TOPICS for Paper: Students will pick two of the following topics and write a paper on the selected topics. Crimes rarely use only one type of evidence to convict a defendant of a crime. During the semester you will see how one helps the other in leading officers from one conclusion to another. Select two topics and write what they are and how they work, then write (or find a case where two topics have worked to close a case- (“The First 48 Hours” TV show is the best) how they could work together to lead YOU the investigator to arrest and convict the suspect/defendant.
Two Topics are: DNA and crime scene photography
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DNA and crime scene photography
Criminal investigation
A crime scene entails several types of evidence that must be documented photographically. The evidence must be photographically captured to show their location and appearance. The scene photographer determines the appropriate techniques to collect evidence (Fish et al.2013). DNA and photography experience a nexus in the evidence such as fingerprints that can also be applied in the laboratory settings. Fingerprints can be photographed at the crime scene or in the laboratory. The decision to photograph the fingerprints first is applied if it can be damaged on its way to the laboratory. The photographed fingerprint is known as a latent fingerprint because it is only developed and visible from the surface thus it cannot be lifted. Photographs bring out the details of the latent which can be enhanced for screening. Fingerprint photography requires accurate location thus the photographer must be keen with the scaling in the close-up photograph of every fingerprint. Besides, effective fingerprints require the best angle of lighting thus it is imperative to be detailed and descriptive using the ambient light exposures (Ogle and Plotking 2012). The fingerprint photographs can also be used for analysis in the courtroom thus the accuracy and integrity requirements of the crime scene photography.
The fingerprint DNA recovered at the crime scene is delivered to the laboratory for comparisons with the available biological samples. The samples are known as reference samples and they are taken from the arrestees during the fingerprinting processes. However, the collection of DNA is an evolving area that is determined by the laws governing the specific states. Technology advances have revolutionized the forensic field in developing DNA profiles (De forest wt al.2013).The touch DNA can be collected from the roughly handled areas on textured surfaces such as automobile dashboards and gun handles surfaces. The DNA samples collected go through the process of extraction of the DNA from the cell. The extracted cell then goes through a process of quantification where the amount of DNA is determined. The DNA collected is then amplified for characterization before being separated to permit subsequent identification. After analysis and interpretation, the DNA is quantitatively and qualitatively compared to create DNA profiles. The end result is a quality assurance for technical accuracy through reviewing the analyst reports.
However, DNA profiling experience challenges where some of the profiles fail to be present in the database system (De forest al.2013). Technology has come up with a new method that links the Y chromosomes for the DNA of the male suspects thus resulting in surnames for clues. Study shows that the DNA forensic field intends to evolve into faster methods that speed up the profiling to enables on-site DNA profiling in crime scenes.
The 48 hours TV show revolves around crime investigation and the documentation of the scene details that reveal the occurrence of crime and illuminates potential suspects. The show uses DNA and crime scene photography as some of their techniques for evidence potential. A basic crime scene entails scenes of dried blood on windowpanes thus they scene will involve the crime investigators deriving latent fingerprints from the scene. The scenes showcased at the show also involves physical evidence such as hair trials, breakages .garments and other materials. The crime investigators undergo a series of steps to find evidence to convict the perpetrator of the committed crime (Ogle and Plotking 2012).
The DNA collection and photography requires precise and careful steps to identify the movement of the perpetrator. For instance, an episode involved of breaking and entry where the perpetrator smashed a hammer through a windowpane to reach for the locked. He cut himself with the pieces of pointed glass thus leaving a trail of blood and hair residuals. In this case, the CSI will scrape off the dried blood from the windowpane in a careful manner to prevent smearing on any prints. Using tweezers, the trails of hair can be lifted whiteout disturbing the traces of evidence. Investigating the crime scene to acquire the DNA and photography evidence will require the necessary steps to ensure that the evidence remains in its original form (De forest wt al.2013). The evidence collected was then submitted in the lab thus reconstructing the crime for analysis and identification of the criminal.
The first step taken when the investigators arrive at the crime scene is that they ensure it is secure by conducting an initial walk to ensure nothing has been tampered with basing on the initial theories and visual examinations (Buckelton et al.2016). The CSI make potential notes before interacting worth the evidence. The second step involves documenting the scene through photographs and filming.At this stage, the visuals such as fingerprints and impressions are captured for further analysis. After this stage, the CSI careful walks around collecting evinces while logging, packaging, and tagging before handing it over to the lead investigator may be involved in the lab process depending on the area of expertise.The evidence processed is processed at the crime lab to acquire results which are handed over to the lead detective on the case. The relationship between the DNA and crime scene photography is that the photos and details around the DNA are used for crime scene investigations while the collected DNA is analyzed in the lab to confirm the identity of the suspects involved. The two sources of evidence collaborate to provide unified solutions and clues to solve the crime through analysis and investigations.
References
Ogle, R. R., & Plotkin, S. (2012). Crime scene investigation and reconstruction. Pearson Prentice Hall.
Fish, J. T., Miller, L. S., Braswell, M. C., & Wallace Jr, E. W. (2013). Crime scene investigation. Routledge.
De Forest, P. R., Gaensslen, R. D., & Lee, H. C. (2013). Forensic science: an introduction to criminalistics. McGraw-Hill Humanities/Social Sciences/Languages.
Buckleton, J. S., Bright, J. A., & Taylor, D. (Eds.). (2016). Forensic DNA evidence interpretation. CRC press.
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Study Notes:
Topic 1: DNA
DNA, or deoxyribonucleic acid, is a genetic material that is unique to each individual and can be used to identify individuals with a high degree of accuracy. In criminal investigations, DNA evidence can be collected from a variety of sources, including blood, semen, hair, and skin cells. This evidence can be used to link a suspect to a crime scene or to exclude a suspect from being the source of the DNA found at a crime scene. DNA evidence can also be used to identify victims of crimes, particularly in cases where the victim’s body is too decomposed or damaged to be identified through traditional means.
Topic 2: Crime Scene Photography
Crime scene photography is the process of taking photographs of a crime scene to document the evidence present at the scene. This includes photographs of the overall scene, as well as close-up photographs of specific pieces of evidence. Crime scene photography is an important tool for investigators because it allows them to document the scene as it was found, which can be critical in court when trying to establish a chain of custody or to recreate the events of the crime. Crime scene photography can also be used to identify potential suspects and to establish the time of death, based on the stage of decomposition of the body.
Together, DNA and crime scene photography can be used to build a comprehensive case against a
