Understanding Forensic Science - Assignment Example

 Understanding Forensic Science Section A 1. Forensic palynology is the use of evidence from pollen and spore in legal cases. In broad application, it also covers other microscopic organisms such as chitinozoans and acritarchs (Byrd, 2005). The use of pollen grains in investigation has been used to link suspects to crime. They are an important tool and work out because of three major reasons. First, each geographic region produces unique pollen which links the suspect to the exact location. Second, plants that are wind pollinated disperse pollen grains and high chances are that they will fall next to the source and thirdly, those that are insect pollinated don’t get dispersed off to far places. For instance, a suspect or an item could be linked to a geographical location of the crime or scene or a suspect or a victim’s possession linked to a primary or secondary crime scene. Palynology can also determine the season in which a crime was committed (Byrd & Castner, 2001). 2. Soil also plays an important role in criminal forensic investigation. It is largely used in physical, chemical, biological and ecological analysis. Most importantly, it helps in site identification and in reducing areas of search. The samples enable links to locations thus helping in connecting them to the suspects. For example, soils are easily characterised by their difference in colour, texture, density, chemical components and particle size among other things which help them linking suspects to crime (King, 2003). 3. The use of insects and other insects in evidence is called forensic entomology and can be used to estimate the time of death of a body. The investigators study the insects and the other arthropods that inhabit the decomposing remains which they later use to estimate the time of death. There are two main methods used. The first is the use of developmental rates which determines the temperatures of the first insects to inhabit the dead body (Boyd, 2006). The second method analyses the changes that occur in the successional character of the insects over a period of time and is mostly used between three weeks and one year. The limitations with the methods is that the information becomes diminishing with time therefore becoming less valuable. 4. Bioweapon is a term derived from the word biological weapons and means weapons made out of living organisms can cause harm to people, to crops and to animals (Byrd, 2005). The micro organisms used range from bacteria, fungi to viruses. On the other hand bio terrorism is the act of terrorism that involves intentional releasing of biologically processed agents that are toxic and harmful to people, either for a political or any other cause. Recently, bioweapons have been confirmed used. For instance in the case of Rajneesh cult in 1984 where the united states was accused of putting salmonella typhimorium in hundreds of foods made in an Oregon salad bar and also in the 1993 Japanese cult of Aum Shinrikyo where they sprayed anthrax from a rooftop. The Japanese group had spent four years trying to make pathogenic biological agents (King, 2003). 5. DNA analysis includes the use of human fingerprints in criminal investigation in order to adduce evidence that can be used in criminal proceedings. The typical forensic procedure involves comparing the genetic patterns of the samples from the evidence collected and the samples from the suspect (Byrd & Castner, 2001). The current methods of DNA analysis used include restriction fragment length polymorphism(RFLP), polymerase chain reaction (PCR), short tandem repeats (STR), and amplified fragment length polymorphism (AmpFLP) (Byrd & Castner, 2001). 6. Notably, the principle of chromatography in forensic science refers to the laboratory techniques that separate mixtures of chemicals into their individual compounds. It is widely known as gas chromatography. The principle is used in forensics to analyse body fluids such as saliva or blood from a crime scene thus helping in linking a suspect to a crime (Ogle, 2005). It enables forensic scientists to identify a murder suspect simply from a laboratory analysis of a blood stain obtained from a crime scene. SECTION B 7. At most of burglary scenes, a well planned order of examination has to be followed. Lack of this destroys the evidence and may be detrimental to the prosecution case. The investigators ought to adhere to the following order. First, there is need to secure the scene which is always the responsibility of the officer that responds the first. Next, separating the witnesses must be the next priority since they should not be allowed to talk to each other. The scene then needs to be scanned for purposes of determining a primary or secondary crime scene. Seeing the scene must be the next priority which also includes taking photos of the scene of burglary. A sketch of the scene then ought to be drawn and lastly followed by securing and collecting the evidence (Ogle, 2005). The Locard exchange principle, developed by Edmond Locard in the simplest form dictates that once there is any form of contact between two people, an exchange certainly occurs. The perpetrator always has to leave something behind with the victims or the objects there and at the same time taking something with him. The suspect may leave fingerprints, hair, skin, blood, footprints, body fluid or even pieces of clothing (Boyd, 2006). This is particularly relevant in linking a suspect to a crime. 8. Officers face a number of issues when trying to identify a person from a photograph or a digital image. The photographs may not be exhaustive, they may fail to show the actual distance and may also be distorted in the process of shooting or processing. On the other hand, the issues faced in identifying fingerprints are that the person may hardly leave behind evidence if they were precautious enough and that the process is neither quick nor cheap (Byrd & Castner, 2001). 9. Nonetheless, glass bottles containing 2cm of clear liquid recovered from a crime scene could be taken to the laboratory for analysis. Mostly, glass bottles containing such portions are associated to poisoning and special attention is crucial at the time of the post-mortem examination in which the tissues and the other organs of the victim suspected to have been poisoned are preserved for further examination. 10. Subsequently, pharmacokinetics refers to the study of what the body does to drugs, once they are swallowed. Every drug affects the body in its own unique way because of their different levels of violability. Once a drug has entered the body, it goes through four different stages. These are the absorption into the blood. It is then distributed throughout the body. Next, the drug goes through metabolism in which it is broken down into small elements. Finally, it is then excreted from the body (Byrd, 2005). 11. The national DNA database is used by law enforcement agencies to identify the suspects of crime. It stores DNA profiles of those that have been suspected or convicted of crime. It however raises some ethical concerns. For instance, it has been argued that it does not uphold the privacy of citizens. If it is open to everyone, the information could be misused or even used to frame innocent civilians. Another ethical issue is that the database could expose personal information in malicious ways. Furthermore, others argue that its inaccuracies may lead to the conviction of innocent citizens which is not an element of the justice system (Byrd & Castner, 2001). 12. Lastly, drug abuse is the wrongful use of drugs for a wrong purpose. It is a pattern of consuming drugs in a pattern that is harmful to one’s health. The Misuse of Drugs Act legislates against drug abuse by preventing non-medical use of certain drugs. The drugs are divided into three classes. Class A has cocaine, ectasy, heroine among others. Class B includes all cathinone derivatives and class C has steroids, minor tranquilisers and other lesser drugs. The Act makes it an offense to possess the drugs, possessing with intent to supply, supplying or allowing ones premises to be used for drug consumption (King, 2003). Section C Q1.The use of insects Insects are used to determine the time lapse of the corpses. Insects feed on decaying matter and algae. They show an evidence of the corpse have been moved from the first scene to the second scene either by the killer or by the animals (Centano 2002) They help in uncovering crime scenes according to the interest of the law administrators. Since most of the insects are mostly involved in feeding on dead bodies, they create a wider knowledge to providing evidence to murder to crime scenes. At crime scenes the ecological and behavioral traits of the insects provide a means to collect the data. Q2. pollen as forensic In forensic science pollen grains aid in strengthening the evidence of a crime case such as murder. Pollens are highly recommended because they are highly durable and they remain preserved for long in the deposits d are not susceptible to being destroyed. Some pollen is reduced in small amount hence the best is found in the forensic sample and the error of contamination by the other factors to alter the evidence is eradicated (Mildenhall 1992). There emergences a weakness in production of low amounts since the chances of pollen being used as forensic sample are minimal. Q3. high performance liquid chromatography The basic components include the mobile phase reservoir, pump, injector, detector, and the data system. They are the components that bring the uniqueness and the performance of HPLC. The mobile reservoir is connected to the pump inlet and also is used to remove the dissolved air. Pumps force the solvents for faster analysis and therefore their flow rate is stable to feature the uniqueness (Shen 2002) The injector continuously introduces the sample into HPLC column. The detector distinguishes the separated bands as we cannot see some compounds with our nake3d eyes. Lastly is the data system which ids in the analysis which can be stored in computers for retrieval. The mechanism of Reverse Phase HPLC is the experimental design which perfects the separation by establishing equilibrium. Q4.Types of earth materials The forensic geologist identifies rocks, minerals and soil as the types of earth material that aid in legal matters. A sample of soil found on one’s body can be used to provide strong evidence against a rape or murder case. Also the analysis which has been used against a suspect who had no connection with the incidence can set the suspect free if the samples do not match. Studying the properties of rocks used in the crime scene aids investigators to trace the area where the crime occurred. Identifying the chemical concentration in the water help the geologist to know that exactly contaminated the water. The analysis contributes a lot to specific science investigation since it helps to connect between the suspect, a victim, the crime scene and the gadgets that were used (Croft 2004) Q5. Bacterial counting and identification techniques There various techniques used in identification of bacteria’s. The commonest way is through the use of microscope but it is time consuming. They can also be identified by use of their metabolic reactions since they react differently when subjected to different environmental conditions. Bacterial counting techniques include the counts in solid media and counts in liquid media (Horwitz 1995) Plate count is the most commonly used in solid media and there is identification of colonies which must be separate for the technique to be applicable. In liquid media the end product are examined and enumeration carried through a process to obtain the count. Q6. History of DNA fingerprinting The history of DNA fingerprinting can be traced back in the early years where it was first used in the forensic science improving the evidence of the strangled girl and also in proving that a boy was a son of the citizen of Britain. A case in the United States of Tommie Lee used the new technology of DNA analysis in proving that he had assaulted a woman. The new technology shows that the possibility of this DNA analysis proving evidence is true or false (Coleman 2003) References Bevel, T., & Gardner, R. M. (2008). Bloodstain pattern analysis: with an introduction to crime scene reconstruction. Boca Raton, CRC Press/Taylor & Francis. Boyd, A. E. (2006). Plants &Amp; Perpetrators: Forensic Investigation in the Botany Classroom. The American Biology Teacher. 68, e145-e147. Byrd J.H (2005). Forensic entomology. S.l, http://www.forensic-entomology.com. Byrd, J. H., & Castner, J. L. (2001). Forensic entomology: the utility of arthropods in legal investigations. Boca Raton, CRC Press. Centano. (2002). Seasonal patterns of arthropodsoccurring on sheltered and unsheltered pig carcasses in BuenosAires Province. Forensic Science International , 63-70. Coleman. (2003). DNA in the courtroom. A trials Watchers Guide . Croft. (2004). Multi-technique comparison of source and primary transfer of soil samples. Science and Justice , 21-28. Horwitz. (1995). Protocol for the design, conduct and interpretation of method performance studies. Pure Application in Chemistry , 331-343. King, L. A. (2003). The Misuse of Drugs Act a guide for forensic scientists. Cambridge, Royal Society of Chemistry. http://books.google.com/books?id=qqebAAAAMAAJ. Mildenhall. (1992). Pollen plays part in crime-busting. Forensic Focus , 1-4. Ogle, R. R. (2012). Crime scene investigation and reconstruction. Upper Saddle River, N.J., Pearson Prentice Hall. Platt, R. (2003). Crime scene: the ultimate guide to forensic science. New York, DK Pub. Ritz, K., Dawson, L., & Miller, D. (2009). Criminal and Environmental Soil Forensics. Dordrecht, Springer Netherlands. Shen. (2002). Electrophoresis. 3106-3124. Read More