Wednesday, September 9, 2009
Comments
You have done well with your blog and have a lot of really good information.
-James Laraia
Crime Scene Investigation
After finishing a refreshing meal of brains and eggs, Mike Kelly went to pay for his breakfast but realized he left his wallet in his car's cupholder. He ran to his car and noticed the windows had been broken. Realizing what had happened, the flustered Mike Kelly called the police first and then went to the cashier. He explained the situation and being such a high valued customer, he was allowed to pay back Salt Works II. However, he waited patiently for the police to come.
Crime Scene Data
- Exh.: 1a - Male Black Hair (Ralph Johnson)
- Exh.: 2a - A man's foot print
- Exh.: 3a - Type A Blood
- Exh.: 4a - Synthetic Hair (Kooladria Jones
- Exh.: 5a - "I have your diamond ring" (Ralph Johnson)
- Exh.: 6a - Ulnar Loop Thumb Print (Mike Kelly)
- Exh.: 7a - Mike Kelly's wallet
Tuesday, September 8, 2009
Blood Lab Findings
We students were handed out blood-typing kits to determine how different types of blood reacted with different serums. This kit comprised of simulation AB, A, B, and O blood with simulation antigen A and B serums. My group tested each blood type with both serums and we recorded the results.
AB: Formed precipitate with both antigen-A and antigen-B serums
A: Formed a precipitate with only antigen-A serum, no reaction with antigen-B serum
B: Formed a precipitate with only antigen-B serum, no reaction with antigen-A serum
O: Formed no precipitate with either antigen-A or antigen-B serum
Positive and Negative Blood Types
Blood Transfusions
Major Types of Blood
Blood Type AB : Red blood cells that are covered with A and B antigens on the surface but the blood stream does not carry either A or B antibodies. Are universal recipients but can only donate blood to other AB blood types.
Blood Type A : Red blood cells that contain A antigens on the surface and the blood serum flows with B antibodies. Donate only to type A's and AB's.
Blood Type B : People whose red blood cells are coated with B antigens and whose blood serum contains A antibodies. Donate only to Type B's and AB's.
Blood Type O : Red blood cells (RBC's) that are cloaked only by a cell membrane. However the blood carries both A and B antigens. The universal blood donor but can only receive type O blood.
Fiber Lab Analysis
Cotton fibers.
Techniques developed to Identify Hairs/Fibers
At a crime scene, hairs that are left may be from the head of a young white male, the fur of a lion, the head of an elderly Asian woman, or really any mammal. To identify hairs at a crime scene, the forensic scientist will take the hairs at the scene and will compare it to samples from the attacked to the arrested. At first glance under a microscope, hairs generally resemble their category such as a long blond fine hair is most likely to be head hair of a young Caucasian. Gender can be determined from hair if they have tissue samples.
Hairs vary from race, the type of hair (pubic hair), and the age of the person. The hairs can be coarse, kinky, fine, black, blond, dyed or really any of a number of traits. Hair analysis also can indicate whether or not a person has experimented with narcotics or not. Also, it displays if the hairs have been cut.
Fibers:
The possibilities for fibers are even more vast than those of hairs due to the fact many types of fibers are manufactured for different reasons. Plant fibers, animal fibers, and man-made fibers all possess unique qualities that separate each other. Due to the many types of fibers and even more types of dyes, a fiber strand may not be on only one article of clothing, but the findings will sure eliminate many possibilities the fiber strand could be.
The coarseness of the fibers also indicates what the material is. A coarser fiber is from the carpet while a finer one is from clothing. Through microscopy, forensic scientists absorb the information about the fibers and looks at the string to determine what its identity is. Scientists can easily compare evidence from the crime scene to similar fibers on the suspect. Due to recent technologies, Hair and Fiber Analysis has really been a reliable source of determining guilt or innocence.
History of Hair/Fiber Analysis
The last 30 year, the advent of hair/fiber analysis has grown in importance. In one situation in a video we watched in Lab class, the fibers of a man's bed were found on rape victims which was the evidence the police needed to arrest him. Through the use of microscopy, forensic scientists may match evidence in a criminal case with other evidence found on the accused. This method is a great one for it is almost impossible for anyone to not leave any hairs or fibers at any one place.
Forgery Practice
The traced forgery was more of a success than the freehand by far. It appears very polished compared to the freehand forgery because you can directly compare the forged passage with the original passage. I still have a long way to go to learn how to forge.
Indicators of Handwriting
- 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?
- Ratio of height, width, and size of letters: Are the letters consistent in height, width, and size?
- Lifting pen: Does the author lift his or her pen to stop writing a word and start a new word?
- Connecting strokes: How are the capital letters connected to lower-case letters?
- Strokes to begin and end: Where does the letter begin and end on a page?
- Unusual letter formation: Are there any letters written with unusual slants or angles? Are some letters printed rather than written in cursive?
- Pen pressure: How much pen pressure is applied on upward and downward strokes?
- Slant: Do letters slant to the left or right? If 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 or below the line?
- Fancy writing habits: Are there any unusual curls or loops or unique styles?
- Placement of diacritics: How does the author cross the t’s or dot the i’s?
Handwriting Analysis : Questioned?
- Illnesses, exhaustion, and drugs may manipulate the handwriting of an individual
- The quality of the handwritten piece must match the handwritten piece being compared in quality
- Handwriting may change over time
The comparisons made between two handwritten pieces may differ from one analyst to the other leaving debate in a courtroom. Although rare, extraordinarily good con artists may forge documents or statements that look exactly like another's handwriting. While gaining popular support in forensic science, many scientists debate it is not a full proof way to sentence the accused (assuming they are guilty).
A Brief history of Handwriting Analysis
During the early 20th century, handwriting analysis became an important part in discovering one's true identity in specific criminal cases. One such famous case was the Baby Lindbergh kidnapping which occurred on March 1, 1932. This case was solved when the handwriting on the ransom note for Baby Lindbergh stuck the observer as almost exactly the same as Bruno Hauptmann. For this reason, Hauptmann was convicted and was sentenced to death via the electric chair. This form of forensic science is not the most accurate evidence in a trial for it requires more human involvement than other forensic sciences such as fingerprint analysis.
Monday, September 7, 2009
Patterns of fingerprints
Plain Arch: A fingerprint whose ridges go from left to right but there is a small peak in the middle of the print.
Tented Arch: Same as a Plain Arch, but the peak consists of an upthrusting peak.
Ulnar Loop: A loop in a print whose loop is directed towards the thumb. Directed away from the radius.
Radial Loop: A loop that is pointed in the opposite direction of an unlar loop. Directed towards the radius.
Plain Whorl: Ridges (usually 2 or 3) that form a circular shape around a small circular ridge.
Central Pocket Loop: A plain whorl that has a ridge bisecting it.
Double Loop Whorl: An overall circular motion in ridges. Two opposite loops that form a circular whole.
Composite: A print made up of a variety of types.
Techniques to Reveal and Collect Prints
Superglue Fuming: A process of revealing fingerprints through the evaporation of super glue. This method may be used for a variety of surfaces such as porous wood to impearmeable glass. The vapor of the super glue sticks to the oils of the fingerprint and exposes it to the naked eye. An overall great method.
Fingerprint Types
Latent: Prints invisible to the naked eye left on non-malleable surfaces. These prints are only detected by the secretion of sweat on the fingertips which leaves a mark on a surface. They are detected by certain techniques such as using powders (chemicals), and apply the use of a source of light to reveal the print. These prints often lack in clarity for they are often smugged, overlapped, and other varieties of manipulation.
Patent: The prints in a dream of any forensic detective. These prints are created by the impression of a finger on a flat surface with a substance on it. An example of this is an ink print because the ink on the print deposits the print on a surface so it is visible to the naked eye.
Tuesday, September 1, 2009
History of Fingerprint Analysis
During the European Enlightenment, many physicians and anatomists published their works on finger ridges. The first of these men was Marcello Malpighi. He is credited with classifying finger ridges (fingerprints) into 3 categories: loops, spirals, and ridges (arches). A later anatomist by the name of PurkynÄ› published a thesis in 1823 about nine types of finger ridges. The first person to utilize fingerprinting on a large scale was William Herschel, a British Raj administrator. He enforced the use of a palm print in contracts with Native Indians which illustrated the contract as a more binding force with the Indians than a written signature.
Dr. Henry Faulds of the late 1800s to early 1900s is historically the first person to use fingerprinting as a tool to discover whether a convict was innocent or guilty. While in Tokyo, he suggested to police in a robbery investigation to test the fingerprints at the crime scene with the fingerprints of the accused robber. They did not match so the man was set free. He told Scotland Yard about his findings but was disregarded due to his negligence to provide evidence.
The first man to use fingerprinting as an acceptable use as a tool in crime scenes was Edward Henry. As a police chief, he learned about Herschel's techniques while in India and implemented them during his time as the Commissioner of Police of the Metropolis. He used them for identification of criminals and soon, his policies spread around the globe.
During the early 20th century, many police forces began adopting the forensic science of fingerprinting and finalized it as a accurate source of identifying criminals. The U.S. Army added this tool as a source of identification in 1905. In 1924, Congress established the identification branch of the Federal Bureau of Investigation. By 1946, the FBI had processed over 100 million fingerprints.
The last century has brought a rapid growth of knowledge to forensic science. Modern-day police forces almost always implement fingerprint testing as a tool in a criminal investigation. Today, if a criminal unintentionally decorates the crime scene with his fingerprints, he will have only a slight glimmer of hope to escape the authority. With the advent of new technologies, a fingerprint can be traced to its origins in a matter of a few seconds.
{http://www.onin.com/fp/fphistory.html}
{http://en.wikipedia.org/wiki/Fingerprint#History_and_validity}
Sunday, August 30, 2009
Bibliography
http://en.wikipedia.org/wiki/Fingerprint#History_and_validity
http://www.biology.arizona.edu/Human_Bio/problem_sets/blood_types/Intro.html
http://en.wikipedia.org/wiki/Forensic_science
http://www.tcamb1.com/forensicscience.htm
http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm
http://www.wisegeek.com/what-is-questioned-document-examination.htm