Advanced testing techniques are used in forensic DNA testing to assist the legal system in a variety of cases. This type of testing is typically used in cases involving identity, such as locating a criminal at a crime scene or determining paternity. Forensic DNA testing relies on samples of bodily fluids, skin, and even hair to accurately determine the identity of the person being tested.
Humans have a unique code embedded in their DNA, similar to a credit card number or a home address. Although relatives may have genetic codes that are similar, there is little evidence that any two people have the same code. Forensic scientists can determine if the DNA from two samples is a match by comparing a reference sample from a suspect, such as a mouth swab, to physical evidence found at a crime scene.
Depending on the type of samples obtained and the test’s requirements, forensic DNA testing employs a variety of methods. In order to determine paternity, forensic scientists may examine the Y-chromosome, which is passed down genetically from father to child. Other methods include examining the nucleus of the cells being studied or comparing specific repeating patterns found in DNA.
Forensic DNA testing is a relatively new method of establishing identity, and new methods are being developed all the time. The legal system has only had access to DNA testing technology since the late 1980s, after Sir Alec Jeffries published a seminal paper on the field’s possibilities in 1985. Although the technique is still in its infancy, it has already proven its worth to the legal system by allowing for more accurate physical evidence to be established.
Many innocent people who were wrongfully convicted due to a lack of physical evidence have been rehabilitated thanks to forensic DNA testing. Nearly 200 people in the United States have been exonerated after DNA evidence was tested or retested using methods that were not available at the time of their trial. These cases have been used by opponents of the death penalty system to reignite debate about capital punishment, pointing to the possibility that the state has executed innocent people.
However, forensic DNA testing is not universally popular, and critics raise a number of serious concerns. Methods of testing are difficult and delicate, and results can be contaminated or destroyed in a number of ways. The suspicious also believe that DNA evidence could be planted at a crime scene to implicate a specific person.
Other critics are concerned about DNA databases being established in the United States, the United Kingdom, and New Zealand. While these databases are intended to record criminals’ genetic evidence in order to link them to possible future crimes, critics fear that they will infringe on people’s privacy and constitute an illegal search. These criticisms clearly show that, while forensic DNA testing is a fantastic tool for the legal system, it is far from perfect and requires more research and testing technique development.