NCJ Number
218314
Journal
Judicial Review Volume: 8 Issue: 1 Dated: September 2006 Pages: 121-144
Date Published
September 2006
Length
24 pages
Annotation
This paper discusses issues related to the nature of DNA evidence and its strengths and weaknesses in proving that a defendant committed the crime charged.
Abstract
The author concludes that because of the many variables that can compromise the reliability of DNA evidence and the fallibility of conclusions drawn from it, DNA evidence alone cannot meet the high standard of certainty required for a conviction. The author advises that, like all evidence, DNA evidence must be carefully scrutinized and be viewed as one piece of evidence that requires other evidence of guilt to meet the burden of proof for a guilty verdict. The author first discusses DNA science and technology, with attention to the information it is capable of bringing as evidence in a criminal case. A second issue discussed pertains to the statistics associated with the probability that a particular DNA sample came from a suspect/defendant. A third issue addressed involves DNA reports. The author advises that the DNA report simply states the results of the DNA analysis. It does not describe the process by which the result was obtained. To make DNA admissible as evidence, the chain of custody and handling of the exhibit from which the DNA was taken and analyzed must be established as reliable and free of contamination and error. A discussion of problems with the science and technology involved in DNA analysis focuses on partial matches, weak readings, mixtures of DNA from more than one contributor, and contamination. Bias in the lab is also discussed, with attention to inadvertent or secondary transfer. Problems with DNA statistics are identified, followed by the author's answer to the question regarding whether DNA evidence is sufficiently reliable to be the only evidence of guilt presented against a defendant. 71 notes