DNA Technology in Forensic Science

DNA Technology in Forensic Science

Introduction

Forensic evidence has been of significant help in many cases over history. Forensic evidence is secured from the crime scene, and some need to be analyzed in a forensic lab. DNA evidence is one of the current forensic evidence that has been applied in solving many cases. However, DNA evidence is admissible in court if the proper procedures have been followed in collection and lab analysis. Due to the reliability and accuracy of DNA evidence, it has been used by the innocence project to exonerate the wrongfully convicted individuals. The courts have now increasingly expected the DNA evidence to be presented in the cases even when other forms of evidence are submitted, which makes the entire evidence to be strong. The paper will DNA evidence, origin, and relationship with the criminal justice system. Also, the article will assess the role of DNA evidence in forensic science and sources of DNA evidence in crime scenes.

DNA Analysis and Origin

The primary role of forensic DNA analysis is the application of deoxyribonucleic acid specimen in the legal proceedings, which helps to link a suspect to the crime. After the crime has been committed, there is various evidence that can be done the DNA analysis to help identify the criminal. For instance, saliva, blood hair, semen, urine, tissues, and cells. The investigators conduct DNA profiling by making a comparison of the suspect’s DNA to the one collected at the crime scene and assess the likelihood of the suspect’s involvement in the crime. DNA testing has become an essential tool in the identification process. The test can now identify individuals with almost 100% certainty and reliability (Ahmed, 2001).

Before the introduction of DNA testing, the scientific community used to apply other biological tools that portrayed the biological relationships. Some of these approaches include serological testing, blood typing, and HLA testing. The DNA testing was introduced in the late 1970s and early 1980s, where scientists discovered they could determine the biological relationships using DNA. The establishment of DNA technology within the criminal justice system was done in the mid-1980s. The technology has been refined with time in crime laboratories such that small amounts of blood, saliva, cells, and other biological materials can be applied to confirm or disapprove a crime. RFLP DNA testing was the first test to be conducted using DNA technology (Stavrianos, Eliades & Kokkas, 2010).

DNA Technology in the Criminal Justice System

DNA technology has played a significant role in solving crimes, and the criminal justice system has embraced technology, especially in the past decade. The technique can be applied to identify the criminals with incredible accuracy if there is a shred of biological evidence related to the crime. Also, DNA technology has been essential in clearing the suspects and exoneration of persons who have been convicted wrongfully. Therefore, technology has become an essential tool in ensuring fairness and accuracy in the criminal justice system (Stavrianos, Eliades & Kokkas, 2010).

The criminal justice system has been applying DNA technology in two approaches. First, in the cases where a suspect has been identified, and the sample of the individual’s DNA is compared to the evidence secured from the crime scene. The outcomes from this comparison help in establishing where the suspect is responsible for the crime committed. Another approach used by the criminal justice system is when the suspect is not identified, but biological evidence has been obtained from the crime scene. At this point, the evidence is analyzed using the DNA technology and then compare with the offender profiles in the national DNA databases, and it helps to identify the offender. The criminal justice system can also use the evidence with other crime scenes by the use of DNA databases (Ribaux, 2003).

Generally, the DNA evidence is linked to the offender profiles in the preserved databases. In the late 1980s, the federal government initiated a crucial groundwork for the system in national, local, and state DNA databases to help in the storage and exchange of the DNA profiles. The system is referred to as the Combined DNA Index System (CODIS). The system maintains all the DNA profiles in a set of databases that are available to law enforcement agencies across the nation for law enforcement. Therefore, CODIS helps in comparison of evidence from the database to the DNA profiles which are obtained from the offenders.

Role of DNA in Forensic Science

DNA technology plays a crucial role in the science of forensics since many offenders have been arrested by matching a piece of DNA with evidence that has been discovered from the crime scene. In forensic science, DNA is one of the most accurate and reliable approaches to link offenders to the crimes committed. Each individual has a unique DNA molecule, and a piece of genetic information for every DNA is different. DNA technology is applied for various purposes in forensics. For instance, the partiality of the child is determined by a comparison of the parent’s and child’s DNA information (Jankowski et al., 2017). Exoneration of the individuals who have been convicted by mistake is one of the great success of DNA technology. If the wrong person has been caught during the crime, then the DNA is matched with the evidence to determine the offender. If the DNA does not match with the suspect’s, later they are released (Prinz et al., 2007).

DNA Technologies in Forensic Science

There are various approaches DNA has been used in forensic science. DNA typing for criminal investigation can be regarded as the extension of forensic blood typing, which has been prevalent for over five decades. DNA testing is an extension of the typing of proteins, which are coded by DNA to the typing of DNA itself. The advancements of DNA technologies have made it possible to study the person-to-person differences in genetics. Identification of the offenders is the everyday contemporary use of DNA technology by the criminal investigators by matching the suspect’s DNA to the ones in the national databases. The identification of the parents is another use of the DNA where a child’s DNA is matched with that of the parent (Butler, 2015).

Businesses involving DNA technologies have become common due to the increasing demand for testing. For instance, the integrated DNA technologies are the primary supplier of the custom sequences of both DNA and RNA for research, diagnostic, and commercial applications. A lot of research is being conducted today and primarily relies on DNA technology. For instance, there are huge caseloads that require DNA testing to make a solid conclusion. Therefore, there is a significant need to establish an approach that will speed up the DNA testing process (Marbach, 2019).

DNA Collection and Comparison

DNA evidence is essential for the crime scene investigators, and therefore there is a need for necessary collection techniques and skills. The DNA evidence can be collected from various sources that require a particular collection approach. At the crime scenes, both the biological and physical evidence could contain the DNA samples, which offers significant insight into the cases. The DNA evidence is not visible to the naked eye; for instance, if a person touched the object, some DNA samples could have been left behind. Therefore, the crime scene investigators should thoroughly inspect and collect as much evidence possible. Swabbing of the evidence should be done for the instances which offer clear sources of DNA like urine, blood, semen, saliva, among other sources (Jiang, 2017).

The investigators should put on protective gloves and take precautions not to contaminate the evidence. However, if the sample is dry or pre-moisten the swab tip with distilled water is used to collect the evidence which allows the DNA to absorb in the fibers. Lap personnel and investigators need to wear protective gear and avoid interacting with other objects when handling the DNA evidence to lower the risk of contamination.         However, the evidence should be allowed to air dry before packing it in an envelope or an evidence bag and take it to the lab as soon as possible.

Sources of DNA at the Crime Scene

There are various possible sources of DNA evidence in the crime scene. An individual can leave DNA samples in different ways, which depends on what occurred at the scene. Bodily fluids are the common sources of DNA at the crime scene, which include blood, urine, semen, saliva, and sweat. Such sources offer readily DNA information, which helps to link the suspects to the crimes committed. However, one or more of these fluids can be secured from the scene, depending on the nature of the crime. The investigators are expected to collect all the evidence available for the DNA analysis. If the fluids are still wet, the forensic technicians should soak the part with stain into an evidence container (Mapes et al., 2019). Skin and hair are other sources of DNA evidence at the crime scene. In most cases, the hair falls from the body, and the presence of such evidence can provide significant information for the DNA analysis. Touch DNA is another source of DNA evidence which refers to the epithelial and oils that are left after an individual touch any object.

Advantages and Disadvantages of DNA technology in forensic science

One of the most significant benefits of using DNA lies in the specificity. Minute quantities of evidence at the crime scene can yield sufficient material for the analysis. Forensic scientists usually compare 13 markers, which means that identical profiles are below 1 in 10 billion. Therefore, the approach is the most reliable and accurate as compared to other forensic evidence. However, there are some disadvantages associated with the use of the DNA technique. The jurors have unrealistic expectations in the DNA analysis as compared to the weight of other physical evidence. Maintaining of the DNA databases helps in the identification of criminals but also poses ethical concerns. The investigators can contaminate the evidence, which can lead to difficulties in the identification of the criminals (Aronson, 2005).

Conclusion

The paper has evaluated the role of DNA technology in forensic science. The criminal investigators have used the approach in linking the suspects to the crimes committed. Also, the innocence project has exonerated wrongfully convicted offenders using DNA analysis. The paper has also assessed various uses of DNA technology and the collection of such evidence at the crime scene. Multiple sources of DNA evidence at the crime scene have been identified, which include body fluids, touch DNA, hair, and skin cells. Therefore, the collection of the DNA evidence should be done skillfully to prevent contamination of the evidence.

References

Ahmed, F. E. (2001). Forensic DNA Typing: Biology & Technology behind STR Markers. John M. Butler. The Quarterly Review of Biology, 76(4), 484-484. doi:10.1086/420565

Aronson, J. D. (2005). DNA fingerprinting on trial: the dramatic early history of a new forensic technique. Endeavor, 29(3), 126-131. doi:10.1016/j.endeavour.2005.04.006

Butler, J. M. (2015). The future of forensic DNA analysis. Philosophical Transactions of the Royal Society B: Biological Sciences, 370(1674), 20140252. doi:10.1098/rstb.2014.0252

Jankowski, Z., Ajanovska, R. J., Stankov, A., Poposka, V., Bitoljanu, N., & Belakaposka, V. (2017). The power of forensic DNA databases in solving crime cases. Forensic Science International: Genetics Supplement Series, 6, e275-e276. doi:10.1016/j.fsigss.2017.09.085

Jiang, C. (2017). Research on Forensic DNA Evidence Base on Criminal Law Vision. Proceedings of the 7th International Conference on Management, Education, Information, and Control (MEICI 2017). doi:10.2991/meici-17.2017.3

Mapes, A., Stoel, R., De Poot, C., Vergeer, P., & Huyck, M. (2019). Decision support for using mobile Rapid DNA analysis at the crime scene. Science & Justice, 59(1), 29-45. doi:10.1016/j.scijus.2018.05.003

Marbach, A. (2019). The System for Evidence Collection from Sexual Assault Victims in Israel. Anti-Terrorism; Forensic Science; Psychology in Police Investigations, 222-228. doi:10.4324/9780429036590-27

Prinz, M., Carracedo, A., Mayr, W., Morling, N., Parsons, T., Sajantila, A., Schneider, P. (2007). DNA Commission of the International Society for Forensic Genetics (ISFG): Recommendations regarding the role of forensic genetics for disaster victim identification (DVI). Forensic Science International: Genetics, 1(1), 3-12. doi:10.1016/j.fsigen.2006.10.003

Ribaux, O. (2003). Forensic intelligence and crime analysis. Law, Probability, and Risk, 2(1), 47-60. doi:10.1093/lpr/2.1.47

Stavrianos, C., Eliades, A., & Kokkas, A. (2010). The Role of DNA in Forensic Odontology (Part I) DNA Analysis Methods. Research Journal of Medical Sciences, 4(6), 334-339. doi:10.3923/rjmsci.2010.334.339