Documenting the Crime Scene - Research Paper Example

Criminal investigations Documenting the crime scene Introduction Documenting the crime scene plays a critical part in case resolution and aids in the collection by ensuring that physical evidence is available during prosecutions (Horswell, 2010). The main purpose of crime scene investigation is to recognize, preserve, collect, interpret and reconstruct all physical evidence that is at the crime scene. Crime scenes can be classified depending on the size, the nature of crime such as assault, the physical location and primary criminal or secondary criminal activity that takes place at the location (Dale & Becker, 2007). The law enforcers and first responders to a crime scene have a responsibility of protecting the scene, preserving the physical evidence, and collecting evidence for more analysis. According to Ogle (2011), crime investigations involve a thoughtful and thorough investigation and advancements in technology has aided in the collection of crime scene evidence and interpretation of the physical evidence thus accurate documentation is critical in resolving complex crimes. From nanogram quantities of the DNA to artificial intelligence systems that identify the fingerprints, crime scene experts are able to document evidence at the crime scenes that will aid in criminal investigations and prosecution (Horswell, 2010). The documentation of the crime scene involves physical evidence recognition, documentation, evidence collection, packaging and preservation and finally scene reconstruction (Pepper, 2010). The investigators must recover the physical clues and take witness statements for objective assessment of the crime scene. Crime investigators use systematic and logical approaches in documenting evidence since all crime scenes are unique in order to attain successful conclusions of serious crimes such as murder, rape, sexual assault, homicides, robbery and carjacking (Horswell, 2010). Duty of first responding officers Pepper (2010) outlines that the initial process of documenting the crime scene will entail the most important aspect that is preserving the scene with minimal contamination and interference with physical evidence by the first responders. The responding offer must assess the scene and treat it as a crime scene through remaining cautious and observing events, potential evidence, persons, and vehicles (Horswell, 2010). According to Orthmann & Hess (2012), the initial responding officer is expected to take not of the physical location, time, address and date of the crime and make observations such as smell and sounds at the scene. Accordingly, the responding officer must take protective and safety measures by remaining attentive while scanning the area for any dangers such as natural gas, gasoline or hazardous chemicals that entail smells and sounds (Pepper, 2010). The next step is provision of medical attention to the victims of the crime without contaminating the scene and minimizing contact with the evidence such as knife tears and bullet holes (Orthmann & Hess, 2012). The officer can take statements from witnesses, the victim and suspects that are at the crime scene and victims or suspects that are sent to health facilities must be accompanied by enforcement officials in order to preserve the evidence (Ogle, 2011). The next step is securing and controlling the scene through limiting the access and movements and separating the suspects and witnesses, removing bystanders, family members and medical personnel in order to prevent scene contamination and destruction of evidence (Dale & Becker, 2007). The responding offers will then put physical barriers to the points of entry and document all people entering the scene. The officer must also take care of possible weather conditions such as rain, wind and sun that may destroy evidence and should consider searches and seizures for more physical clues such as possibility of drugs in the house (Horswell, 2010). Crime scene documentation This is a critical step in criminal investigations and the suppose is to have permanent records of the physical evidence and requires systematic approach (Dale & Becker, 2007). Some tasks that are involved include note taking, photography, videography and sketching. The responding officer will then brief and turn the responsibility to investigators who are tasked with documenting the physical evidence. The observations must be done as soon as possible to preserve evidence and put in permanent records. Some critical issues include the persons and items at the scene, the conditions upon arrival such as the open or closed doors, smells, liquids, furniture, and personal items (Ogle, 2011). The next step is the preliminary documentation and evaluation of the scene that entails determining the type of incident to be investigated and determine the need for more search and seizure warrants (Orthmann & Hess, 2012). The evaluation will focus on the paths of entry to the scene, the size of the scene and personal information of the witnesses. The next step after the scene assessment is the ‘walk-through’ and initial documentation that will offer an overview of the entire scene and photographic documentation on permanent records. During the walk-through, the investigator is expected to protect the perishable evidence and take photographs in to avoid losing perishable evidence (Dale & Becker, 2007). Note taking at the crime scene prevents memory loss and important details that are included include the date, time, methods of notification and methods of arrival at the scene (Dempsey & Forst, 2011). The investigator includes information on scene description such as location, major structures and conditional evidence such as points of entry, weapons at the scene, and ashtrays. The notes include the victims’ description such as wounds, clothing and lying position and duties that have been assigned to crime scene members during the walk-through (Pepper, 2010). The investigator will determine the team composition, specialized resources and skills that are necessary for scene processing. Dale & Becker (2007) asserts that investigators must assess the need of forensic specialists and select qualified people for the specialized tasks such as sketch, evidence collection and latent prints. The investigator will avoid contamination of evidence and maintain safety of specialists through following the established exit points and using protective equipment especially while collecting biological samples (Ogle, 2011). In the documentation part, the investigator is expected to assess the nature of documents that are needed such as photography, sketches, video, measurements and notes. In taking photograph, the investigator is required to utilize overall, medium and close-up coverage including the aerial view of the witnesses, suspects and victims of the crime. Video tapes can supplement photos and sketches that identify the immediate area of the scene, objects and items prior to the movement (Ogle, 2011). Accordingly, transient evidence such as sounds, sights and smells must be documented to supplement the physical evidence. Evidence collection must be prioritized and other available methods such as projectile trajectory analysis and blood pattern documentation can be used in the biological fluids (Dempsey & Forst, 2011). Sketching requires graph paper, ruler, flashlight, folding rule and other equipments and is critical in documenting the spatial relationships and proportional measurements such as bullet trajectory angel and surrounding areas such as objects bodies of persons, exit and entry points and scale of the sketch (Pepper, 2010). Another of types of sketches is the perspective that provides an overview of the vanishing point and relative distance and depth of the crime scene. The projection perspective is of horizontal plane and shows the floor plans from bird’s eye view while the schematic perspective provides the sequence of events such as trajectory of a bullet (Dempsey & Forst, 2011). The detailed perspective of the sketch is useful for large crime scenes and focus on finer details of the crime. Triangulation method that involves taking measurements from fixed points such as objects is useful in sketching while rectangular coordinate method is used to prepare sketches from measuring the distance to an object from two mutually perpendicular objects such as walls forming 90-degree angle (Orthmann & Hess, 2012). The other common sketching method is the polar coordinate method that is utilized for outdoor scenes where only one reference point exists and angles are measured with optical device or large protractor (Pepper, 2010). Photography is a common documentation technique and target of the camera can be overall, midrange or close-up and interior photographs must use vertical orientation. The photos must be named such as blood stains and photographic sessions must be systematic and not interrupted (Dale & Becker, 2007). The overall photographs must be capable of highlighting the locations, angles and perimeter including cars, entry and exit points and any bystanders and should encompass the entire crime scene (Pepper, 2010). Midrange and close-up photographs must be taken for the evidence identifiers and notes must be taken in order to identify the location of the objects in the photos. Midrange photographs establish the relationships between objects and act as transient evidence from perpendicular position the spatter while closed-up photographs involve fingerprints, tire track evidence and cameras are placed in a perpendicular position (Dale & Becker, 2007). Additional photos can include tire impressions, dust impressions, and blood stains, serial numbers of weapons, and aerial photographs. Videography can also be used to record the entry and exit points and important objects at the crime scenes (Ogle, 2011). (crime scene documentation: www.forensicmag.com). (Bullet trajectory crime scene: www.miramarpd.org). Crime scene documentation may entail searches that aim at recognizing evidence and some common methods that are used include strip search, grid search, zone search and spiral search. The search lane must be approximately the arm’s length of the searcher and strip search entails walking in parallel along the search lane in same direction (Pepper, 2010). Grid search involves a lane search in one direction followed by lane search in a perpendicular direction while a zone search involves dividing the searched area in to adjacent zones and conducting multiple searches in each zone (Dempsey & Forst, 2011). Spiral search is usually inward and outward from crime scene, but entails the risk of evidence contamination. The next step will entail preserving, inventory, packaging, transport and submission of evidence through labeling the data of collection and establishing the chain of custody Orthmann & Hess, 2012). There must be control and reference samples and electronically documented evidence must be secured and stored in a tamper-proof manner (Dempsey & Forst, 2011). The evidence is then packaged appropriately, labeled and submitted to crime laboratory or evidence storage facility. The next step is completing and recording the crime scene investigation and will involve establishment of the debriefing team that includes investigators, photographers, evidence technicians, latent print personnel and initial responding officers (Pepper, 2010). The team can discuss the possible forensic tests and post-scene responsibilities for the law enforcement officers. The next step entails performing post final survey of the crime scene so as to ensure dangerous materials or conditions at the crime scene are addressed and all materials used in investigations and evidence collection are removed (Pepper, 2010). The reports and other documents are then compiled in a case file so as to enable independent review including all the technical reports of forensic experts. Documentation of crime scene facilitates identification of crime suspects through forensic examination of the DNA, fingerprint analysis and bloodstain sample analysis. The documentation has facilitated identification of unknown substances such as anthrax, poison and drugs in instances of homicides (Ogle, 2011). Conclusion Crime scene documentation is a critical step in solving complex crimes and involves initial response, undertaking safety procedures, provision of emergency care and securing the boundaries of the crime scene. In addition, the investigators will conduct the preliminary scene assessment, process the scene without any contamination, prioritize evidence collection and preserve the evidence after packaging. The final steps entail debriefing and final surveys of the crime scene and finally forming the case file. Some of the methods that are common in documenting physical evidence include notes, video tapes, photographs and sketches. The trace evidence of firearms, fingerprints, blood stains, motor vehicles, impressions such as footwear and dust by also be collected to facilitate forensic investigations. References: Dale, M & Becker, W.S. (2007). The crime scene: how forensic science works. New York: Kaplan Publications. Dempsey, J & Forst, L. (2011). An introduction to policing. New York: Cengage Learning. Horswell, J. (2010). The practice of crime scene investigation. New York: CRC Press. Ogle, R.R. (2011). Crime scene investigation and reconstruction. London: Pearson Prentice Hall. Orthmann, C.H & Hess, K. (2012). Criminal investigation. New York: Cengage Learning. Pepper, I.K. (2010). Crime scene investigation: methods and procedures. Maidenhead: Open University Press. Read More