Familial searching: a specialist forensic DNA profiling service utilising the National DNA Database to identify unknown offenders via their relatives--the UK experience.

The National DNA Database (NDNAD) of England and Wales was established on April 10th 1995. The NDNAD is governed by a variety of legislative instruments that mean that DNA samples can be taken if an individual is arrested and detained in a police station. The biological samples and the DNA profiles derived from them can be used for purposes related to the prevention and detection of crime, the investigation of an offence and for the conduct of a prosecution. Following the South East Asian Tsunami of December 2004, the legislation was amended to allow the use of the NDNAD to assist in the identification of a deceased person or of a body part where death has occurred from natural causes or from a natural disaster. The UK NDNAD now contains the DNA profiles of approximately 6 million individuals representing 9.6% of the UK population. As the science of DNA profiling advanced, the National DNA Database provided a potential resource for increased intelligence beyond the direct matching for which it was originally created. The familial searching service offered to the police by several UK forensic science providers exploits the size and geographic coverage of the NDNAD and the fact that close relatives of an offender may share a significant proportion of that offender's DNA profile and will often reside in close geographic proximity to him or her. Between 2002 and 2011 Forensic Science Service Ltd. (FSS) provided familial search services to support 188 police investigations, 70 of which are still active cases. This technique, which may be used in serious crime cases or in 'cold case' reviews when there are few or no investigative leads, has led to the identification of 41 perpetrators or suspects. In this paper we discuss the processes, utility, and governance of the familial search service in which the NDNAD is searched for close genetic relatives of an offender who has left DNA evidence at a crime scene, but whose DNA profile is not represented within the NDNAD. We discuss the scientific basis of the familial search approach, other DNA-based methods for eliminating individuals from the candidate lists generated by these NDNAD searches, the value of filtering these lists by age, ethnic appearance and geography and the governance required by the NDNAD Strategy Board when a police force commissions a familial search. We present the FSS data in relation to the utility of the familial searching service and demonstrate the power of the technique by reference to casework examples. We comment on the uptake of familial searching of DNA databases in the USA, the Netherlands, Australia, and New Zealand. Finally, following the adverse ruling by the European Court of Human Rights against the UK in regard to the S & Marper cases and the consequent introduction of the Protection of Freedoms Act (2012), we discuss the impact that changes to regulations concerning the storage of DNA samples will have on the continuing provision of familial searching of the National DNA Database in England and Wales.