The first case using Deoxyribonucleic Acid (DNA) evidence became a milestone for the field of forensic genetics. The original crime occurred in the United Kingdom on November 21st, 1983, where a young girl named Lynda Mann never returned home and was found the next day having been raped and strangled. No perpetrator was ever found, but semen evidence was collected from the body. Shortly after this, the criminal struck again on July 31st, 1986, where another young girl by the name of Dawn Ashworth, was also raped and strangled to death, (Cobain). Semen samples were then collected from the body and compared to that of the first victim. The samples were analyzed by Alec Jeffreys, a genetics professor of the University of Leicester. Jeffreys compared …show more content…
Afterwards, they transferred the DNA into a nylon membrane that has been incubated with radioactive probes that then attaches to the minisatellites. The nylon membrane is then exposed to X-ray film and then enabled for minisatellites to appear, a pattern is then developed which is called the “DNA fingerprint,” (DNA fingerprint). DNA in its essence, contains information that is stored as a code through chemical bases. These chemical bases are, adenine (A), guanine (G), cytosine (C), and thymine (T), which then pair up with one another, A with T, and C with G. The sequence between these bases is the information that enables for the construction of an organism (What is DNA). DNA between two individual humans, “on average, is about 99.9 percent the same,” (What is a DNA fingerprint). However, there exists within DNA, minisatellites, which are sequences of highly variable DNA that have a pattern unique to each individual. Jeffreys and his team determined through the comparison of the two semen samples that was there was enough similarity to conclude that there was a match and that both crimes were committed by the same
On June 19th of 1990, Robert Baltovich’s girlfriend Elizabeth Bain went missing. Elizabeth told her family that she was going to check the tennis schedules at her school, the University of Toronto Scarborough Campus. She never returned, but her car was eventually recovered. It was found with blood on the backseat, with forensic tests showing that it was Elizabeth’s. With no clear evidence, the “solving” of the case was completely based on eyewitness testimonies, which eventually had Robert arrested for the murder of his girlfriend.
Mary Jane Burton a state forensic analyst testified at Burnette’s trail that she examined the pubic hairs from the rape kit and the victim’s sheet. She announced that one hair was consistent with Burnette, others with the victim, and yet the others were consistent with neither Burnette nor the victim. She also determined that sperm cells were present on the vaginal swab from the rape kit. However, the serology testing only showed presence of Type A blood antigens. Burton testified that the victim was a Type A and Burnette was a non-secretor, this meant that his blood type could not be determined from bodily fluids. Although Burnette story changed a bit, he stated that his grandma had heard him come home that early morning. The jury convicted Burnette of rape and burglary. [Exoneration Case Detail . 2014]
As stated before, in the Maher case spermatozoa were found in underwear of the rape victim in Lowell, and also spermatozoa were located in the rape kit on the vaginal swab slide that was developed at the time of the crime. In both the spermatozoa were found, collected, and DNA testing was completed on the sample to determine if Dennis Maher committed the crime.
The Hillside Strangler was the name given to two killers who strangled and killed their victims, dumping their bodies in the hills of Los Angeles. These killings took place during October 1977 and February 1978 involving ten young women ranging from ages 12 to 28. With over one hundred law enforcement task force members working tirelessly to solve this case, the fear with in the community was still undeniable. It wasn’t long before the clues would come in one by one, to help detectives solve this heinous crime. Once two sets of DNA was revele on the crime scenes, police realized they had not just one but two killers. These two killers were cousins Kenneth Alessio Bianchi and Angelo Anthony Buono.
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 samples. One of the more controversial practices of DNA forensics is familial DNA searching, which takes partial, rather than exact, matches between crime scene DNA and DNA stored in a public database as possible leads for further examination and information about the suspect. Using familial DNA searching for investigative purposes is a reliable and advantageous method to convict criminals.
It was in 1984 when Alec Jeffreys, a British geneticist, discovered that specific sequences of DNA did not add to the function of a gene but were still constant throughout it. (Britannica). Jeffreys called these minisatellites and determined that each individual organism had a unique arrangement of minisatellites (Britannica). In the early uses of DNA fingerprinting, it was only used for identifying genetic diseases and disorders but people quickly realized that it could be used in many different areas of science (hubpages). Years after the discovery of DNA fingerprinting, it had been used to solve the first immigration case, the first paternity case, and even helped identify the first identical twins (le.ac.uk). The first methods of DNA fingerprinting were accurate, but you would have had needed to acquire a large amount of DNA. Over time, the advancement of science has led to major advances that formed the basis of DNA profiling techniques. These newer methods are still used today and allow scientist to use skin, blood, semen, and hair to gather DNA (le.ac.uk). In 1988 DNA fingerprinting was used for the first time in a criminal investigation. Timothy Spe...
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).
In July of 1994, a little girl named, Megan Kanka, was raped and strangled. They found her body near her home in Hamilton Township, New Jersey. The story of thing young girl has shocked the nation. The man responsible for this brutal act is named, Jesse Timmendequas. He had been convicted twice prior to this attack.
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...
According to the Innocence Project (2006), “On September 17, 2001, Chad wrote the Innocence Project in New York, which, in 2003, enlisted pro bono counsel from Holland & Knight to file a motion for DNA testing on Tina’s fingernail scrapings.” The state had tested the DNA that was under Tina’s nail from the first case but at that time it was inadequate and could not be tested. It was not until now that we have the technology capable enough to test it. In June 2004, the test came back negative to matching both Jeremey and Chain Heins but did come from an unknown male. The state argued that it was not enough to overturn the conviction so Chad’s attorney asked the state to do some further testing and to compare the DNA from under the fingernails to the hairs that was found on Tina’s body. It was in 2005 that the Florida Department of Law Enforcement confirmed that there was a match between the DNA under Tina’s nail and the pubic hair. According to LaForgia (2006), “this particular type of DNA, the report stated, was found in only about 8 percent of Caucasian American men.” During this process there was a new piece of evidence that Chad’s attorney had learned about during the appeals process, a fingerprint. There were some accusations that the prosecutors never disclosed this information about this third fingerprint and if they did it was too late. The jurors did not even know about this fingerprint and if they did this could have changed the whole case. This fingerprint was found on several objects that included the smoke detector, a piece of glass, and the bathroom sink. It was soon discovered that this fingerprint matched with the DNA found on the bedsheets that Tina was on. This was finally enough evidence to help Chad Heins become exonerated in
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
Before the 1980s, courts relied on testimony and eyewitness accounts as a main source of evidence. Notoriously unreliable, these techniques have since faded away to the stunning reliability of DNA forensics. In 1984, British geneticist Alec Jeffreys of the University of Leicester discovered an interesting new marker in the human genome. Most DNA information is the same in every human, but the junk code between genes is unique to every person. Junk DNA used for investigative purposes can be found in blood, saliva, perspiration, sexual fluid, skin tissue, bone marrow, dental pulp, and hair follicles (Butler, 2011). By analyzing this junk code, Jeffreys found certain sequences of 10 to 100 base pairs repeated multiple times. These tandem repeats are also the same for all people, but the number of repetitions is highly variable. Before this discovery, a drop of blood at a crime scene could only reveal a person’s blood type, plus a few proteins unique to certain people. Now DNA forensics can expose a person’s gender, race, susceptibility to diseases, and even propensity for high aggression or drug abuse (Butler, 2011). More importantly, the certainty of DNA evidence is extremely powerful in court. Astounded at this technology’s almost perfect accuracy, the FBI changed the name of its Serology Unit to the DNA Analysis Unit in 1988 when they began accepting requests for DNA comparisons (Using DNA to Solve Crimes, 2014).
This case started on July 25, 1984, with the death of a nine year old girl by the name of Dawn Hamilton. The story plays out as follows: Dawn approached two boys and an adult male that were fishing at a pond in a wooded area near Golden Ring Mall in eastern Baltimore, Maryland. Dawn asked the boys to help her find her cousin, they declined the adult male however agreed to help her look. This was the last time anyone saw Hamilton alive. Hamilton’s body was found to have been raped, strangled and beaten with a rock. The police collected a boot print at the scene and DNA that was found in Hamilton’s underwear. The police also relied on the witness testimonies and line-ups, which in this case was the photo array. With the five eye witness testimonies and a tip the believed to be suspect was found. Kirk Noble Bloodsworth a prior U.S. Marine with no prior criminal record was taken into custody and charged with intentional first degree murder, sexual assault and rape. Bloodsworth was basically convicted on the eye witness testimonies. The state requested the death penalty. Bloodsworth was sentenced to two consecutive life terms. (BLOODSWORTH v. STATE, 1988)
From Lydia’s case, we can see the science such as DNA testing can prove the true in a court, and it is enough to be evidence which would let people die.