Those authorized to report on the weight of DNA evidence are frequently called upon to address questions on DNA transfer, persistence, prevalence and recovery (DNA-TPPR). Due to a lack of standardization, knowledge and training, these questions are often addressed poorly or inadequately, thus, potentially adversely impacting justice outcomes. As the forensic community moves towards contemplating activity-level assessments, it becomes incumbent on the expert to be well equipped to do so. The likelihood of alternative scenarios must be provided using data and methodologies that are valid both foundationally and as applied. The expert must be aware of the current knowledge of variables potentially impacting any assessment, including those involving DNA-TPPR, and the associated limitations. We have conducted preliminary assessments of DNA reporting scientists on their general understanding of DNA-TPPR and ability to identify key factors that could impact transfer probabilities. Differences were observed between individuals, from between and within laboratories, in their level of comprehension of DNA-TPPR. Apart from the need for further studies to validate the variables impacting DNA-TPPR and the extent of their impact in different situations, we advocate that individuals utilizing this information should be specifically authorized to conduct such analyses and provide expert opinion in criminal investigations and legal proceedings relating to DNA-TPPR. Furthermore, improvements are required in the foundational and ongoing training of these individuals. The setting of standards to be met by such training, how to test competency, and the availability of regular purpose-fit proficiency tests, requires urgent attention.
|Number of pages||3|
|Journal||Forensic Science International: Genetics Supplement Series|
|Early online date||11 Sep 2017|
|Publication status||Published - 1 Dec 2017|
- Activity level
- DNA transfer