Proteins are considered as macromolecules because of the size of such a molecule. These proteins are combined in a long chain of a polymer that are put together by building blocks of amino acids and forms a polypeptide. There are 20 different amino acids that encode for proteins. Proteins are produced in the organelle called ribosomes.
Gene sequencing made use of different markers in the DNA to set-up the linkage map. These markers can be genes, RFLP’s (restriction fragment length polymorphism), STR’s (short tandem repeat). RFLP’s occur when a sequence change takes place in a restriction enzyme and thus changes the length. STR’s are tandem repeated sequences in the DNA and are usually 2-5 base pairs long. The number of repeats in each person is unique and thus gives it a polymorphic feature. Euchromatic DNA can now be sequenced with a 99.99% accuracy after the Human Genome Project decoded the whole genome [9].
2.2. Evidence at crime scene and their DNA
“Every contact leaves a trace”, a very well-known statement by Edmond Locard, known by most forensic scientist. Scientist have to search the scene of a crime for physical evidence of a suspect to link this person to the crime [1]. The intelligent use of your eyes and nose along with judgement and common sense will attribute to the findings of evidence at a crime scene [1].
To make evidence useful at a crime scene, it must be unique to a person [10]. This can then be used as conclusive evidence in a case and carries more weight as evidence [4]. Reconstructing the scene of crime will be helpful when examining the distribution of evidence. The time a material is adhered to another by transfer, named retention time, is also critical for evidence in a crime [10].
Physical fits and b...
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...aterial. The material that is being transferred will have a greater effect when it has a high adherence property [10].
Evidence that contains DNA can be used to produce a DNA profile [10]. These include hair, sweat, skin, saliva, semen, blood, urine, feces, and so forth [10].
2.3. Recovery of DNA from crime scene
When collecting evidence at a crime scene, it should be packaged separately and in a paper bag or envelope [10]. Each sample or evidence piece has to be clearly marked so that is can be recognized when it enters the laboratory. When you have to take a wet sample, it should firstly be dried and then packaged. Tests can be performed before hand to ensure the sample is truly what you think it is. Presumptive tests have been developed for blood, semen and saliva, to mention a few [10]. In Figure 3 is an illustration of the packaging used for evidence.
In order for evidence to be used in court, it must be collected and tested by valid methods. The collection of evidence must be completed carefully and properly to prevent cross-contaminating or destroying the evidence. Before evidence can be collected at a crime scene, the area must be secured to ensure everyone stays safe and that the evidence is not destroyed. After the scene is secured by all proper measures, the collection process can begin. The first items to be collected are those that are transient, fragile or perishable. Hair, fibers and small shards of glass are all
The book gives a general overview of the field of forensic science. The sections of the book include “The Scene of the Crime; Working the Scene--The Evidence; Working the Scene of the Body Human; Working the Scene--Different Stages; and Working the Scene--Different Skills (Genge vii-viii). Included are instructions on what professionals should do upon arriving at a crime scene, what items to bring with them, how to protect the crime scene, and how to protect the evidence from contamination. In addition to writing about the subject of forensic science, the author also included several appendixes and suggested readings to help the reader learn even more information about the subject. In addition, the author included a list of colleges that offer programs in the field of forensic science.
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
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.
Crime scenes are known to have many clues left behind. The obvious would be a the body or bodies, clothing, and sometimes even the murder weapon. While these are great way to solve a case there's another kind of evidence; trace evidence. Trace evidence are small pieces of evidence that are laying around a crime scene. There are many types of trace evidence some of them include metal filings, plastic fragments, gunshot residue, glass fragments, feathers, food stains, building materials, lubricants, fingernail scrapings, pollens and spores, cosmetics, chemicals, paper fibers and sawdust, human and animal hairs, plant and vegetable fibers, blood and other body fluids, asphalt or tar, vegetable fats and oils, dusts and other airborne particles, insulation, textile fibers, soot, soils and mineral grains, and explosive residues. Although these are the most common found elements, they are not the only ones. The Trace Evidence Unit is known to examine the largest variety of evidence types and used the biggest range of analytical methods of any unit. materials are compared with standards or knowns samples to determine whether or not they share any common characteristics. In this paper I will discuss the different kinds of trace evidence and how crime scene investigaros use it to solve cases and convict criminal.
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...
Forensic Science, recognized as Forensics, is the solicitation of science to law to understand evidences for crime investigation. Forensic scientists are investigators that collect evidences at the crime scene and analyse it uses technology to reveal scientific evidence in a range of fields. Physical evidence are included things that can be seen, whether with the naked eye or through the use of magnification or other analytical tools. Some of this evidence is categorized as impression evidence2.In this report I’ll determine the areas of forensic science that are relevant to particular investigation and setting out in what method the forensic science procedures I have recognized that would be useful for the particular crime scene.
Collection of evidence is usually a term designated to refer to the collection of physical evidence, government agencies such as police or environmental protection departments will have their own methods for the collection, storage and conservation of physical evidence and it is the responsibility of forensic personnel to adhere to these set guidelines. General principles which are shared amongst various agencies include, the creation of contemporaneous notes, recording the collection of evidence via photographing, videotaping and/or audiotapes, preserving the crime scene by sealing off the location and only allowing designated personnel to enter, avoiding contamination of the crime scene by investigators through the use of full body covering and also preventing cross-contamination with the scene and any suspects.
In today’s time, modern Crime Scene Investigation has increased rapidly. From throughout the late 1900’s and in the early 2000’s (Taylor 1). For all of the evidence that they find, a solid foundation has formed over the thousands of years of Crime Scene
In addition to, all criminal justice parties including lawyers, law enforcement officers, and forensic science analysis should be positive that the biological evidence has been properly stored, preserved, and tracked properly to prevent contamination. Biological evidence custodians require paying close attention to the evidence labeling and packaging, that way the evidence can efficiently locate from one location to another without degradation being
The transitional growth in the forensic science sector has not been without challenges. Though the world has experienced increased capabilities and scientific knowledge, which has led to faster investigations and results, many forensic experts have argued that forensic laboratory testing, in the light of 21st century technological advancements, is yet to meet the expected rate in quick available testing and analysis (Mennell & Shaw, 2006). This is with respect to the growing rate of crime and the high demand of quick crime scene testing and analysis. In the science of crime scene, analysis and interpretation of evidence is majorly dependent on forensic science, highlighting the change in the role of forensic sciences (Tjin-A-Tsoi, 2013). In the business of forensic science, time is beginning to play important role in the evidence testing and analysis which is becoming crucial in reducing ...
Collecting evidence from a crime scene is a crucial aspect of solving crimes. Before evidence can be seized, there must first be a court order approving the search of the crime scene and the seizure of the evidence found at the scene. Standard protocol for officers is for them to always use latex gloves, avoid plastic bags, double wrap small objects, package each object separately, and to collect as much evidence as possible. It is better to have too much evidence than to not have enough. There are countless amounts of evidence that can be found at a crime scene.
Forensic science has paved the way to a new world of technological advancements in solving crime, through DNA analysis, new technology such as M-Vac, improving systems such as CODIS and other investigative methods. As forensic science technology advances, the chance of an individual being able to commit a crime and walk away free without leaving any trace of evidence will lessen. While forensic science has its limitations, it can be the only way to provide an accurate account of what actually occurred at some crime scenes.
methods when examining crimes scenes or looking at evidences in labs then many cases would be lost in