“Traditionally, the term “fingerprint” refers to the patterns, which are highly characteristic for any human individual, of the ridged skin of the distal finger phalanges…’fingerprinting’ has also been used for the electrophoretic and chromatographic characterization of proteins and, more recently, of deoxyribonucleic acid (DNA) molecules” (2)
DNA fingerprinting has become a big part of our criminal system. Being able to show that someone committed a crime due to DNA is straight out of a science fiction novel but today we do it. In order to understand what DNA Fingerprinting is we first must look at what DNA is. DNA stands for Deoxyribonucleic Acid; DNA is the blueprint for everything in the human body. DNA is a double stranded or a double helix molecule, which means it sort of, looks like a type of ladder, it is made of four nucleotides: Adenine, Cytosine, Guanine, and Thymine. In the molecule, Adenine and thymine always combines and likewise cytosine and guanine always combine. In looking at human DNA across the board, most DNA is the same but only about .10 percent of DNA differs from person to person.
Let us start out by setting the stage a homicide has occurred. Criminal technicians arrive and begin to collect evidence; in the bathroom, they find a spot of blood. Then the blood makes its way to the lab where technicians will examine it.
DNA is the blueprint for everything so it is possible to find DNA in hair, saliva, skin, fingernails, and blood. Once the DNA evidence is collected, it then makes its way to the lab this is when the science of DNA fingerprinting begins. Restriction Fragment Length Polymorphism or RFLP was one of the first methods found to be able to analyze DNA. Alec Jeffreys developed the RFLP approach in 198...
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... as well. DNA fingerprinting is now become successful in determining kinship. Since DNA is heritable and highly specific to an individual (except for monozygotic twins), DNA profiles represent an excellent means of resolving genealogical problems. With the same example as paternity testing law, enforcement agencies are able to use DNA to identify unknown people such as John Does. Other uses of DNA fingerprinting are being used to understand history and evolution of the human population (1).
Works Cited
Krawczak, Michael, and J. Schmidtke. DNA Fingerprinting. 2nd ed. Oxford, UK: Bios Scientific, 1998. Print.
Varsha. "DNA Fingerprinting In The Criminal Justice System: An Overview." DNA & Cell Biology 25.3 (2006): 181-188. Academic Search Premier. Web. 26 Nov. 2013.
Harris, William. "How DNA Evidence Works." HowStuffWorks. Discovery Company, n.d. Web. 26 Nov. 2013.
In certain situations, it is necessary to identify DNA retreived from a sample. When there is a
DNA is the blueprint of life. It stores our genetic information which is what is in charge of how our physical appearance will look like. 99.9% of human DNA is the same in every person yet the remaining .1% is what distinguishes each person (Noble Prize). This small percentage is enough to make each person different and it makes identifying people a lot easier when its necessary. DNA not only serves to test relationships between people it also helps in criminal cases. DNA testing in criminal cases has not been around for many years if fact it was not until the early 1990s when the use of DNA testing for criminal cases was approved and made available. By comparing the DNA of a suspect and that found in the crime scene a person can either be convicted of a crime or they can be exonerated. This method of testing gained more publicity in the 1984 case of Kirk Noble Bloodsworth a man who had been convicted of the rape and first degree murder of a nine year old girl in Maryland. His case was a milestone in the criminal justice system since it involved the use of new technology and it also raised the question of how many people had been wrongly incarcerated for a crime they did not commit.
The repeat segments are cut out of the DNA strand by a restrictive enzyme that acts like scissors and the resulting fragments are sorted out by electrophoresis (Saferstein 391). However, there are some drawbacks using the RFLP method in the forensic science community. The RFLP technique requires a large amount of DNA and must be of high quality and cannot be degraded (Jones). Forensic scientists and the law enforcement community determined a need for a DNA profiling method that could be used on smaller DNA samples. Thus, the RFLP technique has been almost entirely replaced by Polymerase chain reaction.
Keiper L. More states use familial DNA as powerful forensic search tool. Reuters [Internet]. 2011 [cited May 16 2012]; N. page. Available from: http://www.reuters.com/article/2011/03/30/us-crime-dna-familial-idUSTRE72T2QS20110330.
Saltus, Richard. "DNA Fingerprinting: Its A Chance Of Probabilties." The Boston Globe 22 August 1994: 25.
DNA fingerprinting, or sometimes known as DNA typing, is isolating and developing images of sequences of DNA to evaluate the DNA in an individual’s cells. DNA fingerprinting today is used for many different things in many different areas of science. In forensic science, DNA typing can determine which person did which crime by using blood or skin left at a crime scene. In medical science, patients can find out who their siblings, parents, or children are by using DNA fingerprinting (webmd).
DNA, or deoxyribonucleic exists in all living organisms, is self-replicating and gives a person their unique characteristics. No two people have the same matching DNA. There are many different forms of DNA that are tested for situations such as criminal. Bodily fluids, hair follicles and bone tissues are some of the most common types of DNA that is tested in crime labs today. Although the discovery of DNA dates back to 1866 when Gregor Mendel proved the inheritance of factors in pea plants, DNA testing is relatively new and have been the prime factor when solving crimes in general. In 1966, scientists discovered a genetic code that made it possible to predict characteristics by studying DNA. This lead to genetic engineering and genetic counseling. In 1980, Organ was the first to have a conviction based off DNA fingerprinting and DNA testing in forensics cases became famous in 1995 during the O.J. Simpson trial (SMC History , 2011).
The criminal justice system has changed a lot since the good old days of the Wild West when pretty much anything was legal. Criminals were dealt with in any fashion the law enforcement saw fit. The science of catching criminals has evolved since these days. We are better at catching criminals than ever and we owe this advancement to forensic science. The development of forensic science has given us the important techniques of fingerprinting and DNA analysis. We can use these techniques to catch criminals, prove people's innocence, and keep track of inmates after they have been paroled. There are many different ways of solving crimes using forensic evidence. One of these ways is using blood spatter analysis; this is where the distribution and pattern of bloodstains is studied to find the nature of the event that caused the blood spatter. Many things go into the determination of the cause including: the effects of various types of physical forces on blood, the interaction between blood and the surfaces on which it falls, the location of the person shedding the blood, the location and actions of the assailant, and the movement of them both during the incident. Another common type of forensic evidence is trace evidence. This is commonly recovered from any number of items at a crime scene. These items can include carpet fibers, clothing fibers, or hair found in or around the crime scene. Hairs recovered from crime scenes can be used as an important source of DNA. Examination of material recovered from a victim's or suspect's clothing can allow association to be made between the victim and other people, places, or things involved in the investigation. DNA analysis is the most important part of forensic science. DNA evidence can come in many forms at the crime scene. Some of these forms include hair; bodily fluids recovered at the crime scene or on the victim's body, skin under the victim's fingernails, blood, and many others. This DNA can be the basis of someone's guilt or innocence; it has decided many cases in the twentieth century. As the times continue to change and the criminals get smarter we will always need to find new ways to catch them. Forensic science is the most advanced method yet, but is only the beginning. As the field of science grows so will the abilities of the
Forensic genetics has other applications . The " fingerprint " DNA represents a valuable tool for forensic science . As is the case with an ordinary fingerprint genetic fingerprint is unique to each individual (except identical twins ) . The determination involves the observation of specific DNA sequences which can be obtained from extremely small tissue samples , hair, blood or eventually left at the scene . As Fifty microliters of blood, semen or five microliters of ten roots of hairs are enough , and nozzles secretions and cells from the fetus . In addition to its use in the capture of criminals , especially rapists , the genetic fingerprints can be used to establish family relationships . People involved in the conservation of species use them to be sure that captive breeding is among individuals who do not belong to the same family .
Once a crime has been committed the most important item to recover is any type of evidence left at the scene. If the suspect left any Deoxyribonucleic acid (DNA) at the crime scene, he could then be linked to the crime and eventually charged. A suspect’s DNA can be recovered if the suspect leaves a sample of his or her DNA at the crime scene. However, this method was not always used to track down a suspect. Not too long ago, detectives used to use bite marks, blood stain detection, blood grouping as the primary tool to identify a suspect. DNA can be left or collected from the hair, saliva, blood, mucus, semen, urine, fecal matter, and even the bones. DNA analysis has been the most recent technique employed by the forensic science community to identify a suspect or victim since the use of fingerprinting. Moreover, since the introduction of this new technique it has been a la...
U.S. Department of Energy, Office of Science. (2009). DNA Forensics. Retrieved from Human Genome Project Information: http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml
Deoxyribonucleic acid (DNA) is an acclaimed extraordinary discovery that has contributed great benefits in several fields throughout the world. DNA evidence is accounted for in the majority of cases presented in the criminal justice system. It is known as our very own unique genetic fingerprint; “a chromosome molecule which carries genetic coding unique to each person with the only exception of identical twins (that is why it is also called 'DNA fingerprinting ')” (Duhaime, n.d.). DNA is found in the nuclei of cells of nearly all living things.
"Using DNA to Solve Crimes." U.S. Department of Justice: National Institute of Justice. (September 9, 2014). Web. 29 May 2015.
Fingerprint usage dates back to the 1800s. Sir William Herschel used the prints as signatures on civil contracts, before they were found useful towards crimes (History of Fingerprints Timeline, 2012). A British surgeon, Dr. Henry Faulds, wrote about using fingerprints for personal identification. He first looked at prints on clay pottery and studied the ridges and patterns that they had made in the clay. In 1891, Juan Vucetich suggested to start fingerprinting criminals to keep the prints on record. The following year, Vucetich identified a print from a woman who killed her two sons. Investigators found her print and were able to correctly match her identity. Charles Darwin’s cousin, Sir Francis Galton, wrote and published the first book about fingerprints. He wrote about how every individual has a unique print by the certain traits of each fingerprint (History of Fingerprints, 2012). The popularity of fingerprints grew greatly in the United States in the early 1900s. Police departments and the FBI began to use the...
Blood stains are one type of evidence that can be found at a crime scene. Blood that is still in the liquid form should be picked up on a gauze pad. Once the blood is dried thoroughly it should be refrigerated and sent to the Laboratory (Andrus et al., n.d., para. 1). If the blood stain is found dried on clothing, the officer should wrap the piece of clothing in clean paper and place it in a sealed and labeled container. An object with dried blood stains needs to be sent to the Laboratory if it is small enough. If the object is too large to send, then using a clean knife the stain needs to be scraped onto a clean piece of paper, which then can be folded and placed in an envelope (Andrus et al., n.d., para. 2). When collecting autopsy blood samples, the officer should request that the pathologist obtain the sample directly from the heart and place it in a yellow or purple stoppered vacutainer. If the victim is still alive but in serious need of a blood transfusion, then the pre-transfusion blood sample needs to be obtained promptly before the hospital discards it (Andrus et al., n.d., para. 4). It is important for the Laboratory to receive all blood samples within 48 ho...