprint has been successfully lifted.
- When a fingerprint is suspected to be in an area, lightly dust the spot with black carbon powder, then blow on it softly in order to remove excess powder. This action should also reveal where powder is stuck in the ridges of a fingerprint.
- With a soft brush, brush around the fingerprint until it is relativly isolated from other powdered sections and easily visible.
- Take clear tape and carefully place it onto the revealed print. When you pull the tape back, carbon powder should outline the fingerprint on the tape.
- Press tape gently onto a white card. Now the fingerprint has been successfully lifted.
Certain chemicals are used to develop prints on other surfaces.
Iodine: Fuming a fingerfrint with iodine vapor will cause a reaction in which the gas is absorbed by the oils of the fingerprint, turning it dark brown or black. Often used on paper.
Cyanoacrylate: Cyanoacrylate is a chemical that makes up about 98% of super glue. When mixed with sodium hydroxide, it will create fumes that react with amino acids in a fingerprint, creating a visible white print.
Silver Nitrate: Silver nitrate reacts with chloride in fingerprints to form silver chloride, which shows up in a reddish-brown hue under ultraviolet light.
Types of Fingerprints
- Plastic Fingerprints are when a print is left on something and creates an indentation or visible mark. This often happens with wet paint, the gum of envelopes, and substances that can melt from the heat of a hand, such as chocolate.
- Latent Fingerprints are prints that have disappeared to the naked eye as a result of time or some other effect. They can be found by dusting with powder or fuming the area with special types of gasses.
- Patent Fingerprints are prints that have been left because a finger had a foreign substance on it, such as paint, dirt, or blood. They are visible to the naked eye, and thus are usually photographed instead of lifted as is the case of latent prints.
Saturday, August 22, 2009
Blood Types
The major types of blood are A, B, AB, and O. A parent has 2 letters in his or her blood type and passes one of them on to a child. Each parent passes on a letter for the blood type, so a parent with an AA type and a parent with a BB type would only have an AB type child.
Transfering blood from one person or storage to another person is called a transfusion. A person can only take blood that works with his or her body. For example, type O can be given to anyone, and people with an O blood type are called Universal Donors. Type AB can take any type of blood into itself, and thus people with an AB type are Universal Recipients. The bodies of people with type A recognize A as ok to be inside it, but type B blood would set the bodies defenses into action. This works the same way with people with type B blood.
"Negative" and "positive" in a blood type refer to whether an RhD antigen exists in a person's blood cells. This is important for transfusions because a person who is negative (lacking RhD) will produce antibodies to combat the RhD on the new blood's cells.
Blood Types Lab
During the blood types lab, I found that the simulated blood took a little while to react with the serums. I had given up on a reaction occuring and moved on to the next step, and when I came back a few minutes later, the serum had caused precipitation!
Here are my results:
History of Handwriting
Before writing, information was passed on orally, and it wasn't written down in any way recognizable as handwriting until the Phoenicians, early Mediterranean traders, whose alphabet was spread across the Eastern Mediterranean area due to their trading industry.
The Greeks adopted and altered the Phoenician alphabet and later the Greek alphabet was became the basis of many other alphabets in Europe. Since it was people of the European origin who colonized North America, the alphabet we use now is based on the Greek alphabet.
Analyzing Handwriting Samples
- Line quality: do the letters flow or are they written with very intent strokes?
- Spacing of words and letters: what is the average space between words and letters?
- Ration of height, width, and size of letters: are the letters consistent in height, width, and size?
- Connecting strokes: how are capital letter connected to lowercase letters?
- Strokes to begin and end: where do the letters begin and end on the page?
- Unusual letter formation: are any letters written with unusual slants or angles? Are some letters printed rather than written in cursive?
- Pen pressure: how much pressure is applied on upward and downward strokes?
- Slant: do letters slant to the left or right? If the slant is pronounced, a protractor may be used to determine the degree.
- Baseline habits: does the author write on the line or does the writing go above and/or below the line?
- Fancy writing habits: are there any unusual curves and loops or unique styles?
- Placement of diacritics: how does the author cross the t's and dot the i's?
- The pen pressure is higher towards the bottom of the letters.
- Most repeats of the same letter have a different appearance.
- Many letters are started at the bottom rather than the top.
- The sample shows a very quick, intent style rather than a flowing style.
Friday, August 21, 2009
Hair Analysis
Hair has three parts: the Cuticle, Cortex, and Medulla.
Cuticle: The outer "skin," so to speak, of a strand of hair. It comes in three textures: Coronal, Spinous, and Imbricate.
Cortex: The inside of the hair strand.
Medulla: The inner part of a hair. Humans have a medulla that is much darker that the cortex.