DNA Evidence DNA As Evidence Research Paper

All samples must be properly collected, using gloves and other tools in order to prevent contamination, as well as properly stored until analysis can be performed. It is vitally important that this chain of evidence be maintained so that the evidence collected from using the samples can then be admissible in a court of law. This requires those collecting and storing samples not only to use gloves and tools to handle the samples, but also to avoid talking, sneezing, coughing, touching one's own body, as well as making certain samples are air dried before storing, using paper bags or envelopes instead of plastic containers, and to "tape, seal, initial, and date all paper bags or envelopes." (Catalin, p.7)

DNA is a useful tool in the identification of suspects involved in criminal cases, but there are some limitations to the use of DNA in forensics. First of all, forensic DNA use is dependent upon the proper collection, transport, storage, and analysis of samples. While forensic scientists take many precautions to prevent degradation and contamination of samples, sometimes contamination occurs and the DNA evidence is usually found to be inadmissible in court. There is also the problem with how identification is translated into an individual. Most DNA tests cannot, with 100% accuracy, match an individual person to a specific sample. At best, DNA tests can provide a "likelihood ratio," which "is the ratio of the probability of a match if the DNA in the evidence sample and that from the suspect came form the same person to the probability of a match if they came from different persons." (National Research Council, 1996, p.31) in other words, the best that a DNA test can provide is a probability that the sample matches the suspect and not a definitive answer.

References

Catalin, Marian, Anghel Andrei, and Oana Mitrasca. (n.d.). "Modern Methods of Collection and Preservation of Biological Evidence for Human Identification

by DNA Analysis." Abacus Diagnostic. Retrieved from http://www.abacusdiagnostics.com/Modern_Methods_of_Collection.pdf

"DNA Forensics." (n.d.). Human Genome Project Information. Retrieved from http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml

"History of Forensic DNA Analysis." (n.d.). DNA Initiative. Retrieved from http://www.dna.gov/

USA: National Academy of Sciences. Print.