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Recovering trace evidence on a crime scene
Processing of crime scene evidence
The history and development of law enforcement
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Unsolved cold cases such as murder and rapes, allow violent offenders to remain in society. Often times at crime scenes, the offender has deposited some biological evidence within the scene. At all crime scenes, the most reliable evidence tying an offender to the scene is physical evidence, such as biological material, skin, hair, blood and other bodily fluids. This biological evidence left behind by the offender is the key piece of evidence to identify and apprehend an offender. Prior to the advancements in DNA identification technology and databases, cases of murder and rape remained opened and unsolved due to biological evidence was unable to be processed for a DNA profile. In the mid-1980s, DNA testing emerged as a crucial process in determining a genetic profile of biological materials found at crime scenes. The genetic profile could then be compared to known persons to confirm or eliminate the person as an …show more content…
Within the past few decades, the advancement in DNA processing and databases such as Combined DNA Index System (CODIS) has allowed law enforcement to re-examine biological evidence in cold case files in the hopes of identifying and capturing violent
As we learned this week, DNA databases are used by various governmental agencies for several different purposes. We all have seen new magazine shows such as, 20/20 or Dateline, that show the collection of DNA samples from suspects in a case that is compared to those collected at the scene of the crime. But what happens when the sample is an incomplete match, compromised, or contaminated? The answer is the wrongful conviction of innocent citizens. The case that I have decided to highlight, is the wrongful conviction of Herman Atkins. In 1986, Atkins was convicted of two counts of forcible rape, two counts of oral copulation, and robbery in the state of California. It was alleged that Herman entered a shoe store, and raped, beat, and robbed a
The National DNA Index (NDIS) contains over 8,483,906 offender profiles and 324,318 forensic profiles as of June 2010 (Federal Bureau of Investigations, 2010). It has been suggested by Froomkin, a Senior Washington Correspondent, that the FBI is “shifting its resources from forensics to feeding the database” (Froomkin, 2010). This dramatic shift curtails some of the benefits of the CODIS application to the criminal justice system, as the backlogs of DNA samples increase and the statutes of limitations grow nearer and nearer on unsolved crimes.
. 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, there has been a large number of individuals released or convicted of crimes based on DNA left at the crime scene. DNA is the abbreviation for deoxyribonucleic acid.
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.
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.
Crime is a common public issue for people living in the inner city, but is not limited to only urban or highly populated cities as it can undoubtedly happen in small community and rural areas as well. In The Real CSI, the documentary exemplified many way in which experts used forensic science as evidence in trial cases to argue and to prove whether a person is innocent or guilty. In this paper, I explained the difference in fingerprinting technology depicted between television shows and in reality, how DNA technology change the way forensics evidence is used in the court proceedings, and how forensic evidence can be misused in the United States adversarial legal system.
The most important type of evidence is DNA. When DNA testing takes place, the samples are collected from the suspect and the crime scene. These evidences include hair, fingerprint, human secretions, blood, semen and other bodily fluids, are collected and sent to the lab for further investigation.
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
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...
“Advance in Forensics Provide Creative Tools for Solving Crimes.” www.ctcase.org. Np. n.d. Web. 17 March 2014.
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).
Singer, Julie A. "The Impact Of Dna And Other Technology On The Criminal Justice System: Improvements And Complications."Albany Law Journal Of Science & Technology 17.(2007): 87. LexisNexis Academic: Law Reviews. Web. 10 Mar. 2014.
Forensic science has now been recognized as an important part of the law enforcement team to help solve crimes and cold cases. The advances in technology are being used each day and we must continue to strive to develop better advances in this field. The recent discovery of using DNA in criminal cases has helped not only positively identify the suspect, but it has helped exonerate hundreds of innocent individuals. “With new advances in police technology and computer science, crime scene investigation and forensic science will only become more precise as we head into the future.” (Roufa, 2017) Forensic science and evidence helps law enforcement officials solve crimes through the collection, preservation and analysis of evidence. By having a mobile crime laboratory, the scene gets processed quicker and more efficiently. Forensic science will only grow in the future to be a benefit for the criminal justice
Gaensslen, R. E., Harris, H A., & Lee, H. (2008). Introduction to Forensic Science and Criminalistics. New York, NY: The McGraw-Hill Companies, Inc. .
Physical evidence is additionally important in every criminal investigation because too often witness accounts are sometimes biased or unreliable. Physical evidence such as trace evidence, DNA, and fingerprints may objectively attach one or more persons to a victim or suspect to a crime. Favorably, physical evidence can also demonstrate inestimable for exonerating an innocent suspect. Laboratory members and criminal investigators should perform together to resolve the biggest portion of evidence to institute the right suspect for a strong prosecution. Willingly, investigation officers should aggressively contact laboratory personnel when questions arise about the cases because DNA evidence is sensitive.