Your News Feature 'DNA's identity crisis' (Nature 464, 347–348; 2010) implies that the UK Court of Appeal in the Reed brothers' case cast doubt on the validity of analysing small amounts of DNA. This is misleading and not borne out by the judgement of the Court (see http://go.nature.com/msMgum).

Analysis by independent scientists commissioned by my office (B. Caddy et al. A Review of the Science of Low Template DNA Analysis Home Office Forensic Science Regulation Unit, 2008) concluded that the science supporting the delivery of low-template DNA analysis — a term used to cover different methods, including the low-copy-number (LCN) method — is sound and has been validated in accordance with scientific principles. This view has been upheld, with regard to LCN, in considered judgements by Courts of Appeal in London and New Zealand, and the Supreme Court of the State of New York.

In my response as Forensic Science Regulator (see http://go.nature.com/y2ApQ2), I addressed all 21 recommendations of the review, referring several of these recommendations to my Quality Standards Specialist Group and my DNA Specialist Group for monitoring and/or further advice. I also commissioned further work to develop a consensus on the core interpretation methods for low-template DNA analysis.

The Reed brothers abandoned their appeal on the reliability of low-template DNA evidence using the LCN process. The Court nonetheless heard evidence on this and other issues, including one of primary and secondary transfer of DNA, from A. Jamieson, B. Budowle, A. M. T. Linacre and V. Tomlinson (an officer of the Forensic Science Service). Their Lordships ruled that challenging the validity of the method was not justified for DNA amounts above the stochastic threshold of 100–200 picograms. They did not accept the counter argument of Budowle and Jamieson that experts cannot form an opinion on the transfer of DNA in low-template cases.

In an admissibility hearing on LCN DNA analysis in the Supreme Court for the State of New York, the Honorable Robert J. Hanophy ruled in February that “low-copy-number DNA testing ... passes the standard enunciated in Frye and is therefore admissible at trial”. This standard includes the requirement for general acceptance in the scientific community (see http://go.nature.com/y1aVgK).

In March, the Court of Appeal of New Zealand dismissed an attempt to have LCN DNA evidence ruled inadmissible as “a minority view” (see http://go.nature.com/rpInb1). The Court ruled that “on the current state of the law, we consider that blanket attacks on the science as such are not sustainable. ... [In] R v Lepper, ... the proposition was advanced that LCN DNA analysis is unreliable [see http://go.nature.com/ImRTr2]. That proposition has since been specifically rejected by this Court. Crown counsel note that LCN analysis has been accepted in trial evidence in the USA, UK, Australia and Sweden.”

In the case of the Reed brothers, the Court of Appeal provided a considered judgement that I recommend as an informed review of the current state of DNA technology in criminal prosecutions.