Forensic Science as a Very Important Element in Law Enforcement and Administration of Justice - Report Example

The evolution of forensic science can be traced to thousands of years ago. Fingerprint technology is amongst the firsts applications of forensic science. The ancient Chinese people were the first people to use fingerprint technology for purposes of identifying important business documents. In 1892, Sir Francis Galton managed to come up a system of classifying fingerprints of people. In 1896, Sir Edward Henry, who was the police commissioner of London Metropolitan developed his own system of classifying fingerprints which was based on the flow, direction, and pattern of an individual’s fingerprints. This classification by Sir Henry Edward is the standard upon which the current fingerprint technology is based. Henry Goddard, a member of the Scotland Yard detective managed to conduct a physical analysis for purposes of connecting a bullet to the gun used for murder, and this happened in 1835 (Bell, 2012). The examination of bullets became more common during the periods of 1920s, with the development of comparison microscope by Calvin Goddard. This greatly helped in determining the type of bullets that emanated from shell casings. The use of electron microscope in detecting gunshot residue began in 1970s. This was an efficient method of linking the gun used through an analysis of the gun powder produced during the act of committing the crime. Other than the use of electronic microscope, it is important to denote that there are a variety of chemical methods that can be used to analyze evidence (Shelton, 2012). These chemical techniques are always used to identify the elemental composition of a solid or a liquid. This paper identifies chemical techniques of forensic technology under three main categories, namely; Forensic Drug Testing. Forensic Arson investigation and paint analysis. Murder investigations. Under forensic drug testing, forensic labs are greatly used to identify unknown drugs. There are two types of tests that can be conducted, namely presumptive tests also referred to as color tests, and confirmatory tests. Presumptive tests are always used to identify the type of chemical or substance that is available in a specimen. However, they cannot identify a particular substance (Shelton, 2012). On this basis, there is always a risk of developing a conclusion which is not correct. In as much as presumptive testing cannot identify a particular substance, it is always used for purposes of identifying whether there is saliva, semen or blood in a crime scene. On this basis, presumptive tests are always used for purposes of identifying the nature of body fluids present in a crime scene. However, there is always a need of conducting further tests to identify the particular nature of substance. Presumptive tests are always easy to carry out, inexpensive, safe, and normally require little amount of specimen to conduct the tests. Examples of presumptive tests includes the marquis regent tests which is aimed at testing for the presence of drugs. Under this test, the chemicals which are used are the concentrated sulphuric acid and formaldehyde. Drugs such as morphine, heroine and those that contain opium will always turn the solution into purple color (Ubelaker, 2013). Drugs which contain Amphetamines will always turn the solution into an orange-brown color. Another test is the cobalt thiocynate test which is used for testing the presence of cocaine in a substance. In this test, the chemicals used are cobalt thiocynate, glycerin, distilled water, chloroform and hydrochloric acid. The substance that contains cocaine will always turn blue. Another presumptive test includes the ultraviolet spectrophotometry. Under this test, a researcher will seek to analyze the manner in which a substance will react to a ultra-violet ray, and an infrared light. A machine referred to as spectophometry is used to emit infrared lights and ultra-violet lights. It thereafter measures how the sample gives a reflection of these rays. This is for purposes of gathering the general idea of the nature of chemicals present in the substance. Confirmatory tests on the other hand are used to identify a particular substance. This process is advantageous because there is always a smaller of coming up with a conclusion that is not right. However, this process is disadvantageous because it is very expensive and it takes a longer time to achieve results (Engdahl, 2010). An example of a confirmatory test includes the mass spectrometry test. Under this test, a scientist will isolate the drug from substances that are mixed with it. This method involves a scientist injecting a small portion of the mixture into chromatograph. Molecules will move into the columns of the chromatograph at different speeds, basing on their densities. This substance is then passed to a mass spectrometer, which is then hit by an electron beam. This makes the substance to break, and upon examination of the particles, scientists can tell what type of substance it is. Under the arson investigation and paint analysis, there are a number of techniques that forensic experts can use to identify the chemical substance used (Ubelaker, 2013). Investigators usually analyze paints in case of a road accident, and some chips of the automobile involved in an accident remains. It is this chip that investigators will try to analyze the paint used for purposes of getting an idea of the kind of automobile involved in the accident. The first technique under discussion is the solvent test. This test is always used in analyzing the type of paint used in specimen evidence. Under solvent tests, a scientist will use chemicals for in a mixture for purposes of analyzing the reactions, softening and color changes of a substance (Ubelaker, 2013). This method is cheap and easy to use. However, this method is disadvantageous because the risks of coming up with a wrong solution are high. This is because it cannot identify a particular paint substance, but will make presumptions. The next method of paint analysis is Fourier Transform Infrared Spectrometry. Under this method, scientists will analyze the manner in which pigments of paints absorb infrared light. This method manages to identify a particular paint chemical, and on this basis, it is reliable (Engdahl, 2010). However, this method is very expensive because it requires machines in order to achieve results. Mass Spectrometry on the other hand is used for purposes of identifying paint substances that have a similar color, but are characterized by different chemical composition. In this process, the sample of the paint comes under heat, until its fragments break. This paint sample is then separated into various components for purposes of analysis. This process is disadvantageous because it cannot identify a particular paint substance. In analyzing evidences of arson, scientists would need to find the substance used to start the fire. The techniques used are passive, dynamic and static headspace. These techniques are easy to use and reliable. This is because they are able to identify a particular flammable liquid used to start the fire. There are also some chemical forensic techniques that can be used to solve murder cases. It is important to denote that in crime scenes of murder, there is always a wealth of evidence which range from the human hair, human blood and shell casings. For purposes of detecting chemicals produced during a gunshot, forensic experts will use the Greiss Test. This test is easy to use, and it enables scientists to have a clue on the kind of chemicals produced when a gun is fired (Shelton, 2012). However, chances are high that forensic experts can come up with a wrong conclusion. Sodium rhodizonate and dithioxamide can also be used to detect these chemical substances found on a residue of a gunshot. For purposes of detecting body fluids such as semen, saliva and blood, there are a number of forensic chemical tests available. To detect semen, forensic experts use the acid phosphates test. If the solution quickly turns to purple color, then semen is available in the evidence collected. This test is easy to carry out and it takes a little time for the results to occur. However, chances are high that scientists can come up with a wrong conclusion; hence further tests are needed to confirm the presence of semen in evidence (Barrett and Kippert, 2010). To test for blood, the Kastle-Meyer test is always used. This test uses a chemical referred to as phenolphthalein. This chemical is colorless, but when it is introduced in blood, it normally changes to a pink color. Luminal is also another test for blood, and it is always spread all over a room for purposes of detecting even small portions of blood. These two tests are easy to conduct, very cheap, and results usually come out within a short period of time. The only disadvantage with these tests is that they require a series of other tests to confirm whether the substance is actually blood, or another type of liquid. The following table is an analysis of the various tests required under the given samples, and their justification. Samples Tests Justification of the tests Liquid Sample that is dissolved as a single element, e.g. lead. The best way of accurately identifying the presence of lead is the use of potassium dichromate. Under this method, an expert will make the lead solution to be neutral, thereafter; he will add some two drops of potassium dichromate into the solution. The scientist will mix the solution, and the emergence of a yellow precipitate is an indication of the presence of lead iron into the solution. This is an accurate process of determining a single element such as lead in a sample. It is also easy and cheap to use. The scientist will also get the results immediately, and this is because it does not take time for the solution to change its color. Liquid Sample for the identification of a variety of chemical elements. The use of mass spectrometry or gas chromatography can be used in this process. This process has the capability of breaking the molecules of an element into tiny substances. The way these substance break can therefore tell which particles they are. Paste sample where there is a need of identifying a single element, e.g. Arsenic The best method of accurately identifying a paste sample with a single element is through Fourier Transform Infrared Spectrometry. This method has the capability of accurately identifying aan element contained in a paste by passing it through infrared light for purposes of identifying its various characteristics. Solid sample where there is a need of sub-surface or surface elemental composition. The test required under this category is the infrared spectrometry. This method is very accurate because it uses infrared radiation to identify the chemical content and structure of a substance. This method has the capability of identifying soil, fibers or paint in a mixture. In conclusion, forensic science is a very important element in law enforcement and administration of justice. Due to this technology, investigators have been able to match evidence from scenes of crime, to that of a criminal. However, it is important to denote that in some cases, forensic technology has failed, leading to an arrest of the wrong person, or to the dropping of the case under consideration. On this basis, there is a need of hiring hire competent people as forensic experts. Bibliography: Barrett, D., & Kipper, G. (2010). Virtualization and forensics a digital forensic investigators guide to virtual environments. Amsterdam: Syngress/Elsevier. Bell, S. (2012). A dictionary of forensic science. Oxford: Oxford University Press. Engdahl, S. (2010). Forensic technology. Detroit: Greenhaven Press. Shelton, D. E. (2012). Forensic science evidence can the law keep up with science?. El Paso: LFB Scholarly Pub. LLC. Ubelaker, D. H. (2013). Forensic science current issues, future directions. Chichester, West Sussex: Wiley-Blackwell. Read More