Biological Evidence Paper

Biological Evidence Paper David L. Clay CJS/215 November 9, 2015 Mike Catanzarita  INTRODUCTION Crime scenes are the start to any criminal investigation, therefore the preservation of that scene is crucial when collecting biological evidence. The process of collection and intel’s the systematic process of gathering and documentation until it has reached the destination of the lab through the chain-of-custody recorded process. Biological Evidence Paper Biological evidence can control an outcome of a crime and catching the culprit. With the evidence provided, crimes can be solved and criminals can be properly convicted. Without such evidence it may be easier for perpetrators to get away with the crime. Samples of this evidence are needed for testing and are utilized for DNA profiling. Biological identification may also be needed to identify a victim of the crime. Anything that is gathered at the crime scene will be handled carefully and preserved for later use if necessary. Most evidence can be found on the victim’s body if other traces are not available. When examining a crime scene all potential pieces of evidence should be collected and taken in. Pictures of the scene will also assist with remembering where your evidence was placed. Hair and blood have been found at a crime scene. At first, it is hard to tell who the hair and blood may belong to. Loose hair and splatters of blood are collected to pursue testing. The hair found does not have the same color as the victims’ hair, but was found near the body, on the floor. This could possibly be a follicle that had previously fallen off of a quest prior to the murder. Several batches of blood cover the walls and each are swapped and bagged for DNA testing. This may help identify the victim, if he/she can’t otherwise be identified. Or this may give information of who was involved in the crime. Biological evidence is evidence that can be tested through DNA mapping and other profiling methods. Each specific type of evidence, whether it be saliva sample or semen sample, needs special techniques in acquiring and preserving in order to avoid cross contamination. These types of evidences are cross examined with a suspected person to either exclude them or prosecute them for the crime. In this paper I will discuss the different types of evidence and how it is preserved when it is obtained from a crime scene. Different Types of Evidence a forensic team might encounter different types of evidence at a crime scene. (BCA, 2015) It is on the team to handle and ensure the proper transportation of that evidence to the laboratory. There are different teams assigned to a specific type of evidence. Some are in charge of ballistics for example, while others handle blood stains. Different crimes may present different types of evidence to look for. In a sexual assault case, investigators may be looking for bodily fluids or hair samples. Blood is a very good source of evidence. The DNA can be extracted from the blood and help narrow down suspects. The way the blood spatters are found in the crime scene can help investigators piece together the events of the crime. This is why it is important to correctly document and handle it while avoiding cross contamination. Forensic scientists are faced with either dried blood or wet blood. Different methods of extracting the blood sample sometimes depends on the location of it. Each hold their advantages and disadvantages in their approaches to retrieve the best quality of samples. Biological Evidence Pertaining to dried blood stains, different methods are required to retrieve a good sample. One method is “tape lifting” bloodstains by placing fingerprint tape over the area and with some type of blunt object, rub it and be able to lift a print. (Bureau of Criminal Apprehension, 2015) Keeping biological evidence readily available that has been adjucated from a case that has been unsolved holds the benefits for all who are a part of the criminal justice system. Since the power of DNA identification evidence is identified and it is clear and visible that the ability of crime-solving has a great potential in the marginal evidence of the biological from the crime scene. Therefore, it is up to each state where they should consider implementing and making policy on the time limits that evidence should be kept according to the type of crime that is involved. Policy and procedures should be monitored and followed in order for preservation and completeness is accomplished. When securing biological evidence it is very important not to place the evidence in a closed container because the moisture could cause bacteria and contaminate the evidence. To prevent bacteria growth the swab should be dried; if the swab is not dried it should be placed in a breathable paper envelope. Evidence should barley be handled to minimize potential contamination or cross-transfer. Gloves should be changed every time when collecting samples from different sources. Every item should be packaged separately to prevent cross contamination. Loose trace evidence from clothing should be collected prior to handling. If the clothing is damp they should be air dried and stored in paper bags. If the clothing contains biological evidence it should be stored frozen. All biological evidence should be treated as infective material. Refrain from touching your face. After dealing with evidence the gloves should be properly disposed and hands should be washed with germicidal soap. Certain procedures need to be followed when evaluating a crime scene. Not only is it important to follow these guidelines for evaluation but also for preservation and collection of physical evidence, procedures for securing and searching the crime scene, and methods of recording the crime scene. Photographing a crime scene can provide documentation and permanent record for the crime. An investigator should produce instant and high quality images, including a description with each photo (A Guide to Death Scene Investigation: Evaluating the Scene, 2009). It is very important not to remove or move anything at the scene of the crime. This could severely harm the process and the possibility of collecting good data. Whoever is taking the pictures should start with taking one with the whole area. After that, smaller areas can be photographed to show more detail. Different angles can be helpful when showing evidence location. When evidence is photographed it is important to show a scale of how large or small the item may be. For example, setting a pen beside a blood stain can show how many inches long or wide the splatter is. When writing a descriptive documentation of the crime scene be sure to include what the item is, where it is located, what size it is, how much it weighs, different patterns of footsteps or blood, and other characteristics of evidence found. Be sure to take note of any smells, the lighting in the area or room, and the temperature (Layton, 2015). Conclusion The preservation of the evidence is complete once the chain-of-custody records of documentation have been properly handled. When evidence is been put into storage it is preserved until the time of analysis of that evidence is needed. Crime scenes hold all the evidence necessary to start an investigation through the process of eventual prosecution of the offender. Reference Bureau of Criminal Apprehension (2015) Biological Evidence Retrieved from https://dps.mn.gov/divisions/bca/bca-divisions/forensic-science/Pages/forensic-programs-crime-scene-biol.aspx U.S Department of Justice (2009) A Guide to Death Scene Investigation: Evaluating the Scene Retrieved from file:///C:/Users/David/Downloads/167568.pdf BIOLOGICAL EVIDENCE PAPER 8 Running head: BIOLOGICAL EVIDENCE PAPER 1