Limitations of Forensic Science
DNA testing has been useful in solving various crimes such as murder and rape. The procedure of DNA testing is carried out in several steps which include: the extraction of the DNA which is responsible for releasing the molecules of DNA into a solution so that tests are performed on them, the quantitation of the DNA where the recovered DNA is tested to ensure that it belongs to a human being, the amplification of DNA through Polymerase Chain Reaction process in which numerous copies of a given DNA sequence are made in a short time, and the capillarity electrophoresis process in which the amplified DNA molecules from the PCR process are distinguished from one another (Dps.mn.gov, 2015).
After the DNA testing is finished, the DNA from the unknown sample is compared with that of the known sample in order to identify criminals.The difference between DNA testing procedure and eyewitness evidence is that the DNA evidence relies on the evidence which comes from a human’s body such as blood samples to identify criminals while eyewitness employs the use of pictures and line-ups.
An example of an actual case that was solved through DNA testing was the murder of Anna Palmer in 1998. Anna was attacked and killed outside of her front door in Salt Lake City through multiple stab wounds to her body. The investigators had no witnesses and little evidence. In 2009, forensic experts were asked to assist in the case, and they examined the fingernails of DNA samples that do not belong to her (Forensics Colleges, 2015).
They found some DNA sample which was matched to Matthew Brock, who used to live a block away from Anna Palmer at the time of her murder. Brock was in prison when the discovery was made, and he pled guilty in 2011 to having killed Anna Palmer and he is now serving a life sentence on an aggravated murder charge (Forensics Colleges, 2015).
References
Forensics
