Dna Evidence Of A Dna Unit Within A Crime Lab

This paper examines Carrell et al’s research along with three other scholarly research articles to better understand the effects that the DNA recovered from a crime scene has on a particular case and the forensic science community.

DNA forensics is a division of forensic science that focuses on the use of genetic material in criminal investigation to answer questions pertaining to legal situations, including criminal and civil cases. Through DNA testing, law enforcement officers are able to identify human remains or the individual responsible for a crime. DNA testing is a highly advanced scientific process that involves replicating the human DNA sequence to create a genetic map of an individual. Because of its reliability, DNA testing has become a significant factor in criminal cases. However, it has also been identified as having the potential to violate privacy and constitutional rights. The DNA identification process consists of five stages. These five stages

DNA analysts have been profiling DNA since 1985. Then in 1998, the Combined DNA Index System became fully operational (“FAQs” 2010). CODIS’s three levels are the national level, the state level, and the local level. As September 2015, there is 14,740,249 DNA profiles in CODIS (“CODIS”, n.d.). Since everybody has different DNA, except identical twins, DNA analysts have been able to assists with investigator to determine between who is guilty and who is innocent. With some of their findings, they are able to exonerate individuals, who have been wrongfully convicted. Even though television may make DNA analysts’ life look simple on the screen, it is not. There is need for interest and education. Lastly, the actual job that entails for the DNA

crime scene could be analyzed and compared with a sample from a suspect. A match could place

DNA testing was first used in criminal prosecutions in 1985 and is now admissible in all states. (Hails, 184) Scientific and legal communities seem to universally accept the use of DNA as “good” evidence. Questions could arise regarding testing procedures. There are several testing methods that have been proven reliable and easily pass general acceptance and scientific validity tests. This is causes number of Daubert cases questioning DNA to decline. “In most cases, the tests that are used are well established and do not require a separate hearing” (Hails, 160)

DNA testing is a critical and accurate tool in linking accused and even convicted criminals for crimes, and should be widely used to assess guilt or innocence before jail sentences are imposed. It was started up by scientists Francis C. Crick and James D, Watson in 1953 as they had described the uses, structures and purpose of the DNA “deoxyribonucleic acid” genetic fingerprint that contains organism information about an individual (testing

Due to the uniqueness of DNA it has become a powerful tool in criminal investigations

DNA forensics can also narrow down suspect pools, exonerate innocent suspects, and link crimes together if the same DNA is found at both scenes. However, without existing suspects, a DNA profile cannot direct an investigation because current knowledge of genotype-phenotype relation is too vague for DNA phenotyping. For example, a profile from a first time offender that has no match in any database may give the information that the criminal is a left handed male of medium stature with red hair and freckles. It would be impossible to interview every man who fits that description. However, with available suspects, DNA forensics has many advantages over other forms of evidence. One is the longevity of DNA. Although it will deteriorate if exposed to sunlight, it can remain intact for centuries under proper conditions (Sachs, 2004). Because DNA is so durable, investigators can reopen old cases to reexamine evidence.

In the case in which the man that was walking early in the morning and found a leg in the dumpster. It would of been extremely difficult for the FBI if they wouldn't of had the DNA Index System. By using this system in which federal, state, and local crime scene Labratories are allowed to electronically exchange and compare DNA profiles. The FBI was able to take things like scars and past surgeries that were done to the leg, and compare those things to profiles that had been kept in a hospital. This made it to where the police and the FBI could narrow the possible victims down to persons that had that type of knee surgery. The FBI were able to find a match from the hospital because the hospital was required to keep DNA samples for a minimum

Because there are many different types of crimes, it is often difficult to find enough physical evidence to convict a person. For example, in rape cases there is usually only a small amount of physical evidence, so cases are based on word alone. Because of DNA testing we can now take samples from the victim and attempt to match the results with those of the suspect. Therefore, DNA is sometimes the only real way of determining the guilt or innocence of a suspect without having any witnesses. Since many rape cases are left unsolved, DNA testing is believed to be the most accurate way of keeping sex offenders off the street. Because of the growing trend of using DNA in rape cases especially, a company in Brooklyn now advertises a small flashlight-like device intended to be used to jab at attackers in order to collect a sample of his skin for later use (Adler). According to a study by Joseph Peterson, with the Department of Criminal Justice at the University of Illinois, DNA evidence does not have a major impact on the decision to either convict or acquit

With regard to the US, where social science and STS research have, focused less on forensic databases and more on the production of expertise and evidence in court, Jay Aronson provided a historical account of the early practices, the scientific and legal controversies, and the ultimately successful acceptance of forensic DNA evidence in court in 2007. Another particularity of social science and STS research in this domain is that it has so far mostly concentrated its “high end” forensic technologies, namely those which received a lot of public attention because they were new, because stakeholders in the criminal justice system struggled to determine the parameters of scientific reliability and admissibility, or because they were prominently featured in the media. While the use of DNA analysis for police investigations and forensic casework dates back to the late 1980s, the second half of the 1990s marked the beginning of the quest to render DNA profiles systematically and routinely searchable and minable by setting up centralized DNA databases in many countries around the world. A DNA molecule is a long, twisting chain known as a double helix. DNA looks pretty complex, but it's really made of only four nucleotides: Adenine, Cytosine, Guanine, and Thymine. These nucleotides exist as base pairs that link together like a ladder. Adenine and Thymine always bond together as a pair, and Cytosine and Guanine bond together as a pair.

What is DNA? Is it these winding strands that look like ladders or is it what gives a person blonde hair and blue eyes? Actually, DNA is both of these things. DNA is a person’s genetic makeup–their hereditary blueprint passed on by their parents. It is a part of almost every cell in the human body. In each cell, a person’s DNA is the same; it stays the same throughout their lifetime. DNA is found in skin tissue, sweat, bone, the root and shaft of hair, earwax, mucus, urine, semen, and vaginal or rectal cells. The DNA found in a person’s saliva is the same as the DNA found in their blood. Parts of the DNA determine our physical characteristics, such as eye and hair color, height, and bone structure, but the

The procedure for DNA analysis can be complicated. First, to start the analysis, a DNA sample from blood, hair, or even dead skin is needed so that it can be sent to the forensic laboratory for further investigation. There, the sample is inventoried, evaluated, and prepared for the analysis. The sample is then treated with chemicals to help break down or extract DNA. After the DNA is extracted, it is purified by removing cellular material. Then the DNA is amplified, or only interested in a certain part of the DNA. CODIS (Combined DNA Index System) is used to search up the new DNA and match it with similar DNA that had been input before. The police department is given a full report of the analysis.

The convergence of DNA analysis and Forensic sciences is a recent one, given the relatively new discovery of accurate analysis of DNA. 1953 was a critical year for the field of molecular biology; Rosalind Franklin, James Watson, and Francis Crick solved the double-stranded, helical nature of DNA. Nearly three decades later, Kary Mullis invented the polymerase chain reaction (PCR) in 1983, followed only a year later by Sir Alec Jeffreys and his development of the restriction fragment length polymorphism (RFLP) (McDonald et. al, 2012). While many more methods have since been discovered that form an interdisciplinary bridge between forensics and biology, this paper will explore the history and methodology of PCR and RFLP in detail.

DNA analysis permits the identification by reference to the information contained in any human nucleic cell; considering, which body part the cell came from; therefore, DNA evidence helps articulate the procedure for use in a criminal investigation. (Gans & Urbas, 2002) “Crime investigators utilize DNA profiles from two sources: human bodies and small samples of human bodily material” (Gans & Urbas, 2002). DNA is an effective weapon for both prosecutors and defendants; therefore, the DNA crime investigators need to compare a profile believed to be from a crime perpetrator with a known person's profile. (Gans & Urbas, 2002) DNA conclusively establishes identity using such specimens like hair, blood, tissue, and semen from suspect to determine guilt or innocence. (Hall, 2014) DNA evidence is most commonly used in sexual assault and murder cases; it’s not perfect; nevertheless, it’s sufficiently reliable for admission into evidence. DNA testing is used to compare a profile from an unidentified person or corpse with a known person's profile. All fifty states are authorized to collect DNA from individuals convicted of terrorism, violent, sexual, and some property crimes and these samples are entered in CODIS. (Hall, 2014) Law enforcement agencies use DNA fingerprints to place a name to file the charge and obtain an arrest warrant