Crime Scene Evidence Contamination - Assignment Example

CRIME SCENE EVIDENCE CONTAMINATION Student’s Name Course Tutor Date Q. Discuss how effective crime scene processing can maintain evidence integrity and minimise the risk of contamination. Introduction All incidents, be it accident, crime, armed conflict, natural disaster, and other, arguably leaves some valuable traces at the scene. The main aim of carrying out investigation is to try and correctly reconstruct the nature of events, interpret the clues and facts as well as understanding the nature of the event. Due to the fragile and transient nature of such traces, their preservation and reliability of their physical integrity largely depend on the very first actions at the scene of the incident. It is therefore possible to achieve the integrity of evidence by strictly adhering to observation of a specific set of guiding principles. It is important to act with a lot of professionalism and care throughout the process of investigation. This is critical for evidence admissibility for human action, human rights inquiries, and court purposes. The fundamental value of physical evidence to avoid contamination Physical evidence refers to anything from big objects to very minute items that may be generated as part and parcel of a crime recovered either at the crime scene or at other related locations. Considering all the possible sources of information that may be available for crime investigations, for example, testimonies, confessions, and modern concept of video camera surveillance, physical evidence is instrumental and plays a valuable role. Apart from physical evidence, forensic experts have shown that other possible sources of information generally have a lot of challenges with reliability. It is therefore argued that proper recognition and handling of physical evidence can offer the excellent prospect for provision of reliable and objective information about the subject matter under scrutiny. However, it should be noted that the fundamental value of crime scene evidence that have been carefully recovered as well as preserved may be lost if maintenance of the custody chain is poor(Jackson & Jackson 2007, 43-68).Custody chain has more often than not cited as the main weak link in regard to investigations of crimes. It essentially refers to the documentation of crime evidence with great precision and accuracy so as to establish its potential connection to a suspected crime. Good planning is very critical to ensure that the subsequent processes of crime determination are achieved with relative ease. It involves gathering as much information as possible. Other significant aspects of forensic investigations planning include considering the context of the crime, nature of the crime, equipment and expertise planning, adequate management of delays in attending the crime scene by ensuring that it is appropriately protected until the arrival of experts and equipment (Jackson & Jackson 2007, 43-68). The essence of securing crime scene The potential for contamination of crime evidence generally increases as the number of personnel involved in investigations also swells up. Upon securing a scene, there is reduction of the risk of contamination.  However, questions should be asked about the events prior to securing the scene of crime. For example, the number of individuals who might have entered and consequently left without being accounted for is a source of great error. The degree of potential contamination and destruction of physical evidence, especially in public places presents a lot of nightmare for law enforcement (Jackson & Jackson 2007, 43-68).Once a crime scene has been successfully secured, there is still existence of contamination as most of them are secured by only one law enforcement officer. This can be very challenging if no provisions are made to control human traffic entering and leaving the scene of crime.  In some situations, it is totally difficult to adequately protect the scene of crime from unauthorized individuals.  The potential risk of crime scenes contamination can be effectively reduced by ensuring thorough protection of the incident scene.  Consequently, the first priority should be the determination of the crime scene dimensionality.  It is unworthy to protect something which is not in any way recognized as part of the crime scene Vij (2008, 123-129). Indoor crime scenes, owing to the fact that they occur in enclosed structures are not difficult to secure.  On the other hand, outdoor scenes are hard to secure due to the potential danger of contamination by prevailing conditions such as weather and rowdy crowds.  As a result, such types of crime scenes calls for more personnel to adequately secure and protect it.  Physical barriers are mandatory for effective definition and securing of crime scene as they are indicated as restricted to the general public and other unauthorized law enforcement officers.  In order to reduce the risk of further contamination, once a crime scene is secured, the establishment of a command post should follow suit.  Formation of a command post is essential as it limits the access of personnel to a crime scene as screening of people entering and leaving the place is thoroughly carried out (Svenson, Wendel & Fisher 1993, pp 8-15) A major occurrence of crime may call for deployment of firemen, paramedics, investigators, crime scene personnel, patrol officers, medical examiners as well as others.  All of the people involved may have the ability of interfering with the evidence, thus contamination through transfer and confiscation of evidence.  Equipment as a source of evidence contamination According to Vij (2008, 123-129).The equipment that is used in the documentation and subsequent processing of scenes of crime are also a potential source of evidence contamination.  The personnel at any scene of crime need to be well aware of the possible evidence cross contamination that can emanate from their treasured equipment.  Since examiners of the scenes of crime travel from one incident to another, they potentially run the risk of transferring biological fluid, fibers, and other things from other incidents to the new unrelated crime scene.  However, this source of contamination can be sufficiently controlled if the scene of crime personnel can decontaminate their tools of work prior to and after every scene crime.  Equipment that need decontamination encompasses, but is not limited to photography equipment, clothing, sketching equipment, note pads, and processing equipment that might be in scene of crime kits.Crime experts have demonstrated that crimes which involve numerous scenes have closely related contamination issues, more specifically if a suspected criminal or even a gang commits a number of crimes within the same period of time Vij (2008, 123-129). When there is involvement of multiple scenes, there transfer of physical evidence from one crime scene to the other can be so easy if adequate precautionary measures are not taken by the scene of crime personnel. Therefore, in case of involvement of multiple crime scenes, the mandated personnel must be very aware of the critical issue of cross contamination by taking the necessary steps to reduce chances of their occurrence.  According to Eliopulos (1993, 12-25), what should also be taken into consideration and comprehensively addressed by the crime scene personnel is the involuntary transfer of crime scene evidence from one crime scene to another.  This may be carried out by proper identification of personal protective equipment (PPE) requirements as well as a decontamination zone. Required PPE generally includes, but not limited to a mask, head cover, jumpsuit, boots, and gloves.  One of the conditions of the PPEs is that they must be disposable.  Most personnel involved in crime scene examinations wear gloves, masks and boots not only to avoid risk of contamination, but also as a precaution against biohazard exposure.  However, PPE use has been shown to be very effective in reduction of contamination potential and increase the investigative value of some evidence, most notably biological that may be may be further analysed by forensic DNA laboratories. In order to reduce chances of cross scene contamination, it is imperative to establish a decontamination zone.  This is a safe area where crime scene PPE and equipment can be safely removed, cleaned, and properly disposed.  It should be noted that decontamination zone may vary from one crime scene to another.  For example, at a burglary crime scene, the zone of decontamination may simply be a safe area for passage of residence and also a possible place the residence where crime scene equipment can be placed Eliopulos, L.N., (1993), By having supplies and equipment in one area, the chances of contaminating other scene of evidence is considerably minimized. In a chaotic crime scene abundant with biological fluids, scene of crime personnel should take ultimate care not to transfer bits of biological fluid from their footwear to other parts of the crime scene.  Apart from contamination issues, biological fluids are known to create issues of safety. Prevention of packaging and collection. Crime scene evidence is normally packaged to prevent contamination and further destruction.  It is recommended that new packaging containers should be used put every piece of evidence.  Sterile packaging material may be required fro some crime scene evidence.  The equipment used for packaging should also be free of contaminates.  This is ensured by keeping all supplies of packaging in one container and careful handling from one crime scene to another. Containers with evidence must be properly sealed at the scene of crime (Eliopulos, L.N,1993), This is a necessary measure to the potential of contamination and also keeps intact the integrity of the scene of crime evidence intact.  Containers should also be properly sealed and marked for easy identification.  Conclusion In conclusion, contamination of evidence has been an issue of concern to forensic and law practitioners. However, if crime scene evidence is collected in a proper way, carefully packaged and subsequently handled correctly from transportation to storage, and procedures of decontamination are followed, definitely, the potential risk for contamination will be minimised. The potential impact of a contaminated scene of crime is therefore putting forensic experts on toes to ensure efficiency in the outcome of any criminal investigation. Bibliography Eliopulos, L.N., (1993), Death Investigator’s Handbook: A Guide to Crime Scene Processing, Forensic Evaluations and Investigative Techniques, Paladin Press, Boulder, Colorado. Jackson, A.W & Jackson, M.J, 2007 Forensic Science. Prentice hall. Svenson, A., Wendel, O., & Fisher, B.A.J., (1993), Techniques of Crime Scene Investigation, Elsevier Science Publishing Company, Inc., New York, New York 10017. Vij, K (2008), Textbook of Forensic Medicine and Toxicology: Principles and Practice. Elsevier India.   Read More