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OJ Simpon's Murder Trial and DNA Fingerprinting
Transcript of OJ Simpon's Murder Trial and DNA Fingerprinting
Orenthal James Simpson, best known as OJ Simpson, is well-known as a successful running back in American football. He is also well-known for the murder trial in which he was charged with the murder of his ex-wife Nicole Brown Simpson, Ronald Goldman, a friend of Brown, and a waiter. Both bodies were found approximately at 10:00 p.m. on June 12th, 1994, and it became apparent that this was no casual murder. Why Was, and Still Is, THIS Murder Case SO IMPORTANT? This murder case proved to be important for several different reasons:
On June 17th, 1994, after failing to turn himself in, OJ Simpson became the object of a low speed car pursuit by police, This speed chase captured the attention of 95 million television viewers.
The trial lasted 133 days.
At the end of the trial, a jury did not convict OJ Simpsonof murder, even though his DNA told another story. OJ Simpson's lawyers brought into play the ethnicity of OJ Simpson, stating that he was being discriminated against, thus diverting the jurors' attention from the DNA evidence.
This was the first major trial to use DNA fIngerprinting.
How Was DNA Fingerprinting Involved In This Murder Trial? DNA fingerprinting is a test used to identify and determine the genetic information-called DNA (deoxyribonucleic acid)-in a person's cells. What is DNA Fingerprinting?
DNA? DNA, also known as deoxyribonucleic acid, is a chemical substance that stores the genetic information needed to make an organism. DNA is found in the nucleus of a cell; therefore, when a cell reproduces or divides, the cell splits into two and the DNA is in both of the cells' nuclei. Why is DNA Important? In order for a living organism to
reproduce, DNA is essential. DNA is what gives each person their unique features and characteristics. Without DNA, there can be no cell division or growth. What Does DNA Do? DNA controls the structure and some functions of the body and, as previously stated, is present in every cell. DNA is located in the nucleus of the cell, allowing it to control all of the chemical reactions inside of the cell, and the actions of the cell. Where is DNA Found? DNA is found in every nucleus of
every cell. Most commonly, however,
DNA is extracted from saliva, hair follicles, other bodily fluids, blood, and tissue. Why DNA,
and Not Just a
Fingerprint? What Is So Special About DNA? Each person has a different DNA structure; therefore, each
person is unique and different. Why Not Just Fingerprints? Although fingerprints are unique to each person, they are not as unique as the structure of a person's DNA. When fingerprints are taken, the fingerprints are slightly twisted and stretched. In order to get the 'full' fingerprint, the finger must be rolled and pressed down firmly. This results in a twisted, stretched fingerprint that can sometimes not match up with another fingerprint from the same person. It has been stated, therefore, that DNA fingerprinting is more reliable than normal fingerprinting, given the usual inaccuracies of normal fingerprinting.
DNA is used to create a genetic fingerprint of a human because of it's
accuracy and reliablility. As stated above, DNA cannot be altered
or changed easily, like fingerprints. Furthermore, DNA cannot form a new structure, or even become tampered with, because it is very, very small and complex. Thus, it can be easily concluded that the complexity and high level of difficulty tampering with DNA makes it much more reliable than normal fingerprinting, and is the reason why it has now become the new 'fingerprint' of modern day humans. How is the DNA Obtained? Where Does the DNA Come From? The DNA usually comes from prime sources such as: hair
follicles, blood, bodily fluids, or tissue from the body. How is a DNA Profile Created? A DNA profile is created once a sample of DNA
is obtained. This means that once DNA is collected, forensic scientists
are able to use different devices, enzymes, or techniques to study
the unique patterns and repetitions of the DNA. This creates a profile because each pattern of the DNA is unique to the individual, allowing
the DNA of the person to be matched to their profile extremely easily.
The profiles are usually stored in a database that is accessible only to authorized personnel. How Does It Work? How is DNA Fingerprinting Carried Out? DNA profiling works by first obtaining a DNA sample. Then, special enzymes, called restriction enzymes, are used to cut the DNA at specific places. Some enzymes, like bacteria enzymes, will only cut the DNA when the sequence GAATTC occurs. Next, the DNA pieces are sorted by size using a technique called electrophoresis. The DNA pieces are then passed through a gel made from seaweed. This technique is the equivalent of screening sand through gradually finer mesh screens to sort out particle sizes. The diifferent sizes of DNA pieces are then transferred to a nylon sheet by placing the sheet on the gel and soaking it overnight. Following this, radioactive or colored probes are added to the nylon sheet. By doing this a pattern called a DNA fingerprint is produced. Each probe usually sticks in only one or two specific places on the nylon sheet. This allows a pattern to be seen, and this pattern is unique to each person. Lastly, the final DNA fingerprint or pattern is built by using many probes (usually 5 to 10) simultaneously. At the end of the process, the DNA fingerprint looks like a barcode that is seen at a grocery store. Has DNA Profiling
Ever Failed? In the case of identical twins, DNA fingerprinting
can fail. The DNA in identical twins
is the same, meaning that if one twin commits a
crime, the other twin can be wrongly convicted,
based on identical DNA structures. Non-identical
twins, however, have different DNA structures,
making DNA fingerprinting an effective method for identifying a criminal. How Effective is DNA Fingerprinting? Because each person, except for identical twins, has a unique DNA pattern, DNA profiling is extremely effective. There are little to no variations or complications that can go wrong in matching and comparing DNA to a person's DNA profile. Furthermore, unlike normal fingerprinting, DNA profiling is extremely effective because a person's DNA cannot be changed or altered. Therefore, DNA profiling is
extremely effective due to the complexity and diversity of each person's DNA in one person. In this murder trial DNA fingerprinting was used to match the blood from the door of Simpson's Ford Bronco to blood found on articles at the crime scene and to blood found adjacent to a shoeprint fitting Simpson's shoe size. This evidence clearly proved that Simpson played a key role in the murders. Simpson's attorneys argued, however, that the evidence had been tampered with and that the prosecutorial attorneys made errors in their presentation of the DNA evidence. The defense lawyers also argued also that Simpson was being discriminated against because of his African- American descent. Despite this useful evidence gathered, OJ Simpson was not convicted of murder, This case proved to be a breakthrough for the use of DNA fingerprinting, however, allowing it to become more useful - and successful - when convicting criminals in other cases. This short video shows
the basics of DNA fingerprinting. A picture of the murder scene Simpson's Low-Speed Pursuit A picture of the product of DNA
profiling that looks like a barcode.