DNA In Criminal Investigation Essay

When an investigation runs out of ways to identify human remains, DNA can play a key role in the identification process. The most common methods of identification by a forensic anthropologist include "detailed skeletal and dental features," of the remains, but they are sometimes asked to perform DNA profiles as well (Arismendi, Baker, & Matteson, 2004). According to the paper by Arismendi, Baker, and Matteson, when the common modes of identification do not yield any results, "DNA typing may provide a further avenue of investigation (Arismendi, Baker, & Matteson, 2004)." Usually when the forensic anthropologist collects the DNA, it's from any tissues that remain on the bones themselves, and as they examine the remains, "it is usually necessary to remove any of the remaining soft tissue," leading some to wonder if the techniques used to do this may compromise the
samples themselves (Arismendi, Baker, & Matteson, 2004). There have been many cases where "anthropological expertise by its own, without genetics, is not able to provide a clear-cut result," therefore investigators have come to the conclusion that DNA is an extremely useful tool when it comes to forensic anthropology (Cunha, E., Pinheiro, J., & Vieira, D.N., 2006). According to the article Effects of Processing Techniques on the Forensic DNA Analysis of Human Skeletal Remains, there has been no evidence to "determine if any of the common processing techniques used by forensic anthropologists to remove soft tissue from human remains affects the subsequent DNA analysis (Arismendi, Baker, & Matteson, 2004)." It's a frequent problem during an investigation to "encounter samples containing degraded DNA," and this can actually be the result of the environment the remains were found in (Arismendi, Baker, & Matteson, 2004). As the human body decomposes, it releases "nucleic acids" that can actually degrade the DNA and cause it to unravel (Arismendi, Baker, & Matteson, 2004). Additionally, "environmental factors" such as "weather, temperature, chemical exposure, and biological activity" can have negative effects on DNA, and has nothing at all to do with how the forensic anthropologist processes the remains (Arismendi, Baker, & Matteson, 2004). As stated earlier, it is not typically the responsibility of the forensic anthropologist to collect DNA for "identification purposes," but it is more convenient to the investigative team to have them not only examine the remains, but to collect the DNA samples as well (Tersigni-Tarrant & Shirley, P.409).
This is more convenient because "having the anthropologists perform both the skeletal and molecular analyses...is that the close proximity of skeletal and molecular analyses can save a great amount of time (Tersigni-Tarrant & Shirley, P.409)." This can also lessen the amount of people who are handling the remains and the evidence, which means less chances of contamination. Additionally, forensic anthropologists are the best choice for deciding how the DNA may be "utilized" when it comes to identifying the remains (Tersigni-Tarrant & Shirley, P.409). It's also helpful for the forensic anthropologist to conduct the DNA analysis themselves because it's a good way to differentiate between "compromised remains," where the only way to identify the body is through DNA testing (Tersigni-Tarrant & Shirley,
P.409). Another factor that needs to be taken into account when it comes to how the forensic anthropologist processes the remains and the DNA is: "Which tissue types will and will not produce a full DNA profile (Tersigni-Tarrant & Shirley, P.409)." Most people would think that investigators can retrieve a full DNA sample from anywhere on the remains, even from bone, but in point of fact human bone has very little "nuclear DNA" in it, and yields mostly mitochondrial DNA, the "maternal bloodline (The Forensics Library, 2016)." According to the Oxford Handbook of Forensic Medicine, the tissue types that will most likely yield a "full DNA profile" include skin cells, hair, saliva, and some bone (depending on its condition) (Wyatt, Squires, & Norfolk, P.529). Additionally, according to the textbook Missing People, DNA Analysis and Identification of Human Remains, soft tissues degrade extremely fast, so in order for them to be tested, they need to be collected fairly quickly (ICRC, 2005). The article also mentions that while all bone contains DNA, "some bones are better at preserving DNA," such as longer bones like the femur, or the ribs, which "provide a good source of DNA (ICRC, 2005)." Some common misconceptions about DNA collection is that it can be obtained through urine and faeces tests, which actually yield very little in the way of DNA, as anything that could be used has been degraded through the digestive process (Wyatt, Squires, & Norfolk, P.529).