DNA Profiling In Criminal Investigations

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.

Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA

In addition to undeserved charges, DNA testing has exonerated hundreds of people for crimes in which they were convicted over the past few years. When DNA testing became readily available to the criminal justice system, crucial flaws began to surface. It was realized that people were serving hard-time for felony crimes they didn’t commit.

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.

DNA profiling involves testing mini-satellites one at a time which then goes on to produce an image which is much simpler than genetic fingerprinting. It provides a pattern which is unique to a particular person and is therefore suitable for forensic purposes. (Turnpenny, P et al 2005).

Abstract: Over the past twenty years, advancement in DNA technology has directly led to the exoneration of nearly 300 people in the United States. In addition to these scientific advancements, a growing body of literature has focused on the significant roles eyewitness misidentification, so-called “jailhouse snitches,” and false confessions have played in contributing to wrongful convictions in U.S. courts. The aim of this paper is to examine the occurrence of wrongful conviction in criminal trials and the effect of DNA testing on bringing attention to the alarming frequency of these unjust judicial outcomes. Through an examination of previous wrongful conviction research and appellate court rulings, this paper will also explore the extent to which permitting wrongful convictions to be upheld constitutes a violation of civil liberties. Finally, this paper will discuss an important contradiction that advancements in science have exposed within our criminal justice system; while DNA technology and other advanced forensic techniques are increasingly being relied upon to secure criminal convictions, the justice system seems to be correspondingly reluctant to consider these forms of evidence for the

Since the late 1980s, there have been thousands of cases in which prime suspects have been wrongfully convicted, the most common causes being eyewitness misidentification, incriminating statements, and statements from informants. According to The Innocence Project, there have been almost four hundred post-conviction DNA exoneration cases in our country, and they are working to investigate even more wrongful conviction cases. This life changing program, along with their six attorneys, gather information about thousands of cases and determine whether or not DNA evidence can be reevaluated. Kenneth Ireland’s case was submitted for litigation after they found that the court relied heavily on false statements from witnesses. Researchers working

In the essay, “DNA fingerprinting: Cracking Our Genetic ‘Barcode’,” by Elaine Marieb, illustrates how significant DNA fingerprinting is today. She initiates a candid example of how New York City’s World Trade Center massacre killed more than 3, 000, left millions of bodies distorted, charred, and decayed. It was the staple for the ever-increasing need for DNA fingerprinting.

In November of 1983, 15 year old Lynda Mann was found raped and murdered on a deserted road, and although police were able to obtain a semen sample from her murderer the case remained unsolved. In 1986 the killer struck again murdering 15 year old Dawn Ashworth, once again leaving behind semen, but this time the police were able to use DNA profiling to match the semen to a suspect. Colin Pitchfork became the first person to be caught based on mass DNA screening, and the first to be convicted based on DNA profiling. The use of Deoxyribonucleic Acid (DNA) in the criminal justice system has greatly tipped the scales in favor of law enforcement, and changed the world that we live in. Court cases that in the past relied heavily on eye witness testimony and circumstantial evidence now have science to back them up. DNA analysis has revolutionized the criminal justice system, and even though there are some flaws, the use of DNA evidence should continue to be used by law enforcement.

DNA profiling can also be used to compare the DNA of a mother, her child, and the purported father can settle a question of paternity. An example is when DNA profiling proved that Thomas Jefferson or a close relative father a child of a slave named

The first DNA-based conviction in the United States occurred shortly after in 1987 when the Circuit Court in Orange County, Florida, convicted Tommy Lee Andrews of rape after DNA tests matched his DNA from a blood sample with that of semen traces found in a rape victim (Calandro, 2005). It was two years later that DNA was again ruled admissible in a Virginia state ruling. In the years that followed the use of DNA in trial proceeding was not disputed. It was not until the technique of obtaining the evidence was more largely used did the practice become questionable.

One huge technological breakthrough that has directly impacted the field of homicide investigation is DNA fingerprinting. DNA fingerprinting can be very helpful, especially in rape and murder cases. It was first used in 1984 to solve a double rape and murder case of two girls, three years apart. The first victim was Lynda Mann, a fifteen-year-old girl from Narborough, England. She was walking from one friend 's house to another, when she noticed someone standing by a lamppost close to the entrance gate of the Carlton Hayes psychiatric hospital. (McCrery, x) Lynda’s father called the police when she wasn’t home by 1:30am, but because she had not been missing for long the police were not very worried. The next morning, a hospital orderly on his way to work stumbled across what he thought to be a partially clothed mannequin, but was actually the rigid, pale body of Lynda Mann. While at the time there was not the technology to completely solve the case, “the technology that was to prove decisive in solving it [the case] was developed only a few miles from Narborough, at the University of Leicester, roughly a year after Lynda’s tragic death.” (McCrery, xi) On September 10, 1984, a biochemist by the name of Dr. Alec Jeffreys was examining an X-ray film image of a DNA experiment. While examining it, he noticed “that the DNA of different members of his technician’s family showed both

Law Enforcement keep notes on arrests that have founded people innocent of crimes, and retention of an innocent person's DNA can be charge or otherwise, seen as a invasion of that person’s privacy and civil liberties. Dr. Alec Jeffrey, a former professor at the University of Leicester laboratory, consulted with his lawyers to develop the new type of technique called DNA profiling. His technique would prove that DNA fingerprinting (profiling) can individualize evidence compared to the blood typing. DNA profiling compares 13 standard STRs to form a profile. The analysis used by the scientists, uses PCR and STRs to profile an individual. It is highly unlike that two individuals’ identical numbers of repeats for all 13 STRs, will match, which DNA fails is hardly never due to a successful match of 385 million to 1. This makes DNA profiling the most accurate tool in Forensics.

DNA profiling is a forensic technique used to identify individuals by characteristics of their DNA. A DNA profile is a small set of DNA variations that is very likely to be different in all unrelated individuals, thereby being as unique to individuals as are fingerprints. First developed and used in 1985, DNA profiling is used in, for example, parentage testing and criminal investigation, to identify a person or to place a person at a crime scene, techniques which are now employed globally in forensic science to facilitate police detective work and help clarify paternity and immigration disputes. This essay is one that will be discussing DNA profiling strengths and weaknesses, what it entails, limitations and how such evidence is presented