Forensic Investigation Assignment- Role and responsbility of SIO during major incident and discuss types of impression evidence during examination of crime scene. PDF

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Discuss the roles and responsibilities of the Senior Investigating Officer during a major incident, Discuss the various types of impression evidence that can be found during the examination of a crime scene,...

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Discuss the roles and responsibilities of the Senior Investigating Officer during a major incident The College of Policing (2013) stated that “The Senior Investigator leads, as Senior Investigating Officer (SIO) for major crime investigations, accountable to chief officers for the conduct of the investigation”. SIO’s are only brought in for major incidents such as suspicious death, unexplained deaths or preplanned enquiries. A suspicious death refers to any death suspected as a result of criminal activity. An unexplained death is whereby the cause is not clear. Pre-planned enquiries include exhumations and mass raids on houses of suspected gang members. Major incidents comprise of the most serious incidents of violence and death. Due to the complexity these type of crime scenes can incorporate, it is imperative the SIO implements and documents an investigative strategy. To form an overall strategic investigative strategy, a SIO is responsible for setting out short, medium and long term objectives which ensure only appropriate lines of enquiry are pursued and avoid any unnecessary actions. Implementing a thorough investigative strategy is a key role and responsibility of an SIO in order for material to be located and gathered effectively. They must have a policy book whereby they record their plan of the investigation and set out strategic and investigative aims, which document the direction and progress of an investigation. Each strategy should be clearly explained with an objective that is to be achieved. The clear explanation will avoid a lack of focus and ensure close attention is paid to the main aims and objectives. A secondary reason which compels the SIO to hold a thorough policy book is under the unfortunate event of a cold case. Failure to locate a suspect to a major crime will mean the policy book will be taken and scrutinised, to determine if the cold case was a result of a mistake done by the SIO, such as missing material out in the investigative process. Another responsibility of the SIO is producing a forensic strategy, which sets out a clear plan detailing the resources associated with the investigation, how they are managed and whom they will be allocated to accordingly. This is recorded in their policy book. Regardless of the severity of the major crime, resources must be identified as soon as possible to determine the necessary level of investigative response. The SIO will liaise with the Scientific Management Team, Crime Team Manager and the Crime Team Coordinator to make sure they are aware of and understand the resources allocated to them and their expenditure. Setting out a forensic strategy will enable the evidence recovered during a major crime scene examination to be maximised and efficient. During the liaison with the necessary teams, it is the SIO’s role to ensure they conduct briefs and debriefs to ensure intelligence is obtained and used ethically and legally. When determining the resources required, the SIO must take into consideration the availability and cost. This responsibility of managing and allocating the budgets is vital, to ensure investigations are carried out in a cost-effective manner, and in proportion with the level of material to the crime. The SIO can supervise the performance of personnel within the investigation. For example, liaising with the forensic laboratory technicians to ensure the examination of the evidence that will be presented in court, will be the best evidence that's going to get a conviction. Evaluating the overall performance of the teams will establish the work being carried out is thoroughly completed, and in accordance with the guidelines. As well as the responsibilities discussed, there are five building blocks which define the main roles of a SIO. The first building block is the preservation of life and the second is the preservation of the scene. These combine as the SIO must preserve the scene to preserve life. The SIO is not permitted to enter the inner cordons; however, when initially arriving at the crime scene; they must ensure the perimeters of the scene are defined. This crucial role will eliminate any threat of risk or harm upon the

preservation of life. Risks that could affect the preservation of life include, media/press being involved and contamination of evidence by unauthorised personnel entering the scene. Upon attending, the SIO will liaise with the Crime Scene Manager and Crime Team Coordinators to gain an overall understanding of the scene. If there is a large crime scene, it is down to the SIO to define the parameters accordingly and ensure there are enough personnel. The larger the crime scene and the more personnel needed will mean a higher level of health and safety is required for everyone which, the SIO must establish is apparent. After liaising with the necessary personnel, the SIO will be able to estimate the duration of the scene and therefore be able to determine the appropriate level of protection required such as crime scene tents, lighting the scene and access routes. The third building block is to secure the evidence. The SIO must make sure the evidence is thoroughly secured in accordance with the correct procedure by the Crime Scene Investigators (CSI), which will be handed to the exhibit officer. This is done by keeping in contact with the Crime Scene Manager and checking that the CSI’s are being briefed properly. After evidence leaves the scene, the SIO must check the evidence is secured in a protected room that only authorised personnel have access to. The role of securing the evidence will avoid losing vital information. The fourth building block is identifying the victim. It is imperative to find and identify the victim so the investigation can progress. Once the victim has been identified, the SIO is responsible for managing a Family Liaison strategy. As stated in the Family Liasion Officer Guidance (2008): “The strategy must take into account… identifying the family; strategic objectives; selection and deployment; supporting and supervising the FLO.” The victim in a major crime can bring grave trauma to their family. This is heightened during the investigation process as the FLO’s will be asking them for information regarding the victim. Therefore, the role of creating a Family Liaison strategy must be clearly explained and ensure the FLO is compassionate, whilst remaining professional and focused on achieving the objectives set for them in the policy book. The final building block is whereby the SIOs identify a suspect. They will set out a TIE strategy (Trace, Interview, Eliminate) in their policy book regarding the major incident. This includes establishing a TIE category which comprises common characteristics e.g. geographical area, establishing elimination criteria and conducting enquiries. The roles and responsibilities of a Senior Investigating Officer at a major crime incident are extremely complex and in-depth which, must be dealt with thoroughly and documented in accordance with the correct guidelines. The SIO must yield an error-free policy book and be accurate within their work to ensure all evidence is gathered, secured and tested correctly to ensure a conviction. Discuss the various types of impression evidence that can be found during the examination of a crime scene When it comes to examining a crime scene, locating and recovering evidence is paramount. The collecting of evidence done by the Crime Scene Investigators gives a better understanding of what happened at the scene and supports the investigation into why it happened and the individuals involved. One type of evidence found at a crime scene is impression evidence. Impression evidence is when an object comes into direct contact with a surface consequently leaving behind some form of indentation or print. These impressions can leave a negative impression, whereby the donor removes residue from the recipient leaving behind a clear image of the impression on the surface, or a positive image whereby the donor deposits material onto the recipient. Impression evidence can be divided into three categories. Firstly patent impressions are twodimensional prints, visible to the eye, that are transferred onto a hard surface from material that coats

the donor such as blood on a fingertip found on a tile. Secondly, latent impressions are prints which are not visible to the naked eye but can be seen through the use of dusting or the electrostatic detection technique. The final category are plastic impressions. These are three-dimensional prints left in soft materials such as a footprint found in the snow. A problem with having a soft substrate such as snow, is that these prints can often be lost for example by melting. To prevent this, impressions must be photographed immediately. Such evidence includes fabric marks, bite marks, indentation marks, ligature marks, firing pin marks, questioned documents, lip prints, ear prints, instrument/tool marks and tyre marks. Fabric marks refer to the transfer of the pattern of the fabric onto a surface of another material. Transference “can occur from the addition of a substrate, removal of material, and/or a material being embedded” as stated by Bureau of Criminal Apprehension (2013). An example of an addition of a substrate is a muddy glove printed onto a surface. Removal of material could be a blood in an undried bloody area producing a negative image. An embedded material example could be dirt on a suspect's trousers where he has knelt down. Fabric marks are frequently found when examining burglaries, robberies and criminal damage crime scenes. This is because it is common for criminals committing such crimes to wear gloves to avoid being caught by their fingerprints. However, fabric marks are also found at murder and serious sexual assault scenes too. This type of impression has class characteristics which are unavoidable attributes that are produced during the manufacturing phase such as the fabric construction, fibre direction and stitching type. These characteristics are able to create a conclusive association between fabric and the suspected impression recovered from a crime scene. A study (Clarke 1992) defined a bite mark as “a pattern produced by human or animal dentitions and associated structures in any substance capable of being marked by these means.” A bite mark can either be compressed or scraped. A compressed impression refers to each tooth deeply penetrates the skin, leaving a clear indentation of the bite itself. A bite mark that's been scraped is caused from the teeth moving over the surface of the skin leaving a minor uneven impression. Bite marks are most commonly found when examining crimes involving sexual assault or cases involving children. Bite marks are frequently prevalent when there is food present at a crime scene. These provide a three-dimensional impression of the suspect’s teeth arrangement which can assist the odontologist in the bite mark analysis regarding who the perpetrator is. Discovering a threedimensional impression of dentition is valuable at a crime scene, as the rate at which permanent teeth develop varies from each individual and, an odontologist will be able to estimate a person’s age. When a bite mark is discovered it must be photographed imminently before the mark’s characteristics change as indentations can disappear within hours. Lip print impressions are useful discoveries when examining a crime scene in regards to the identification of a suspect. Lips have individual characteristics called grooves and furrows which are unique to each person, and do not alter during a lifetime, which provides an accurate correlation between a lip print impression found at a crime scene and the suspect. Ear prints are similar to lip print impressions in regards to having anatomical characteristics variant to each individual. This can assist in identifying a suspect. The height of the ear impression found when examining a crime scene can provide investigators with information regarding an individual’s stature. A tool mark was defined in Criminalistics: An Introduction to Forensic Science (2006) as: “ Any impression, cut, gouge or abrasion caused by a tool coming into contact with another object.” There are three types of tool mark impressions: compression, sliding and cutting. Compression impressions are whereby a tool has been pressed into a softer surface with no drag. These tend to be mirror images of the tool therefore forming a negative impression. Sliding or abrasion marks are made whereby a tool scrapes across a surface creating striations, that run parallel to each other and following the direction of the scrape. These are commonly found when examining

crime scenes of criminal damage when an individual has keyed a car. Cutting is a combination of compression and sliding. All three types have class and individual characteristics. Class characteristics include the general shape and dimensions of the tool mark. This allows the type of tool that created the impression to be used for comparison, and be determined and the question of how it was created to be answered. However, class characteristics do not always necessarily display the accurate identification of the exact tool used to create the impression as, for example, if a burglar has used a specific tool in seven different burglaries, defects and imperfections are going to have formed on this tool thus impressions made in the first crime would not correlate with the tool marks made at the seventh crime scene. The presence of any imperfections on a tool shows individuality to that tool which is known as individual characteristics. The history of the use and maintenance of that tool will create these imperfections and defects which can include indentations, striations and ridges. Individual characteristics can positively help identify the use of the actual tool that created the impression thus possibly linking to a perpetrator. Tool marks are most commonly found when examining crime scenes such as burglary where forced entry is involved. Serial numbers are often either stamped or printed on the product itself. These can be recovered and used as evidence. Tyre marks are impressions left on the surface which a vehicle has driven on. Tyres can leave patent, latent or plastic impressions. Patent impressions occur when a vehicle drives through a liquid material such as blood leaving a two-dimensional tyre mark. Latent impressions occur from the oil used to soften the tyre. Plastic impressions are three-dimensional impressions left in soft surfaces such as mud. Tyres are all made from rubber but categorised by class and individual characteristics. Class characteristics refer to the manufacturing production of the tyre such as the general size, tread design and dimensions. Individual characteristics refer to imperfections unique to each tyre resulting from any damage such as cuts, cracks or the wear and tear consequent from the use of the vehicle. The tread design found on tyres refers to the manufacturer’s unique design in forms of ridges and grooves found on the tyre. These provide traction for the vehicle as it displaces water and can be displayed in the impressions left by the tyre. The tread, track width and wheelbase length are measured and used to identify the type and brand of the tyre which occasionally, can help determine the make and model of the vehicle. The impression can help place the suspect at the scene by matching the tyres found at the crime scene to the suspect’s vehicle thus, giving an indication of what happened. There are three types of tyre marks which can help reconstruct the crime scene thus gaining a better understanding of what occurred. Firstly, skid marks indicate the distance when the brakes were applied and help calculate the speed of the vehicle. Secondly, yaw marks occur when a vehicle brakes faster than it can handle. This will be displayed as a sideways skid. Thirdly a tyre scrub refers to a wheel that has locked which will display damage to the tyres and indicate the area of impact. There is a range of impression evidence which can be recovered when examining a crime scene. This is extremely useful as with a wider range of evidence that can be gathered, it yields more success in finding the perpetrator and a successful conviction. REFERENCES Clark, D.H., 1992. Practical Forensic Odontology. Oxford: Butterworth Heinemann Ltd. College of Policing, 2013. Senior Investigator Major Crime (PIP 3 SIO) [online]. London: College of Policing. Available from: https://profdev.college.police.uk/professional-profile/1477/ [Accessed 20 January 2021]. National Policing Improvement Agency., (NPIA)., 2008. Family Liaison Officer Guidance [online]. Bedfordshire: NPIA. Saferstein, R., 2005. Criminalistics: An Introduction to Forensic Science. 9th Edition. Pearson.

Bureau of Criminal Apprehension, 2021. Fabric Impressions [online]. Minnesota: Bureau of Criminal Apprehension. Available from: https://dps.mn.gov/divisions/bca/bca-divisions/forensicscience/Pages/trace-fabric.aspx [Accessed 20 January 2021]....