DNA, Fingerprints AND Blood Evidence In Criminal Investigation Essays Example

DNA technologies are regarded as transcendent of the contingencies of human action that also symbolizes neutrality and truth (Santos 200). In fact, it is through these DNA technologies that provide the source of neutrality and objectivity that will explain the circumstances surrounding the commission of crimes. Thus, the conduct of forensic examinations using DNA, fingerprints and blood evidence serve as keys towards the resolution of criminal cases. The role of the laboratories and forensic experts is to preserve their professional autonomy by providing scientific expertise through the translation and conversion of criminal traces that will help in the resolution of crimes that turn out to be scientific artifacts (Santos 200).
Wyatt argued that DNA profiling is one of the methods through which social order can be maintained by rendering these specific members of the population identifiable (75). Another advantage of using DNA and obtaining fingerprints and blood evidence in a crime scene will allow the crime investigators to conduct autopsy to find out the cause of death of the victim (Layman 109). The DNA of the victim is the best evidence that will determine the identity of the victim. After the identity of the victim is known, the forensic evidence will serve as the missing link that will solve the mystery behind the death of the victim. The forensic evidence now becomes the missing piece in the puzzle that will lead towards the resolution of the case. Santos explained that DNA is usually presented and perceived as an objective truth, or that piece of jigsaw puzzle that has its own destined size, shape and form (183).
The responsibility of the initial responding officer is critical since he has to strictly follow the procedures and the protocol for the documentation in identifying the victim. At the same time, it will also reassure the family members of the deceased that the cause of death of the victim was due to a natural cause, suicide, or homicide (Reno, Marcus & Robinson 33). There are other scientific methods to be followed in order to obtain fingerprints, DNA samples from the body of the victim that will enable the investigators to match the evidence with the previous records of the victim. Reno, et al. argued that will also determine the circumstances regarding the death of the victim by carefully studying the physical characteristics, personal effects, and markings in the body including tattoos and other anthropologic data (33).
Aside from the gathered forensic evidence and information based on the postmortem changes to the body of the victim, it is mandatory to match the findings with the available circumstantial information such as the color, location, and position of the body to discover the approximate time of death (Reno, et al 34).
Since the DNA of every person is unique, the DNA analysis plays an essential role for the resolution of criminal cases that will provide the needed assistance to the investigators and law enforcement agencies to solve crimes (Isenberg 17). It is through joint efforts of the police and the crime laboratory that will produce the scientific evidence in order to identify the suspects that will also support the expert testimony during trial (Layman 109). The crime laboratory uses the wonder of science for the completion of the DNA analysis by obtaining microscopic components which can be found in tissues, semen, blood samples, or saliva found in the crime scene (Layman 109).
The quality assurance standards established by the FBI Standards for Forensic DNA Testing Laboratories and the American Society of Crime Laboratory Directors-Laboratory Accreditation Board or the ASCLDLAB are to be followed to maintain the accuracy and integrity of the DNA results (Isenberg 17). The DNA analysis process has three main components including primary visual analysis, sample preparation and DNA processing that makes use of fingerprints, blood samples and body fluids obtained from the victims and suspects (Isenberg 17).
DNA databases have been regarded as critical tools in order to solve crimes based on DNA evidence when the other pieces of evidence, such as fingerprints, cannot be retrieved or found to be inconclusive (Na, Bin, et al 312). Through the use of these various DNA evidence, the crime scene investigators are able to identify suspects by looking for a DNA perfect match based on the DNA samples such as semen, saliva, blood, among others. However, it bears to stress that large and comprehensive networked database of DNA profiles is required in order to be able to fully realize the benefits of DNA profiling (Na, et al 312).
The use of fingerprints is also one of the useful tools for crime investigators to identify the suspect. However, some experts believe that there should be a more systematic scientific study to ensure the accuracy of latent fingerprint identification to remove any margin of error (Kellman, et al 1). The latent prints, called the ‘‘latents’’ are the friction ridge impressions derived from fingerprints, palm prints, or footprints, that had been left unintentionally on items found in crime scenes (Ulery, et al 1). On the other hand, the exemplar prints are those which are considered to possess higher quality of prints that had been collected under controlled conditions from a known subject using ink on paper or digitally with a live scan device to ensure the accuracy of the fingerprint analysis (Ulery, et al 1).
For the past decades, fingerprint identification had been regarded to be an efficient method by forensic experts who considered it to be ‘‘infallible’’ or to has a ‘‘zero error rate’’, provided that the method was correctly applied by an experienced examiner (Kellman, et al 1). However, for high-profile cases, there were incidents when errors had been discovered, along with the inherent implausibility of assertions of infallibility (Kellman, et al 1). As a result, many forensic experts had doubted the accuracy of fingerprint identification.
With the recent developments in fingerprint identification technology, scientific efforts had been exerted to assess the strengths and limitations of fingerprint analysis by taking into account the various factors to ensure accuracy of the evidence. The recent report of Kellman, et al. argued that there are six important features which can predict the accuracy of the fingerprints which include: “ridge sum, area ratio, visibility of deltas in the latent print, mean block contrast of the known print, interaction between SD block contrast for latent and known prints, and the interaction between DEAI (deviation from expected average intensity) between the latent and known prints” (Kellman, et al 11).
Finally, the forensic use of latent fingerprints and palm prints as the basis for identifying suspect should depend on the analysis, comparison, and evaluation decisions made by expert latent print examiners (Ulery, et al 1). Thus, the accuracy and reliability of the assessment made by forensic experts is critical to validate the use of latent prints in forensic science (Ulery, et al 1). Other factors to consider by the recipients of these fingerprint assessments include the correctness of the decisions taken by latent print examiners, and whether they will obtain similar decisions on a different occasion (Ulery, et al 1).

Works Cited:

Byrne-Dugan, Cathryn J., et al. “The Processing of Surgical Specimens with Forensic Evidence.” Archives of Pathology & Laboratory Medicine 139.8 (2015): 1024-1027.
Isenberg, Alice R. “Forensic Mitochondrial DNA Analysis: A Different Crime-Solving Tool.” FBI Law Enforcement Bulletin 71.8 (2002): 16-22.
Kellman, Philip J., et al. “Forensic Comparison And Matching Of Fingerprints: Using Quantitative Image Measures For Estimating Error Rates Through Understanding and Predicting Difficulty.” Plos ONE 9.5 (2014): 1-14. Academic Search Complete. Web. 7 Jan. 2016.
Layman, Micheal, D. Criminal Investigation: The Art and Science. New York: Pearson Education, 2002. Print.
Na, Hu, Cong Bin, and Shujin Li, et al “Current Developments in Forensic Interpretation of Mixed DNA Samples.” Biomedical Reports 2.3 (2014): 309-316.
Reno, Janet, Marcus, Daniel and Laurie Robinson. Death Investigation A Guide for the Scene Investigator. U.S. Department of Justice, 1999. Print.
Santos, Filipe. “Making Sense of the Story – The Dialogues Between The Police And Forensic Laboratories in the Construction of DNA Evidence.” New Genetics & Society 33.2 (2014): 181.
Ulery, Bradford T., et al. “Repeatability And Reproducibility of Decisions by Latent Fingerprint Examiners.” Plos ONE 7.3 (2012): 1-12. Academic Search Complete. Web. 7 Jan. 2016.
Wyatt, David. “Genetic Policing: The Use of DNA in Criminal Investigations/ Genetic Suspects: Global Governance of Forensic DNA Profiling and Databasing.” Genomics, Society & Policy 6.1 (2010): 75-79. Academic Search Complete. Web. 7 Jan. 2016.