DNA Strengths & Weaknesses
DNA is a critical tool in law enforcement and subsequently, Homeland Security. Discuss DNA and why it is important in the identification of criminals and potential terrorists. What are DNA’s strengths and what are its weaknesses and challenges?
DNA (Deoxyribonucleic acid) is a long molecule located in the nucleus of every cell of living organisms. DNA encodes information about that individuals characteristics including eye colour, gender, skin colour, hair colour etc. It is unique to every individual in that each person can be identified by their DNA profile. The DNA of a person is inherited from their parents, with each parent contributing 50% of the profile that determines the characteristics. Among human beings, 99.9% of DNA is similar. However, the remaining 0.1% is unique to each person and only this portion is used to uniquely identify a person (Behrouzfard, 2006).
In the criminal justice system, the use of DNA evidence has been greatly credited for the exoneration and incrimination of criminals. Since DNA is unique, the DNA collected at a crime scene can be compared to the suspect’s DNA profile to conclusively determine whether or not the suspect was involved in the crime. Therefore, two samples are required to link a suspect to a crime. DNA can also be used to identify a corpse found at a crime scene especially a situation where the corpse was disfigured. Moreover, for a repeat offender such as a serial killer, DNA profiles collected at different crime scenes can be used to link the crimes to the perpetrator. DNA profiles can be easily quantified into a series of numbers which can then be stored electronically. This means that a large DNA database can be created to ease in the linking of a DNA profile to an individual. DNA, unlike other identifying features such as fingerprints, cannot be adversely affected by injury.
DNA, however, has its shortcomings. As it is a test being performed by human beings, it is susceptible to laboratory errors. Such errors have led to the wrongful conviction of suspect due to the laboratory’s malpractice. Moreover, DNA evidence is rarely left at crime scenes. The use of DNA evidence only accounts for less than 10% of all homicide cases (Behrouzfard, 2006).
References
Behrouzfard, N. (2006). Strengths, Limitations, and Controversies of DNA Evidence. New England: Southern New England School of Law.
