Validation issues around DNA typing of low level DNA.

A recent ruling in the Crown Court of Northern Ireland, R v. Hoey, [R v Sean Hoey. 2007, Crown Court of Northern Ireland] has raised questions about the validity of one variant of DNA analysis, often termed LCN. The ruling and subsequent discussion also raises questions about what constitutes validation of a technique. This paper examines what can be achieved in a laboratory based validation study against the Daubert standard and against guidance given in the UK. There is a significant discrepancy between what can be achieved and the Daubert standard but much less of a discrepancy against the UK guidance. Much of the difference relates to differences in word usage, definitional difficulties, and a lack of mutual understanding and communication between the judiciary and forensic scientists. This highlights a gap that needs attention.