The characterization of deoxyribonucleic acid (DNA) lies at the center of criminal investigation as an extension of forensic typing of blood or any other biomedical samples that are relevant in critically analyzing the nexus that exists between the molecular identification and characterization techniques and forensic science. Advances in mapping and sequencing techniques of the human genome have not only yielded benefits to medicine and basic biology but also to forensic science.
Genetically determined variation in the proteins: the end products of DNA transcription and translation, is the basis of differences in human blood groups(US-NRC 1992). Since the advent of blood typing and its use in criminal investigation, the differences in blood groups has been instrumental in narrowing down the number of suspected individuals based on the biochemical results derived from serotyping of samples from the crime scene.
DNA samples which can be isolated from a host of other biomedical samples usually left in the crime scene such as strands of hair, nail clippings, skin scrapings, blood spills and semen are instrumental in elucidating personal identification of suspected criminals and therefore a plus in criminal investigations and justice. Basically, DNA is the active substance necessary for hereditary passage of information from parental organisms to their offspring.
Such genetic information is unique to each and every individual. It is on this basis that techniques such as PCR DNA fingerprinting thrive. This means that so long as samples are taken through thorough isolation, mapping and sequencing, the chances of misrepresentations of false identity are obliterated unless there are manipulations of results by the forensic laboratories. While the judicial system itself must possess the capacity to carry parallel tests to guard against false accusations.
Moreover, such results ideally constitute personal information, and therefore the privacy and confidentiality statutes fully apply to safeguard against unauthorized infiltration into DNA databases, dissemination, abuse and misuse which violate an individuals rights both in the human rights context and the forensic context (Lazer 2004; US-NRC 1992). While there has been obstacles to DNA evidence admissibility in courts, such obstacles are fading away since the evidentiary successes of such evidence are nothing but astronomical in comparison to eyewitness recollections of criminal identity (Clark et al 2007).
Sex crimes are easily determinable as samples such as semen, hair and saliva can be collected and handed over to for DNA isolation, mapping and sequencing using molecular techniques such as PCR, RFLP, short tandem repeat markers (STR). However, since DNA samples come from an environment that is not as pristine as the molecular biology laboratory environment such sample are less than ideal and therefore forensic experts must be especially careful when performing analysis of such samples.
Most importantly, contamination of samples, handling of degraded samples, overcoming PCR inhibitions as well as low copy DNA profiling are key issues in forensic isolation, mapping and sequencing of DNA (Butler 2005). As opposed to other techniques that have been in use in criminal investigations, DNA technology offer reliability, simplicity, speed, cost effectiveness and most crucial, information return(Bonnet et al 1990). to apply these technologies cost efficiently an element of discrimination of individuals must exist.
For instance, it is only cost efficient to isolate specific suspects in the population and subject their genomic DNA forensic investigation, the results of which are compared with those from samples collected from the crime scene. A positive correlation between the two samples constitutes a reliable connection between the individual suspected and the criminal act and consequently furthering criminal justice.
List of References
Bonnett, Raymond. , Robertson, James. , Ross, A. M,. Burgoyne, L. A. 1990. DNA in Forensic Science: Theory, Techniques and Applications.Routledge Press. Butler, J. Marshall. 2005. Forensic DNA Typing: Biology, Technology, and Genetics of STR Markers. Academic Press. Clarke, G. , Reno, J. 2007. Justice and Science: Trials and Triumphs of DNA Evidence. University Press Lazer, David. 2004. DNA and the Criminal Justice System: The Technology of Justice. MIT Press. United States National Research Council(US-NRC). DNA Technology in Forensic Science: Summary. 1992. National Research Council (U. S. ). Committee on DNA Technology in Forensic Science. National Academies Press.