Taxonomicclassification is a system used to categorize living things accordingto the species level. The method is also used in the classificationof bloodstains to identify the physical characteristics, includingshape, size, orientation, and volume that must be present to assistin defining if the stains belong to a given category. Thecharacteristics are expressed as a sequence of circular or ellipticalstains, linear or curvilinear orientation, and directional or gammaangles. There exist three main types for classifying bloodstains,namely low, medium, and high-velocity impact. In the low-velocitycategory, there is no force applied. It occurs when an individualsuffers from a self-inflicted injury and the blood drips. The secondis the medium velocity that happens during the stabbing, with a mildforce experienced. The high velocity category is where the force isextremely. It is experienced after a gunshot or other high powerincidents that injure the body. Other patterns such as spatter andarterial are also used to classify blood stains. The analysis ofbloodstain patterns can either be complex or simple (Arthur,Cockerton, de Bruin, & Taylor, 2015).
Anobjective approach is required when classifying blood stains toenhance the attainment of the expected, credible, and dependableresults. Normally, homicide units use the classification to reachvarious conclusions in the course of their duties in criminology. Ina crime scene, the trails of blood are rationally straightforward andunderstandable. Moreover, lawyers are utilizing every trick to attackthe precepts of forensics hence, the need for practitioners andinvestigators to remain objective in their work. Previously, theclassification of bloodstains suffered numerous setbacks,particularly ruining the reputation of the legal system. As such, thefailure to identify the right taxonomy for bloodstains hascontributed to ambiguities and non-prosecution. The classificationwill, thus, require a trained specialist who has extensive experienceto assist in the generation of credible results (Arthur, Cockerton,de Bruin, & Taylor, 2015).
DNAis a flexible molecule that can exist in various formations dependingon the environment. The naturally occurring DNA molecules arecategorized into three forms namely A, B, and Z-types. The A andB-forms are right handed while the Z-DNA type is left handed. Upondehydration, the DNA adopts the B-formation. The A-type is found ininstances where there is minimal interaction with water moleculessimilar to the formation of RNA. The Z-DNA form occurs with themethylation of deoxycytosine residues as well as during transcriptionwhere negative supercoiling happens to make it assume a stable state(Hoy, 2013).
Thereexist different methods of analyzing DNA depending on theirformations. The first method is the polymerase chain reaction (PCR)that allows advanced testing of the DNA. The technique utilizessmaller amounts of DNA molecules from the biological evidence beforemaking millions of copies (Hoy, 2013). It allows a laboratory analystto create a DNA profile. It is also possible to analyze the degradedbiological materials using the technique. The other common methodsinclude the restrictionfragment length polymorphism (RFLP)testing and PCR testing on DNA from the mitochondria of the cell. TheRFLP technique demands the usage of a sample that has over 100,000cells. It also requires that the cells are not degraded or brokeninto small pieces. The method has managed to assist in excludingindividuals from wrongful accusation. PCR testing on DNA frommitochondria cells is utilized in instances where the RFLP is notapplicable (Hoy, 2013).
Someconditions at the crime scene have the potential to affect successfulcoding of the DNA. Such instances include tampering with thebloodstains through physical means. Still, the mix of blood in acrime scene can influence positive identification by making theprocess complicated (Swanson, Chamelin, Territo, & Taylor, 2012).
Fingerprintsgathered from a crime scene are used extensively to supportinvestigations. The method helps identify any evidence that cansupport investigations in an ongoing case. Its usage is driven by thefact that every individual has unique fingerprints. The method hasproven to improve criminal investigations, especially murder androbbery cases. It has confirmed to be an effective way to ascertainthe innocence or guilt of an individual. The law enforcers usefingerprinting to identify potential suspects during aninvestigation. The technique is appropriate in investigations byenhancing the credibility of the evidence (Wang et al., 2014).
Variousitems in a crime scene are dusted to assist in laboratory analysis ofthe fingerprints. A window and firearm, for instance, are dusted toidentify the trails of fingerprints that can help in generating moreevidence about the individuals using the items. Similarly, a darkglass beer bottle can be dusted and placed on a light to enhance thevisibility of the fingerprints. A note with the address written on itcan help to identify the culprit for ease in the collection of theoriginal evidence (Wang et al., 2014).
Theusage of the technique is important as it has helped in utilizingbetter approaches in convicting criminals. It has also made it easyfor the investigators to use the method to support other judicialfunctions. Identifying the history of a suspect has been made easywith the forensic scientists using the approach to collaborating withthe evidence from other arms in the justice system. In thecontemporary setting, the investigators use technology andfingerprinting to hasten court cases. It has also helped to reducethe backlog in the court systems that arise due to lengthy andinappropriate investigations process. We cannot underestimate thesignificance of fingerprinting in enhancing the speed and integrityof the evidence presented to courts (Swanson, Chamelin, Territo, &Taylor, 2012).
Theadvancement in technology has contributed to the utilization ofdigital methods in the presentation of evidence in a court of law.Digital methods allow the jury to gather valuable information thatcan assist in a case. In some instances, the courts receive evidencethat can be gathered without the assistance of digital technology.The evidence is presented in the form of audio, photograph, andlatent fingerprints enhancement as well as forensic video analysis.One example of a case the utilized digital technology is the Englishv.the State of Georgia, 422 S.E.2d 924 in1992. During the case, an undercover officer is said to havevideotaped a cocaine sale. The evidence was enhanced using computertechnology, with the original film admitted as an exhibit during thetrial. There was a concern during the case on whether the computerenhanced image was admissible or not. The producer of the enhancedimage testified before the court that the evidence was accurate andtruthful. In the judgment, the jury asserted that the enhanced imagewas admissible thereby, upholding the conviction.
Digitaltechnology has been effective to add more evidence that can assist inthe prosecution of a case. Nonetheless, not all evidence is worth thetime and effort as seen in some cases due to tampering with theoriginal data. The United States and Canada have successfullyutilized the technique in some of the complicated situations.However, it is proper for the jury to examine the process ofenhancement properly to ensure fairness and accuracy on the evidencepresented before the courts.
Arthur,R. M., Cockerton, S. L., de Bruin, K. G., & Taylor, M. C. (2015).A novel, element-based approach for the objective classification ofbloodstain patterns. Forensicscience international,257,220-228.
Hoy,M. A. (2013). Insectmolecular genetics: An introduction to principles and applications.San Diego: Academic Press.
Swanson,C. R., Chamelin, N. C., Territo, L., & Taylor, R. W. (2012).Criminal investigation (11th ed.). New York, NY: McGraw-Hill.
Wang,J., Wei, T., Li, X., Zhang, B., Wang, J., Huang, C., & Yuan, Q.(2014). Near‐infrared‐light‐mediatedimaging of latent fingerprints based on molecular recognition.AngewandteChemie,126(6),1642-1646.