Monday, September 7, 2009

THE CRIME SCENE!

Evidence:
1.Hair: White Male
2.Hair: Asian
3.Ripped up Note/Handwriting: Ralph Johnson "I have your diamond ring"
4.Wallet: Mr. Kelly Information
5.Footprint: Large Sneaker
6.Blood: Type A
7. Fingerprint:

People Involved:
Jenny Cho
Ralph Johnson
Mike Kelly

Story: In the beginning Ralph Johnson and Jenny Cho teamed up and began planning a robbery against Mike Kelly. However, while watching Mike Kelly, trying to pick up information and figure out the best time to rob the house, Jenny Cho began to fall in love with Mike Kelly. Seeing this Ralph Johnson began to fear that Jenny Cho was trying to grow closer to Mike Kelly in order to get herself onto his will. Ralph Johnson predicted that once Mike Kelly put his new girlfriend onto his will then she would kill him and take all the money. Ralph Johnson soon discovered that Mike Kelly planned to propose to Jenny Cho. Ralph Johnson knew he shouldn't stand for that so on the night when he knew that Mike Kelly and Jenny Cho were together Ralph Johnson broke into Mike Kelly's house shooting at everything he saw. Jenny Cho was killed instantly, however, Mike Kelly was able to get away. On his way out Ralph Johnson picked up the diamond ring and left a note hoping to crush Mike Kelly's dream. Today Mike Kelly is said to be working undercover as a teacher at some fancy school somewhere in North Carolina while Ralph Johnson continues to roam the country looking for the money he unsuccessful tried to steal.

Positive or Negative Blood

When people are told there blood type they are usually told a letter, based on the ABO blood grouping system, and either a positive or negative, based on the Rh factor blood grouping system. If you have positive blood then you have an Rh antigen in their blood plasma. Those who have negative blood do not have the Rh antigen present in their blood plasma, however, they can obtain the Rh antigen by being the receiver in a transfusion involving positive blood. A person with positive blood can receive blood from a person with negative blood with no problems because they already have the Rh antigen.

Blood Mixing and Transfusions

Blood Mixing: Over the years the use of mixing blood has become very useful in the different fields f science including medical science. Mixing two people's blood can cause the blood the clump leading to fatal consequences. In the medical field today there are studies going on to observe the effects of mixing human blood with blood from certain animals. In some cases it can be hard to find blood transfusions for life threatening patients so scientists today are trying to find substitutes to save lives.

Transfusions: A person can always give blood to another person if they have the same type of blood, however, this isn't the only way to receive blood from another person. A transfusion can also work if the receiver's blood doesn't have any antibodies against the donor's blood antigens. If the receiver's blood has antibodies that match the donor's blood's antigens then the red cells in the donated blood will clump and the transfusion will fail. To see if who can donate to who see the chart to the left.

Types of Blood



When you are born you are given one out of the four different types of blood. You are either given:



  • Type A: Type A blood has B antigens in the blood plasma and A antigens on surface of the red blood cells.

  • Type B: Type B blood is the opposite of type A blood for it has A antigens in the blood plasma and B antigens on the surface of the red blood cells.

  • Type AB: Type AB blood has both A and B antigens on the surface of the red blood cells but has neither A or B antigens in the blood plasma.

  • Type O: Type O blood is the opposite of type AB blood because it has neither A or B antigens on the surface the red blood cells but has both A and B antigens in the blood plasma.

For more information see: http://nobelprize.org/educational_games/medicine/landsteiner/readmore.html

Sunday, September 6, 2009

Blood Lab

After completing the blood lab I was able to understand how blood type works in a lab. I now know that anti-serum A and anti-serum B can be used to figure out the type of blood for an unknown blood sample. Also I understood, after researching and doing this lab, how you can't mix certain bloods during a blood transfusion.

Purpose: To observe the four different types of blood by using anti serum A and anti serum B.

Procedure:
1. Place two small dots of the type of blood on a slide
2. To one of the dots add a dot of anti serum A and mix
3. To the second dot add a small dot of anti serum B and mix
4. Observe the effects and record
5. Repeat for the other three types of blood.

Data:
1. Blood Type A: Anti serum A produced hair like precipitate and turns the blood pink while anti serum B turned the blood orange.
2. Blood Type B: Anti serum A produced no results while anti serum B produced a cloudy precipitate
3. Blood Type AB: Anti serum A produced little white precipitates while anti serum B produced a cloudy precipitate
4. Blood Type O: Anti serum A turned the blood pale pink while anti serum B turned the blood orange

Wednesday, September 2, 2009

History of Hair/Fiber Analysis


Hair: Over the years crime scene investigators have been developing new ways to catch criminals. Two of the newest ways that have been discovered are done by using hair and fibers, found at the scene of the crime, to help determine who did it and with what. In 1899 Francois Goron, a forensic scientists, was able to tell the court the the victim of the murder, which he was researching, had dyed his hair before the crime took place. This important discovery led to the identity of the body and brought the case a step closer to finding the criminal. In later years forensic scientists would discover that by studying a piece of a victim you can tell whether or not metal toxicity or different types of drugs were involved.



Fiber: the study of fibers has been used in many criminal cases to catch who ever was guilty. In a trail held in 1997 the FBI was able to catch the two criminals by finding a tiny tread of the criminals jeans at the crime scene. Over the next few years crime scene investigators have been able to discover the guilty and the story behind the crime by observing tiny fibers left behind by the criminal. Tiny threads of cotton, fabric, skin, or clothing can help end a very difficult case.

For more information see:
http://www.crimeandclues.com/hair_evidence.htmto
http://www.hairanalysistest.com/
http://www.google.com/search?q=forensic+fiber+analysis+history&hl=en&rlz=1R2GGLL_en&sa=X&tbo=p&tbs=tl:1,tll:2000,tlh:2004&ei=uh-lSuHlM4KRtgeSwr0F&oi=timeline_histogram_main&ct=timeline-histogram&cd=11

Tuesday, September 1, 2009

Techniques to Identify Hair/Fibers

Hair: The most basic form of identifying hair samples is looking at different samples under a lightened microscope and comparing it to various originals. For example male hair usually looks alike so if you were able to math an unknown sample to an Asian hair sample then you would be able to conclude that your suspect is Asian. However, there are many things that makes hair analysis unreliable for example if you use any type of bleach, shampoo, or hair dyes in your hair it can change the way that it looks under to microscope therefore causing a negative test for any forensic scientist. techniques
http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm


Fibers: Almost the same technique is used when identifying fibers. In order to find the identity of a fiber you would need to take a small piece of the fiber and look at it under a microscope and then compare it to original samples of fibers to find a match. Another method would be the stain test which proves if a fiber is hydrophobic, meaning it will not absorb water, or hydrophilic, meaning it will absorb water. A density test can also be used to see if the fiber will either float or sink, however, fiber blends can skew the results.

http://www.associatedcontent.com/article/80155/textile_fiber_identification_pg2.html?cat=51

Guesses of Fiber Lab

Based on the look of the different fibers under the microscope and the look and feel of the fibers when scene by the naked eye these are my guesses of the identities of the six fibers in the fiber analysis lab.

1.Cotton
2.Rubber (Rubber band)
3.Some type of hair (fake hair or doll hair)
4.Polyester
5.Ribbon
6.Thread

Inaccuracy in Handwriting Analysis



When examining handwriting evidence at a crime scene a forensic scientist may think that they know who the criminal is, however, they must take in to account these things:
*If a criminal was really smart they could forge their own handwriting
*Handwriting can change depending on what writing instrument you are using, for example a pen or a pencil
*Handwriting can change depending on your mood, if your happy your handwriting tends to go up while if you are mad your handwriting may go down
*Handwriting can be smugged depending on where the piece of paper goes or if it gets wet
*A criminal can trace another person's handwriting in order to frame the other person

History of Handwriting Analysis

The study of handwriting, or graphology, can become a very useful tool during an investigation. It all started back in 1622 when the first record of handwriting was published by an Italian physician, and professor of philosophy at the University of Bologna, by the name of Camillo Baldi. In his book A Method to Recognize the Nature and Quality of a Writer from His Letters Camillo made the observation that like snowflakes all human writings have their own unique style. In the late 1800's Crepieux Jamin used his partner Abbe Michon books on the analysis of handwriting in order to classify the many features of handwriting into a comprehensive system. Today handwriting is difficult to use during an investigation for some criminals may try to disguise their original handwriting, however, some companies still hire graphology experts to help profile their job candidates. Also crime scene investigators have found that if a criminal is in a hurry they often forget to change their original handwriting and the criminal can be tracked using graphology. Over all graphology may not be the best way to find the criminal, however, in a big investigation every little bit of information can help to put it to an end.

For more information see: http://www.enotes.com/forensic-science/handwriting-analysis or http://www.graphicinsight.co.za/background.htm