Introduction
The quest for justice for victims of crimes has and continues to generate an immense debate across various settings all around the world. On a similar note, the quest to administer adequate judgment for criminals suspected for perpetuating different crimes remains a prime objective for judicial systems all over the globe. Overall, the process of administering justice is a delicate process that calls for somber minds and adequate strategies that facilitate administration of justice that is beyond any reasonable doubt. DNA evidence and testing occurs as one of the major strategies that have been adopted by criminal investigations departments all over the world with a sole aim of protecting innocent people from being convicted for crimes they did not partake in (Gregory, 2005). Besides, this strategy ensures that the suspects convicted for certain crimes are the real perpetuators of the said crimes.
The scope of DNA evidence and testing
The scope of DNA evidence and testing can be traced back to the close of the year 1986, when the first case involving DNA evidence and testing made its way to the courts. Historically, DNA evidence and testing was utilized to carry out paternity tests, which aimed at linking children to their true parents. In the year 1986, criminal investigations in England were prompted to utilize DNA evidence to carry out forensics in a case involving a seventeen year old boy who had confessed to having been involved two rape-murders. Indeed the tests proved these confessions and this marked the beginning of the use of DNA evidence and testing in different criminal cases (Salmasi, 2010). In the first cases involving the use of DNA evidence and testing, the admissibility of DNA evidence was not highly doubtable. However, admissibility in the use of DNA evidence and testing was later challenge by a number of defense attorneys. As a result, various changes were initiated with an aim of streamlining DNA evidence and testing to avoid any further disputes.
How DNA evidence and testing works
As previously connoted herein, DNA evidence and testing occurs as an immensely powerful strategy in crime investigations. This can be accredited to the fact that the DNA is unique for every individual, except for identical twins; hence, linking a suspect to a certain crime with the use DNA evidence and testing is a feasible endeavor. Precisely, DNA evidence derived from a crime scene can elusively eliminate a crime suspect from suspicion and provide a link to the ideal perpetuator of a given crime (Killoran, 1996). An example of how DNA evidence and testing works is in cases of sexual assault. In such cases, biological evidence such as blood, semen, skin cells and hairs left on a crime scene or on the victim’s body can be compared with the samples drawn from the suspect. As such, if the DNA of the biological evidence drawn from the scene and those drawn from the suspect are similar, the suspect will be held liable for the crime.
In addition, the profile of the DNA drawn from the crimes scenes can be entered into a DNA database devised by various crime agencies such as the FBI. This will identify and link suspects to the crime. Supplemented with reports drawn from other investigations, the suspects will be convicted in a just and fair manner. In fact, such convictions will assure justice for the victim and the accused. It is essential to note that the effectiveness of DNA testing as judicial evidence calls for collation and analysis of elimination samples in order to ascertain the true source of the DNA. Speaking of elimination samples, these refer to samples taken from individuals who might have had legal access to the crime scene and left traces of biological materials (Gregory, 2005). An example of elimination samples in cases of sexual assault is samples of semen taken from a person who in the recent past (in less than seventy two hours) had consensual intercourse with the victim of sexual assault. This accounts for the DNA of such people that are likely to be found in the crime scene; hence, cushion such people from being convicted wrongly.
Procedures that should be adhered to while collecting DNA evidence
Collection of DNA evidence does not occur in isolation, but calls for the availability of various professionals. Besides, collection of DNA evidence from a crime scene calls for swiftness in order to minimize the chances of contamination of such evidences (Killoran, 1996). There are different professionals who are often involved in collection of DNA evidence who include medical personnel, crime scene technicians, victim service providers, and nurse examiners. These professionals should be distraughtly aware on the crucial protocols that should be observed while identifying, collating, transporting, and storing DNA data. Failure to observe any of these protocols certainly results in tampering of DNA data, which is likely to jeopardize crime investigations. In addition, victims of crimes play a phenomenal role in fostering the collection of DNA evidences. For example, victim of rape are often advised not to change clothes or take a bath after their ordeals with the rapists. This assists in DNA testing because biological evidences of the rapist are likely to be found on the victims clothing, and other parts of their bodies such as the vagina (Salmasi, 2010). Such biological evidence provides crucial leads to the rape suspects.
On another note, collection of DNA evidence does not center only on the evidence found in the crime scene. Instead it encompasses the execution of medical examinations in order to treat any injuries inflicted on the crime victims. Furthermore, references samples of the victim’s biological evidence such as blood or saliva should be collected for use as a control standard. There are some cases of DNA testing that may require analysis of certain evidence such as the hair. In such cases, the control standard derived from the victim is utilized to compare and contrast the victims DNA with other DNA evidence found at the crime scene (Gregory, 2005). These offer a viable platform that eases the determination of the probable suspects. Overall, DNA evidences are very sensitive. Therefore all the professionals involved in the process of DNA identification, collection, and analysis should take adequate precautions such as involving personnel from crime laboratories who are well conversant with various issues aligned with DNA evidences.
How to prevent DNA contamination
Notably, DNA evidences are highly prone to contamination. For this reason, various strategies have been set in place in order to minimize the occurrence of such contaminations. More importantly, arrival at the crime scene in a timely manner by the crime scene investigators minimizes the chances that crimes scenes will be tampered with, which contributes immensely to the contamination of DNA evidences (Killoran, 1996). Another way in which DNA evidence can get contaminated is when it mixes with DNA from other sources. To curb this, all the personnel involved in the handling of DNA should utilize disposable gloves because gloves have proofed to be the most comprehensive avenues that result in missing of certain DNA samples with others. In addition, these personnel’s should use clean tools in handling DNA, and avoid coming in contact with other things while they are handling DNA evidence.
It is also crucial to note that environmental factors such as temperatures and humidity can precipitate the contamination of DNA evidences. Precisely, high and low temperatures result in DNA contamination in various ways. There exists certain bacterial species that grow well in cold temperatures whereas others grow well in hot temperatures. Therefore, high or low temperatures can result in growth of bacteria, which are likely to destroy the DNA. To prevent such occurrences, DNA evidences should be packaged and stored efficiently.
DNA testing
After identification and collection of DNA evidences within a crime scene, DNA testing is carried out using the Polymerase Chain Reaction (PCR). This process allows crime investigators to easily analyze sample evidences, which are often of limited quantity and quality. The PCR process produces numerous DNA samples that allow laboratory technicians to generate DNA samples of the evidences collected in a crime scene (Gregory, 2005), which are the compares with DNA samples from the suspects. Statistical analyses are then utilized to ascertain the probability of finding similar DNA samples from all the populations.
Conclusion
References
Gregory, N. (2005). Offender Profiling: A Review of the Literature. The British Journal of Forensic Practice, 7(3), 29-34.
Killoran, K. (1996). Forensic Science: A Library Research Guide. Reference Services Review, 24 (4), 15-30.
Salmasi, A. (2010). DNA Dataveillance: Protecting the innocent?. Journal of Information, Communication and Ethics in Society, 8 (3): 270-288.
