DNA evidence and police investigations: a health warning

Much has been made of recent advances in DNA science and technology with particular emphasis placed on its bewildering implications for policing and the detection of serious offenders. Operation Phoenix for example, conducted by Northumbria Police in conjunction with the Forensic Science Service (FSS), has seen a total of 42 named DNA matches obtained against the National DNA Database (NDNAD) for more than 400 unsolved sexual offences over a 14 year period, resulting in 14 convictions up to 2005 (Forensic Science Service Annual Report 2004-05). Both technical advances in DNA serology and the infrastructure of analysis and retention bring forensic DNA analysis into the mainstream of detection, with accompanying public interest. For example the development of Low Copy Number techniques (LCN) now render very small samples usable. The size of the National DNA Database (well over three million by early 2006) aspires to cover the active criminal population.