DNA evidence is a powerful investigative tool, able to incriminate as well as exculpate. Yet, increasingly common portrayals of DNA as being able to solve crimes almost instantaneously, beyond any doubt, even from ‘beyond the grave’, may overstate the degree to which DNA currently assists in criminal investigations. Strong government support, and financial investment in the DNA Expansion Programme, have been bolstered by repeated legislative extensions of police powers to obtain and retain DNA samples. Despite this, DNA evidence remains marginal in terms of assisting with overall criminal detections and experts now suggest that the massive National DNA Database expansion has not resulted in the improvement in detection rates originally anticipated. This paper also suggests potential concerns over the ‘tactical’ use of DNA evidence during suspect interviews, and the risk of abbreviated police investigations. Insufficiently ‘forensically aware’ police officers may resort to DNA evidence in lieu of proper detective work, with literature on ‘case construction’ informing analysis of potential pitfalls of early reliance on DNA results, which may increase the risk ‘tunnel vision’ in criminal investigations.

A growing chorus of forensic professionals believe that forensic science has undersold its potential contribution to crime reduction and has a more significant role to play in policing, with collation and analysis of forensic information used to inform policing tactics, operations or strategy. Domestic law enforcement agencies, as producers, consumers and purveyors of forensic information and intelligence, are also responding to political pressures to expand and accelerate their technological abilities to gather and disseminate forensic information and intelligence within expanding operational boundaries. For example, there are a number of agreements that promise the automated exchange of forensic data internationally, in particular fingerprints and DNA profiles, and many that share other law enforcement information via a variety of channels. However, there is yet to be any detailed consideration of the multifaceted issues raised by the production of forensic intelligence, and the impact of direct access and/or exchanges of forensic intelligence. While technologies are increasingly interoperable, traditional parameters restraining law enforcement information sharing are increasingly inadequate. The lack of oversight of the transnational flows of law enforcement information mean that current processes lack transparency and, consequently, citizens’ ability to know of, understand, and challenge exchanges of their data is almost non-existent. Yet the expectation is that the power to generate, gather, store and share forensic intelligence will be used with integrity. Integrity is essential for generalised trust among not just the direct consumers of forensic intelligence, but also the public. For the integrity of forensic intelligence to be maintained, critical attention must be paid not only to the viability of forensic intelligence production and sharing, but also to its legitimacy and acceptability.

Since the emergence of forensic DNA profiling and the corollary creation of DNA databases, efforts to maximise the efficiency and utility of DNA technology have intensified. Such efforts are expedient given the imperative that expenditure on DNA should be cost-effective and the benefits demonstrable. The practice of retaining DNA profiles in databases, either obtained from individuals involved in criminal investigations, or retrieved from suspected crime scenes, has spread globally. The UK's National DNA Database (NDNAD), created in 1995, is both one of the longest established, and biggest of such forensic DNA databases internationally. As such, it is instructive to look at whether there is evidence to demonstrate the effectiveness of this DNA database. This paper thus examines efforts to gauge the effectiveness of forensic DNA databases, concluding that while the UK NDNAD may have led directly to convictions in high profile crimes, its broader impact upon public security goals remains elusive.

In this article, we consider the effectiveness of DNA analysis in criminal investigations. Through this investigative tool, unknown victims, suspects, and serial offenders have been identified. At the same time, wrongly charged and convicted individuals have been eliminated from investigations or released from custody following DNA testing. We know forensic DNA analysis is powerful in individual cases/certain crime types, but its aggregate contribution to criminal detections is low and questioned. There is little evidence to demonstrate its actual contribution. We examined the possible reasons for the low impact of forensic DNA, with some recommendations that may further maximize its utility. Available evidence demonstrates that there remains a need to ensure value for money in continued investment in forensic DNA analysis. An evaluation of trends in criminal activities and detection opportunities utilizing DNA evidence may help in identifying specific areas where DNA is most useful, and resources can be focused. Additionally, the potential of integrated multi‐biometric analysis/systems and other evidence types should be explored.This article is categorized under: Forensic Biology > DNA Databases and Biometrics Forensic Biology > Forensic DNA Technologies Jurisprudence and Regulatory Oversight > Expert Evidence and Narrative